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1
Askin, David. "Carotenoproteins in marine invertebrates." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316509.
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Sandler, Joel Stuart. "Anticancer compounds from marine invertebrates /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3247792.
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Reese, David Stephen. "Marine invertebrates and Mediterranean archaeology." Thesis, University of Cambridge, 1988. https://www.repository.cam.ac.uk/handle/1810/272352.
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Bat, Levent. "Pollution effects on marine invertebrates." Thesis, University of Aberdeen, 1996. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU083075.
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In this study, the amphipod Corophium volutator and the polychaete Arenicola marina were evaluated as test organisms for use in sediment toxicity tests by adapting standard protocols developed by the EPA/COE and Thain et al. (1994) respectively for conducting 10-day sediment toxicity tests. Although these species have been used to assess the toxicity of marine and estuarine sediments, the detailed ecotoxicologies of these animals are not well documented. In particular, the effects of specific contaminants of known concentrations on this bioassay are not known. Here, I report several experiments carried out using clean intertidal sediment contaminated with the heavy metals copper, zinc and cadmium, and employing the Corophium and the Arenicola bioassay protocol. Concentrations of copper, zinc and cadmium were determined in tissues of Corophium exposed for 4 and 10 days to contaminated sediment using four protocols to allow for any material present in the gut. Significant differences in metal concentrations occurred between the protocols where gut contents were removed and those where they were left intact. These findings have implications for the way in which analyses of metal burdens are carried out for invertebrates in ecotoxicological work. Corophium survival in seawater with dissolved copper, zinc and cadmium was higher in the presence of sediment than without sediment, although the concentrations of these metals in Corophium tissues were the same in both cases. Bioconcentration factors (BCF) were inversely related to seawater concentrations of copper, zinc and cadium, with the lowest exposure concentration, (0.1 mg l-1 for both copper and zinc, 0.01 mg l-1 cadmium) having the highest BCF. Both live amphipods and those that had died accumulated copper, zinc and cadmium in their bodies during the bioassay, and bioconcentration factors were always higher for dead than for living amphipods for each metal.
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Sumner-Rooney, Lauren Héloïse. "Sensory systems in marine invertebrates." Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709845.
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Sensory systems form the first point of contact between animals and their surroundings. The study of sensory systems is both a rich and diverse anatomical and behavioural field, and a potentially invaluable tool in evolutionary biology. This thesis examines four systems in three molluscan classes and ophiuroid echinoderms, addressing novel or poorly-understood systems and examining evolutionary trends by assessing the anatomy of more familiar structures in a phylogenetic context. The primary study system is a novel discovery reported herein throughout the chiton order Lepidopleurida, named the Schwabe organ. By combining detailed anatomical study, electrophysiology and behavioural experiments, 1 demonstrated that the Schwabe organ mediates light-avoidance behaviour and likely shares developmental origins with the chiton larval eye. A similar integrative approach was applied to a putative ‘visual* system in the ophiuroid Ophiocoma wendtii. Anatomical and behavioural results indicated that animals may use an extensive network of dermal photoreceptors for image formation, however this system differs substantially from the established model. The two final chapters focus on sensory and nervous systems in evolution. A re-description of scaphopod neuroanatomy in Rhabdus rectius demonstrates the potential power of a neurocladistic approach in solving deep phylogenetic questions, highlighting important similarities with cephalopod neural architecture and prompting the re-assignment of the major body axes in adult scaphopods. Finally, a study of eye reduction and eye loss in deep sea solariellid gastropods found surprising morphological diversity and differential progression between independent eye reductions, even within genera. This thesis makes several important contributions to our knowledge of four sensory systems and their evolution across two major invertebrate phyla: the Schwabe organ, extra-ocular photoreception in 0. wendtii, the Steiner organ and gastropod eyes. Overall, it also demonstrates the powerful nature of cross-disciplinary projects as well as the versatile role of sensory biology in broader evolutionary studies.
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Graiff, Kaitlin W. "The abundance and distribution of megafaunal marine invertebrates in relation to fishing intensity off central California." Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Thesis/Fall2008/K_Graiff_111808.pdf.
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Thesis (M.S. in environmental science)--Washington State University, December 2008.<br>Title from PDF title page (viewed on Mar. 4, 2009). "School of Earth and Environmental Science." Includes bibliographical references (p. 24-27).
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Morrison, Joan Olivia. "Cretaceous marine invertebrates: A geochemical perspective." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7784.
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A diagenetic evaluation was performed on marine fossil shell material from Cretaceous sediments of North America, the Arctic, the Antarctic and several localities in Europe. Trace element chemistry, XRD, SEM and stable isotope geochemistry were consistent in their results. Preservation of the original shell material of the low-Mg calcite organisms, brachiopods and belemnites, and the numerous aragonitic organisms was slightly variable with the majority of samples well preserved. Those samples that were altered underwent diagenetic stabilization in both reducing and oxic environments. Using the chemical data from only well preserved fossil shell material, basin paleo-reconstructions showed that from Aptian to Maastrichtian time, the Cretaceous seas were generally aerobic with some dysaerobia evident at the sediment/water interface and in the shallow sediment column. Paleosalinities fluctuated from brackish to normal marine, especially in the Western Interior Seaway of North America and the Paris Basin. The Lower Saxony basin, the Arctic and Antarctic were mainly normal marine with brackish conditions developing on occasion. Paleotemperatures determined from $\partial\sp $O data of preserved aragonite and low-Mg calcite shell material, also showed some variance. The Arctic and Antarctic were coolest, with Campanian/Maastrichtian temperatures about 12 or 13$\sp\circ$C, whereas the Lower Saxony basin and the Western Interior Seaway were slightly warmer, ranging from 11 to 20$\sp\circ$C. The Barremian/Aptian appeared to be the warmest time and a cooling trend was fairly consistent from then on.
8
Voparil, Ian M. "Lipid Solubilization by Marine Benthic Invertebrates." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/VoparilIM2003.pdf.
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Nisbet, Katherine. "Exploring connectivity of marine benthic invertebrates." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569247.
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With the marine environment subjected to ever increasing anthropogenic pressures resulting in biodiversity and habitat losses, there is an urgent need to implement effective management and conservation strategies to limit these losses. One such strategy is the designation of Marine Protected Area (MPA) networks, with the central concept that individual MPAs are connected to its neighbours within the network However, determining scales of connectivity in an environment that varies considerably both spatially and temporally is inherently difficult. Larval dispersal is a main driver of population connectivity, and planktonic larval duration (PLD) is frequently used to infer dispersal distance. Thus far studies have predominantly focused on fish and tropical species, using approaches such as larval dispersal modelling, otolith microchemistry or genetic estimates of connectivity. This thesis aimed to assess the levels of connectivity in a range of benthic invertebrates characteristic of offshore shelf seas of the Northeast Atlantic, at a range of spatial and temporal scales. This was achieved by: (1) examining the variation in PLDs of a typical benthic assemblage, then using this information to examine the variation in realised dispersal at multiple locations using particle tracking software; (2) assessing habitat preferences for the same species, and exploring how the distribution of broad habitats would affect connectivity of species; and (3) using microsatellite markers to determine the genetic structure of the exploited scallop Pecten maximus at both a localised scale (Isle of Man) and a regional scale covering over half its range. While biological variation, in the form of PLD, did affect dispersal potential of common benthic invertebrates, it was the physical factors of hydrographic regime and substrate type within a species given dispersal range that played the most important role in determining ultimate dispersal distance and location. Additionally, the scale of genetic structure of the scallop Pecten maximus, with Norway genetically distinct from Scotland, Ireland and Isle of Man but weaker or no structure within those regions, highlighted the interaction of biological and physical factors. Ultimately, this thesis has provided valuable insight into the drivers of connectivity in the marine benthos, but further work, particularly more collaborative studies across multiple fields, is required if MPAs are to achieve their aims in the face of a changing environment.
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Grange, Laura Joanne. "Reproductive success in Antarctic marine invertebrates." Thesis, University of Southampton, 2005. https://eprints.soton.ac.uk/41355/.
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The nearshore Antarctic marine environment is unique, characterised by low but constant temperatures that contrast with an intense peak in productivity. As a result of this stenothermal environment, energy input has a profound ecological effect. These conditions have developed over several millions of years and have resulted in an animal physiology that is highly stenothermal and sometimes closely coupled with the seasonal food supply, e.g. reproductive periodicity and food storage. Therefore, Antarctic marine animals are likely to be amongst the most vulnerable species worldwide to environmental modifications and can be regarded as highly sensitive barometers for change. Reproductive success is a vital characteristic in species survival and evaluation of change in reproductive condition with time key to identifying vulnerable taxa. Characterising reproductive success with time is a major requirement in predicting species response to change and the early stages of species loss. Some invertebrates are highly abundant in shallow water sites around the Antarctic and form conspicuous members of the Antarctic benthos. Three common echinoderms and one nemertean were sampled from sites adjacent to the British Antarctic Survey’s Rothera Research Station, Adelaide Island, on the West Antarctic Peninsula between 1997-2001. Reproductive patterns were determined by histological analyses of gonad tissue. This study provided further evidence for inter-annual variation in Antarctic gametogenic development, which appeared to be driven to some extent by trophic position and reliance on the seasonal phytoplankton bloom. The largest variation in reproductive condition was demonstrated for the detritivorous brittle star, Ophionotus victoriae. The seasonal tempos of this echinoderm have been attributed in part, to the seasonal sedimentation events common in the high Antarctic. The reproductive patterns in the scavenging starfish, Odontaster validus and the predatory nemertean, Parborlasia corrugatus showed less inter-annual variation. The de-coupling of these invertebrates from the intensely seasonal phytoplankton bloom appeared to partially account for the reproductive trends observed. The lack of inter-annual variation in the reproduction of the filter-feeding sea-cucumber, Heterocucumis steineni, was somewhat counterintuitive, although problems with sample processing probably accounted for the majority of this anomaly. Echinoderms were also collected during the Antarctic summer field seasons in 2003 and 2004. A series of fertilisation success studies were undertaken comparing the adaptations in an Antarctic and an equivalent temperate starfish to achieve optimal numbers of fertilised eggs, and elemental analyses were used to estimate the nutritional and energetic condition of the bodily and reproductive tissues in two Antarctic echinoderms. Fertilisation studies indicated that Antarctic invertebrates require 1-2 orders of magnitude more sperm to ensure optimal fertilisation success. These sperm tended to be long-lived and capable of fertilising eggs 24+ hours after release. The study suggested that synchronous spawning, aggregations and specific pre-spawning behaviour are employed to help counter the deleterious effects of sperm limitation. The Antarctic eggs and sperm were also highly sensitive to even small modifications in temperature and salinity, affecting the number of eggs fertilised. Such stenothermy is of particular relevance if the 1-2ºC rise in global temperature, predicted over the next century, is realised. Biochemical composition of body components of two species of Antarctic echinoderm indicated a significant difference in the composition between the male and female gonad, particularly in the Antarctic brittle star Ophionotus victoriae. The ovaries contained a much larger proportion of lipid compared to the testes, and demonstrated a distinct seasonality in composition. Higher levels of lipid were observed in the ovary during the austral winter coincident with a period of reproductive investment and maturing oocytes in the gonad. O. victoriae exhibited lower amounts of lipid in the late austral spring suggesting the removal of mature oocytes from the ovary through spawning. The seasonality in composition and the high levels of lipid and protein measured in the ophiuroid gut tissue, suggested the gut might play a role in providing material and energy for metabolic function and possibly gametogenesis; higher lipid levels were apparent during the period of seasonal phytodetrital flux. The role of the pyloric ceaca in asteroids as a nutrient storage organ was also evident in the high levels of both protein and lipid observed in this bodily component in the star fish, Odontaster validus.
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Miao, Shichang. "Novel secondary metabolites from selected marine invertebrates." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31133.
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Chemical studies of a Northeastern Pacific tunicate and three Papua New Guinea sponges have led to the isolation of sixteen new secondary metabolites. The structures of the new compounds were determined by spectroscopic analysis and chemical interconversions. The absolute stereochemistry of imbricatine, a previously reported starfish metabolite, has also been determined.
The northeastern Pacific tunicate Ritterella rubra has been found to contain a novel series of aromatic butenolides, rubrolides A-H (149-156). The structures of the rubrolides were solved by the analysis of NMR (¹H, ¹³C, COSY, nOe, HETCOR, FLOCK, HMQC and HMBC), MS and IR data combined with chemical interconversions. FLOCK, a new ¹H/¹³C long-range correlation experiment, played a key role in establishing the rubrolide carbon skeleton. The rubrolides represent the largest family of non-nitrogenous tunicate metabolites. The protein phosphatase inhibitory activity and the potent antibiotic activities of the rubrolides warrant further investigation.
The absolute stereochemistry of imbricatine (179), a compound reported from the starfish Dermasterias imbricata, has been determined by comparing the optical properties of its chemical degradation products with those of model compounds. Raney nickel reduction of 179 yielded benzyltetrahydroisoquinoline 188a which was methylated to give 188b. Comparison between the CD spectrum of 188b and those of model compounds 189 and 190 solved the absolute stereochemistry of the tetrahydroisoquinoline fragment of 179. Reductive hydrolysis of 179 followed by oxidation yielded histidine disulphide 182. Comparison of the optical rotation of 182 with the reported value solved the absolute stereochemistry of the histidine fragment of 179. Attempts to study the biogenesis of 179 were unsuccessful.
Examination of three Papua New Guinea sponges resulted in the isolation of eight new compounds. Six new bastadins (211-216) were isolated from Ianthella basta. The structures were elucidated by spectroscopic analysis as well as comparison with the previously reported bastadins. A Xestospongia species was found to contain xestospongin E (238), a new metabolite, and a number of known xestospongins. Both the bastadins and the xestospongins possess antibiotic and cytotoxic activities. A symmetrical enyne, callydiyne (247), was isolated from Callyspongia flammea. The structure of 247 was determined by spectroscopic studies.<br>Science, Faculty of<br>Chemistry, Department of<br>Graduate
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Morrisey, D. J. "Competitive avoidance in marine deposit feeding invertebrates." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332468.
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Williams, Mark Elliott. "Fertilization ecology of broadcast spawning marine invertebrates." Thesis, University of St Andrews, 1999. http://hdl.handle.net/10023/14544.
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In situ measurements of the fertilization success of broadcast spawning marine invertebrates have been conducted mainly on shallow subtidal echinoderm and coral species. In this study, field fertilization success was measured for two infaunal, intertidal polychaetes Arenicola marina and Nereis virens. Both species are epidemic spawners, with populations of A. marina spawning over a few days in autumn while N. virens spawns in early spring. The fertilization success of female Arenicola marina is highly variable, ranging from 0 to 100%, and is determined by male spawning density. It is hypothesised that fertilization success over the entire spawning period is the result of an accumulation of fertilizations each day in the spawning period. Fertilization success was measured indirectly in Nereis virens by transplanting oocytes into the field. At least two spawning periods occurred for the population studied here. Fertilization success was uniformly high during the first period, and in the second fertilization success was highest among those eggs located high in the water column as opposed to those at substratum level. The fertilization strategies of these polychaetes are discussed in the light of these results. Comparative laboratory experiments were performed on factors that affect fertilization success in Arenicola marina. Nereis virens, Asterias rubens and Echinus esculentus, including sperm:egg ratio, sperm-egg contact time and sperm concentration. The extent to which each of these factors affects fertilization success varies with species, and this is explained by gamete attributes and mathematical models. Gamete longevity significantly affects fertilization success, and eggs and sperm of Arenicola marina are extraordinarily long lived compared to those of the other species studied here and elsewhere. Eggs are viable for 5 days after spawning, while dilute sperm remains capable of fertilizing eggs for more than 48 hours. The laboratory data are discussed in terms of the fertilization strategies of each of the species.
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Scott, Robyn. "Biogeographical patterns of southern African marine invertebrates." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/6187.
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Includes abstract.<br>Includes bibliographical references (p. 156-171).<br>Biogeography is defined as the study of life, in a spatial and temporal context, with respect to the analysis and explanation of patterns for a given area. The tendency for species richness and diversity to increases towards the equator, where both peak, is a much debated and tested pattern. Underlying mechanisms thought to cause this pattern are: gradients in temperature, stress, productivity, competition, predation, stability, effective evolutionary time, niche breadth, range size and area of occupancy. Evidence exists that both supports and negates most of these mechanisms. In addition to the richness gradient, a latitudinal gradient in geographical range size exists, whereby species range sizes decrease with latitude, referred to as Rapoport's Rule. This has been linked to species ability to tolerate changes in climate. The latitudinal gradient in species richness is thought to be a by-product of Rapoport's Rule and the "Rescue Effect".
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Flowers, Andrew E. "Metal-binding proteins in tropical marine invertebrates." Thesis, Queensland University of Technology, 1995.
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Orav-Kotta, Helen. "Habitat choice and feeding activity of benthic suspension feeders and mesograzers in the northern Baltic Sea /." Tartu, Estonia : Tartu University Press, 2004. http://dspace.utlib.ee/dspace/bitstream/10062/489/5/Kotta.pdf.
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Morris, Sandra Anne. "Novel secondary metabolites isolated from selected marine invertebrates." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/31073.
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A study of the secondary metabolism of two northeastern Pacific sponges and two Sri Lankan nudibranchs has led to the isolation of thirteen new and one previously known natural products. The structures of all of the compounds were determined by a combination of spectroscopic data analysis and chemical interconversions.
A study of the chemistry of the northeastern Pacific sponge Hexadella sp. has resulted in the isolation of six new brominated alkaloids. Two of these, hexadellins A (77) and B (78), are derived from dibromotyrosine. The structures of compounds 77 and 78 were determined via their acetylated derivatives 79 and 80. Four compounds possessing novel bis(indole) structures have also been isolated. Topsentin B2 (74) was isolated as a mixture of two slowly interconverting tautomers, 74a and 74b. Methylation of 74 resulted in the production of trimethyltopsentin B2 (75); the structure of 75 was determined spectroscopically. The structures of dragmacidons A (81), B (82), and C (83) were determined by a combination of spectral data interpretation and chemical interconversions. Dragmacidon C (83) was originally incorrectly assigned as 88; the correct structure was determined based upon synthesis of the model compound 94. Compounds 77 and 78 possess antimicrobial activities. Compounds 74 and 81 show considerable cytotoxic and antineoplastic activities.
Five new triterpene glycosides have been isolated from the northeastern Pacific sponge Xestospongia vanilla. The structures of isoxestovanin A (125), xestovanin C (127), dehydroxestovanin A (129), epi-dehydroxestovanin A (131), and dehydroxestovanin C (132) were all determined by a combination of spectral data interpretation and chemical interconversions. These compounds all contain the deoxy sugars L-rhamnose and D-fucose. Isoxestovanin A (125) possesses a new carbon skeleton and xestovanin C (127) and dehydroxestovanin C (132) possess linear
trisaccharide fragments which have not been previously encountered in triterpene
glycosides isolated from X. vanilla.
The Sri Lankan nudibranch Chromodoris glenei has yielded the known compound 12-desacetoxyshahamin C (153) and the new metabolite shahamin K (155). Both compounds possess dendrillane diterpene skeletons. The compound chromodorolide B (156) was isolated from specimens of Chromodoris cavae. It is only the second known diterpene natural product possessing the chromodorane skeleton.<br>Science, Faculty of<br>Chemistry, Department of<br>Graduate
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Dewi, Ariyanti Suhita. "Biologically active secondary metabolites from tropical marine invertebrates." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/15299.
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In our effort to discover promising anticancer agents, we have screened a series of
compounds for their activities as indoleamine-2,3-dioxygenase (IDO) inhibitor and SHcontaining
inositol 5-phosphatase (SHIP1) activator. In comparison to aaptamine (2.1) and
demethylaaptamine (2.2), isoaaptamine (2.4) from Aaptos cf. suberitoides appears to be the most
promising IDO inhibitor with an IC₅₀ of 0.00215 mg/mL, owing to the presence of hydroxyl
group at C9 position and the methylation at N1 position. A study on the sponge extract of RJA
55275 for its SHIP activator yielded theonellapeptolide Id (3.4), the first peptide that enhanced
the SHIP with 25% activity at concentration 124 μM, thus makes it the most potent SHIP
activator known to date. The third project studied the crystals of a novel eunicellin-based
diterpenoid (4.39) with a modest SHIP activity from an unidentified Micronesian soft coral RJA
47686. The X-ray analysis illustrated that the crystals are monoclinic, space group P21/b, with a
= 9.3711(14) A; α = 90⁰; b = 13.5349(17) A; β = 99.142(7)⁰; c = 10.9891(17) A; γ = 90⁰; V =
1376.1 (3) ų; Z value = 2; Dcalc 1.189. 10-³ g/cm³; F₀₀₀ 536.00; Cu (MoKα) 0.84 cm-¹.
Based on the NMR and x–ray data 4.39 was shown to possess (1R*, 2R*, 3R*, 6R*, 7S*, 10R*,
14R*, 18R*)-configuration with an ether linkage connecting C2 and C6.
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Hagger, Josephine Anne. "Evaluation of radionuclide induced damage in marine invertebrates." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/2483.
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Limited studies have been carried out to assess the potential effects of ionising radiation on marine organisms. Therefore the general aims ofthis thesis were, (a) to assess the cytotoxic, genotoxic and developmental effects of ionising radiation on the embryolarvae of two ecologically relevant marine invertebrates Mytilus edulis and Platynereis dumerilii, (2) to assess the effects of an environmentally relevant cocktail of radionuclides (3) to monitor the potential impact of radiation in the natural environment and finally (4) attempt to predict the potential effects of radiation at a population level. Following validation of developmental stages and mammalian based cytotoxic and genotoxic assays, chromosomal aberrations (Cabs), sister chromatid exchanges (SCEs) and proliferation rate index (PRJ), on the embryo-larvae ofMedulis and P.dumerilii, the embryo-larvae stages were exposed to a reference radionuclide, tritium, (0.37, 3.7, 37 & 370 kBq/ml). Low doses of radiation delivered by tritium were shown to be detrimental to the development of embryo-larvae with an increase in abnormality for P.dumerilii and an increase in mortality for Medulis. Tritium increased the induction of chromosomal aberrations and sister chromatid exchanges, in exposed embryo-larvae, indicating that tritium is potentially genotoxic. Cytotoxic effects (reduction in the cell proliferation rate) were also observed following exposure of embryo-larvae to tritium. In collaboration with the Royal Devonport Dockyard (DML) investigations on the cytotoxic, genotoxic and developmental effects of a cocktail of radionuclides (radioactive liquid waste diluted to 1.8, 3.2, 5.6, 18%) were carried out. All embryo-larvae exposed to 18% radioactive waste were dead within 24h. Both species exhibited increased abnormality, SCEs and Cabs and a reduction in PRJ in dilutions 1.8-5.6%. In general M edulis appeared to be more sensitive to ionising radiation than P.dumerilii embryolarvae. Following experiments on the embryo-larvae stages of the two marine invertebrates studies were carried out to assess the effects of ionising radiation on adult life stages. Following validation of mammalian based genotoxic assays (comet and micronucleus assays) on adult M edulis, the mussels were exposed to a reference radionuclide, tritium, (0.37,3.7,37 & 370 kBq/ml) in an attempt to assess the genotoxic effects of ionising radiation on the adult life stage. An increase in the levels of single strand breaks (comet assay) and in the induction ofmicronuclei (micronucleus assay) in haemocyte cells was observed in adults exposed to tritium. In collaboration with the Royal Devonport Dockyard (DML) a field study was carried out to assess the use ofthe genotoxic assays (comet and micronucleus assays) as biomarkers of exposure to radiation in adult mussels transplanted to an area of radionuclide discharge. Statistical analysis detected no correlation between the health of the deployed mussels and the levels of environmentally realistic radioactivity. After development ofP.dumerilii embryo-larvae to sexual maturity there appeared to be no affect on the number or sex ofthe worms that reached adulthood in comparison to control worms. Although at the highest concentration oftritium (370 kBq/ml) there was a reduction in the number ofeggs produced from sexually matured females. In conclusion, from the current studies it can be stated that ionising radiation is cytotoxic and genotoxic to sensitive embryo-larvae stages ofmarine invertebrates. However further studies need to be carried out to correlate the effects seen at molecular levels with the potential long-term effects observed at population and community levels of these species. 111
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Smith, Karen Lesley. "Immunotoxic biomarkers of anthropogenic impact in marine invertebrates." Thesis, University of Plymouth, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394702.
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Many chemicals enter the marine environment as a result of human activities where they are available to exert a range of effects upon biota. Research has previously focused on the effects of chemicals upon various biological functions of biota in situ. However the impact of chemicals with immunotoxic functions has received little attention. The current research focused on the immunotoxicity of environmental pollutants on marine invertebrates, primarily Mytilus edulis. The aim of the research was to determine to what extent immune function altered in M edulis following exposure to environmental contaminants and how these alterations could be measured and incorporated into environmental monitoring programmes. Exposure of M edulis to the immunotoxicants copper and tributyltin in the laboratory indicated that biochemical measures of immune function were too sensitive for experimental manipulations to be used as biomarkers of pollution-induced stress. However, cellular analysis of immune function, as measured by an adapted immunotoxicity assay in combination with a measure of cell viability, was responsive to pollution-induced stress in a concentration-dependant manner. Cellular immune activity appeared to be regulated by the cytokine IL-1 and involved the release of lytic factors from haemocyte populations. Field evaluation of the immunotoxicity assay in New Bedford Harbour, USA, indicated that environmental contaminants within the estuary had an immuntoxic effect upon in situ mussel populations. The measure of immunotoxicity in mussel populations in New Bedford Harbour was a more sensitive measure of environmental impact than routinely used biomarkers such as lysosomal neutral red, cardiac monitoring and condition index. The immunotoxicity assay is therefore proposed as a sensitive, low cost and reliable biomarker of effect in mussel populations both in the laboratory and the field.
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Suckling, Coleen Claire. "Calcified marine invertebrates : the effects of ocean acidification." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608228.
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Miller, Robert J. "Ecological factors shaping subtidal rock wall communities in the Gulf of Maine." View this thesis online, 2005. http://libraries.maine.edu/gateway/oroauth.asp?file=orono/etheses/37803141.pdf.
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Thesis (Ph.D.)--University of Massachusetts Boston, 2005.<br>Title from PDF title page. Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (p. 82-102). Also issued in print.
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Ayer, Stephen William. "Novel secondary metabolites from selected British Columbian marine invertebrates." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25557.
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Marine organisms show potential as sources for novel, biologically and pharmacologically active, secondary metabolites. Examination of three nudibranch and one bryozoan species for biologically active metabolites has led to the isolation and structural elucidation of nine new and two known secondary metabolites. The structures of all the compounds were determined by using a combination of spectral analysis, chemical interconversion, synthesis, and single-crystal X-ray diffraction analysis.
The British Columbian dorid nudibranch Acanthodoris nanaimoensis yielded three new sesquiterpenoids. The structures
of nanaimoal (61) , acanthodoral (64) , and isoacanthodoral (65) represent novel sesquiterpenoid carbon skeletons. The natural mixture of aldehydes 61, 64, and 65 exhibited antibacterial and antifungal activity. From Aldisa cooperi, two ∆⁴-3-ketosteroidal acids 23 and 24, and glycerol ether 25 were isolated. Acid 23 showed feeding deterrent activity against fish. The dendronotid nudibranch Meli be leonina gave 2,6-dimethy1-5-heptenal 53 and 2,6-dimethyl-5-heptenoic acid 54. The aldehyde 53 was responsible for the "grapefruit like" odour of the nudibranch. The bryozoan Phidolopora pacifica was examined in an attempt to correlate the absence of surface fouling, in the field, with the presence of biologically active secondary metabolites. The purine alkaloids 179 and 180, which contain the rare naturally occurring nitro functionality, were responsible for much of the antifungal and antialgal activity of the crude extracts. Three nitrophenols 181, 189, and 209 were also isolated from P. pacifica. Nitrophenol 181 had been previously shown to inhibit chloroplast development both in green plants and in the unicellular algae Euglena sp.<br>Science, Faculty of<br>Chemistry, Department of<br>Graduate
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Williams, David Ellis. "Novel secondary metabolites from selected cold water marine invertebrates." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/29175.
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A study of the secondary metabolism of two nudibranchs and one soft coral has led to the isolation of eighteen new and two known secondary metabolites. The structures of all compounds were determined by a combination of the interpretation of spectral data, chemical degradations and interconversions, and single crystal x-ray diffraction analysis.
The British Columbian dorid nudibranch Diaulula sandiegensis yielded two new steroidal metabolites, diaulusterols A (41) and B (42). The 25-(3-hydroxybutanoate) residue of diaulusterol A (41) and the 2α,3α-diol array of both 41 and 42 are not commonly encountered in naturally occurring steroids. Both metabolites exhibited considerable antibacterial and antifungal activity. Steroid 41 exhibited fish antifeedant activity. The relative concentration of 4.1 and 42 in the skin extracts of D. sandiegensis appears to be related to the animals' seasonal abundance.
Extracts of the British Columbian soft coral Gersemia rubiformis yielded a series of ten diterpenes possessing cembrane (170-175), pseudopterane (167-169) and gersolane (176) carbon skeletons. The structure of an eleventh diterpene remains unresolved. In addition, the structure of a degraded diterpene possessing a 13-membered ring (177) is tentatively proposed. G. rubiformis represents the first example of a soft coral to yield pseudopterane diterpenes. The organism is the first to contain cembrane, pseudopterane and gersolane metabolites, a fact which has biogenetic implications. Two new sesquiterpenes were also isolated. Tochuinyl acetate (165) and dihydrotochuinyl acetate (166) represent the first examples of cuparane sesquiterpenes to be isolated from a soft coral. A biogenesis is proposed. Metabolite 166 exhibited fish antifeedant activity.
Investigations of Gersemia rubiformis collected in Newfoundland waters revealed that the secondary metabolism differed from west coast specimens. The isolation of the new unstable sesquiterpene (+)-β-cubebene-3-acetate (178) resulted.
Skin extracts of the dendronotoid nudibranch Toquina tetraquetra were examined in an attempt to correlate its feeding dependency and lack of predation to the presence of allomones. Metabolites 165, 166, 170, 179 and the new butanoate diterpene 180 could be traced to the coelenterates which make up the animal's diet. Tochuinyl acetate (165), dihydrotochuinyl acetate (166) and rubifolide (170) were previously found in extracts of Gersemia rubiformis. Ptilosarcenone (179) has been reported as one of the major metabolites of the sea pen Ptilosarcus
gurneyi²¹³. The exact origin of a sixth metabolite, pukalide (63), remains unknown. It is proposed that Tochuina tetraquetra selectively sequesters dietary metabolites for defensive purposes.<br>Science, Faculty of<br>Chemistry, Department of<br>Graduate
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Nienhuis, Sarah Bethune. "Multiple impacts of ocean acidification on calcifying marine invertebrates." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/13390.
Full textAbstract:
Increasing anthropogenic atmospheric CO₂ is altering the chemistry of surface seawater worldwide, resulting in ocean acidification. Experiments have begun to demonstrate the detrimental consequences that a CO₂-mediated decline in ocean pH can have on the growth and survival of calcifying organisms. However, significant knowledge gaps exist both in our understanding of the mechanisms driving the observed reductions in shell growth rates of organisms exposed to increases in CO₂, and in our ability to predict how these individual-level effects could scale-up to the population or community-level.
Using laboratory exposure experiments in which levels of dissolved CO₂ were carefully manipulated, we tested the effects of climatically relevant increases in CO₂ levels on a) both shell deposition rate and shell dissolution rate in the intertidal snail, Nucella lamellosa, and b) the growth and feeding behaviour of juvenile red sea urchins, Strongylocentrotus franciscanus. Based on the results of the former study, we found that shell weight gain per day in live snails decreased linearly with increasing CO₂ level while shell weight loss per day in empty shells more than doubled over this same range. These results suggest that for some species, elevated CO₂ levels may have a much greater effect on shell dissolution than shell deposition. In the latter study, although we found no effect of a doubling of current CO₂ concentration on the individual feeding rates or absorption efficiency of juvenile urchins, there was a significant reduction in relative growth rates at the higher CO₂ concentration after 4 months of exposure.
Applying the urchin growth data to a simple demographic matrix model, and incorporating empirical relationships between urchin test diameter, biomass and kelp consumption rates to the model outputs, we estimated that if current CO₂ levels were to double by the end of the century, it would take significantly longer for urchins to reach reproductive and harvestable sizes, and their per capita kelp grazing rates would be significantly reduced. These simple model applications illustrate how CO₂-mediated reductions in individual growth rates could indirectly impact important population-level attributes such as time to first reproduction, and could have community- or ecosystem-level effects by moderating the importance of top-down biological control.
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Bjørnstad, Anne. "Proteomics and ecotoxicoldgy : marine invertebrates and endocrine disrupting chemicals." Thesis, University of Plymouth, 2008. http://hdl.handle.net/10026.1/1067.
Full textAbstract:
The key problem faced by environmental scientists is to predictand recognize the damaging effects of chemical pollutants on natural biota. The aim of this thesis was to evaluate the potential for proteomics in ecotoxicology and environmental risk assessment (ERA), with the hypothesis that proteomic technologies (i.e. ProteinChip technology in combination with SELDI TOF MS) could be a useftil supplement to existing methods of environmental assessment, by providing a sensitive, non-invasive, rapid multi-endpoint assessment of effects of anthropogenic chemicals on organism in vivo. Three invertebrate species, Mytilus edulis, Hyas araneus and Strongylocentrotus droebachiensis was exposed to natural and anthropogenic chemicals in laboratory and field studies. Results revealed that proteomics was a sensitive endpoint, as all exposure regimes significantly affected protein expression. It was shown that plasma protein expression profiles contained information that was compound, dose, site, species and gender-specific. Regarding the latter; male and female organisms responded differently to all exposures both quantitatively (e.g. in terms of number of affected protein species) and qualitatively (e.g. in terms of tj^e of affected protein species). Furthermore, genders have shown opposite responses following the same exposure regime. Equally, species-specific responses were observed. Moreover, exposing organisms to graded levels of contamination under controlled laboratory conditions and in the field revealed that different subsets of proteomes were affected at different levels of exposure. This finding represents an opportunity for appljdng proteomics for both prognostic (e.g. early warning of potential adverse effects or assessment of recovery) and diagnostic purposes. Moreover, those protein features that were changed by all exposure concentrations showed complex dose-response relationships, including both linear and various types of biphasic response-curves. In summary, results from the present study indicate that proteomics have the potential to be a useftil tool in ERA. For example, identification of key molecules could elucidate mechanism of action related to mixture effects, gender and species-specific susceptibility to environmental pollutants as well as dose-response relationships at low doses. Furthermore, key proteins (i.e. putative biomarkers) could, be purified and coupled to e.g. a biosensor for automated monitoring.
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Wale, Matthew A. "The effects of anthropogenic noise playbacks on marine invertebrates." Thesis, Edinburgh Napier University, 2018. http://researchrepository.napier.ac.uk/Output/1255476.
Full textAbstract:
Anthropogenic sound has profoundly changed the acoustic environment of aquatic habitats, with growing evidence that even a short exposure to man-made sound sources can negatively affect marine organisms. Marine invertebrates have received little attention regarding their responses to anthropogenic sound, despite their pivotal role in marine ecosystems, and preliminary evidence of their sensitivity. In this thesis, I critically review the methods used in studies investigating the effects of anthropogenic noise on marine invertebrates. I identify methodological trends that have developed along the timeline of this topic, and use this information to suggest three research strategies to further the development of research in this field. From this review, current knowledge gaps are identified, and two main routes to address them are taken in this thesis. Firstly, to address the shortage of particle motion data in anthropogenic sound literature, two new low-cost and easily accessible particle motion sensors were developed and tested, one of them at 0.1% of the cost of currently commercially available models. These sensors will allow the measurement and reproduction of the sound fields experienced by marine invertebrates in bioacoustic research, even when research budgets are tight. Particle motion is the main sound component detected by invertebrates, yet neglected in many aquatic bioacoustical studies. Secondly, to expand on the comparably small quantity of research investigating the effects of anthropogenic sound on marine invertebrates, a series of controlled laboratory experiments were conducted. Two commercially and ecologically important model species were chosen, the blue mussel Mytilus edulis, representing sessile benthic invertebrates, and the European lobster Homarus gammarus, representing mobile benthic invertebrates. Experiments on M. edulis were conducted taking a mechanistic, integrative approach to investigate the effects of sound on multiple levels of biological organisation, including biochemistry, physiology, and behaviour. The ultimate aim was to understand the underlying drivers behind, and interactions between, responses. Comet assay analysis of haemocytes and gill cells demonstrated a significant six-fold higher single strand breakage in the DNA of cells of mussels exposed to ship-noise playback, compared to those kept under ambient conditions. Superoxide dismutase analysis did not identify an excess of superoxide ions, and glutathione, and glutathione peroxidase assays showed no increase in either glutathione or glutathione peroxidase. TBAR assays however revealed 68% more thiobarbituric acid reactive substances, indicating lipid peroxidation in the gill epithelia of noise exposed specimens. Algal clearance rates and oxygen-consumption rates of noise-exposed mussels were significantly lower (84% reduction and 12% reduction respectively), than those of control animals, while valve gape was significantly (60%) wider. This seemingly converse reaction indicates a shock response in mussels with the onset of noise exposure. Finally, at the genetic level, heat shock protein 70 expression was investigated, but no change was identified during noise exposure. Investigation into the noise induced behavioural responses of H. gammarus suggests seasonal differences in behaviour, using movement as a metric, in response to anthropogenic noise playbacks. During both summer and winter exposures, lobsters spent most time away from the highest noise area (98% of the observed time in summer and 78% in winter). The observed seasonal differences in the time spent in the highest noise area (2% in summer and 22% in winter) could be linked to the lobsters' requirement for shelter during winter. This requirement seems to have had a stronger influence over the animals' behaviour than any desire to avoid high noise levels. The information generated in this thesis can be used by researchers working in the field of marine sound to develop well rounded studies exploring the effects of sound on not only marine invertebrates but other faunal groups as well. The construction details provided to produce low cost particle motion sensors, will allow bioacoustic researchers to easily include particle motion measurements in all future studies investigating the effects of sound on fish and invertebrates. The results of the conducted mussel and lobster experiments evidence how multiple aspects of invertebrate biology can be affected by noise. The observed impacts on both sessile and mobile life forms highlight that the effects of noise cannot be fully understood before a wide range of species with different biological and ecological traits have been studied. The integrative approach to noise research used here can serve as a model for other species, and the results pooled to inform governments and industry of the effects of anthropogenic noise in the marine environment.
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Hooper, Gregory John. "Biologically active natural products from South African marine invertebrates." Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1003239.
Full textAbstract:
This thesis describes the chemical and biological investigation of the extracts of six different marine invertebrate organisms collected along the South African coastline. The work on these extracts has resulted in the isolation and structural elucidation of twenty-one previously undescribed secondary metabolites; The history of marine natural product chemistry in South Africa has not previously been reviewed and so a comprehensive review covering the literature from the 1940's up until the end of 1995 is presented here. The marine ascidian Pseudodistoma species collected in the Tsitsikamma Marine Reserve was shown to contain four new unsaturated amino alcohols [47], [48], [49] and [50] which were isolated as their acetyl derivatives. These compounds exhibited strong antimicrobial activity. Four new pyrroloiminoquinone alkaloids, the tsitsikammamines A [90] to D [93],were isolated from a new genus of Latrunculid sponge collected in the Tsitsikamma Marine Reserve. These highly pigmented compounds also possessed strong antimicrobial activity. An investigation of two phenotypic colour variants of the soft coral Capnella thyrsoidea resulted in the isolation of the known steroid 5α-pregna-1, 20-dien-3-one [97] and an additional six new metabolites, 16β-hydroxy-5α-pregna-1 ,20-dien-3-one 16-acetate [98], 3α,16β-dihydroxy-5α-pregna-1, 20-diene 3,16-diacetate [99] and four xenicane diterpenes, the tsitsixenicins A [100] to D [103]. This is the first reported isolation of xenicane diterpenes from the soft coral family Nephtheiidae. Tsitsixenicin A and B showed good anti-inflammatory activity by inhibiting superoxide production in both rabbit and human cell neutrophils. A further four new metabolites were isolated from two soft corals which could only be identified to the genus level and were designated Alcyonium species A and species B. Alcyonium species A was collected in the Tsitsikamma Marine Reserve and yielded two new polyhydroxysterols, cholest-5-ene-3β, 7β, 19-triol 19-acetate [121] and cholest-5,24-diene-3β, 7β, 19-triol 19-acetate [122]. The soft coral Alcyonium species B was collected off Aliwal Shoal and was found to contain two known xenicane diterpenes, 9-deacetoxy-14, 15-deepoxyxeniculin [110] and zahavin A [16], and two new xenicane diterpenes, 7 -epoxyzahavin A [123] and xeniolide C [124]. Compounds [110], [16] and [123] exhibited strong anti-inflammatory activity and compounds [110] and [16] showed good antithrombotic activity. The endemic soft coral A/cyanium fauri collected at Riet Point near Port Alfred yielded the new sesquiterpene hydroquinone rietone [141] in high yierd, fogether with the minor compounds 8'-acetoxyrietone [142] and 8'-desoxyrietone [143]. Rietone exhibited moderate activity in the NCl's in-vitro anti-HIV bioassays.
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Stapleton, Bronwin Louise. "Structural studies of bioactive natural products from marine invertebrates /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16452.pdf.
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Johnson, Kevin Brett. "Predation on planktonic marine invertebrate larvae." Thesis, Thesis (Ph. D.)--University of Oregon, 1998, 1998. http://hdl.handle.net/1794/10086.
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李嵐 and Laam Li. "Effects of hypoxia on marine benthic communities : from bacteria to invertebrates." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/193402.
Full textAbstract:
Because of the eutrophication resulting from increasing anthropogenic activities, hypoxia (i.e. dissolved oxygen < 2.8 mg O2 L-1) is on the rise globally. The objective of this research was to understand more about the effects of hypoxia on the marine benthic communities. Particularly, it focused on the latent effects and indirect effects of hypoxia by investigating how early exposure to hypoxia affect the later life stage of a marine gastropod Crepidula onyx, and how hypoxia alter the bacterial composition of biofilms and the subsequent larval settlement of marine invertebrates.
In the first study, the larvae of C. onyx were exposed to 2, 3, and 6 mg O2 l-1. Under low food concentration (Isochrysis galbana at 1 × 105 cells l-1), larvae in both hypoxic treatments (2 and 3 mg O2 l-1) required a longer time to become competent to metamorphose. But when they did, they had a similar size and total lipid content to the control larvae. Moreover, the latent effects of early hypoxic exposure on the juvenile growth were evident. After 2 weeks development in field, the growth rate, mean dry weight and filtration rate of juveniles were significantly reduced in the hypoxic treatments. However, there was no discernible effect on larvae or juveniles when the food concentration during the larval stage was doubled (I. galbana at 2 × 105 cells l-1), suggesting that the latent effects of hypoxia can be offset by larval access to high algal concentration.
In the second study, the biofilms were exposed to hypoxia and normoxia in microcosms for up to 7 days, and their bacterial community composition was analysed by terminal-restriction fragment length polymorphism (T-RFLP). The results suggested that hypoxia altered the bacterial community structure within biofilms, and the difference between the hypoxia and normoxia treatments increased through the length of exposure period. The resulting changes in biofilms did not alter the larval settlement response of a model species (i.e. C. onyx) in laboratory assays. Nevertheless, when the biofilms were deployed in the field to allow natural larval settlement and recruitment, biofilms that had been exposed to hypoxia altered the overall larval settlement pattern of different marine invertebrates, potentially leading to a shift in the benthic invertebrate community.
This research suggested that periodic hypoxic events and the resulting exposure of organisms to hypoxia during their early development might have effects that persist across the life history. Moreover, it highlighted the possibility that the effects of hypoxia on species composition and structure of benthic invertebrate communities might be mediated through changes in biofilms and subsequently larval settlement and recruitment. To conclude, this research demonstrated that hypoxia could affect the growth in the later life stages of marine invertebrates and the recruitment of the benthic communities.<br>published_or_final_version<br>Biological Sciences<br>Master<br>Master of Philosophy
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Blanco, Sánchez Marta. "Historia de vida temprana e inversión reproductiva de invertebrados bentónicos: integración al manejo y conservación a través de modelos de dispersión = Early life and reproductive investment of benthic invertebrates: integration to management and conservation throught dispersal models." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/666608.
Full textAbstract:
Las zonas costeras son uno de los ecosistemas que sufre mayor impacto antrópico a nivel mundial. La sobreexplotación de los recursos marinos es una de las actividades humanas que genera mayor impacto, reduciendo la abundancia y tamaño de las especies objetivo. Una de las medidas para proteger estos ecosistemas consiste en el establecimiento de áreas marinas protegidas. En Chile, el sistema actual de manejo de las pesquerías artesanales de especies bentónicas está basado en áreas parcialmente protegidas, las Áreas de Manejo y Explotación de Recursos Bentónicos (AMERBs), lo que ha supuesto una mejora en la sostenibilidad de una actividad de larga tradición en el país. Estas áreas entregan derechos de usos territoriales, conocidos mundialmente como TURF (sigla en inglés de Territorial Use Right for Fisheries). Sin embargo, actualmente estas áreas se gestionan de forma individualizada, de tal manera que la escala espacial de manejo no está acoplada a la escala de la dinámica de las poblaciones de invertebrados bentónicos. El objetivo de esta tesis es identificar áreas de alto valor para la producción, exportación y llegada de larvas en base a los patrones de historia de vida temprana, considerando variables y/o condicionantes relevantes de la fase adulta bentónica, como (a) la inversión reproductiva, (b) la densidad y talla de los adultos reproductores, variables determinantes de la distribución espacial de la producción de huevos y larvas, así como también variables que intervienen en la fase larval planctónica, como (c) los rasgos biológicos larvales, para acoplarlo con los patrones de circulación costera con el fin de contribuir a un mejor entendimiento de la dispersión y conectividad larval. Para este fin se seleccionaron dos especies relevantes social, comercial y ecológicamente: el erizo rojo (Loxechinus albus) y la lapa (Fissurella latimarginata). En primer lugar, se evaluó mediante muestreos de campo el efecto de la protección (relacionada con el régimen de explotación) y afloramiento costero sobre la inversión reproductiva y la condición individual de los adultos reproductores. Esta información sumada a los datos empíricos de distribución de tallas, densidad de individuos y fecundidad de las hembras reproductoras se utilizó para desarrollar un modelo de producción potencial de huevos en la costa central de Chile. Para el estudio del reclutamiento y dispersión se desarrolló un modelo biofísico de dispersión larvaria que permite evaluar el efecto de la variabilidad oceanográfica y los rasgos biológicos (migración vertical de las larvas y desarrollo dependiente de la temperatura) en la distancia de dispersión, el éxito del reclutamiento, y los patrones de conectividad larval. Los resultados sugieren que, para ambas especies, la protección y el afloramiento costero no tienen un efecto sobre la inversión reproductiva y la condición de los individuos. Sin embargo, la protección sí tuvo un efecto sobre la talla y densidad de individuos generando claros patrones espaciales de producción de gametos. Se observó que la variación geográfica y temporal de los procesos de circulación dominaneltransportey la dispersióndelas larvas enlaregión, independientemente de los rasgos biológicos evaluados. La mayoría del reclutamiento fue alóctono, con niveles bajos de auto-reclutamiento y retención local, incluso para la especie con un tiempo de vida planctónica corto (F. latimarginata). Los patrones geográficos de salida y llegada fueron similares para ambas especies, observándose una mayor importancia relativa de la región norte del dominio de estudio. Estos resultados permiten identificar los principales determinantes de la producción de huevos, el éxito del reclutamiento y la distancia de dispersión para dos especies de gran interés comercial en Chile, información que podría guiar recomendaciones para el manejo y la conservación en una de las regiones costeras más productivas pero también más explotadas del mundo.<br>Coastal zones are one of the ecosystems receiving higher anthropic impact. Fishing is a major source of human impact, reducing density and size of exploited species. Marine protected areas are one of the strategies established to control fishing impacts. The current artisanal fisheries management system in Chile is based on partially protected areas, TURFs (Territorial Use Right for Fisheries). This system enhances sustainability of one of the traditional activity in the country. However, these areas are individually managed so the scale of resource management is not coupled with the scale of exploited population dynamics. The objective of this thesis dissertation is to identify areas of high value for propagule production as well as source and sink areas based on early life history patterns, considering variables relevant for the adult phase such as (a) reproductive output,
(b) density and size of reproductive adults as both variables define the spatial distribution of eggs and larvae, as well as variables that affect the larval phase such as (c) larval biological traits, coupling these pieces of information with coastal circulation models to reach a better understanding of dispersal and larval connectivity. Two benthic invertebrates species exploited by artisanal fisheries
in Chile, the red sea urchin (Loxechinus albus) and keyhole limpet (Fissurella
latimarginata) were used as models. First, I evaluated the effect of protection and coastal upwelling on reproductive output and individual condition of reproductive adults. Based on size distribution, density of individuals and fecundity data I developed an egg production model along the central coast of Chile. Finally, I developed a biophysical larval dispersal model to assess the effect of oceanographic variability and larval biological traits (larval diel vertical migration and temperature-dependent larval development) on dispersal distance, recruitment success and connectivity patterns. These results showed that fishing regime and coastal upwelling did not affect individual reproductive output either individual condition for both species. However, fishing regime had an effect on size and density of individuals. I found that the geographic and temporal variation in circulation processes dominate transport and effective dispersal of larvae in the study region, regardless of larval biological traits. Most recruitment to local population was allochthonous, with low levels of self-recruitment and local retention even for the species with short planktonic larval duration. Similar geographic patterns of source and destination strengths were observed in both species, with the northern region of the studied domain showing relatively higher importance. These findings allow identifying primary determinants of recruitment success and dispersal distance for two important exploited species in Chile, and to provide the bases to advance recommendations for management and conservation in one the most productive, but also exploited, coastal regions in the world.
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Chan, Ying-shan, and 陳映姗. "Effects of silver nanoparticles on marine invertebrate larvae." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/208175.
Full textAbstract:
Silver nanoparticles (AgNPs) have gained much popularity in consumer products due to their strong antimicrobial ability. The majority of research concerning the biological effects of AgNPs has been limited to humans, mammals and freshwater organisms. Marine organisms, especially invertebrates, have been studied to a lesser extent. The objective of this thesis was to understand the effects of AgNPs on the marine benthic invertebrates. Specifically, we focused on the acute and sub-lethal toxicity of two AgNPs (Oleic acid coated AgNP (OAgNP) and Polyvinylpyrrolidone coated AgNP (PAgNP)) on marine invertebrate larvae across three phyla (i.e. the barnacle Balanus amphitrite, the limpet Crepidula onyx and the polychaete Hydroides elegans) in terms of mortality, growth, development and metamorphosis. Bioaccumulation and biodistribution of silver, as well as apoptosis induction were also investigated. To distinguish the toxic effects derived from nano-silver and aqueous form of silver, larvae were also exposed to silver nitrate (SN) in parallel.
In the acute toxicity test, larvae were exposed to OAgNPs and PAgNPs for 48 hours, and the concentration leading to 10 % mortality (〖LC〗_10) were determined and compared. The results indicated that B. amphitrite and H. elegans were more sensitive to OAgNPs (〖LC〗_10: 0.138 and 2.63 × 〖10〗^(-4) μμg L-1, respectively) than PAgNPs (〖LC〗_10: 0.502 and 0.317 μμg L^(-1), respectively). In contrast, C. onyx was more susceptible to PAgNPs (LC10: 38.5 μμg L^(-1)) than OAgNPs (〖LC〗_10: 467 μμg L^(-1)). Among the three taxonomic groups, C. onyx was most tolerant of AgNPs, following by B. amphitrite and H. elegans.
The sub-lethal effect of AgNPs resulted in a significant retardation in growth and development, and the reduction of settlement rate of all three species tested. In particular, the settlement rate of H. elegans was significantly lower in AgNPs treatment than in SN treatment, suggesting that toxicity of AgNPs might not be solely evoked by the release of silver ion (Ag+) into the test solution. The three species took up and accumulated silver efficiently from all forms. Importantly, AgNP aggregates were found along the digestive tract of C. onyx and the TEM images further confirmed that AgNPs were able to move across the plasma membrane. In addition, TUNEL assay indicated that AgNPs could induce apoptosis in B. amphitrite and C. onyx. In view of the very low number of detected apoptotic cells and the random occurrence of cell death found, AgNP-induced apoptosis does not appear to be the major toxicity mechanism in causing delayed growth and settlement failure. Unlike the results revealed from acute toxicity test, surface coatings did not affect the sub-lethal toxicity of AgNPs.
This research clearly demonstrated that AgNPs exerted toxic effects in a speciesspecific manner, and long-term exposure of AgNPs might allow bioaccumulation of silver, induce apoptosis, and affect growth, development and recruitment of marine invertebrates. This study also highlighted the possibility that toxicity of AgNPs might be mediated through toxic Ag+ as well as the novel modalities of AgNPs.<br>published_or_final_version<br>Biological Sciences<br>Master<br>Master of Philosophy
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Dodd, Matthew. "Arsenic speciation studies on some marine invertebrates of British Columbia." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28664.
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Graphite furnace and hydride generation atomic absorption, GFAA and HGAA, techniques have been developed and applied to the determination of arsenic concentrations in some marine invertebrates, mainly bivalves and gastropods, of British Columbia. Total arsenic concentrations in bivalves vary with species, ranging from 0.6-9.1 μg g⁻¹ (wet weight basis). Arsenic concentrations in the bivalve shells show a wider range of 0.1 to 26.3 μg g⁻¹ (dry weight basis). Gastropods show relatively higher arsenic concentrations in the soft tissues, 17.3-48.4 fig μg g⁻¹, and concentrations in the shells range from 1.4 to 16.3 fig μg g⁻¹. There is no correlation between arsenic levels in the soft-tissues and shells. There is also no correlation between arsenic levels in the organisms and the surrounding sediments and sediment pore waters.
HPLC-GFAA techniques have been developed and used for the separation and quantitation of-arsenite, arsenate, methylarsonic acid, dimethylar-sinic acid, arsenobetaine, arsenocholine iodide and tetramethylarsonium iodide. This technique together with TLC, NMR, FAB and thermospray LCMS were employed for the detection of water-soluble arsenic compounds in 5 species of clams - Butter clam Saxidomus giganteus. Horse clam Schizothoerus nuttalli. Soft-shelled clam Mva arenaria. Native-littleneck clam Protothaca staminea and Manila clam Venerupis laponica. Varying amounts of arsenobetaine and tetramethylarsonium ion are found in all the clams. Butter clams show the pres ence of a third compound which appears to be trimethylarsine oxide. Small amounts of unknown arsenic containing compounds are present which are yet to be characterized
.
Arsenic speciation in 3 gastropods was also examined. The Northwest neptune Neptunea lvrata. the Thick-ribbed whelk Berinpius crebriscotata and Phoenician whelk Neptunea phoenicius all contain arsenobetaine and at least two unidentified arsenicals.<br>Science, Faculty of<br>Chemistry, Department of<br>Graduate
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Stanwell-Smith, Damon Peter. "Larval ecology of benthic marine invertebrates at Signy Island, Antarctica." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338610.
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Cheung, Victoria Vikki. "The detection of genetic toxicity in marine organisms." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/2186.
Full textAbstract:
Studies were undertaken to measure genetic toxicity at the molecular and cytogenetic levels of biological organisation in marine invertebrates and flatfish. The responses in the early life stages and adult life stages of marine invertebrates (Mytilus edulis and Platynereis dumerilii) were measured following exposures to the physical agent ultraviolet radiation (UVR) and representative compounds of the chemical group, polycyclic aromatic hydrocarbons (PAHs) in laboratory conditions. Also, the potential changes of toxicity of PAH contaminants caused by interactive effects with UVR were evaluated. In a collaborative study with researchers at the Centre for Environment, Fisheries and Aquaculture Science (CEFAS), genotoxic measurements were carried out in marine flounder (Platichthys flesus) which had been chronically exposed in vivo to PAHs administered via their food in controlled laboratory conditions. Significantly elevated levels of DNA damage were only observed in fish exposed to the highest PAH concentrations. Dose-dependent cytogenetic responses were observed in the early life stages of both of the invertebrate species investigated following exposure to UVR. However, statistically significant increases in chromosomal aberration induction and sister chromatid exchange (SCE) induction, and decreases in proliferation rate index (PRI) and normal development were only observed at UVR levels exceeding that of equivalent environmentally realistic conditions, when related to historical and predicted ozone levels in the south west of England. The interactive effects of UVR and PAHs indicated that the genotoxic potential of PAHs is increased when photoactivation takes place, measured by increases in genotoxic responses in both the early and adult life stages. Following a series of laboratory studies, a field study was conducted whereby indigenous populations of marine invertebrates {Mytilus edulis and Cerastoderma edule) were used as target organisms. Haemolymph samples were collected from the animals and tested for genotoxic and cytotoxic effects, employing assays validated in the earlier laboratory studies. Correlations between samples showing high levels of DNA damage measured with the comet assay and sites with high levels of heavy metals in the sediments and soft tissue of the animals were established. Finally, an attempt was made to evaluate the DNA repair capabilities of haemocytes collected from M.edulis, A series of in vitro exposures were carried out using hydrogen peroxide (H2O2) an oxidising agent, and methyl methane sulfonate (MMS) an alkylating agent to induce DNA damage. These were incubated with cytosine β-D-arabino furanoside (AraC), to establish whether these cells had the capacity to repair DNA damage induced by the model chemicals. The results showed that DNA damage induced by H2O2 required DNA polymerases for repair, whereas MMS-induced damage and repair did not appear to be affected by the presence of AraC. In conclusion, the data collated from the research undertaken for this project showed that UVR and PAHs are able to induce genotoxic lesions measurable at the cytogenetic level and whole organism levels in early life stages; and at the molecular and cellular levels in the adult stages. The assays employed appeared to be useful for identifying potential "hotspots" for genotoxic agents in the environment as indicated by the results of the field study, however, the endpoints measured are not contaminant-specific and provide little information about the type of contaminant or agent which might be present. Nonetheless, it has been shown here that comet assay is applicable to different marine species (including Cerastoderma edule and Platichthys flesus) and it is a potentially useful method for detecting DNA damage as well as DNA repair.
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Neil, Thomas Robert. "Muscle mechanics and hydrodynamics of jet propulsion swimming in marine invertebrates." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/15435/.
Full textAbstract:
Locomotion amongst animals is widespread and diverse. Movement is of fundamental biological importance to animals, enabling them to forage, migrate, pursue prey and mate. Animals have evolved a great range of locomotor mechanisms that span huge size ranges and diversity across the animal kingdom, yet several common principles underlie most of these mechanisms, the understanding of which can help explain why certain biological locomotor systems have evolved for particular environments. Constraints on an animal’s morphological traits are bought about by body size, meaning that several aspects of locomotor performance are found to vary with body mass. Burst performance plays a crucial role in many animals lives, with the ability to accelerate and manoeuvre quickly often being essential for survival. The power available from the muscles during this type of locomotion is generally thought to decrease with increasing body size, with cycle frequency predicted to limit maximal muscle mass-specific performance. Muscle mass-specific power was measured in vivo in scallops covering a 96-fold range in body mass. Power was measured using sonomicrometry crystals to measure muscle length changes during swimming whilst pressure was simultaneously monitored within the mantle cavity. The scaling of the contractile characteristics of the adductor muscles of scallops was investigated to determine what affect the intrinsic properties of the muscle have on the scaling of muscle power output. Muscle fibre bundles were dissected and attached to a force transducer to measure force and muscle length change. Muscles were electrically stimulated via platinum plate electrodes. The scaling of twitch kinetics and the force velocity relationship were characterised in vitro. Jet propulsion via pulsed jets have been shown to be able to produce more thrust per unit of ejected fluid then an equivalent steady jet. The benefit is bought about through the production of isolated vortex rings, which entrain additional ambient fluid into the wake. There are numerous biological swimmers that use jet propulsion as their primary form of locomotion, however, their ability to be able to use vortex rings to enhance their propulsive performance has only been investigated in a few systems. Jet wake structure and swimming performance were quantified in three animals that swim by jet propulsion; scallops, Nautilus and jellyfish. The properties of the wakes were characterised using particle image velocimetry to measure the wake structure of the jets that were produced. Muscle mass-specific power output was found to decrease with increasing size in scallops. Frequency decreased with increasing size, muscle stress was found to be approximately constant whilst muscle strain decreased with increasing size in king scallops. The scaling exponents for muscle power were greater than those of the scaling of cycle frequency, suggesting that cycle frequency is not the sole determinant of the scaling of muscle power output. Muscle power output measured in vitro was also found to decrease with increasing body mass, but scaled with an exponent greater than that measured in vivo. The Vmax of the muscles decreased with increasing size, but did not scale in the same way as cycle frequency, suggesting that the intrinsic contractile properties of the muscle were not the sole determinant of cycle frequency in scallops. King scallops and Nautilus were found to produce two distinct jet modes, one in which isolated vortex rings were produced (Jet mode 1) and one which consisted of a leading vortex ring followed by a trailing jet of fluid (Jet mode 2). No differences were found in jet mode and the thrust produced from the jet, although enhanced thrust was found in king scallops producing jets at formation numbers of ~4. The wake structure of Rhizostomeae jellyfish revealed that they propel themselves via and interaction of two vortex rings that are produced as they swim. They were also found to manipulate the formation of a vortex ring that is formed as they swim, manoeuvring it to within their sub-umbrella cavity, providing them with an additional boost during swimming.
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Saphörster, Julia [Verfasser]. "Molecular mechanisms of cellular immune responses in marine invertebrates / Julia Saphörster." Kiel : Universitätsbibliothek Kiel, 2017. http://d-nb.info/1138980315/34.
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Wasson-Hetherington, Lesley H. "Metabolism and molecular mechanisms of toxicity of nitroaromatics in marine invertebrates." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309556.
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Meyer, Kirstin S. "Community assembly of benthic invertebrates on island-like marine hard substrata." Thesis, University of Oregon, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10192050.
Full textAbstract:
<p>Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial island communities, drawing on classical island biogeography theory and assembly rules, and describe how benthic invertebrate communities assemble in these island-like habitats.
Higher species richness occurred on larger substrata (dropstones and shipwrecks), paralleling terrestrial island communities. However, while larger islands have greater habitat diversity and primary productivity, marine hard substrata are simpler habitats. Greater elevation in the benthic boundary layer may expose fauna to faster current, higher food supply and larval flux. Substrata located closer together had more similar communities, another pattern that resembles terrestrial islands. Dropstone fauna had a clumped distribution, indicating that larvae may disperse among substrata located close together, resulting in similar communities.
In Svalbard fjords, benthic megafaunal communities were significantly different between Arctic- and Atlantic-influenced fjords. Depth and temperature had the greatest influence, with the highest diversity occurring in cold Rijpfjorden and on the north Svalbard shelf.
Recruitment in Svalbard fjords was spatially and temporally variable, with lower recruitment in Rijpfjorden than in Atlantic-influenced fjords and lower recruitment at greater depth. Most of the recruits in Svalbard fjords were fast-growing, poor-competitive opportunists. On shipwrecks, communities showed two mechanisms of colonization: mobile fauna with long-dispersing planktotrophic larvae, and encrusting fauna with lecithotrophic larvae. Encrusting species reproduce asexually to cover the wreck surface, and philopatry may build up dense populations, leading to uneven communities.
On terrestrial islands, non-random co-occurrence is attributed to interspecific competition, but for marine substrata, there may not be a relationship. Fauna were distributed randomly on settlement plates in Svalbard fjords, even when interspecific competition was observed. On dropstones, some morphotypes co-occurred non-randomly in the absence of overgrowth competition. Non-random co-occurrence on isolated marine hard substrata may be a result of restricted larval dispersal (for pairs co-occurring less than by chance) or epibiontism (for pairs co-occurring more often than by chance). While species distribution patterns on island-like marine hard substrata resemble terrestrial islands, the mechanisms are not necessarily the same.
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Binnaser, Yaser Saad. "Physiological effects of global climate change on common British marine invertebrates." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2684.
Full textAbstract:
Climate change is likely to have profound effects on marine animals due to the predicted increases in water temperature and acidity. Many studies have examined the effects of these elevated temperatures and decreased pH at the extreme temperatures expected in the summer season, but few studies have investigated how climate change may affect animals in the winter. In this study, we investigate the effects of both winter and summer temperatures on the growth rates, body composition and metabolic rate of four species of intertidal marine invertebrates: two calcified (common mussel - Mytilus edulis and edible periwinkle – Littorina littorea) and two non-calcified (beadlet anemone – Actinia equina and sea squirts – Ascidiella aspersa) species. Samples divided to two groups, one group exposed to winter temperature condition and the second group exposed to summer temperature condition. Following a period of acclimatization during which temperature was gradually increased and pH decreased, animals were exposed to the predicted climatic conditions of 2050 (TR 2050) and 2100 (TR 2100) for six weeks. During the study period, the mortality rates were monitored as well as growth rates by taking body weight, buoyant weight and body morphometrics (length and Width). At the end of experiments, body composition were measured by taking water content, dry shell and dry body weight weight, fat content and C:N ratio. In addition, metabolic rates were measured using a closed-system respirometry. During the experiments, seawater parameters such as acidity, temperature, salinity and dissolved oxygen were measured. The results of the experiments found that there was a significant increase in mortality of A. aspersa at the higher temperatures and water acidity in winter. Furthermore, growth rates of A. equina and A. aspersa were significantly reduced at TR 2050. On the other hand, it was observed that the C:N ratio of L. littorea was significantly increased at TR 2050 and that metabolic rate was significantly higher at TR 2100. However, under summer conditions, L. littorea there was a significant decrease in buoyant weight at TR 2050. While there was no mortality amongst A. equina, a significant reduction growth was found at elevated temperature and decreased pH level. The results in this study indicate that inter-species responses to environmental changes are likely to differ but also that the inter-species response will also vary depending on the season and life stage of the animal.
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Rapson, Trevor Douglas. "Bioactive 4-methoxypyrrolic natural products from two South African marine invertebrates." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1006766.
Full textAbstract:
This thesis presents an investigation of the 4-methoxypyrrolic constituents of two South African marine invertebrates, the nudibranch Tambja capensis and the bryozoan Bugula dentata. Three known compounds tambjamine A (7), tambjamine E (13) and the tetrapyrrole (15) were isolated during this investigation. All three compounds were shown to be active against oesophageal cancer in accordance with the general anticancer and immunosuppressive properties observed for 4-methoxypyrrolic natural products. Tambjamine A (7), tambjamine E (13) and the tetrapyrrole (15), together with tambjamine K (21) and L (22) (previously isolated in our laboratory) were used as standards to quantitatively assess the presence of these tambjamines in T. capensis and B. dentata collected from three different sites along the South African coast. This study confirmed that B. dentata is the source of the 4-methoxypyrrolic natural products sequestered by T. capensis and eliminated the closely related bryozoan B. neritina as a source of these metabolites. The paucity of tambjamine L (21) and K (22) obtained in previous investigations of the sequestered chemistry of T. capensis prompted an attempt at the development of synthetic methodology that could be used to synthesize tambjamines in sufficient yield for in depth bioactivity studies. In order to by pass the extensively reported problems associated with the synthesis of this group of compound 3-methoxy-2-formylpyrrole (47), readily accessible from 3-methoxypyridine N-oxide (48), was used as the starting material in a singlet oxygen induced 2,2’ bipyrrole coupling reaction. Although 47 proved unreactive in this coupling reaction, when the N-Boc protected analogue of 47 was used, and the reaction worked up in the dark, the novel methyl 4-aza-5-oxo-6,6-di-(2-pyrrolyl)-2(Z)-hexenoate (57) was obtained in low yield. The physical properties of tambjamine (E) (13) and the tetrapyrrole (15) were investigated to further the understanding of the proposed oxidative DNA cleavage mechanism and to determine the potential of the 4-methoxypyrrolic natural products as photodynamic therapy agents.
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Hanekom, Thea. "Screening bacterial symbionts of marine invertebrates for ribosomally synthesized natural products." University of the Western Cape, 2016. http://hdl.handle.net/11394/5441.
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>Magister Scientiae - MSc<br>Pharmaceutical research and development strategies rely on the constant discovery of novel natural products as potential drugs. Recent studies have shown that the
microorganisms associated with sponges are the true producers of some previously
isolated compounds. This study created a large collection of bacterial symbionts
associated with the South African marine sponge, Hamacantha esperioides. The
bioactivity assays performed, showed that 44 isolates produced compounds with
antimicrobial or anti-inflammatory activity. The successful identification of novel
species that produce potential natural products highlights the importance of cultivation-dependent methods. To further screen for natural products, a cultivation-independent approach was used. A sequenced-based method, based on the biosynthetic genes of polytheonamide, was developed to screen for proteusins in sponge metagenomic DNA and the genomes of bacterial symbionts. The degenerate primers could amplify the targeted genes from DNA known to contain homologues. Evaluation of the primers' specificity showed non-specific amplification of genes, some containing similar conserved domains as the target genes. This study demonstrated that the use and development of cultivation-dependent and -independent screens are important for the discovery of novel natural products from the symbiotic bacteria of South African sponges.<br>National Research Foundation (NRF)
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Meyer, Kirstin. "Community assembly of benthic invertebrates on island-like marine hard substrata." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20686.
Full textAbstract:
Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial island communities, drawing on classical island biogeography theory and assembly rules, and describe how benthic invertebrate communities assemble in these island-like habitats.
Higher species richness occurred on larger substrata (dropstones and shipwrecks), paralleling terrestrial island communities. However, while larger islands have greater habitat diversity and primary productivity, marine hard substrata are simpler habitats. Greater elevation in the benthic boundary layer may expose fauna to faster current, higher food supply and larval flux. Substrata located closer together had more similar communities, another pattern that resembles terrestrial islands. Dropstone fauna had a clumped distribution, indicating that larvae may disperse among substrata located close together, resulting in similar communities.
In Svalbard fjords, benthic megafaunal communities were significantly different between Arctic- and Atlantic-influenced fjords. Depth and temperature had the greatest influence, with the highest diversity occurring in cold Rijpfjorden and on the north Svalbard shelf.
Recruitment in Svalbard fjords was spatially and temporally variable, with lower recruitment in Rijpfjorden than in Atlantic-influenced fjords and lower recruitment at greater depth. Most of the recruits in Svalbard fjords were fast-growing, poor-competitive opportunists. On shipwrecks, communities showed two mechanisms of colonization: mobile fauna with long-dispersing planktotrophic larvae, and encrusting fauna with lecithotrophic larvae. Encrusting species reproduce asexually to cover the wreck surface, and philopatry may build up dense populations, leading to uneven communities.
On terrestrial islands, non-random co-occurrence is attributed to interspecific competition, but for marine substrata, there may not be a relationship. Fauna were distributed randomly on settlement plates in Svalbard fjords, even when interspecific competition was observed. On dropstones, some morphotypes co-occurred non-randomly in the absence of overgrowth competition. Non-random co-occurrence on isolated marine hard substrata may be a result of restricted larval dispersal (for pairs co-occurring less than by chance) or epibiontism (for pairs co-occurring more often than by chance). While species distribution patterns on island-like marine hard substrata resemble terrestrial islands, the mechanisms are not necessarily the same.
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Fewtrell, Jane Leah. "The response of marine finfish and invertebrates to seismic survey noise." Thesis, Curtin University, 2003. http://hdl.handle.net/20.500.11937/1202.
Full textAbstract:
The oil and gas industry is of major economic importance to Australia. Offshore seismic surveys are an essential component of exploration for fossil fuel reserves. Offshore seismic surveys involve the use of arrays of air-guns that produce repetitive high energy, low frequency sound. There is increasing concern about the effect that the noise generated by a seismic survey has on the surrounding marine life. Various species of captive marine fish and one species of squid were exposed to the noise from a single Bolt PAR 600 B air-gun with a 20 cui firing chamber and a source level at 1 m of 203.6 dB re 1 μPa mean squared pressure. Ten trials were conducted in Jervoise Bay and two were carried out off the coast of Exmouth. A different noise regime was used in each trial, however most involved the use of approach-depart scenarios to simulate an actual seismic survey and a 10 second duty cycle. Noise levels received by the animals ranged between 128 - 192 dB re 1 μPa mean squared pressure. Behavioural observations of the fish and squid were made before, during and after air-gun noise exposure. The physiological stress response of the fish was monitored by measuring plasma cortisol and glucose levels before and after noise exposure. The sensory epithelium was removed from the ears of the fish prior to, immediately after and up to 86 days after air-gun noise exposure and examined using a scanning electron microscope. No statistically significant physiological stress response in fish was detected as a result of the air-gun noise exposure regimes used. Significant damage to the ciliary bundles of the sensory epithelium of the sacculus was observed in pink snapper (Pugrus auratus) that had been exposed to air-gun noise between 144 - 191 dB re 1 μPa for 1.71 hours. No regeneration of the hair bundles was observed 58 days after exposure to air-gun noise.However, evidence of regeneration was observed between 58 and 86 days after noise exposure. Behavioural observations suggested that as air-gun noise levels increase, fish respond by swimming faster, in tighter groups and towards the bottom of the water column. Significant increases in alarm responses were observed in fish and squid to air-gun noise exceeding 158 - 163 dB re 1μPa. An increasing proportion of alarm responses were also observed as the noise level increased. A decrease in the frequency of alarm responses for repeated exposures was observed in squid and some fish. The implications of these findings are discussed with comparisons of noise levels measured from an actual 2678 cui seismic survey air-gun array.
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Fewtrell, Jane Leah. "The response of marine finfish and invertebrates to seismic survey noise." Curtin University of Technology, Muresk Institute of Agriculture, 2003. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=15125.
Full textAbstract:
The oil and gas industry is of major economic importance to Australia. Offshore seismic surveys are an essential component of exploration for fossil fuel reserves. Offshore seismic surveys involve the use of arrays of air-guns that produce repetitive high energy, low frequency sound. There is increasing concern about the effect that the noise generated by a seismic survey has on the surrounding marine life. Various species of captive marine fish and one species of squid were exposed to the noise from a single Bolt PAR 600 B air-gun with a 20 cui firing chamber and a source level at 1 m of 203.6 dB re 1 μPa mean squared pressure. Ten trials were conducted in Jervoise Bay and two were carried out off the coast of Exmouth. A different noise regime was used in each trial, however most involved the use of approach-depart scenarios to simulate an actual seismic survey and a 10 second duty cycle. Noise levels received by the animals ranged between 128 - 192 dB re 1 μPa mean squared pressure. Behavioural observations of the fish and squid were made before, during and after air-gun noise exposure. The physiological stress response of the fish was monitored by measuring plasma cortisol and glucose levels before and after noise exposure. The sensory epithelium was removed from the ears of the fish prior to, immediately after and up to 86 days after air-gun noise exposure and examined using a scanning electron microscope. No statistically significant physiological stress response in fish was detected as a result of the air-gun noise exposure regimes used. Significant damage to the ciliary bundles of the sensory epithelium of the sacculus was observed in pink snapper (Pugrus auratus) that had been exposed to air-gun noise between 144 - 191 dB re 1 μPa for 1.71 hours. No regeneration of the hair bundles was observed 58 days after exposure to air-gun noise.<br>However, evidence of regeneration was observed between 58 and 86 days after noise exposure. Behavioural observations suggested that as air-gun noise levels increase, fish respond by swimming faster, in tighter groups and towards the bottom of the water column. Significant increases in alarm responses were observed in fish and squid to air-gun noise exceeding 158 - 163 dB re 1μPa. An increasing proportion of alarm responses were also observed as the noise level increased. A decrease in the frequency of alarm responses for repeated exposures was observed in squid and some fish. The implications of these findings are discussed with comparisons of noise levels measured from an actual 2678 cui seismic survey air-gun array.
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Ferry, Romain. "Les inventaires taxonomiques de la biodiversité des invertébrés macroscopiques marins : des outils pour la connaissance et la gestion de la protection de la biodiversité marine (exemples en Martinique)." Thesis, Antilles, 2019. http://www.theses.fr/2019ANTI0597.
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Les travaux menés dans cette thèse explorent les différents apports possibles des inventaires taxonomiques d’invertébrés macroscopiques marins, qu’ils s’intéressent à un groupe taxonomique particulier ou à la biodiversité d’espèces dans un habitat, afin d’apporter de la connaissance mais aussi pour répondre à des problématiques de gestion telles que : Quelle espèce protéger ? Quel habitat protéger ? Quelle espèce exotique envahissante éradiquer ?Le premier axe de ces travaux s’intéresse à l’inventaire d’espèces par groupe taxonomique et à l’inventaire multitaxon pour une zone afin d’en évaluer la biodiversité. Dans une première partie, deux des inventaires taxonomiques sont centrés sur des groupes taxonomiques, ils sont réalisés en collaboration avec des spécialistes, ils concernent : l’inventaire taxonomique des hydraires et celui des gorgones. La seconde partie utilise des inventaires simplifiés, s’intéressant à la majorité des taxons, mais centré sur des zones spécifiques afin d’en évaluer la biodiversité : Une étude concerne les parties marines qui sont à proximité des mangroves, et la seconde étude à la caye Grande Sèche au cœur la baie de Fort-de-France. Dans une troisième partie, les inventaires de la biodiversité d’espèces sont mis à profit pour mettre à jour la typologie des habitats marins benthiques, à partir de données collectées lors de l’expédition Madibenthos (MNHN) et notamment de photographies prises par les participants. Et enfin, dans une dernière partie les inventaires multitaxons réalisés à l’échelle de la Martinique sont mis à profit pour évaluer quelles sont les espèces d’invertébrés rares en Martinique qui peuvent être candidate à une protection ou au statut d’espèce déterminante pour l’établissement de ZNIEFF.Le second axe de ces travaux s’intéresse à l’inventaire d’espèces protégées d’invertébrés macroscopiques, notamment les coraux, dont l’état des populations est préoccupant, ceci en vue de cartographier leur répartition et d’évaluer des sources des pressions et menaces constatées. Dans un premier temps, il est indiqué la mise au point d’une méthode qui a permis de cartographier une espèce de corail protégée de petite taille, Oculina diffusa. L’étude montre que l’habitat de cette espèce est très spécifique et qu’elle subit de nombreuses pressions. Dans un second temps, une méthode utilisant différentes techniques de télédétection et d’inventaire in situ a été mise au point pour cartographier la répartition d’espèces de coraux de grande taille (Orbicella favelolata, O. annularis, O. franksii) sur une caye. Enfin, dans un troisième temps, les résultats d’inventaires multitaxon ont permis de caractériser la rareté ou la faible abondance de certaines espèces de coraux en Martinique, résultats qui ont œuvré pour la protection des coraux.Le troisième axe s’intéresse à l’inventaire des espèces non-indigènes et d’espèces exotiques envahissantes d’invertébrés macroscopiques en vue de cartographier leur répartition et d’évaluer leurs impacts sur les espèces autochtones et leurs habitats. L’étude présente trois espèces non indigènes dont le statut est attesté pour certaines en tant qu’espèce exotique envahissante ou est en cours d’évaluation pour d’autre. La première espèce présentée, étudiée en 2015, est un crabe invasif Charybdis hellerii. L’étude de cette espèce a permis de signaler sa présence pour la première fois dans les Petites Antilles. L’étude biométrique des populations et du sex-ratio, a permis de caractériser la population. Une étude de l’habitat occupé permet de mieux étudier son impact et mieux cibler les habitats à surveiller. La seconde espèce est une d’ophiure non-indigène, Ophiothela mirabilis, étudiée en 2017 sur la côte atlantique de la Martinique<br>The work carried out in this thesis explores the various possible contributions of taxonomic inventories of marine macroscopic invertebrates, whether they are interested in a particular taxonomic group or the biodiversity of species in a habitat, in order to bring knowledge but also to respond to management problems such as: What species to protect? What habitat to protect? Which invasive alien species to eradicate?The first aspect of this work is the inventory of species by taxonomic group and the multitaxon inventory for an area, in order to assess its biodiversity. In the first part, two of the taxonomic inventories are centered on taxonomic groups, they are carried out in collaboration with specialists and concern the taxonomic inventory of hydraries and that of gorgonians. The second part uses simplified inventories, focusing on the majority of taxa, but focused on specific areas in order to assess their biodiversity: A study concerns the marine parts that are close to the mangroves, and the second study at the caye “Grande Sèche” in the heart of the bay of Fort-de-France. In a third part, species biodiversity inventories are used to update the typology of benthic marine habitats, using data collected during the Madibenthos Expedition (MNHN) and in photographs taken by the participants. And in the final part, the multitaxons inventories carried out throughout Martinique are used to evaluate which species of invertebrates are rare in Martinique and that can be candidates for protection or species status determining the establishment of ZNIEFF.The second aspect of this work is the inventory of protected species of macroscopic invertebrates, including corals, whose population status is of concern, in order to map their distribution and assess sources of pressures and threats. First, it is indicated the development of a method that allowed to map a small protected coral species, Oculina diffusa. The study shows that the habitat of this species is very specific and that it is under many pressures. Second, a method using different remote sensing and in situ inventory techniques was developed to map the distribution of large coral species (Orbicella favelolata, O. annularis, O. franksii) on a caye. Finally, in a third phase, the results of multitaxon inventories have helped to characterize the rarity or low abundance of certain coral species in Martinique, results that have worked towards the protection of corals..The third axis focuses on the inventory of non-native species and invasive alien species of macroscopic invertebrates to map their distribution and assess their impacts on native species and their habitats. The study presents three non-native species, some of which are certified as invasive alien species or are being evaluated for others. The first species presented, studied in 2015, is an invasive crab Charybdis hellerii. The study of this species made it possible to report its presence for the first time in the Lesser Antilles. The biometric study of populations and sex ratios has helped to characterize the population. A study of occupied habitat allows for a better study of its impact and better targeting of the habitats to be monitored. The second species is a non-native ophiure, Ophiothela mirabilis, studied in 2017 on the Atlantic coast of Martinique. Finally the third species studied is a non-native coral, Tubastraea coccinea, its population has increased in recent years, a first mapping is proposed. This study was conducted at the very beginning of the expansion of the non-native species, it specifies the number of species of host gorgonians and the maximum colonization density reached in some gorgonians. The results obtained during these inventories have provided a more accurate view of the state of marine biodiversity, they have contributed to the protection of species and areas. They should contribute to better management and protection of the marine environment in Martinique
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Huggett, Megan Jane School of Biological Earth & Environmental Sciences UNSW. "Settlement of generalist marine invertebrate herbivores in response to bacterial biofilms and other cues." Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2006. http://handle.unsw.edu.au/1959.4/23324.
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Most marine invertebrates have a complex life cycle involving a benthic adult phase, and a planktonic larval phase. The process whereby tiny larvae are able to locate, settle and metamorphose in a habitat where juveniles are then capable of successfully establishing themselves is a key stage in the life cycle and a central theme of current marine research. Bacterial biofilms are an important settlement cue for many larvae, and it appears that particular strains within environmental communities may be responsible for the inducing ability of some biofilms. The focus of this thesis is the importance of biofilms for larval settlement of the blacklip abalone Haliotis rubra and the sea urchin Heliocidaris erythrogramma. Larval development of the sea urchin Centrostephanus rodgersii was also examined, but this species was problematic for a larval settlement study. H. rubra larval settlement occurred in response to several macroalgal species. Biofilmed (but otherwise abiotic) surfaces did not induce settlement of H. rubra larvae and reduction of surface films of bacteria and diatoms on inducing algae did not reduce the settlement response. Macroalgae, particularly green algal species, may play an important role in the recruitment of H. rubra larvae in the field and can be used to induce settlement in hatcheries. H. erythrogramma settled in response to a range of surfaces with highest settlement on coralline algae. Settlement was reduced by autoclaving plants and treating plants with antibiotics. Molecular and culture based analysis revealed a shift in microbial community structure between plants treated with antibiotics and unmanipulated plants. Many bacterial strains, dominated by the genera Pseudoalteromonas, Shewanella and Vibrio, induced larval settlement. Three probes targeting Pseudoalteromonas, Shewanella and Vibrio were developed for CARD-FISH, enabling quantification of these genera in biofilms on algae. The three genera were found in highest numbers on coralline algae and in variable numbers on the surfaces of other algae. Recruitment of H. erythrogramma also occurs in highest numbers on coralline algae, and in low amounts on co-occurring algae. This is the first example demonstrating that bacteria that induce settlement in the laboratory are also present in the juvenile recruitment habitat.
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Hung, Oi Shing. "Effects of environmental factors on biofilms and subsequent larval attachment of benthic marine invertebrates /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?AMCE%202007%20HUNG.
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Hidas, Eszter Zsofia. "The patterns of abundance and demography of rocky intertidal marine invertebrates indicate that recruitment can set geographical range limits." Access electronically, 2007. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20080917.090811/index.html.
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