To see the other types of publications on this topic, follow the link: Marine fishes.
Dissertations / Theses on the topic 'Marine fishes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Marine fishes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Turner, Jonathan Russell. "Vision in marine fishes." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528093.
Full text
2
Miller, Jessica Adele. "Local and regional patterns of transport, dispersal, and exchange in coastal fishes /." view abstract or download file of text, 2004. http://wwwlib.umi.com/cr/uoregon/fullcit?p3136435.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 2004.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 215-240). Also available for download via the World Wide Web; free to University of Oregon users.
3
Dygert, Peter H. "Management implications of variability in reproduction and growth of commerical [sic] marine fishes /." Thesis, Connect to this title online; UW restricted, 1986. http://hdl.handle.net/1773/5380.
Full text
4
Zamzow, Jill P. "The physiological ecology of UV-absorbing compounds from the mucus of marine fishes." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=764803761&SrchMode=1&sid=2&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1233342067&clientId=23440.
Full text
5
Mead, Angela. "The role of restocking in enhancing marine fisheries : a way forward /." Thesis, View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34737911.
Full text
6
Hudson, Elodie Jacqueline. "Conservation status assessment of exploited marine fishes." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271312.
Full text
7
Yuen, Pui-sze. "Feasibility of total prohibition of fishing in marine protected areas of Hong Kong." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43784598.
Full text
8
Jordaan, Adrian. "Determining Environmental Drivers of Fish Community Structure along the Coast of Maine." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/JordaanA2006.pdf.
Full text
9
Sweetman, Christopher James. "Consumption Patterns of Chesapeake Bay Fishes." W&M ScholarWorks, 2018. https://scholarworks.wm.edu/etd/1550153634.
Full textAbstract:
As fisheries management moves away from single-species approaches and towards more holistic, ecosystem-based approaches, physiological and ecological interactions need to be explicitly considered and mechanistically understood. Accurate portrayals of food web interactions and the direction and magnitude of energy flow between predator and prey populations are fundamental components to further develop ecosystem-based fisheries management (EBFM). to bolster information that is required within an EBFM framework in the Chesapeake Bay, I conducted research designed to advance traditional dietary studies and better understand the form and structure within the Bay's food web. This research relied on controlled feeding experiments, comprehensive sampling of predator and prey communities, and over 10 years of data from the Chesapeake Bay Monitoring and Assessment Program (ChesMMAP) and the Juvenile Fish and Blue Crab surveys. The dissertation presented here has two main objectives: 1) incorporate additional methodologies to improve stomach content identification, and 2) examine the drivers of trophic interactions and consumption within a suite of abundant and economically valuable predatory fishes in the Chesapeake Bay. Prey that is considered unidentifiable is often ignored in stomach content analyses, but can account for a significant proportion of fish diets. in Chapter 1, I demonstrate the use of molecular techniques to detect specific prey consumed by Atlantic croaker (Micropogonias undulatus) and evaluate factors that influence the rate of gastric evacuation. Molecular protocols developed to identify specific prey DNA from stomach contents determined that DNA from blue mussel (Mytilus edulis) can be detected as long as prey resides in the stomach (~30 hours), which is long after prey can be considered visually identifiable. Furthermore, temperature significantly influenced gastric evacuation rates and therefore should be considered throughout the collection process to ensure accurate identification of prey. Chapter 2 evaluated prey selection patterns among three sympatric predators in the Chesapeake Bay: weakfish (Cynoscion regalis), summer flounder (Paralichthys dentatus), and Atlantic croaker. Comprehensive sampling of predator and prey (midwater, zooplankton, benthic) populations revealed selection patterns on dominant prey selection taxa driven by a variety of mechanisms. Bay anchovy selection was significantly influenced by predator size in both weakfish and summer flounder. Mysid selection was driven by both fish size and Julian Day in weakfish and by temperature in summer flounder. Atlantic croaker select for both polychaetes and bivalves, with selection patterns relating to predator size and Julian Day. to evaluate how trophic linkages and environmental conditions influence consumption, bioenergetics models were developed in Chapter 3 for young-of-the-year Atlantic croaker and weakfish. Annual consumption from 2006 – 2016 was estimated and subsequent analyses demonstrated that prey abundance metrics significantly influenced the observed consumption patterns. This research represents a comprehensive study on predator-prey interactions within the Chesapeake Bay and contributes to a broader understanding of fish ecology and production patterns. The results from this dissertation provides a better understanding of food web structure and aids in the development EBFM strategies towards the sustainable use of marine living resources.
10
Vine, Niall Gordon. "Towards the development of a protocol for the selection of probiotics in marine fish larviculture." Connect to this title online, 2004. http://eprints.ru.ac.za/196/.
Full text
11
Vine, Niall Gordon. "Towards the development of a protocol for the selection of probiotics in marine fish larviculture." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1005175.
Full textAbstract:
Manipulation or control of the microbiological aquaculture environment has been identified as an important focus area for future hatchery development. Subsequently, alternatives to obtain control of the microbiological environment are being sought of which the field of probiotics appears highly promising. Probiotics are usually selected based on various in vitro characteristics, however, the methods used differ and are sometimes unsuccessful due to poor experimentation. The aim of this work is to contribute towards the development of a protocol for the in vitro screening of bacterial candidate probiotics for marine fish larviculture. To reduce the number of candidate probiotics to be tested in vivo, various in vitro experiments need to be conducted, each screening for a particular mode of action – antagonism towards pathogen through production of antimicrobial compounds, growth and attachment to fish intestinal mucus, and the production of other beneficial compounds such as vitamins, fatty-acids and digestive enzymes. A total of 108 bacteria species were isolated from the digestive tract of the adult common clownfish, Amphiprion percula to screen for potential probiotics to be used in clownfish larval rearing. The antagonistic compounds assay identified twelve isolates which showed antagonism towards two or more aquatic pathogens. This was followed by an in vitro test that involved growing the organisms in fish intestinal mucus and modeling their growth parameters. A ranking index (RI) was developed using the lag period (λ) and doubling time (td) of the organism, where (1over λ x td) x 100. Five candidate probionts (AP1-AP5) with varied growth parameters were used for further in vitro experiments. The attachment to mucus assay introduced a novel tool for quantifying competition for attachment sites between candidate probionts and pathogens on mucus. Candidate probiont Pseudoalteromonas AP5 reduced the attachment ability of Vibrio alginolyticus when added before the pathogen and partially out-competed the pathogen for attachment sites when added second. In vitro screening for the production of beneficial compounds tested the candidate probiotics’ ability to produce digestive enzymes - trypsin, lipase and alkaline phosphatase as well as carotenoids and vitamin C. Candidate probiont Pseudoalteromonas AP5 produced high levels of the enzymes (98.2, 34.1 and 91.3 mU product liberated.ml⁻¹, respectively) and contained carotenoids while Kocuria AP4 contained carotenoids but produced low quantities of enzymes (7.8, 0 and 59 mU product liberated.ml⁻¹, respectively). None of the candidate probiotics produced vitamin C. To eliminate potential pathogenic or toxic candidate probionts, Artemia nauplii were exposed to each candidate probiont and the percentage Artemia mortality after 24-hours was determined. Candidate probiont AP2 caused high mortality of Artemia nauplii (98.4%) and was excluded from further studies. Identification of candidate probionts AP3-AP5 was performed using 16S-rDNA molecular techniques and the bacteria were assigned the names Bacillus AP3, Kocuria AP4 and Pseudoalteromonas AP5, respectively. Two methods of larval probiont delivery were tested – attachment to Artemia, and in-water delivery. Attachment to Artemia was high for both Kocuria AP4 and Pseudoalteromonas AP5 (7.2 x10³ and 2.7x10⁴ bacteria.nauplius⁻¹, respectively) while the in-water viability experiment showed that Kocuria AP4 comprised 23.9% of the total culturable water microflora after 24 hours while Pseudoalteromonas AP5 contributed 100%. To validate the findings from the in vitro experiments, in vivo trials using clownfish larvae were performed. Of the four candidate probiotics tested, only Kocuria AP4 showed potential to increase larval survival. In vitro tests produced a better understanding of the possible mode of action and strategies of competition between bacteria, however, the number of criteria in which a candidate probiont is successful in vitro may not be the best predictor for its effectiveness in vivo. Commercial studies that reduce between-treatment variation are required to test predictions about the most suitable probiont or combinations thereof.
12
Wraith, James A. "Assessing reef fish assemblages in a temperate marine park using baited remote underwater video." School of Biological Sciences, 2007. http://ro.uow.edu.au/theses/12.
Full textAbstract:
Baited remote underwater video (BRUV) is becoming an increasing popular tool for examining reef fish assemblages in depths less than 100m. This sampling technique is relatively new in the literature and several gaps remain to be filled. Scientists using this technique have selected bait based on results from trapping experiments. Therefore the first objective of the study was to compare commonly used baits and test if different fish species and fish assemblages were recorded. I planned to apply results from the first study towards further research using BRUV. Management at Jervis Bay Marine Park, located in southeast Australia, have applied a strategy to protect a comprehensive and representative sample of local habitats and associated flora and fauna. In doing so, sanctuary “no take” zones have been put in place. Surprisingly, there are no patch reefs afforded this protection. My second objective was to provide the Jervis Bay Marine Park management with baseline data on deep patch reef locations and to draw comparisons between deep patch, deep coastal, and shallow coastal reefs. I compared three different baits (pilchard, abalone, and urchin) at three locations in two separate years. A total of 63 “drops” (30 min recordings) were conducted in two years and a total of 47 species were recorded. There were no differences in the diversity and abundance of fish recorded while baited with pilchard and abalone. In contrast, in the second year of sampling I detected a greater species richness and abundance using pilchard, compared to urchin, at most locations (p<0.05). The two most speciose families recorded in the study were Labridae and Monacanthidae. These families, as well as several individual fish species, were examined but there were no significant differences in their relative abundance among bait treatments. Additionally, in the second year of sampling I detected differences in H′ and time of first arrival among locations (p<0.05). Surprisingly, large differences between the baits were greatly reduced at one location - Plantation Point. I interpret this finding as there being a high density of fish at Plantation Point that masks the differences in the attraction of these baits. I concluded that as the behaviour and structure of the fish assemblage can vary in space, pilchard was the best choice of bait for consistently detecting species richness and abundance. A total of 144 BRUV “drops” (30 min recordings) in 9 locations in 2005 and 2006 were completed in the second study. The composition of fish assemblage at shallow and deep water habitats was different (p<0.05). Indeed, depth related differences for temperate reef fish are well documented and my findings emphasise the need for the Marine Park management to maintain protection of reef habitats across abroad range of depths. I did not detect any differences in the composition of the fish assemblage or the relative abundance of fish between the two deep habitats (p>0.05), although the presence of several rarely encountered species including Bodianus unimaculatus, Coris sandageri, Meuschenia scaber, Caesioperca lepidoptera, and Eubalichthys mosaicus were recorded in the deep patch reef habitat. I concluded that the inclusion of the deep habitat in the sanctuary zoning plan is important for protecting fish biodiversity. By generating permanent baseline data, this study aims to assist Marine Park management in making sound decisions on future zoning plans.
13
Jones, Angela M. "Aspects of the biology of some marine ascaridoid nematodes." Thesis, University of Stirling, 1994. http://hdl.handle.net/1893/1498.
Full textAbstract:
Larval Anisakis simplex, Pseudoterranova decipiens, Contracaecum osculatum and larvae and adults of Hysterothylacium aduncum were recovered from specimens of cod, haddock, blue whiting and bull rout; however, only A.simplex were retrieved from long rough dab. The epidemiology of infection by these four nematode species was examined both in whole fish, and in individual host tissues and organs. Frequency distributions of nematodes were found to be generally overdispersed in fish. Preliminary investigations revealed no strong evidence to suggest that competi tive interactions occurred between ascaridoid nematodes wi thin fish. Stomach lesions in gadoids were associated with single (partially penetrated) and mul tiple (throughout stomach wall) worm infections of larval A.simplex; such lesions were discrete and raised in appearance. Lesions associated with 1-3 larval P.decipiens in an open cavity within the stomach of angler fish were diffuse and not significantly raised. Histological examination of each form of ulcer revealed general similarities in pathology, with infil tration of inflamatory cells being the initial response to the nematode\s. Changes in the cephalic morphology of A.simplex, P.decip1ens, C.osculatum and H.aduncu were examined at different life cycle stages under scanning electron microscopy. Due to their small size, newly hatched third stage larvae of P .decip1ens were cultured in a bacterial mat prior to fixation for S.E.M., and the external ultrastructure of these larvae is described. The most prominent external feature at this stage is the cephalic boring tooth. Aspects of the internal ultrastructure of A. simplex, P.decipiens, C.osculatum and H.aduncu were examined using transmission electron microscopy. Newly hatched third stage larvae of P.decipiens show little differentiation of internal organs. The ultrastructure of sensory amphids in H.aduncum and A. simplex is cons i stent wi th that of a chemoreceptor, that of the single papilla in P.decipiens a mechanoreceptor. The ultrastructure of the digestive tract, excretory gland and body wall of marine ascaridoids were also examined.
14
Carlson, Kimberly. "Digenetic trematodes of marine fishes of Jamaica, West Indies." Scholarly Commons, 1992. https://scholarlycommons.pacific.edu/uop_etds/2238.
Full text
15
Zangiabadi, Enayatollah. "Using 3D-CFD methods to investigate hydrology of oceans and fish passage through tidal stream turbines." Thesis, Swansea University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678377.
Full text
16
Alós, Crespí Josep. "Selection drivers of life-history traits in marine coastal fishes." Doctoral thesis, Universitat de les Illes Balears, 2013. http://hdl.handle.net/10803/123496.
Full textAbstract:
Humans can induce contemporary evolution through harvesting wild animals. This thesis provides evidence of this process for recreational fishing at surprisingly small geographical scales. Marine fish populations are characterized by high variability in heritable individual life‐history traits which are exposed to biased fishing mortality. The life histories strategies of actual populations, which collectively reduce adult body size, mirror such biased mortality in populations exposed to limited gene flow. Because the relationship between life history and behaviour, it is very likely that fishing also induces adaptive responses in behavioural traits. Due the potential negative effects of fishing selection the productivity and quality of the fishery, this thesis recommend considering the evolutionary impacts of fishing in the management plans of species exploited by the recreational fishingEl humans poden produir evolució contemporània a través de la recol∙lecció de animals salvatges. Aquesta tesis proporciona evidencies d’aquest procés per la pesca recreativa a una sorprenent escala espacial petita. Les poblacions marines de peixos tenen una alta variabilitat individual en caràcters heretables de la història exposada a una mortalitat selectiva per pesca. Les estratègies vitals de les poblacions actuals de peixos costaners, les quals conjuntament produeixin una reducció en la mida del individu, són el reflexa d’aquesta pesca selectiva en poblacions amb baixa connectivitat. Degut a la correlació entre història vital i comportament, la pesca pot induir també respostes adaptatives en cert caràcters comportamentals. Considerant els efectes negatius de la selecció per pesca en la productivitat i la qualitat de les pesqueries, aquesta tesis recomana considerar els possibles efectes evolutius produïts per la pesca en les estratègies de gestió d’espècies explotades per la pesca recreativa.
El hombre puede producir evolución contemporánea por la recolección de animales salvajes. La presente tesis proporciona evidencias de este proceso por la pesca recreativa en una sorprendente escala espacial pequeña. Las poblaciones de peces marinos presentan una alta variabilidad en caracteres heredables de la historia vital expuesta a mortalidad selectiva por pesca. Las estrategias vitales de las poblaciones actuales de los peces costeros, las cuales conjuntamente producen una reducción en el tamaño del individuo, son el reflejo de esta mortalidad selectiva en poblaciones con baja conectividad. Debido a la relación entre historia vital y comportamiento, la pesca puede también inducir cambios adaptativos en ciertos rasgos de comportamiento. Considerando los efectos negativos de la selección por pesca en al productividad y calidad de la pesquería, esta tesis recomienda considerara los posibles efectos evolutivos inducidos por la pesca en la estrategias de gestión de especies explotadas por la pesca recreativa.
17
Cruz-MartiÌnez, Alicia. "Life histories and biogeography of marine fishes : implications for conservation." Thesis, University of East Anglia, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426605.
Full text
18
Roberts, Louise. "Behavioural responses by marine fishes and macroinvertebrates to underwater noise." Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:11515.
Full textAbstract:
The aim of this thesis was to explore and evaluate the key behavioural responses of coastal UK marine fishes and macroinvertebrates to anthropogenic noise. Work focussed upon two key aspects, water-borne acoustics and the relatively unstudied substrate-borne vibration, with a combination of laboratory and field work using grouped and solitary individuals. A literature review on underwater vibroacoustics, detection abilities, anthropogenic noise sources and the effects of such stimuli was provided (Chapter 1). Playbacks were undertaken in the field using a purpose-built underwater transducer array capable of accurately reproducing man-made signatures (Chapter 2 – 3). The behavioural responses of wild, unrestrained schooling pelagic fish to impulsive sound were observed using an acoustic observation system. Precise exposure levels were linked to specific responses, with dose response curves produced for two pelagic species of varied hearing abilities. Baited remote underwater video (BRUV) was used to observe the behavioural responses of free-ranging individual fish and crustaceans exposed to impulsive sound and shipping noise. In both cases responses varied according to the level of sound, the type of school and the species. In the laboratory, animals were exposed to sinusoidal vibratory signals using a fully calibrated electromagnetic shaker system. The sensitivity of unconditioned invertebrates (crustaceans and molluscs) to substrate-borne vibration was quantified with controlled vibratory exposures, allowing the production of a sensory threshold curve for three species (Chapters 4 - 5). Response variation was described in terms of two behavioural indicators, and related to consistency within individuals (personality), morphological parameters and time in the laboratory prior to tests. Further work investigated the response of sessile invertebrates to vibration, with the observations fully described in terms of response occurrence, duration and variation for both grouped and solitary animals. The responses described in each chapter were related to actual measurements of anthropogenic noise sources in terms of water-borne and substrate-borne energy, allowing behavioural responses to be translated to actual conditions. The data here provide evidence for the levels of playback sound to induce a behavioural response, and are fully reproducible to allow further testing of the responsiveness of fish to different sound levels and signatures. Furthermore, the data are a first step towards understanding the sensitivity of benthic invertebrates to substrate-borne vibration and indicate that the effects of substrate transmission should not be overlooked when investigating the effects of noise pollution on the marine environment. The results from the current work, along with the recommendations for future work, will be important to aid the filling of the ‘information gaps’ that exist within the underwater bioacoustics field.
19
Brock, Chad Daniel. "Comparative phylogenetic approaches to macroevolution methods, models, and marine fishes /." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Spring2009/c_brock_041509.pdf.
Full text
20
Jaafar, Tun Nurul Aimi Mat. "DNA barcoding and population genetic structure of Malaysian marine fishes." Thesis, Bangor University, 2014. https://research.bangor.ac.uk/portal/en/theses/dna-barcoding-and-population-genetic-structure-of-malaysian-marine-fishes(79b4a0eb-48cf-46a1-b44f-8b09d5eed6c4).html.
Full textAbstract:
The development of a widely available global database of DNA barcodes has been proposed as a species-identification tool for large taxonomic assemblages of animals. The approach has particular value in revealing cryptic species, which typically have high incidence in marine environments. Despite the wealth of DNA barcode data for fish from many temperate regions, there are relatively few such data available for SE Asian waters. In Chapter 2, an initial reference DNA barcode library was produced for the marine fish Family Carangidae, one of the most commercially-important families from the Indo-Malay Archipelago (IMA). Thirty-species of Family Carangidae were collected from the IMA to examine the accuracy of DNA barcoding concepts and protocols, such as ease of amplification of the barcode gene cytochrome c oxidase I (CO/), and implementation of the 'barcoding gap' concept for species delimitation. All described species formed monophyletic clusters in Neighbour-joining phylogenetic tree, although three species representing complexes of six potential cryptic species were detected. Within 723 individuals, three described species (Atule mate, Selar crumenophthalmus and Seriolina nigrofasciata) exhibited conspecific divergences up to ten times greater (4.32-4.82%) than mean estimates (0.24-0.39%) indicating a discrepancy with assigned morphological taxonomic identification, and the existence of cryptic species within the IMA. Additional conspecifics sequences available from other geographical regions revealed the existence of several more complexes of potentially cryptic species outside the IMA. However, to explain the hypothesis of species richness in the IMA, it is necessary to sample the whole family across their broad geographic range. Such information will contribute to the development of an integrated taxonomic framework, thus informing management strategies for subsequent conservation and management of Carangidae. Additionally, the results will provide greater understanding of recruitment, and processes driving species diversification in the IMA.
21
Powell, Frank. "Effects of salinity on eggs and yolk-sac larvae of Atlantic cod, Atlantic halibut, haddock and winter flounder." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0004/MQ42426.pdf.
Full text
22
Roux, Maryanne. "The diversity and distribution patterns of intertidal fish in the Agulhas bioregion." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1019712.
Full textAbstract:
This study aimed to expand the existing knowledge on the diversity and distribution patterns of intertidal fishes in the Sardinia Bay MPA and adjacent open access areas. It focussed particularly on in intertidal fish communities along the Agulhas Bioregion coast which has been understudied, especially in recent years. Typical resident species belonging to the family Clinidae were the most abundant, conforming to previous studies. Species from the family Gobiidae were the second most abundant in this study but this family was not previously recorded as being abundant. Transient species were unimportant in the current study which is in contrast to previous studies in the region and suggests a change in species composition. Certain transient species utilised intertidal rockpools as part of their nursery areas in the Eastern Cape, as has previously been found around Algoa Bay. A decrease in species richness from east to west was recorded in this study which has been noted by previous authors and the diversity and distribution patterns of the intertidal fish in the current study conformed to patterns found previously. The position of the biogeographic boundary between the Agulhas and Natal Bioregions could not be confirmed but Wavecrest (along the Transkei coastline) appeared to be part of a transition zone rather than a fixed break. More sampling around this area is recommended to determine the location and understand the dynamic nature of this boundary. The fish species were found to be vertically distributed across the shore with most of the resident species being more abundant across the low shore while the transient species were more abundant in the middle to low shore pools. This vertical distribution has been found at many sites around the world. The volume of the pools proved to be the primary controlling factor while the effect of temperature on vertical distribution could not be demonstrated. The benefits of the Sardinia Bay Marine Protected Area on this unexploited community of fishes could not be demonstrated but the long term benefit of protection has yet to be shown. Results from this study suggest that despite the correspondence with general biogeographic trends, the intertidal fish community has changed in composition (at least in terms of transient species) during the last 30 years and the cause for these changes may in part be reduced recruitment from exploited linefish.
23
Wallett, Lane A. "Eocene selachian fauna from nearshore marine deposits, Ampazony, Northwestern Madagascar /." Connect to online version, 2006. http://ada.mtholyoke.edu/setr/websrc/pdfs/www/2006/147.pdf.
Full text
24
Holmgren, Diego. "Decadal-centennial variability in marine ecosystems of the northeast Pacific Ocean : the use of fish scales deposition in sediments /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/5308.
Full text
25
Deacon, Neil. "Determination of the optimum environmental requirements of juvenile marine fish : the development of a protocol." Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1005097.
Full textAbstract:
The spotted grunter, Pomodasys commersonnii, has been identified as a candidate species for mariculture in South Africa due to its high market demand and apparent biological suitability for culture. In common with most other potential mariculture species the spotted grunter has an estuarine juvenile phase. In this respect, the difficulties encountered in determining the optimum environmental requirements of spotted grunter are applicable to the majority of other potential mariculture species. Due the variability of estuarine habitats determination of the optimum environmental requirements of estuarine species under laboratory conditions are a prerequisite to subsequent evaluation of aquaculture potential. Therefore, using the spotted grunter as a representative of a typical potent ial mariculture species, the aim of this study was to contribute to the protocol for evaluating the environmental requirements of potential aquaculture species. The growth of fish is dependent on the relationship between food intake, metabolism and environmental factors. In this relationship, environmental factors do not act on growth per se, but rather act through metabolism on growth. Consequently, the environmental factors affecting the growth of a fish species can be classified into functional categories according to their respective influence on metabolic processes. Five functional categories are recognised, namely: controlling, limiting, masking, directive and lethal factors. In this study, the functional categories were sequenced to develop a theoretical protocol for determining the optimum environmental requirements of potential mariculture species under artificial conditions. It was hypothesised that the correct sequence for experimentally determining the optimum environmental requirements of a species should correspond to theoretical protocol. The hypothesis was tested from the experimental investigation into the individual effects of temperature, salinity, light intensity, photoperiod and food intake on growth performance of juvenile spotted grunter. The investigations quantified the relative effects of controlling, masking, directive and limiting factors on growth performance. The results of the studies were statistically compared to obtain a ranking of the effects of the environmental factors (e.g. temperature, salinity, etc.) on growth performance of juvenile spotted grunter. The statistical ranking facilitated the formulation of a second protocol for sequentially determining the optimum environmental requirements of a species. The second protocol was derived purely from the experimental data. Based on the corroboration between the theoretical protocol and that formulated from the experimental investigations, the hypothesis was accepted. Confirmation of the protocol for examining the effects of controlling, limiting, masking and directive factors provided a basis for the development of a preliminary experimental sequence for determining the optimum environmental requirements of juvenile marine fish. In the development of the experimental sequence, the protocol was interpreted in conjunction with the experimental methods used to determine the effects of environmental factors on the growth of juvenile spotted grunter. The experimental sequence provides a logical frame work within which the optimum environmental requirements of other marine fish species can be determined. In addition, evaluation of growth performance by this method provides a basis for comparison of the mariculture potential between species.
26
Aaby, Alyssa Anne. "Testing the ArcGIS Marine Data Model : using spatial information to examine habitat utilization patterns of reef fish along the west coast of Hawaii /." Connect to this title online, 2004. http://hdl.handle.net/1957/4061.
Full text
27
Meyer, Carl G. "An empirical evaluation of the design and function of a small marine reserve (Waikīkī Marine Life Conservation District)." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=765959691&SrchMode=1&sid=7&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1209403781&clientId=23440.
Full text
28
Zapata, Fernando Alberto. "Local and regional patterns of distribution and abundance in marine reef fishes." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/184983.
Full textAbstract:
Local and regional patterns of distribution and abundance are documented in marine rocky-reef fishes. Chapter one describes limits of distribution and patterns of density variation of two fishes in a northern Gulf of California intertidal shore. The density of Sonora gobies (Gobiosoma chiquita) increases with tidal height over its intertidal range (-1.2 to 0.9 m), whereas the density of patchscale gobies (Gobiosoma sp.) decreases from the subtidal zone to 0.6 m above mean low water level. Both species exhibit higher densities during the warmer season when intertidal temperature gradients are weaker than during the colder season. Sonora gobies show a broader range of temperature tolerance than patchscale gobies but there is no evidence of shifts in distribution between seasons suggesting that the distributions of these species are not determined by temperature. Interspecific interactions may contribute to the patterns of intertidal distribution and abundance in these species despite the rigorous physical environment of the area. Chapter two documents a positive correlation between average local abundance and extent of geographic distribution in rocky-shore fishes from the Gulf of California. This correlation is not an artifact of sampling an arbitrarily defined region and is unlikely to be an artifact of sampling bias. The occurrence of this relationship in a variety of organisms suggests that the processes responsible for this pattern are likely to be similar in both terrestrial and marine environments despite fundamental differences between the two. Chapter three demonstrates that egg type and adult body size explain a considerable portion of the variation in extent of geographic range in marine reef fishes. Species with pelagic eggs have larger geographic ranges, longer larval lives, and larger body sizes than species with non-pelagic eggs. Small species with non-pelagic eggs show smaller geographic ranges than any other combination of body size and egg type. These biogeographic patterns predict a greater degree of genetic isolation among populations, and a greater species turnover over evolutionary time in clades of small species with non-pelagic eggs than in clades of species with other combinations of body size and egg type.
29
Yuen, Pui-sze, and 原佩詩. "Feasibility of total prohibition of fishing in marine protected areas of Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43784598.
Full text
30
Zhang, Li. "Bioavailability of Cd, Zn and Se in two marine fish /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202007%20ZHANG.
Full text
31
Hall, Colin Mark. "Some aspects of the ecological structure of a segmented barrier lagoon system with particular reference to the distribution of fishes." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1004936.
Full textAbstract:
The Wilderness lakes system represents a segmented barrier lagoon and comprises three interconnected lakes; Rondevlei, Langvlei and Eilandvlei. The latter is further linked by the Serpentine channel to the Touw river and Wilderness lagoon. The role of these channels, as well as a sluice in the Serpentine, in structuring certain aspects of the ecology of the system was investigated. An analysis of the salt budget of the lakes suggests that the Serpentine dampens tidaI processes to such an extent that they play only a minor role in the overall budget. Furthermore, the channel between Eilandvlei and Langvlei prevents any tidal salt input to the upper lakes. Their estuarine environments are however maintained by salt inputs which occur when the mouth is closed. This unusual phenemenon means that the sluice may have a minimal effect on the salt budget of the system because it is only closed when the mouth of the lagoon is open. Environmental conditions in each of the lakes, the Touw river and Wilderness lagoon were compared in terms of their physico-chemical characteristics and submerged macrophyte communities. A principal components analysis suggests that the physico-chemical environment of each lake is similar. The Touw river however has a very different environment, whilst that of Wilderness lagoon has some similarities to both the lakes and the river. During the study macrophyte communities recovered from a major recession which occurred between 1979 and 1981 . Biomasses in excess of 1000g m⁻² were recorded in both Langvlei and Eilandvlei. In the latter however, macrophyte growth was less prolific than in the former, as some areas of the littoral supported no growth at all. Macrophyte encroachment in the channels is a major factor inhibiting water flow between the lakes. This encroachment is most severe in the Eilandvlei/Langvlei channel where macrophytes covered 80% of the channel's area.The dominant fish fauna throughout the system is composed of a marine/estuarine migratory component. In the lakes the Mugilidae and Sparidae are the most common families, whilst in the lagoon and Touw river predators such as Lichia amia and Argyrosomus hololepidotus also commonly occur. Eilandvlei serves as the initial nursery area for most migratory species. An estimated 52000 fish migrated up the Serpentine towards Eilandvlei during February 1984 . Most fish do not penetrate as far as Langvlei, and this can be related to macrophyte encroachment in the Eilandvlei/Langvlei channel. However, it is argued that should this channel be dredged and the macrophytes removed, the nursery potential of the system would not be greatly enhanced . This is because environmental heterogeneity, in association with an abundance of food in Eilandvlei, make this lake the most attractive nursery area to juvenile marine/estuarine fish.
32
Rose, Andrew Stuart. "Epidemiological aspects of Aeromonas salmonicida in the marine environment." Thesis, University of Stirling, 1990. http://hdl.handle.net/1893/21887.
Full textAbstract:
The epidemiology of Aeromonas salmonicida subsp. salmonicida in the marine environment was investigated. Nutrient resuscitation and infectivity studies did not support a previous claim of dormancy in A. salmonicida and validated the use of colony-forming units (cfu) in survival studies. Survival of A. salmonicida in seawater was assessed and found to be of short duration «10 days). Survival of the bacterium in non-sterile sediment, obtained from beneath a salmon cage, appeared to be limited. The minimum infective dose of A. salmonicida to Atlantic salmon in short duration (1-3 days) bath exposure in sea water was 10' cfu ml-I. Prolonged exposure for three weeks resulted in infection with 102 cfu ml- I. Intragastric intubation of the bacterium established infection with doses >105 cfu. Shedding of A. salmonicida from infected salmon was 105-108 cfu/fish/hr. Survival and shedding results were combined in a computer model. A. salmonicida was predicted to travel >6 km suspended within the water column of a sea loch. Covert infection in freshwater farmed salmon was assessed by ELISA and the standard stress test. Results indicated that ELISA may be useful as a routine monitor of furunculosis infection. The efficacy of dot-blot immunoassay was found to be 108 cfu A. salmonicida in fish kidney tissue. Rainbow trout (Oncorhynchus mykiss) and salmon mucus were not found to inhibit the growth of A. salmonicida supporting recent evidence that fish skin is a site of carriage. In vitro studies suggested that trout serum proteins do not confer protection from fish antibody on A. salmonicida in covert infections. Preliminary work was undertaken to develop a specific DNA probe for A. salmonicida which will allow its detection in environmental samples and carrier fish. A gene library of A. salmonicida was constructed in lambda gtll and screened for "A"-protein with antibodies.
33
Casazza, Tara L. "Community structure and diets of fishes associated with pelagic Sargassum and open-water habitats off North Carolina." View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-3/casazzat/taracasazza.pdf.
Full text
34
King, Timothy L. (Timothy Lee). "Stock and Species Identification of Selected Marine Fishes and Shellfishes Using Allozyme Analysis and Isoelectric Focusing: Implications for Texas Fisheries Management." Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc277919/.
Full textAbstract:
Allozyme frequencies and general protein patterns were surveyed among selected Texas marine fishes and shellfishes to illustrate the application of biochemical genetic techniques to stock and species identification in fisheries management.
35
Harding, Juliana Maria. "Ecological interactions between benthic oyster reef fishes and oysters." W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1539616684.
Full textAbstract:
Restoration of oyster reef structures rehabilitates habitats and the multi-level ecological communities built on eastern oysters (Crassostrea virginica), the keystone species. Quantitative descriptions of ecological interactions within a habitat are required to delineate essential fish habitats for management and protection. Parallel development of primary (oysters) and secondary trophic levels (benthic fishes) offer an ecological metric of restoration progress over time. The interaction between larval oysters and larval fishes (e.g., Gobiosoma bosc, Chasmodes bosquianus) is quantitatively examined. Oyster settlement estimates for Palace Bar reef, Piankatank River, Virginia are of the same order of magnitude as field densities of recently settled oysters. Benthic fish settlement estimates are within an order of magnitude of observed adult densities. Zooplankton community composition around the reef is temporally variable and plankton densities range from 10 2--106 animals per m3 across temporal scales. Nocturnal densities of naked goby and striped blenny larvae around Palace Bar reef were 3 to 4 orders of magnitude higher than densities observed during daylight hours. Diurnal changes in larval fish abundance near Palace Bar reef are related to ambient light intensities and diurnal vertical migration by prey species. Naked goby, striped blenny, and feather blenny (Hypsoblennius hentzi) larvae selectively consumed bivalve veligers, in multi-factorial laboratory feeding experiments. Temporal co-occurrence of larval oysters and larval fishes was not observed in 1996 field collections although historic oyster settlement data strongly support the probability of co-occurrence during most years. Two different methods are used to estimate the larval oyster - larval fish interaction in the absence of field data. Given existing oyster and fish demographics on Palace Bar reef, larval fishes have the capacity to drastically reduce, perhaps eliminate, local veliger populations if they co-occur. The strength of this interaction is directly related to oyster demography-fecundity relationships. In the absence of veligers, larval fishes consume other plankton taxa that are abundant around the reef. Naked gobies and striped blennies are generalists. Oyster reefs provide optimal rather than essential habitat. Reef restoration will facilitate development of related ecological communities by providing optimal habitat conditions for these ubiquitous estuarine species.
36
Mushanganyisi, Kanakana S. "Seasonal and spatial variability of pelagic fishes in relation to environmental variability in St Helena Bay." Master's thesis, Faculty of Science, 2019. https://hdl.handle.net/11427/31795.
Full textAbstract:
The St Helena Bay Monitoring Line (SHBML) stretches 197 nautical miles off Elands Bay on the west coast of South Africa. It is an extensive long term project on environmental monitoring, running from 2000 till 2012 on an almost monthly basis but currently running on a quarterly basis. It extends through the nursery grounds and part of the transport zone for hydrology and productivity in areas that are significant to early life history of small pelagic fish. Environmental, acoustic and zooplankton data have been collected along the SHBML to obtain information on ocean environment, pelagic fish abundance and also zooplankton abundance. This study used an interdisciplinary approach, analysing historical data collected during biannual surveys of small pelagic fish, to investigate seasonal and spatial variability of pelagic fishes in relation to environmental variability in St Helena Bay. Surface values from 2000 to 2010 of temperature, salinity, oxygen and chlorophyll were analysed in relation to zooplankton and fish densities. The results show partial / weak seasonality of SST in offshore and also in coastal stations. Zooplankton, chlorophyll and oxygen show limited seasonality only in nearshore stations. Strong cross-shelf patterns of SST, chlorophyll, salinity, oxygen, zooplankton biomass and fish abundance were noted. These were expected results from a coastal upwelling system where primary productivity during summer is increased in the nearshore zone. There was a positive relationship between salinity and SST (r = 0.821, p< 0.0001) and a negative relationship between chlorophyll and SST (r = -0.549, p< 0.001), as would be expected in a coastal upwelling environment. When other variables were examined (also in pairs), there were no relationships between SST and oxygen, fish and zooplankton, fish and chlorophyll, fish and SST, fish and oxygen, and chlorophyll and zooplankton. A GLM was fitted to the data to investigate the relationship of pelagic fish density with zooplankton biovolume, chlorophyll, SST and oxygen; the GLM results showed a negative relationship between zooplankton abundance and pelagic fish (t=-1.980, p=0.049). Based on these results, it appears that the SHBML data were not able to pick up seasonal signals but have shown interannual variability and also some inshore-offshore differences.
37
McIntyre, Fiona Doreen. "Development of visual survey methods to support environmental monitoring and fisheries management." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=226947.
Full textAbstract:
Visual surveys provide for non-invasive sampling of organisms and habitats in the marine environment. They are particularly important in deep-sea habitats which are vulnerable to damage caused by alternative destructive sampling devices such as bottom trawls. However, traditional visual survey platforms tend to have limited area coverage which is insufficient for mapping the vast expanses of the deep-sea, particularly for relatively sparsely distributed organisms such as fish. This thesis presents the development of a visual survey method capable of surveying large areas of the seabed in deep waters (> 200 m) using a towed video camera system. The area of seabed sampled was similar to that sampled by a bottom trawl, making the system effective for surveying fish. Anglerfish densities were found to be comparable to those determined by trawl surveys in adjacent areas. For other deep-sea fish, the two survey methods (towed camera and bottom trawl) provided different results which were explained by the behavioural reactions of different fish taxa to the respective gears. Fish that exhibited detectable avoidance behaviour to the towed video camera system (e.g. Chimaeridae) resulted in significantly lower density estimates than trawl estimates. On the other hand, skates and rays showed no reaction to the towed video camera system, and density estimates of these were an order of magnitude higher than the trawl. The towed video camera survey was also deployed to gather data on the cold-water coral Lophelia pertusa on the Rockall Bank. These data were used together with Species Distribution Modelling (SDM) to predict the distribution of Lophelia pertusa habitat. The current closed areas on the Rockall Bank cover sizeable areas of potential Lophelia pertusa habitat, however, based on the predictions further areas could be considered to ensure the continued protection of this species.
38
Gon, O. (Ofer) 1949. "The history of marine fish systematics in South Africa." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1007800.
Full textAbstract:
South African marine fish collections and systematic research are relatively young, essentially a product of the 20th century. Their history in South Africa comprises three distinct periods: the emergence of fish collections (before 1895), the beginning of research (1895-1945) and modern research (1945-1999). From the outset of their arrival in South Africa in the mid-17th century, the European settlers of the Cape Colony supplemented their diet with fishes. Therefore it is not surprising that when natural history museums appeared in the 19th century fishes were among the first specimens they procured or received from the public. In these early days, fishes were acquired for display purposes and were curated together with other natural history specimens. There were no fish collections as such and, in many ways, the early history of South African fish collections closely followed the history of the institutions in which they were housed. Major political events in South Africa between 1850-1910 had little effect on the slow growth offish collections as the low influx of specimens from the public did not change. None of the museums did any active fish collecting and no fish research as such took place during these years. The second period in the growth of fish collections in South Africa was characterised by a general shift to collecting for research rather than display. It was also a period during which the need for aquatic research was recognized by and began to attract funding from the South African government, starting with the establishment of the Marine Biological Survey in Cape Town. However, with the exception of the Albany Museum's self-trained J.L.B. Smith, no trained marine fish systematists were working in museums either as curators or as researchers. In the first half of the 20"' century South Africa experienced the fast growth of the fishing industry, the development of academic and applied research in marine biology, and the thriving of sport fishing. These developments created a demand for well-trained professional ichthyologists. J.L.B. Smith was the first to fill this professional gap. The growth rate offish collections increased significantly through the interaction between museum scientists, such as Smith in Grahamstown and K.H. Barnard in Cape Town, with the fishing industry, government biologists and fisheries officers, and anglers. Barnard's review of the South African marine fish fauna was published in mid-I920s. The discovery of the first living coelacanth placed South African ichthyology and Smith on the international stage. The identification of this fish, made by a relatively inexperienced Smith, changed the way ichthyology has been viewed in South Africa. At the beginning of the third period, largely due to the establishment of the Council for Scientific and Industrial Research in 1945, science in South Africa underwent a process of reorganisation. As funding became more available museums were able to enlarge their research staff. Natural history museums hired qualified experts to conduct research and manage collections of specific groups of organisms. For the first time, trained ichthyologists started working in museums and initiated research projects that were the main contributors to the growth of fish collections around the country. Furthermore it was a period of consolidation offish collections resulting in two large marine fish collections, one at the South African Museum, Cape Town, and another at the J .L.B. Smith Institute of Ichthyology, Grahamstown. This period also witnessed the establishment of the latter as a research institute dedicated to the study of fishes and its rise to international prominence. The last 55 years at J.L.B. Smith Institute of Ichthyology can be divided into two distinct periods, 1945-1967 and 1968-1999, each consisting of similar elements of research work and objectives. These included the research and production of major reviews of the fish faunas of South Africa, the western Indian Ocean and the Southern Ocean, as well as research on the coelacanth. While in the former period the work was done by one scientist, J.L.B. Smith, the latter period has been characterised by collaborative projects including scientists from South Africa and abroad. As this history shows, the establishment of a viable, long-lasting collection is a lengthy process. For about 60 years the durability of fish collections depended on the enthusiasm and persistence of individual curators and scientists who were not ichthyologists. More often than not, enthusiasm disappeared when such individuals left their museums. This dependence existed until Rhodes University College established the Department of Ichthyology (1947) and the South African Museum created a post specifically for the curation of the fish collection (1957) and thus ensured continuity. The continuity of biosystematic research in South Africa has been a minor concern for the nation's systematists for decades. The threats to marine fish systematics have been of a financial, political and professional nature. The latter has been the most serious one because of the dearth of South Africans trained in marine fish systematics. After J.L.B. Smith's death in 1968 M.M. Smith had to work hard to convince the Council for Scientific and Industrial Research and Rhodes University that she could step into her late husband's shoes. Realizing that there was nobody to take over from her she initiated the first and only postgraduate programme in ichthyology in South Africa. The teaching started in the academic year of 1970171 at the J.L.B. Smith Institute of Ichthyology, but to date only one student has completed a thesis in marine fish systematics. Due to the government's transformation policy all the practising marine fish systematists in South Africa will be retiring in the course of the present decade. Consequently, if no aspiring, motivated students appear on the scene in the next couple of years marine fish systematics in this country will be in a deep crisis by the year 2010, possibly even earlier.
39
Minkoff, Gideon. "The effect of secondarily enriched rotifers on growth and survival of marine fish larvae." Thesis, University of Stirling, 1988. http://hdl.handle.net/1893/2536.
Full textAbstract:
Nutritional aspects of three species of marine fish larvae, herring Clupea harengus L., plaice Pleuronectes platessa L. and turbot, Scophthalmus maximus L. were examined. Larvae were fed three different diets all of which were derived from rotifers Brachionus plicatilis (O.F. Mtlller). These rotifers had been mass cultivated on baker's yeast and then enriched with baker's yeast, or with one of two unicellular algae, Isochrysis galbana Park or Nannochloropsis (Nannochloris) oculata (Droop) Hibberd. The biochemical changes that these enrichments conferred on the rotifer were examined. There was little difference in proximate and amino acid compositions. Dry weights, and calorific contents of the rotifers fluctuated according to the type, temperature and duration of enrichment, with the yeast enriched rotifers tending to weigh less (200-320 ng) than their algal counterparts (250-370ng). Major differences were found in the total fatty acid profiles of the rotifers. Yeast-enriched rotifers had no 18:3n-3 or 20:5n-3 and only trace amounts of 22:6n-3 fatty acids. The Nanrinochioropsis-enriched rotifers had substantial amounts of n-3 fatty acids though only of 20:5n-3 (11-14%), while rotifers enriched with Isochrysis had only trace amounts of 20:5n-3 (2-4%). All three species of fish responded similarly to the yeast enriched rotifer diet. Their growth, in terms of length and weight, was minimal and they never developed any fin ray elements. Both flatfishes developed a looped gut in the short growth duration on this diet and some turbot (20%) inflated their swim bladder. This retardation of growth was attributed to the lack of long chain highly unsaturated n-3 fatty acids (n-3 HUFA) in the diet. During one month feeding trials it was shown that herring and plaice were able to exploit both algal-enriched rotifer diets equally well. Turbot, on the other hand grew better, over 14 days, on rotifers enriched with lsochrysis compared with Nannochioropsis. The reaction of the different species was linked to the fatty acid profiles of the diet. Hence, turbot require a dietary input of 22:6n-3 while herring and plaice thrived equally well on diets containing only 20:n-3. Juvenile plaice consistently exhibited improved pigmentation when Isochrysis compared to Nannochloropsis were used as the rotifer enrichment. The effect was attributed to specific nutrients particular to algal chloroplasts, which need to be present in the diet of the larvae up to metamorphosis. Assessment of daily rations, employing the rotifer enriched with Isochrysis diet only, showed herring to reduce their food intake from 46 to 19% body dry weight/d between days 10-21 post hatch while turbot consumed between 34-169% body dry weight/d with no apparent age related effects. The gross growth efficiencies (Ki, Brett & Groves, 1979) for both species were seemingly unaffected by age related processes and fluctuated between 15-50% in turbot and 20-61% in herring according to fluctuations in daily food intake. Ingestion is further described for both species with a linear model that related food intake to larval weight. The weight-specific ingestion was found to be a constant 13% and 43% of body dry weight in herring and turbot respectively. The weight-specific ingestion and specific growth rate estimates were combined with other data available from the literature, revealing that larvae tend to consume food (in dry weight) at a level equivalent to approximately twice their daily dry weight increase.
40
Purchase, David Bryce. "Patterns of distribution, abundance and community composition of rock pool fishes in Goukamma Nature Reserve, South Africa." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/28158.
Full textAbstract:
Rock pools can be found in most rocky intertidal marine environments across the globe. Despite the vast body of literature describing the organization of ecological communities and biota inhabiting the greater rocky intertidal, very little effort has been given to rock pools. As a result they are far less understood than the adjacent emergent intertidal, particularly with respect to their fish communities. This is mostly due to the relative small size of rock pool fishes, their cryptic behaviour and morphologies, the relative difficulty in sampling intertidal fish utilizing conventional methods, and the low economic value of rock pool fishes. Rock pool fishes may have significant ecological value, as they are involved in structuring intertidal communities. Due to reduced environmental fluctuations within rock pools, these habitats may serve as crucial refuges from adjacent stressors. Furthermore, rock pools may play an important role in the early life histories of sub-littoral fish species that utilize these habitats as juveniles, some of which are valuable to fisheries as adults. It has been suggested that due to the lack of exposure at low tide, rock pools do not represent a true intertidal habitat, as organisms are not subject to the full range of environmental fluctuations seen in adjacent habitats. There is unequivocal evidence indicating that, like the surrounding emergent substrata, conditions in rock pools are highly regulated by the tidal cycle and that the degree of environmental fluctuations will vary greatly with intertidal height and degree of exposure of individual pools, much like patterns seen in adjacent habitats. Fishes inhabiting rock pools can be broadly categorised into groups based on their major zoographic provinces, life history traits and their behavioural affinities, on top of basic taxonomic categorizations. Global patterns indicate two main rock pool fish communities, those of Gondwanan origin and those of Laurasian origin. South African rock pools are relatively well studied from a taxonomic perspective compared to elsewhere, however, like the rest of the globe, factors influencing their fish communities are far less understood. The aim of this study was to determine which, if any, physical and biological rock pool characteristics have any significant influence on the Abundance, Diversity and Community of fishes at Goukamma MPA, South Africa. This site was chosen due to a lack of previous surveys of rock pool fishes at this site and because of a need for an inventory of faunal communities in protected areas in South Africa. The shoreline within the reserve is dominated by sandy shores and interspersed with mixed rock-based habitats. Aelonite platforms form mixed shores and are found along areas west of the Goukamma estuary. Hard, predominantly older Table Mountain Sandstone layers are found along the eastern shore near Buffalo Bay. Rock pools are found at both shore types. Aelonite platforms were formed geologically recently from sand dunes formed during the interglacial periods of the Pleistocene and as a result are relatively flat and easily eroded into circular pools by loose rocks. The hard table mountain sandstone pools formed in cracks and faults caused by geological tilting action, and tend to long and thin rather than circular. Fifty-five rock pools were sampled, to investigate the influence of spatial (Location and Headland), temporal (Season), abiotic (Area, Height, Depth, Rugosity) and biological (Rock, Algae,) characteristics of rock pools on the distribution, abundance, diversity and community composition of rock pool fishes. A total of 747 fishes, representing seven families and 16 species were collected, using a non-lethal anesthetic, clove oil. Clinus cottoides, Parablennius cornutus and Caffrogobius caffer were the most dominant species, together making up almost 85% of the fish community. Total fish Abundance was not found to significantly change with any of the variables. The Shannon-Wiener Species Diversity Index for the whole of Goukamma was 1.64, however, it differed significantly among Locations, was greatest in pools of larger Area, lower Heights and higher cover of Rock. Community was found to significantly change with Location and was significantly influenced by Area, Rugosity, Height and Depth. Rock pool fish communities in South Africa show clear biogeographical patterns. These patterns show five distinct bioregions along the South African coastline in that familial distributions tend to be broken by the same oceanographic barriers seen in the distributions of many other marine taxa. The results suggest that rock pool fishes tend to exhibit distinct preferences to pools of certain typology and will seldom move over even small distances in search of new pools. Overall the study followed past findings from studies of similar type, both within South African and elsewhere.
41
Aspillaga, Cuevas Eneko. "Movement ecology of coastal fishes in a marine protected area: implications for management and conservation." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/406075.
Full textAbstract:
Animal movement is a key biological process for the maintenance of ecosystem services, and a major concern for the conservation of biodiversity. The aim of movement ecology is to understand the causes and consequences of these movements, including the effect of internal and external factors and its ecological implications. This research field has rapidly grown in the last decades fostered by recent technological and analytical developments, and is making substantial contributions to conservation biology, such as allowing the incorporation of the spatial and temporal scales of movements into management policies to enhance their scope and efficiency.
Marine protected areas (MPAs) are the most used tools to face the effects of anthropogenic impacts on marine ecosystems. They play a major role in restoring and conserving overfished fish populations, and also potentially enhancing fisheries yield in adjacent areas through the direct spillover of juvenile and adult individuals. However, in order to be effective and generate such benefits, MPAs must be designed according to the movement attributes of targeted species, but this information is still rarely available, specially in temperate regions. In the last decades, passive acoustic telemetry techniques have demonstrated to be a valuable tool to study the movements and behavior of fishes covering large spatial and temporal scales, but the acoustic nature of the signals and the large amounts of data that they provide entail a series of challenges for their analysis and interpretation.
The main objective of this thesis is to characterize the movement ecology of coastal fishes in relation to MPAs. This constitutes a basic information on the biology of species, which is required to understand changes in populations and ecosystems driven by natural or human induced impacts, as well as to correctly evaluate the outcomes of management actions. Specifically, the movements of two species, the white seabream (Diplodus sargus) and the common dentex (Dentex dentex), were monitored using acoustic telemetry in the Medes Islands MPA (Catalonia, NW Mediterranean Sea). Both species play important ecological and economical roles, shaping the structure and functioning of biological communities through top-down controls, and being an important resource for local artisanal and recreational fisheries. Nevertheless, they present a contrasting biology (omnivorous vs. predator), and therefore, different conservation needs.
Firstly, we characterized the general movement attributes of the two species, including their habitat requirements and space use and activity patterns, within zones with different protection levels of the MPA. Secondly, we studied the behavioral responses of the two species to environmental fluctuations, by adding environmental information (seawater temperature and wave height) to movement analysis. These behavioral responses provide essential information on the ecology of the species such as their resistance to perturbations. Thirdly, we characterized their movement behavior during the spawning season, describing, for the first time, the formation of spawning aggregations for both species. Finally, this thesis also has an important computational and numerical component. A special effort has been done to adapt and develop new methods to visualize and analyze acoustic telemetry data, specially to improve the space use estimations by incorporating the vertical dimension, in order to provide a more comprehensive view of complex movement patterns.
By studying the movement ecology of these species, we provide general mechanistic insights to understand the effects of protection on coastal fish species, as well as to predict future changes in their populations derived from climate change. We specially highlight the importance of studying the movement ecology of diverse species in order to propose integrative and more efficient management actions.Las áreas marinas protegidas (AMPs), son las herramientas de gestión más utilizadas para contrarrestar los impactos antropogénicos sobre los ecosistemas marinos y juegan un papel fundamental en la protección y restauración de las poblaciones de peces afectadas por la sobrepesca. Sin embargo, para ser efectivas y generar los beneficios que se esperan de ellas, las AMPs deben ser diseñadas en concordancia con los atributos de los movimientos de las especies de peces que se pretenden proteger, pero esta información no suele estar disponible. El principal objetivo de esta tesis es caracterizar, mediante técnicas de telemetría acústica, la ecología del movimiento de especies de peces costeros en relación a AMPs, mediante el estudio del movimiento de dos especies: el sargo común (Diplodus sargus) y el dentón (Dentex dentex), en la reserva marina de las islas Medas (Catalunya, Mediterráneo NO). Específicamente, se han caracterizado los patrones de movimiento y actividad generales de las dos especies, la presencia de respuestas comportamentales a fluctuaciones ambientales (temperatura y oleaje), y su comportamiento reproductor. Además, se ha hecho un esfuerzo especial en adaptar y desarrollar nuevas técnicas de análisis y visualización para datos de telemetría acústica, con el objetivo de mejorar las estimaciones del uso del espacio, incorporando la dimensión vertical, y de proporcionar una visión más exhaustiva de los complejos patrones de movimiento. Toda esta información es de gran aplicabilidad para la gestión de estas y otras especies costeras, así como para entender los cambios en las poblaciones y en los ecosistemas derivados del cambio global.
42
Bradley, Scott. "Benthic lander systems' architecture and a new method for tracking deep-ocean fishes." Thesis, University of Aberdeen, 1998. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602311.
Full textAbstract:
Deep-ocean (benthic) landers are free-falling vehicles that are deployed from a ship and descend to the ocean floor by virtue of attached ballast. They carry with them scientific instrumentation to carry out in-situ experiments, and once operation is complete, an acoustic command from the surface vessel causes the lander to release its ballast and allow buoyancy to return it to the surface for recovery. Landers function autonomously, typically under the control of a central micro-controller and data-logger. The extreme environment in which landers operate require that all electronics is contained in special pressure housings and interconnection between modules is made using expensive deep-ocean cables and connectors. This thesis presents the concept of a new Controller Area Network (CAN)-based architecture, and a report is given of the development of a miniature network interface board suitable for use on benthic landers. One application of lander technology is in tracking the movements of abyssal fishes that forage close above the ocean floor. Small acoustic transponders are wrapped in bait and attached to the ballast of the lander. Scavenging fish attracted to the bait consume the transponders, after which a sonar system on the vehicle can track their movements. A new method for tracking these fishes is presented that uses a short-baseline hydrophone array mounted on a specially designed lander, AUDOS II. With no moving parts, this method has many advantages over previous systems that relied on scanning directional sonar. Tracking resolution has been greatly improved, and new software tools allow the movements of tracked fish to be viewed quickly and with ease.
43
Chapman, Matthew R. "Coral reef fish movements and the effectiveness of the Barbados Marine Reserve." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20560.
Full textAbstract:
This study examined whether movements of fishes across reserve boundaries reduced the difference in density and size of fish between reserve and non-reserve areas. Visual censuses, experimental trapping, habitat measurements and tagging were performed at 10 sites on two nearly contiguous fringing coral reefs at the northern edge of the Barbados Marine Reserve and at 10 sites on the two fringing reefs closest to the boundary in the non-reserve. The visual censuses showed that overall density and size of fishes large enough to be caught in Antillean fish traps were higher on reserve reefs than on non-reserve reefs. The differences in density and size varied considerably among species and were not statistically significant for individual species. In contrast to a previous study, experimental trap catches were not higher in the reserve than in the non-reserve. Visual censuses, trap catches, and their ratio (trappability) were affected by habitat variables. Species mobility, estimated by the maximum distance between locations at which an individual was captured, corrected for the sampling effort at that distance, was highly variable among species (medians 0--116m). For the more mobile species, movements within fringing reefs and between the nearly contiguous reserve reefs was high but extremely rare among reefs separated by expanses of sand and rubble. For this discrete fringing reef system, there is no evidence that movement across the reserve boundary influences the relative density or size of fish between the reserve and non-reserve.
44
McPhail, Kerry Lee. "Extractives from six species of South African Marine Opisthobranch Molluscs." Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1007412.
Full textAbstract:
The natural product chemistry of six species of South African opisthobranch molluscs and some of their dietary marine invertebrates was investigated. Nineteen previously undescribed secondary metabolites and twelve known compounds were isolated and their structures determined by a combination of spectroscopic and chemical methods. The circumtropical sea hares Aplysia parvula and A. dactylomela were found to contain halogenated red algal metabolites. 3Z-bromofucin (120), the Z analogue of a known Laurencia CIS acetogenin, was isolated from A. parvula. A. dactylomela yielded a series of novel non-aromatic cuparanes, the algoanes (121-123), the novel tricyclic Iaurane ether ibhayinol (124) and three known chamigrane sesquiterpenes, prepacifenol epoxide (101), pacif-7-enediol (104) and nidificene (125). A variety of new octocoral sesquiterpenes were isolated from the endemic South African arminacean nudibranch Leminda millecra including algoafuran (150), cubebenone (151), 8-hydroxycalamenene (152) and a series of seven triprenylated toluquinones and toluquinols (153-159). L. millecra also yielded the known sesquiterpenes millecrones A (142) and B (143) and isofuranodiene (149). Twenty eight voucher specimens and eighteen crude extracts of South African octocorals collected by the Coral Reef Research Foundation were screened by GC and GC-MS and 142 was found in Alcyonium fauri, while 143, 151 and possibly 149 were present in Leptogorgia palma. An investigation of southern African chromodorids yielded the known macrocyc1e latrunculin B (220) and two new spongiane diterpenes (221) and (222) from Chromodoris hamiltoni, while the known spongiane diterpene (210) was isolated from the endemic nudibranch Glossodoris sp. 4. The endemic nudibranch Hypselodoris capensis contained the known furanosesquiterpenes nakafuran-8 (223) and -9 (224) and the known furanosesterterpenes variabilin (195), 22-deoxyvariabilin (225) and furospinosulin (227) together with the new variant 22-deoxy-23-hydroxymethylvariabilin (226). Compounds 223 and 224 were also found in a Dysidea sponge, while the furanosesterterpenes 195, and 225-227 were present in a Fasciospongia sponge upon which H capensis specimens were found. The Dysidea dietary sponge of H capensis also yielded a new aromatic sesquiterpene, tsitsikarnmafuran (266), whose structure was confirmed by the synthesis of two possible regioisomers.
45
Hayes, Polly May. "Gnathiids, leeches and blood protozoans of marine fishes : morphological, pathological, developmental and molecular approaches." Thesis, Kingston University, 2007. http://eprints.kingston.ac.uk/20385/.
Full textAbstract:
Haematophagous, metazoan ectoparasites and protozoan blood parasites of intertidal fishes from Wales and South Africa formed the main focus of this study. The ectoparasites examined were largely juvenile isopods of the genus Gnathia, and specimens ofthe leech, Zeylanico~della arugamensis. These taxonomically distinct ectoparasites were suspected vectors of the blood protozoans, and the latter were mostly apicomple{(ans of the genus Haemogregarina and euglenozoans ofthe genus Trypanosoma. Knowledge of digestive tract anatomy in juvenile gnathiids is essential for assessing their role as potential vectors and this system was examined using histological, microscopical and computer-based techniques. Features that had been unreported, or insufficiently recorded, previously' included several structures within the dorsal afid ventral stomach chambers, a typhlosolelike formation in the anterior hindgut, haemozoin-like deposits in the digestive caeca of Gnathia africana and Gnathia pantherina, and an extensive gut flora. Connections between the stomach, anterior hindgut and digestive caeca were identified, salivary gland ducts were followed towards the mouthparts, and the digestive cycles of Gnathia maxillaris and G. africana juveniles were examined over a period of 30 days. The pathology associated with the attachment sites of G. africana and Gnathia sp A to teleosts, and with G. pantherina to an elasmobranch, was found to be considerable in the case of G. pantherina, while Gnathia sp A prompted the death ofits host unde: experimental conditions. Oocyst stages, presumed to be those ofHaemogregarina bigemina, were ,' . located in sections through the digestive caeca of G. africana, confirming the vector status ofthe isopod. Development stages of a new species, Haemogregarina curvata, were observed in the leech, Z. arugamensis, and within peripheral blood smears from several fishes. The life cycle oftrypanosomes found in Z. arugamensis and in fishes was also established, although interpreting the morphometries ofthese flagellates was challenging and speciation proved difficult. Identical molecular sequences oftrypanosomes were derived from separate leech samples and these were close to published sequences for marine fish trypanosomes. Thus, both gnathiids and leeches were likely vectors ofthe fish blood protozoans. Finally, probable dual transmission of a haemogregarine and trypanosomes by a leech was illustrated, a rare event, reported infrequently in the literature.
46
Colvocoresses, James Alden. "Abundance, seasonality and community structure of fishes on the Mid-Atlantic Bight continental shelf." W&M ScholarWorks, 1985. https://scholarworks.wm.edu/etd/1539616615.
Full textAbstract:
Cluster analyses of seasonal (spring and fall) National Marine Fisheries Service Groundfish Survey bottom trawl catches on the Middle Atlantic Bight continental shelf revealed consistent species associations and faunal zones over a nine year period during. Boundaries between faunal zones tended to follow isotherms on the inner portions of the shelf and isobaths along the outer shelf. During the late winter/early spring, four faunal zones were identified: a northern inner and middle shelf zone extending from Cape Cod southward to about Delaware Bay, a northern middle and outer shelf zone offshore of the first zone, a southern middle and outer shelf zone, and a fourth zone on the shelf break and upper slope. The southern inner shelf was a transition zone between the first and third zones. Five species groups were identified: a small cryophilic group restricted to the first zone, a cold-water boreal group found in the first two zones, a ubiquitous boreal/resident group containing the major dominants, a warm-temperate group confined to the warmer southern and outer shelf waters, and a group of slope residents confined to the deepest zone. During the fall, five faunal zones were identified: a southern inner and middle shelf zone, a northern inner shelf zone, a northern mid-shelf zone, an outer shelf zone and a shelf break/upper slope zone. The five species associations recognized were largely analogous to those in the spring, with the following exceptions: the cryophilic group was absent, the ubiquitous group contained mixed boreal and warm-temperate elements, and a second outer shelf group was recognized. The most notable change in the distribution of groups from the spring was a general northward shift in the distributions of the boreal species and a sharply defined inshore movement of the warm temperate group. Analyses of a single summer cruise showed patterns of distribution intermediate to those seen during the spring and fall. Absolute abundances, both of individual species and the total fish community, were highly variable between areas, seasons and years. Species diversity and its components appear to be of little utility in describing the fish communities of the open continental shelves.
47
Gilbert, Deidre F. "Modeling the Role of No-Take Marine Reserves in Fisheries Management." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/GilbertDF2002.pdf.
Full text
48
PETERSEN, CHRISTOPHER WILLIAM. "MATING SYSTEMS IN TROPICAL MARINE FISHES: THEORY AND CASE STUDIES OF SIMULTANEOUS HERMAPHRODITISM AND PATERNAL CARE (SERRANUS, LABRISOMIDAE, GULF CALIFORNIA)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187934.
Full textAbstract:
This study investigates two aspects of tropical reef fish mating systems: the prevalence of paternal care in those species that exhibit some form of parental care, and the evolutionary stability of simultaneous hermaphroditism. Studies of three species of tropical reef fishes from the Gulf of California were used to investigate these two different types of mating systems. Two species of demersal egg guarders with paternal care, Malacoctenus hubbsi and Abudefduf troschelii, were studied to determine the importance of a male's mating status (the number of eggs in his territory) in regard to female choice of mates. In both species, females did not base their choice of mates on the number of eggs in the male's territory, males increased their level of parental care with increasing egg number, and egg survivorship where estimated was independent of brood size. These results corroborate, and offer the first experimental field verification of a crucial assumption of a minimal-care hypothesis proposed a decade ago by Williams (1975). Male reproductive success was studied in greater detail in one species, M. hubbsi. Territory parameters, rather than male size, were the major determinants of male reproductive success. This independence relative to male size was attributed to the unpredictability of good future territories. In Serranus fasciatus all individuals begin reproduction as simultaneous hermaphrodites, but lose female function at large sizes to become males. Males obtain disproportionate reproductive success by maintaining harems of hermaphrodites and defending them from adjacent males. These harems are similar to those found in some sequentially hermaphroditic species. Hermaphrodites obtain most of their reproductive success through female function by spawning with a male, but also engage in an alternative male strategy--streaking on pair spawns--to obtain some male reproductive success. This small amount of male reproductive success by hermaphrodites appears to stabilize simultaneous hermaphroditism with most resources allocated to female function. Facultative alternative male mating strategies in hermaphroditic individuals joins spawning reciprocation as the only known behavioral strategies that provide evolutionary stability for simultaneous hermaphroditic individuals in populations of tropical reef fishes.
49
Geange, Shane Wallace. "An evaluation of prior residency and habitat effects on the persistence of settling reef fishes : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Doctor of Philosophy in Marine Biology /." ResearchArchive@Victoria e-Thesis, 2010. http://hdl.handle.net/10063/1169.
Full text
50
Wheatley, Melissa Jane 1969. "Ecology of populations and assemblages of temperate reef fish in Port Phillip Bay, Australia." Monash University, Dept. of Biological Sciences, 2000. http://arrow.monash.edu.au/hdl/1959.1/8776.
Full text