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Pasic, Aljosa. „Governance Mesh Approach for Cybersecurity Ecosystem“. Information & Security: An International Journal 53 (2022): 105–30. http://dx.doi.org/10.11610/isij.5308.
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Ferreira, Verónica, Arturo Elosegi, Scott D. Tiegs, Daniel von Schiller und Roger Young. „Organic Matter Decomposition and Ecosystem Metabolism as Tools to Assess the Functional Integrity of Streams and Rivers–A Systematic Review“. Water 12, Nr. 12 (15.12.2020): 3523. http://dx.doi.org/10.3390/w12123523.
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Streams and rivers provide important services to humans, and therefore, their ecological integrity should be a societal goal. Although ecological integrity encompasses structural and functional integrity, stream bioassessment rarely considers ecosystem functioning. Organic matter decomposition and ecosystem metabolism are prime candidate indicators of stream functional integrity, and here we review each of these functions, the methods used for their determination, and their strengths and limitations for bioassessment. We also provide a systematic review of studies that have addressed organic matter decomposition (88 studies) and ecosystem metabolism (50 studies) for stream bioassessment since the year 2000. Most studies were conducted in temperate regions. Bioassessment based on organic matter decomposition mostly used leaf litter in coarse-mesh bags, but fine-mesh bags were also common, and cotton strips and wood were frequent in New Zealand. Ecosystem metabolism was most often based on the open-channel method and used a single-station approach. Organic matter decomposition and ecosystem metabolism performed well at detecting environmental change (≈75% studies), with performances varying between 50 and 100% depending on the type of environmental change; both functions were sensitive to restoration practices in 100% of the studies examined. Finally, we provide examples where functional tools are used to complement the assessments of stream ecological integrity. With this review, we hope to facilitate the widespread incorporation of ecosystem processes into bioassessment programs with the broader aim of more effectively managing stream and river ecosystems.
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Karimi, James D., Ron Corstanje und Jim A. Harris. „Understanding the importance of landscape configuration on ecosystem service bundles at a high resolution in urban landscapes in the UK“. Landscape Ecology 36, Nr. 7 (10.02.2021): 2007–24. http://dx.doi.org/10.1007/s10980-021-01200-2.
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Abstract Context Landscape structure is thought to affect the provision of ecosystem service bundles. However, studies of the influence of landscape configuration on ecosystem service trade-offs and synergies in urban areas are limited. This study used Bayesian Belief Networks to predict ecosystem service trade-offs and synergies in the urban area comprising the towns of Milton Keynes, Bedford and Luton, UK. Objectives The objectives of this study were to test (1) a Bayesian Belief Network approach for predicting ecosystem service trade-offs and synergies in urban areas and (2) assess whether landscape configuration characteristics affect ecosystem service trade-offs and synergies. Methods Bayesian Belief Network models were used to test the influence of landscape configuration on ecosystem service interactions. The outputs of a Principal Component Analysis (PCA) on six ecosystem services and landscape configuration metrics were used as response and explanatory variables, respectively. We employed Spearman’s rank correlation and principal component analysis to identify redundancies between landscape metrics. Results We found that landscape configuration affects ecosystem service trade-offs and synergies. A sensitivity analysis conducted on the principal components showed that landscape configuration metrics core area (CORE) and effective mesh size (MESH) are strong influential determinants of ecosystem service trade-offs and synergies. Conclusions This study demonstrates that landscape configuration characteristics affect ecosystem service trade-offs and synergies and that a core set of metrics could be used to assess ecosystem service (ES) trade-offs and synergies. The findings may be relevant to planning and urban design and improved ecosystem management.
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Sotiriou, Effimia, und Margarita Arianoutsou. „Soil moisture effects on cellulose decomposition in a Mediterranean ecosystem of Attica, Greece“. Israel Journal of Ecology and Evolution 55, Nr. 1 (06.05.2009): 63–76. http://dx.doi.org/10.1560/ijee.55.1.63.
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Water is the most critical limiting factor for decomposition processes in Mediterranean climate ecosystems. The aim of this study was to investigate the effects of increased soil moisture levels upon cellulose mass loss in an eastern Mediterranean ecosystem. We used a split plot experimental design to evaluate the effect of seasonality on the decomposition process by manipulating water availability in situ during different seasons. Nylon litterbags of mesh size 20 μm and 1 mm were filled with cellulose filter paper and placed on the plots during each season. The treatment consisted of a systematic uniform watering of the plots with 7 L/m2/week. Litterbags were randomly removed from each plot on a monthly basis. Cellulose mass loss showed differences between treatment and control plots and between seasons but was significant only in the spring. Cellulose mass loss was significantly affected by irrigation treatment, season, and their interaction, while moisture seemed to be affected only by season. There was no significant difference in cellulose mass loss due to different mesh sizes.
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Eissenstat, David. „ROOT TURNOVER: METHODS OF ANALYSIS“. HortScience 25, Nr. 9 (September 1990): 1176b—1176. http://dx.doi.org/10.21273/hortsci.25.9.1176b.
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Root turnover has been determined primarily in ecosystem studies with perennial vegetation since it is a key for understanding primary production and nutrient cycling. These topics have become of interest to agriculturalists as well. Apart from ecosystem-level questions, there has been limited study of the environmental factors that influence root death. Many techniques have been devised to estimate root turnover, each with its own set of limitations. In forest ecosystems, one of the most popular methods of estimating root production turnover is sequential biomass sampling. However, this method fails to account for the simultaneous production and decomposition of roots during active periods of net biomass increase. A second method is a mesh-bag technique, which estimates root production/turnover from the amount of new roots that grow into a mesh bag. A method that uses radiocarbon is one of the most accurate, since estimates of root turnover include losses by exudation, cortical cell sloughing, as well as root loss. A fourth method of estimating root turnover involves tracking the roots visible behind transparent glass or plastic. Ultimately, the choice of method depends to a large extent on the type of plants used in the investigation and resources available for study.
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Wang, Zhongqiu, Hao Tang, Liuxiong Xu, Jian Zhang und Fuxiang Hu. „Application of a Controlled Aquarium Experiment to Assess the Effect of Mesh Sizes and Mesh Opening Angles on the Netting Selectivity of Antarctic Krill (Euphausia superba)“. Journal of Marine Science and Engineering 9, Nr. 4 (01.04.2021): 372. http://dx.doi.org/10.3390/jmse9040372.
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Understanding the interactions between target species and netting is paramount for increasing the sustainability of trawling activities. The selectivity of the utilized netting depends on the sizes and opening angles of the mesh. The effects of the mesh size and mesh opening angle on the fishing selectivity of Antarctic krill (Euphausia superba) were assessed via micro-cosmos experiments. The results show that both the absolute abundance and the incidence of larger krill individuals passing through experimental panels are proportional to the utilized mesh size. Krill individuals larger than 35 mm passed through experimental panels at mesh opening angles larger than 50° for a 15 mm mesh size, 35° for a 20 mm mesh size and 20° for a 30 mm mesh size. Additionally, all L50 values increased with an increasing mesh size and an increasing mesh opening angle at the same mesh size. Furthermore, the selection range increased with an increasing mesh size and with an increasing mesh opening angle at the same mesh size. This paper provides scientific guidance for the choice of liner mesh sizes of krill trawl with the aim to improve fishing efficiency while minimizing fishing losses and potential negative ecosystem impacts from fisheries.
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Burns, J. H. R., D. Delparte, R. D. Gates und M. Takabayashi. „UTILIZING UNDERWATER THREE-DIMENSIONAL MODELING TO ENHANCE ECOLOGICAL AND BIOLOGICAL STUDIES OF CORAL REEFS“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-5/W5 (09.04.2015): 61–66. http://dx.doi.org/10.5194/isprsarchives-xl-5-w5-61-2015.
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The structural complexity of coral reefs profoundly affects the biodiversity, productivity, and overall functionality of reef ecosystems. Conventional survey techniques utilize 2-dimensional metrics that are inadequate for accurately capturing and quantifying the intricate structural complexity of scleractinian corals. A 3-dimensional (3D) approach improves the capacity to accurately measure architectural complexity, topography, rugosity, volume, and other structural characteristics that play a significant role in habitat facilitation and ecosystem processes. This study utilized Structure-from-Motion (SfM) photogrammetry techniques to create 3D mesh models for several Hawaiian corals that represent distinct morphological phenotypes. The orthophotos and digital elevation models generated from the SfM process were imported into geospatial analysis software in order to quantify several metrics pertaining to 3D complexity that are known to affect ecosystem biodiversity and productivity. The 3D structural properties of the reconstructed coral colonies were statistically analyzed to determine if the each species represents a unique morpho-functional group. The SfM reconstruction techniques described in this paper can be utilized for an array of research purposes to improve our understanding of how changes in coral composition affect habitat structure and ecological processes in coral reef ecosystems.
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Guijarro, Beatriz, und Enric Massutí. „Selectivity of diamond- and square-mesh codends in the deepwater crustacean trawl fishery off the Balearic Islands (western Mediterranean)“. ICES Journal of Marine Science 63, Nr. 1 (01.01.2006): 52–67. http://dx.doi.org/10.1016/j.icesjms.2005.08.011.
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Abstract An analysis of 38 bottom trawl hauls at depths of 251–737 m off the Balearic Islands (western Mediterranean) during autumn 2002 and spring 2003 was used to compare the species and size selectivity of 40-mm diamond- and square-mesh codends under commercial conditions. There was no difference in the catch composition or the yield that could be attributable to mesh shape, although the percentage of total and commercial species discarded with a diamond mesh was higher than with a square mesh. At least in the short term, the escapement ratio and the economic loss with the diamond mesh were lower than with square mesh, but economic efficiency was no different between them. For all the main species compared, except one flatfish, size selectivity parameters were lower for the diamond-than for the square-mesh codend. Selectivity values for the one flatfish species were similar. From the results it is concluded that, within the context of precautionary management, introduction of a 40-mm square mesh in the codend could be an appropriate and plausible measure to improve the state of the resources exploited by the deepwater crustacean trawl fishery of the upper slope off the Balearic Islands, and to reduce the impact of the fishery on the ecosystem.
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Sagi, Nevo, José M. Grünzweig und Dror Hawlena. „Burrowing detritivores regulate nutrient cycling in a desert ecosystem“. Proceedings of the Royal Society B: Biological Sciences 286, Nr. 1914 (30.10.2019): 20191647. http://dx.doi.org/10.1098/rspb.2019.1647.
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Nutrient cycling in most terrestrial ecosystems is controlled by moisture-dependent decomposer activity. In arid ecosystems, plant litter cycling exceeds rates predicted based on precipitation amounts, suggesting that additional factors are involved. Attempts to reveal these factors have focused on abiotic degradation, soil–litter mixing and alternative moisture sources. Our aim was to explore an additional hypothesis that macro-detritivores control litter cycling in deserts. We quantified the role different organisms play in clearing plant detritus from the desert surface, using litter baskets with different mesh sizes that allow selective entry of micro-, meso- or macrofauna. We also measured soil nutrient concentrations in increasing distances from the burrows of a highly abundant macro-detritivore, the desert isopod Hemilepistus reaumuri . Macro-detritivores controlled the clearing of plant litter in our field site. The highest rates of litter removal were measured during the hot and dry summer when isopod activity peaks and microbial activity is minimal. We also found substantial enrichment of inorganic nitrogen and phosphorous near isopod burrows. We conclude that burrowing macro-detritivores are important regulators of litter cycling in this arid ecosystem, providing a plausible general mechanism that explains the unexpectedly high rates of plant litter cycling in deserts.
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Boyero, Luz, Naiara López-Rojo, Javier Pérez, Alan M. Tonin, Francisco Correa-Araneda, Aaron Davis und Richard G. Pearson. „Effects of gamma irradiation on instream leaf litter decomposition“. Hydrobiologia 848, Nr. 21 (04.10.2021): 5223–32. http://dx.doi.org/10.1007/s10750-021-04703-w.
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AbstractLeaf litter decomposition is a key process in stream ecosystems, the rates of which can vary with changes in litter quality or its colonization by microorganisms. Decomposition in streams is increasingly used to compare ecosystem functioning globally, often requiring the distribution of litter across countries. It is important to understand whether litter sterilization, which is required by some countries, can alter the rates of decomposition and associated processes. We examined whether litter sterilization with gamma irradiation (25 kGy) influenced decomposition rates, litter stoichiometry, and colonization by invertebrates after weeks of instream incubation within coarse-mesh and fine-mesh litterbags. We used nine plant species from three families that varied widely in litter chemistry but found mostly consistent responses, with no differences in decomposition rates or numbers of invertebrates found at the end of the incubation period. However, litter stoichiometry differed between irradiated and control litter, with greater nutrient losses (mostly phosphorus) in the former. Therefore, the effects of irradiation on litter chemistry should be taken into account in studies focused on stoichiometry but not necessarily in those focused on decomposition rates, at least within the experimental timescale considered here.
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Boyero, Luz, Naiara López-Rojo, Javier Pérez, Alan M. Tonin, Francisco Correa-Araneda, Aaron Davis und Richard G. Pearson. „Effects of gamma irradiation on instream leaf litter decomposition“. Hydrobiologia 848, Nr. 21 (04.10.2021): 5223–32. http://dx.doi.org/10.1007/s10750-021-04703-w.
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AbstractLeaf litter decomposition is a key process in stream ecosystems, the rates of which can vary with changes in litter quality or its colonization by microorganisms. Decomposition in streams is increasingly used to compare ecosystem functioning globally, often requiring the distribution of litter across countries. It is important to understand whether litter sterilization, which is required by some countries, can alter the rates of decomposition and associated processes. We examined whether litter sterilization with gamma irradiation (25 kGy) influenced decomposition rates, litter stoichiometry, and colonization by invertebrates after weeks of instream incubation within coarse-mesh and fine-mesh litterbags. We used nine plant species from three families that varied widely in litter chemistry but found mostly consistent responses, with no differences in decomposition rates or numbers of invertebrates found at the end of the incubation period. However, litter stoichiometry differed between irradiated and control litter, with greater nutrient losses (mostly phosphorus) in the former. Therefore, the effects of irradiation on litter chemistry should be taken into account in studies focused on stoichiometry but not necessarily in those focused on decomposition rates, at least within the experimental timescale considered here.
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Douligeri, Alexandra, Ioanna Tsionki, Olga Petriki, Dimitrios K. Moutopoulos und Maria Th Stoumboudi. „Length-weight relationships and condition factors of the sand smelt Atherina boyeri (Risso, 1810) estimated from commercial and experimental catches in Lake Trichonis (Western Greece)“. Acta Adriatica 62, Nr. 2 (22.12.2021): 209–18. http://dx.doi.org/10.32582/aa.62.2.8.
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Total length-weight relationships (LWRs) from 3583 individuals of Atherina boyeri (Risso, 1810) caught in Lake Trichonis (Western Greece), using a commercial encircled net and experimental Nordic type benthic and pelagic multi-mesh gillnets, were estimated during 2019-2020. The variation of the parameter b for all seasons combined was significantly allometric, for both encircled towed and gillnets, with a quite robust fit (R^2 equals 0.925 and 0.947, respectively) and values equal to 2.254 and 2.089, respectively. The specimens were significantly lighter in summer than in the other seasons. The slopes of the LWRs significantly differ between seasons and exhibited relatively low values when compared to other ecosystems worldwide and in the same ecosystem in previous periods of time. Τhe estimated values of the Le Cren index were significantly higher than the Allometric and the Fulton ones.
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Almubarak, Norah, und Dimo Dimov. „Value adding in venture capital as a mesh of practices“. International Journal of Entrepreneurial Behavior & Research 28, Nr. 9 (14.11.2022): 427–47. http://dx.doi.org/10.1108/ijebr-03-2022-0283.
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PurposeThis paper aims to adopt a practice-theory, “site ontology” perspective to understand how venture capitalists (VCs) add value to their portfolio companies (PCs).Design/methodology/approachThe empirical research involves a field ethnographic study of a VC firm in Dubai, focused on revealing what constitutes value and what VCs do to add this value to their PCs.FindingsValue adding is a profoundly social, embedded process interconnected with other ecosystem actors, investment practices and organizations. The value adding threads of VC activity are part of a holistic configuration of practices that span the investment lifecycle and different levels within the firm.Originality/valueThis research contributes a rich account of the social, symbolic nature of VC activity, depicting the everyday activities that comprise value adding practices. It is among the first to introduce practice theory to the VC context and open up a new conversation about its social ontology.
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Kolding, Jeppe, Nis S. Jacobsen, Ken H. Andersen und Paul A. M. van Zwieten. „Maximizing fisheries yields while maintaining community structure“. Canadian Journal of Fisheries and Aquatic Sciences 73, Nr. 4 (April 2016): 644–55. http://dx.doi.org/10.1139/cjfas-2015-0098.
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Under the ecosystem approach to fisheries, an optimal fishing pattern is one that gives the highest possible yield while having the least structural impact on the community. Unregulated, open-access African inland fisheries have been observed to sustain high catches by harvesting a broad spectrum of species and sizes, often in conflict with current management regulations in terms of mesh and gear regulations. Using a size- and trait-based model, we explore whether such exploitation patterns are commensurable with the ecosystem approach to fisheries by comparing the impacts on size spectrum slope and yield with the different size limit regimes employed in the Zambian and Zimbabwean sides of man-made Lake Kariba. Long-term multispecies data under fished and unfished conditions are used to compare and validate the model results. Both model and observations show that the highest yields and low structural impact on the ecosystem are obtained by targeting small individuals in the community. These results call for a re-evaluation of the size-based management regulations that are ubiquitous in most fisheries.
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ALTUKHOV, D., I. SIOKOU, M. PANTAZI, K. STEFANOVA, F. TIMOFTE, A. GUBANOVA, A. NIKISHINA und E. ARASHKEVICH. „Intercomparison of five nets used for mesozooplankton sampling“. Mediterranean Marine Science 16, Nr. 3 (14.09.2015): 550. http://dx.doi.org/10.12681/mms.1100.
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Intercomparison of nets commonly used for mesozooplankton sampling in the Black and Mediterranean seas was attempted within SESAME (Southern European Seas: Assessing and Modelling Ecosystem Changes) project. Five nets were compared: three Juday nets equipped with 150 μm, 180 μm and 200 μm mesh size, Nansen net (100 μm mesh size) and WP2 (200 μm mesh size). Replicated samples were collected at one station in the western Black Sea offshore waters in April 2009. Collected samples were analyzed at species level (except for meroplankton), stages (for copepods) and size length. A decrease of total abundance values was observed with increasing mesh size, due to the significantly higher numbers of animals smaller than 1 mm in the samples obtained by fine mesh size than with coarser nets. Few comparisons were revealed significant for the abundance of animals with 1-2 mm length, while no significance was detected for specimens larger than 2 mm. The above differences resulted in discripancies between nets regarding species and stages composition. Biomass values did not differ significantly between nets, due to the strong contribution to total biomass of the large animals fraction (Calanus euxinus). The smallest and the largest animals revealed high variability between replicates collected by Nansen, Juday- 200 μm and WP2 nets. Correction factors were calculated for the conversion of abundance values between each couple of nets. The detected differences between nets regarding the abundance and biomass, the community taxonomic composition and size structure, as well as the estimated correction factors, provide useful information for the harmonization of data obtained by the above nets in the Black Sea.
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Beaumont, K. L., und G. W. Hosie. „Mesoscale distribution and abundance of four pelagic copepod species in Prydz Bay“. Antarctic Science 9, Nr. 2 (Juni 1997): 121–33. http://dx.doi.org/10.1017/s0954102097000163.
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Knowledge of copepod abundance and distribution has been limited, particularly in the Indian Ocean sector, as the use of coarse sampling gear has meant that copepods were frequently lost from the catch. This study analyses samples obtained from Prydz Bay using a fine mesh (300 μm) Rectangular Midwater Trawl (RMT1) net during summer 1992–93. Results demonstrate that a net of mesh 4.5 mm used in previous studies underestimates total copepod abundance by a factor of 38. The abundance of the smaller species has been underestimated the most. New estimates of copepod biomass indicate that copepods represent approximately 27% of krill biomass. Copepod and krill distributions are shown to be discrete at 82.4% dissimilarity. Mean temperature accounted for 33.6% of the variation in copepod distribution while two of the species showed a slight correlation with chlorophyll a pigment data. These results highlight the numerical importance of copepods and the species' distributions in the East Antarctic marine ecosystem.
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Haanes, Hallvard, und Runhild Gjelsvik. „Reduced soil fauna decomposition in a high background radiation area“. PLOS ONE 16, Nr. 3 (17.03.2021): e0247793. http://dx.doi.org/10.1371/journal.pone.0247793.
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Decomposition of litter and organic matter is a very important soil ecosystem function where soil fauna play an important role. Knowledge of the responses in decomposition and soil fauna to different stressors is therefore crucial. However, the extent to which radioactivity may affect soil fauna is not so well known. There are some results showing effects on soil fauna at uranium mines and near Chernobyl from relatively high levels of anthropogenic radionuclides. We hypothesize that naturally occurring radionuclides affect soil fauna and thus litter decomposition, which will covary with radionuclide levels when accounting for important soil parameters. We have therefore used standardised litterbags with two different mesh sizes filled with birch leaves (Betula pubescens) to assess litter decomposition in an area with enhanced levels of naturally occurring radionuclides in the thorium (232Th) and uranium (238U) decay chains while controlling for variation in important soil parameters like pH, organic matter content, moisture and large grain size. We show that decomposition rate is higher in litterbags with large mesh size compared to litterbags with a fine mesh size that excludes soil fauna. We also find that litter dried at room temperature is decomposed at a faster rate than litter dried in oven (60⁰C). This was surprising given the associated denaturation of proteins and anticipated increased nutritional level but may be explained by the increased stiffness of oven-dried litter. This result is important since different studies often use either oven-dried or room temperature-dried litter. Taking the above into account, we explore statistical models to show large and expected effects of soil parameters but also significant effects on litter decomposition of the naturally occurring radionuclide levels. We use the ERICA tool to estimate total dose rate per coarse litterbag for four different model organisms, and in subsequent different statistical models we identify that the model including the dose rates of a small tube-shape is the best statistical model. In another statistical model including soil parameters and radionuclide distributions, 226Ra (or uranium precursory radionuclides) explain variation in litter decomposition while 228Ra (and precursors) do not. This may hint to chemical toxicity effects of uranium. However, when combining this model with the best model, the resulting simplified model is equal to the tube-shape dose-rate model. There is thus a need for more research on how naturally occurring radionuclides affect soil fauna, but the study at hand show the importance of an ecosystem approach and the ecosystem parameter soil decomposition.
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Kuikka, S. „The impacts of increased codend mesh size on the northern Baltic herring fishery: ecosystem and market uncertainties“. ICES Journal of Marine Science 53, Nr. 4 (August 1996): 723–30. http://dx.doi.org/10.1006/jmsc.1996.0091.
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Sánchez-González, Jorge Rubén, Amadeo Arbonés und Frederic Casals. „Variation over Time of Length–Weight Relationships and Condition Factors for Four Exotic Fish Species from a Restored Shallow Lake in NE Iberian Peninsula“. Fishes 5, Nr. 1 (04.02.2020): 7. http://dx.doi.org/10.3390/fishes5010007.
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Length–weight relationships (LWRs), condition factors, and their variation over time were analyzed for four exotic freshwater fish (bleak, common carp, pikeperch, and roach) in the Estany d’Ivars i Vila-sana shallow lake in Catalonia, Northern Spain. Fish samples were collected twice a year (early summer and autumn), between 2008 and 2016, by using between three and five multi-mesh nylon gillnets. This study provides novel information about four common exotic fishes outside of their natural range and within the context of a restored shallow lake, where the ichthyologic community is evolving in concordance with the ecosystem conditions and the fish community dynamics.
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Kekenusa, Nikita, Rose O. S. E. Mantiri und Gaspar D. Manu. „Structure Of Phytoplankton Communities In Seagraas Ecosystem Of Kelurahan Tongkeina Bunaken Darat District“. JURNAL PERIKANAN DAN KELAUTAN TROPIS 10, Nr. 2 (25.07.2019): 60. http://dx.doi.org/10.35800/jpkt.10.2.2019.24478.
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This research was conducted at 3 stations in the seagrass ecosystem of the Tongkeina coastal waters district of Bunaken Darat Manado on March 16, 2019, at 10:35 - 13:45 WITA. This study aims to know the types and community structures of phytoplankton in the Tongkeina seagrass ecosystem and its environmental conditions. The method used to collect the sample is sampling. Samples were taken using a plankton net measuring 20 cm in mouth diameter with a mesh size of 60 microns. Based on the results of observations obtained by the composition of phytoplankton species, namely 17 genera of 22 species in 3 classes namely Bacillariophyceae, Cyanophyceae, and Pyramimonadophyceae. The highest density of phytoplankton in Tongkeina waters is at Station 2 (0.360 cells / l) with the highest relative density of Chaetoceros sp. (19.10%). While the highest density of phytoplankton is found at Station 3 (0.516 cells / l) with the highest relative density of Melosira sp. (21.69%). The lowest Diversity Index at Station 2 (H '= 2,217) and the highest at station 3 (H' = 2,284). This shows that overall these waters have moderate diversity values. The lowest Uniformity Index at Station 1 (e = 0.858) and the highest at Station 2 (e = 0.924). This shows that overall these waters have a medium uniformity value. The lowest dominance index at Station 3 (C = 0.119) and the highest at Station 1 (C = 0.127). This shows that no species dominate the waters. The water conditions such as temperature, salinity, pH, and brightness still support the growth of phytoplankton.Keywords: phytoplankton, community structure, seagrass, Tongkeina ABSTRAKPenelitian ini dilakukan pada 3 stasiun di perairan ekosistem lamun kelurahan Tongkeina kecamatan Bunaken Darat pada tanggal 16 Maret 2019 pukul 10:35 – 13:45 WITA, dengan tujuan mengetahui jenis dan struktur komunitas fitoplankton yang ada di perairan ekosistem lamun Tongkeina serta kondisi lingkungannya. Metode yang digunakan adalah Metode sampling. Sampel diambil dengan menggunakan plankton net berdiameter mulut berukuran 20 cm dengan mesh size 60 mikron. Berdasarkan hasil pengamatan diperoleh komposisi jenis fitoplankton yakni 17 genus 22 spesies dalam 3 kelas yaitu Bacillariophyceae, Cyanophyceae, dan Pyramimonadophyceae.Kepadatan tertinggi fitoplankton di perairan Tongkeina terdapat pada Stasiun 2 (0.360 sel/l) dengan kepadatan relatif tertinggi Chaetoceros sp. (19.10%). Sedangkan kepadatan fitoplankton tertinggi terdapat pada Stasiun 3 (0.516 sel/l) dengan kepadatan relatif tertinggi Melosira sp. (21.69%). Indeks Keanekaragaman terrendah pada Stasiun 2 (H’= 2.217) dan tertinggi pada stasiun 3 (H’= 2.284). Hal ini menunjukkan bahwa secara keseluruhan perairan ini memiliki nilai keanekaragaman sedang. Indeks Keseragaman terrendah pada Stasiun 1 (e= 0.858) dan tertinggi pada Stasiun 2 (e= 0.924). Hal ini menunjukkan bahwa secara keseluruhan perairan ini memiliki nilai keseragaman sedang. Indeks Dominansi terrendah pada Stasiun 3 (C= 0.119) dan yang tertinggi pada Stasiun 1 (C= 0.127). Hal ini menunjukkan bahwa tidak ada jenis yang mendominasi perairan. Adapun kondisi perairannya seperti suhu, salinitas, pH dan kecerahan masih menunjang pertumbuhan fitoplankton.Kata Kunci :Fitoplankton, Struktur Komunitas, Lamun, Tongkeina,
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Lee, Eun-Seok, und Byeong-Seok Shin. „Hardware-Based Adaptive Terrain Mesh Using Temporal Coherence for Real-Time Landscape Visualization“. Sustainability 11, Nr. 7 (10.04.2019): 2137. http://dx.doi.org/10.3390/su11072137.
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In general, changes in society or the environment are expected depending on changes in terrain. The faster and more accurately these terrain changes can be observed, the faster and more accurately predictions can be made. Recently, three-dimensional (3D) terrain visualization programs, such as flight simulation, allow for interaction with various datasets to predict ecosystem influences in real time. Elaborate terrain data require a very large capacity. To render these large terrain data, the computing power of graphics devices cannot always satisfy the real-time conditions. Consequently, a large number of graphics devices in computing systems need to be replaced on a periodic basis. As the industry evolves, the replacement cycle of graphic devices shortens. To solve this problem, we present a novel acceleration approach for generating an adaptive terrain mesh using temporal coherence. By using our method, it is possible to prevent artifacts such as frame drop or screen flickering due to lack of computing power of the GPU in a specific viewing condition. Instead of generating the new terrain mesh on every frame, our method reuses the detail level of terrain mesh that was used in a previous frame. Therefore, it can maintain the frame coherency and improve the rendering speed. This allows the proposed method to more quickly provide more detailed information about the terrain to predict environmental changes more accurately on existing equipment. Thus, the proposed method can reduce the need to frequently replace GPUs. The proposed method can guarantee sufficient performance even with a resilient graphic device and can effectively slow down the replacement period of existing equipment.
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Ditya, Yoga Candra, Arif Wibowo und Husnah Husnah. „SPATIAL AND TEMPORAL DISTRIBUTION OF FISH IN THE FLOODPLAIN OF KUMBE RIVER. PAPUA“. Indonesian Fisheries Research Journal 24, Nr. 1 (13.08.2018): 1. http://dx.doi.org/10.15578/ifrj.24.1.2018.1-13.
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Expansion of land clearance mostly for plantation is the big issue in Indonesia including in Papua. Its effect is not only to the catchment area but it also affects fisheries resources. The stress effect occurs worsen in Kumbe River and its floodplain area by the present of introduced fish species such as snakehead (Channa striata) and nile tilapia (Oreochromis niloticus). Spatial and temporal fish distributions are important information for the sustainable fisheries resource and theirs utilization. Study on spatial and temporal fish distribution covering four types of swamp ecosystem of Kumbe River was conducted during April-September 2014 and Mei-November 2015. Explorative field survey was conducted in four different ecosystem types in Kumbe River floodplain areas. Ecological data was collected from four sampling sites in each ecosystem type during high water precipitation (April and May) and low water precipitation (August. September and November). and fish samples were collected with different mesh sizes of gillnet fishing experiment conducted in four sampling sites. Parameters measured were fish important relative index and physical and chemical water quality parameters. The results noted 18 fish species deriving from 13 families. The Arridae with its blue catfish (Neoarius graeffei) dominated almost 90% of fish catch both spatial and temporal. Hydrological dynamic seems the key of trigger factor for the spatial and temporal distribution of fish and dynamic of habitat and water quality characteristic in the floodplain of Kumbe River.
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Oikonomou, Panagiotis, Anna Karanika, Christos Anagnostopoulos und Kostas Kolomvatsos. „On the Use of Intelligent Models towards Meeting the Challenges of the Edge Mesh“. ACM Computing Surveys 54, Nr. 6 (Juli 2021): 1–42. http://dx.doi.org/10.1145/3456630.
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Nowadays, we are witnessing the advent of the Internet of Things (IoT) with numerous devices performing interactions between them or with their environment. The huge number of devices leads to huge volumes of data that demand the appropriate processing. The “legacy” approach is to rely on Cloud where increased computational resources can realize any desired processing. However, the need for supporting real-time applications requires a reduced latency in the provision of outcomes. Edge Computing (EC) comes as the “solver” of the latency problem. Various processing activities can be performed at EC nodes having direct connection with IoT devices. A number of challenges should be met before we conclude a fully automated ecosystem where nodes can cooperate or understand their status to efficiently serve applications. In this article, we perform a survey of the relevant research activities towards the vision of Edge Mesh (EM), i.e., a “cover” of intelligence upon the EC. We present the necessary hardware and discuss research outcomes in every aspect of EC/EM nodes functioning. We present technologies and theories adopted for data, tasks, and resource management while discussing how machine learning and optimization can be adopted in the domain.
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Wang, Cunguo, Shengwei Zong und Mai-He Li. „The Contrasting Responses of Mycorrhizal Fungal Mycelium Associated with Woody Plants to Multiple Environmental Factors“. Forests 10, Nr. 11 (04.11.2019): 973. http://dx.doi.org/10.3390/f10110973.
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Research Highlights: Extraradical mycorrhizal fungal mycelium (MFM) plays critical roles in nutrient absorption and carbon cycling in forest ecosystems. However, it is often ignored or treated as a root uptake apparatus in existing biogeochemical models. Methods: We conducted a meta-analysis to reveal how MFM responds to various, coinciding environmental factors and their interactions. Results: Nitrogen (N) addition and N-phosphorus (P)-potassium (K) combination significantly decreased MFM. However, elevated CO2, organic matter addition, P addition, and CO2-N combination significantly increased MFM. In contrast, warming, K addition, N-P combination, and P-K combination did not affect MFM. Mycorrhizal fungal levels (individual vs. community), mycorrhizal type (ectomycorrhizal fungi vs. arbuscular mycorrhizal fungi), treatment time (<1 year vs. >1 year), and mycelium estimation/sampling method (biomarker vs. non-biomarker; ingrowth mesh bag vs. soil core) significantly affected the responses of MFM to elevated CO2 and N addition. The effect sizes of N addition significantly increased with mean annual precipitation, but decreased with soil pH and host tree age. The effect sizes of P addition significantly increased with N concentration in host plant leaves. Conclusions: The differential responses revealed emphasize the importance of incorporating MFM in existing biogeochemical models to precisely assess and predict the impacts of global changes on forest ecosystem functions.
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Graham, Norman, Richard S. T. Ferro, William A. Karp und Philip MacMullen. „Fishing practice, gear design, and the ecosystem approach—three case studies demonstrating the effect of management strategy on gear selectivity and discards“. ICES Journal of Marine Science 64, Nr. 4 (01.05.2007): 744–50. http://dx.doi.org/10.1093/icesjms/fsm059.
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Abstract Graham, N., Ferro, R. S. T., Karp, W. A., and MacMullen, P. 2007. Fishing practice, gear design, and the ecosystem approach—three case studies demonstrating the effect of management strategy on gear selectivity and discards. – ICES Journal of Marine Science, 64: 744–750. A basic tenet of the ecosystem approach to fisheries management is that harvesting is conducted with minimal impact on juvenile fish, non-target species, and marine habitats. A range of technical modifications of fishing gears aimed at improving their selective properties is available to help achieve these goals, but their effectiveness varies. Through three case studies, we describe how management controls influence fishing behaviour and the adoption of more selective gear, and demonstrate how conservation goals can be discouraged or encouraged by the strategy. In Norway, limits set on the maximum quantity of sublegal fish that may be retained on board, in combination with a ban on discarding, resulted in substantial area closures in the Barents Sea. Therefore, to gain access, fishers developed technical modifications to enhance gear selectivity. In both shrimp and demersal trawl fisheries, the modifications are now being used by virtually the whole fleet. To reduce cod mortality in the North Sea, mesh sizes were increased and effort restrictions introduced, but the measures also affected other fleets, notably those targeting Nephrops: fishers for that species reduced their mesh size to prevent loss of target species and to avoid effort restrictions. Although management measures may have resulted in reduced fishing mortality on cod, they placed additional pressure on other stocks by encouraging vessels to switch gears, and it is likely that discard rates have increased. In the eastern Bering Sea fishery for walleye pollock, the adoption of more-selective fishing gears was encouraged by regulations requiring fisheries to be curtailed when bycatch rates of prohibited species are exceeded, leading to underutilization of the target species through premature closures. Fishers now act cooperatively by providing real-time data on bycatch hot spots, allowing tactical fishing decisions to be taken to avoid such areas.
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Sarkar, Indra Neil. „Transforming Health Data to Actionable Information: Recent Progress and Future Opportunities in Health Information Exchange“. Yearbook of Medical Informatics 31, Nr. 01 (August 2022): 203–14. http://dx.doi.org/10.1055/s-0042-1742519.
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Objectives: Provide a systematic review of literature pertaining to health information exchange (HIE) since 2018. Summarize HIE-associated literature for most frequently occurring topics, as well as within the context of the COVID-19 pandemic and health equity. Finally, provide recommendations for how HIE can advance the vision of a digital healthcare ecosystem. Methods: A computer program was developed to mediate a literature search of primary literature indexed in MEDLINE that was: (1) indexed with “Health Information Exchange” MeSH descriptor as a major topic; and (2) published between January 2018 and December 2021. Frequency of MeSH descriptors was then used to identify and to rank topics associated with the retrieved literature. COVID-19 literature was identified using the general COVID-19 PubMed Clinical Query filter. Health equity literature was identified using additional MeSH descriptor-based searches. The retrieved literature was then reviewed and summarized. Results: A total of 256 articles were retrieved and reviewed for this survey. The major thematic areas summarized were: (1) Information Dissemination; (2) Delivery of Health Care; (3) Hospitals; (4) Hospital Emergency Service; (5) COVID-19; (6) Health Disparities; and (7) Computer Security and Confidentiality. A common theme across all areas examined for this survey was the maturity of HIE to support data-driven healthcare delivery. Recommendations were developed based on opportunities identified across the reviewed literature. Conclusions: HIE is an essential advance in next generation healthcare delivery. The review of the recent literature (2018-2021) indicates that successful HIE improves healthcare delivery, often resulting in improved health outcomes. There remain major opportunities for expanded use of HIE, including the active engagement of clinical and patient stakeholders. The maturity of HIE reflects the maturity of the biomedical informatics and health data science fields.
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ADHIKARI, ASHIM, JASH HANG LIMBU und SOMIKA PATHAK. „Fish Diversity and Water Quality Parameters of Mechi River, Jhapa, Province No. 1, Nepal“. Borneo Journal of Resource Science and Technology 11, Nr. 1 (30.06.2021): 24–34. http://dx.doi.org/10.33736/bjrst.2954.2021.
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Species diversity is widely recognised as an important trait of functioning and resilient ecosystem. Spatio-temporal patterns of fish community structure in the Mechi River was studied based on stratified random survey, conducted between September 2018 and April 2019. The survey was conducted at three different sampling stations in three different seasons. For the fish sampling, two cast nets of different sizes were used, one having large mesh size of 0.5 cm, 3 m diameter and 2 kg weight and another having mesh size of 2 cm, 6 m diameter and 6 kg weight. In addition, drag net and gill net were also used to collect the fish samples. A total of 1,772 fishes belonging to 4 orders, 8 families, 16 genera and 33 species were documented. The results from the similarity percentage analysis indicated that, the species Schistura devdevi, Brachydanio rerio, Puntius sophore, Barilius barila, Schistura beveani and Puntius terio were the most copious fish species recorded from the Mechi River. One-way analysis of similarity testing for space and time variations in fish community indicated that there was a significant difference in space (R = 0.66, p<0.01) but no significant difference in time (R = -0.0123, p>0.433). The Canonical Correspondence Analysis hinted that dissolved oxygen, water velocity and pH have shown to influence the fish assemblage structure in Mechi River.
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Siagian, Pratiwi Genesi, Djuwito Djuwito und Suradi Wijaya Saputra. „KELIMPAHAN LARVA UDANG PENAEID PADA EKOSISTEM MANGROVE DI DESA PASAR BANGGI, KABUPATEN REMBANG“. Management of Aquatic Resources Journal (MAQUARES) 5, Nr. 4 (06.01.2017): 412–19. http://dx.doi.org/10.14710/marj.v5i4.14651.
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ABSTRAKPeran ekosistem mangrove sebagai daerah asuhan dan daerah mencari makan bagi larva udang, dimana sumber benih udang secara alami dapat dimanfaatkan oleh petambak. Oleh karena itu, keberadaan larva udang penaeid dapat memberikan informasi tentang data sebaran larva. Tujuan penelitian ini untuk mengetahui jenis larva udang penaeid di ekosistem mangrove, mengetahui kelimpahan dan dominansi larva udang penaeid dan mengetahui hubungan dan pengaruh variabel kualitas air terhadap kelimpahan larva udang penaeid pada ekosistem mangrove di Desa Pasar Banggi, Kabupaten Rembang. Penelitian dilakukan pada bulan April-Mei 2016. Lokasi penelitian terdiri dari mangrove umur 50 tahun, 7 tahun dan 3 tahun. Teknik pengambilan sampel larva udang dalam penelitian menggunakan metode stratified sampling. Pengambilan sampel larva udang penaeiddengan mendorong scoop netsejauh 50 meter, mesh size 0,5 mm. Jenis larva udang penaeid yang ditemukan selama penelitianyaitu Sicyonia, Trachypenaeus, Xyphopenaeus, Penaeus dan larva tidak teridentifikasi.Larva genus Trachypenaeus dan Penaeus selalu muncul pada ketiga wilayah, sedangkan genus Sicyonia dan Xyphopenaeus tidak muncul satu kali pada mangrove umur 7 tahun dan 3 tahun.Kelimpahan larva udang penaeid tertinggi diperolehselama penelitian pada mangrove umur 3 tahun diikuti mangrove umur 7 tahun dan kelimpahan terendah mangrove umur 50 tahun. Jenis larva udang penaeid yang paling banyak ditemukan adalah Penaeus 76,559%, sedangkan yang paling sedikit adalah Sicyonia 0,215%. Nilai indeks dominansi berkisar 0,371-0,523. Berdasarkan hasil uji multikolinieritas menunjukkan antara suhu, kecepatan arus, kecerahan dan salinitas memiliki hubungan korelasi kuat. Uji analisis regresi berganda menunjukkan antara suhu, kecepatan arus, kecerahan dengan kelimpahan larva udang penaeid berpengaruh positif, sedangkan salinitas dengan kelimpahan larva udang penaeid berpengaruh negatif. Kata Kunci : Ekosistem mangrove; Larva udang penaeid; Kelimpahan; Desa Pasar Banggi, Kabupaten Rembang ABSTRACTThe role of mangrove ecosystems as the breeding and feeding area for shrimp larvae can be used by farmers naturally. Therefore, the existence of penaeid shrimp larvae can provide information about the distribution of the larvae. The purpose of this study is to determine the type of penaeid shrimp larvae in the mangrove ecosystem, to determine the abundance and dominance of penaeid shrimp larvae and to determine the results of multicoliniearity test and multiple regression analysisof penaeid shrimp larvae in the mangrove ecosystem in Pasar Banggi Village, Rembang. The study was conducted on April-Mei 2016. The location of research consists of mangrove age of 50 years, mangrove age of 7 years and mangrove age of 3 years. The sampling technique for collecting the shrimp larvae is stratified sampling method. Penaeid shrimp larvae sampling was done by pushing scoop net as far as 50 meters, mesh size of 0.5 mm. Penaeid shrimp larvae type that were found during the researchare Sicyonia, Trachypenaeus, Xyphopenaeus, Penaeus and unidentified larvae. Larvae genus Trachypenaeus and Penaeus always appear in the all three areas, while the genus Sicyonia and Xyphopenaeus do not appear once in mangrove age of 7 years and mangrove age of 3 years. The highest abundance of penaeid shrimp larvae obtained during the study in mangrove age of 3 years followed mangrove age of 7 years and the lowest abundance in mangrove age of 50 years. Penaeid shrimp larvae type most commonly found are Penaeus 76.559%, while the least is Sicyonia 0.215%. Dominance index values ranged from 0.371 to 0.523. Based on the results of multi-coliniearity test, temperature, current speed, brightness and salinity have strong correlation. Multiple regression analysis showed that the relation between temperature, current speed, brightness with the abundance of penaeid shrimp larvae are positive, while the relation between salinity with the abundance of penaeid shrimp larvae is negative. Keywords :Mangrove ecosystem; Penaeid shrimp larvae; Abundance; Pasar Banggi Village, Rembang
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Lacerda, S. R., M. L. Koening, S. Neumann-Leitão und M. J. Flores-Montes. „Phytoplankton nyctemeral variation at a tropical river estuary (Itamaracá - Pernambuco - Brazil)“. Brazilian Journal of Biology 64, Nr. 1 (Februar 2004): 81–94. http://dx.doi.org/10.1590/s1519-69842004000100010.
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The Botafogo estuary is of socio-economical importance for Pernambuco State. It is located at the north of Santa Cruz Channel, Itamaracá, Pernambuco, Brazil (07º42'50"S and 34º52'10"W). There is a critical need to understand its functioning because of the rate at which this area is being converted to land uses. The phytoplankton dynamics was studied to enhance the knowledge of and verify the possible changes which have occurred in this ecosystem. Sampling was carried out with a plankton net 65 micrometers mesh size for qualitative data, and a Van Dorn bottle for quantitative data. Concurrent hydrological and chlorophyll-a data were collected. Samplings were made in one fixed station in July 1996 (rainy season) and December 1996 (dry season), at 3-hour intervals during 24 hours. Eighty-seven specific and infra-specific taxa were identified from net plankton samples. Diatoms were most frequent, mainly Coscinodiscus centralis and Odontella regia in the rainy and dry seasons, respectively. Phytoplankton density varied from 205,000 to 1,210,000 cell.L-1 in the dry season, and from 230,000 to 2,510,000 cell.L-1 in the rainy season, indicating eutrophic conditions. Most numerically abundant were the diatoms Cyclotella meneghiniana and Cylindrotheca closterium and the phytoflagellates. The ecosystem is polluted, and deleterious effects are minimized by the marine influence which allows periodic water renewal.
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Mohd Rosli, Nor Aziella, Nurul Shafikah Mohd Noor und Khaironizam Md Zain. „Ichthyofauna Checklist in Tributaries of Muda Reservoir, Kedah, Peninsular Malaysia“. Indonesian Journal of Limnology 2, Nr. 1 (30.06.2021): 17–24. http://dx.doi.org/10.51264/inajl.v2i1.13.
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Ichthyofauna checklist was scrutinized in tributaries of Muda Reservoir. A total of 5998 specimens were caught using a cast net of 2.5 cm mesh size. Amongst these specimen, 30 fish species from 12 families were recorded. The most dominant fish family in this lotic ecosystem was Cyprinidae. Rasbora dusonensis, Cyclocheilichthys apogon and Mystacoleucus marginatus recorded the uppermost distribution compared to other fish species found in this tributaries. Six fish species were the newly recorded species found in tributaries of Muda Reservoir; Barbonymus gonionotus, Luciosoma setigerum, Toxabramis houdemeri, Mystus singaringan, Anabas testudineus and Trichopodus pectoralis. In accordance with the previous combination of recorded fish species in tributaries of Muda Reservoir, a total of 57 updated total numbers of fish species were recorded. The information obtained in present study will update the latest ichthyofauna checklist in tributaries of Muda Reservoir, as well as for the future comparison in other geographical locations.
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Pech, Tatiani, Guilherme Diego Fockink, Alexandre Siminski und Júlia Carina Niemeyer. „Role of soil fauna to litter decomposition in pine stands under Atlantic Forest biome“. Ciência Florestal 31, Nr. 4 (17.11.2021): 1849–66. http://dx.doi.org/10.5902/1980509852839.
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Litter production and its decomposition play an important role in the terrestrial carbon cycle and soil quality, being a crucial process involved in ecosystem productivity and functioning. Understanding this process under pine commercial stands or pine invasions is crucial to design forest management or ecosystems restoration. We conducted a study in a commercial pine plantation (Pinus taeda L.) under Atlantic Forest biome to investigate (1) the contribution of soil fauna to pine litter mass loss; (2) the litter fauna feeding activity within seasons. Litter bags with pine needles (5 g dry weight) were prepared as exclusion treatments for different sized soil fauna by varying mesh size (2 mm and 0.06 mm). Litter bags were removed after 60, 120, 180, 240, 300, and 365 days to estimate the decomposition rates. Bait lamina sticks were exposed seasonally and horizontally in soil surface to determine the fauna feeding activity on litter. We found: (1) no differences in litter mass loss and decomposition rate when soil macrofauna and most of the mesofauna were excluded; (2) feeding activity of litter organisms was higher in the summer, probably stimulated by a combination of high temperature and rainfall. In commercial pine stands, we can conclude that the nutrient cycling is slower than in natural areas, related to litter traits, as described in the scientific literature. Our results indicated that soil macro and mesofauna play a low role in the pine litter decomposition, where the organic material decomposition is more related to microorganism’s activity.
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Vostokov, S. V., A. A. Gadzhiev, A. S. Vostokova und N. I. Rabazanov. „The ctenophore Beroe cf. ovata in the Caspian Sea. The beginning of a new stage in the evolution of the Caspian ecosystem?“ South of Russia: ecology, development 15, Nr. 4 (17.01.2021): 21–35. http://dx.doi.org/10.18470/1992-1098-2020-4-21-35.
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Aim. Analysis of the first data regarding the arrival of the predatory ctenophore Beroe cf. ovata in the Caspian Sea and assessment of possible effects of its introduction for the Caspian ecosystem.Material and Methods. The material was obtained in the deep-water region of the western shelf of the middle Caspian Sea in the first ten days of October 2020. Zooplankton samples were collected using a Juday plankton net (0.1 m2 opening, 180 μm mesh size). Large ctenophores were collected using a big cone plankton net (CB) with a 0.5 m2 opening, 500 μm mesh size. Samples were taken at five stations in the 0-40 m layer. Combs larger than 5 mm were counted and measured on board the ship. The number and size of small ctenophores, larvae and eggs were determined in zooplankton samples fixed with formalin to a final concentration of 4%.Results. The presence of a new alien Beroe cf. ovata was recorded in the Dagestan shelf waters of the Caspian Sea in the beginning of October 2020. The average number of Beroe cf. ovata for five stations was 22 ind/m2 and the biomass was 6.15 g/m2. Larvae and small individuals from 5 to 20 mm in size predominated. Mnemiopsis leidyi was absent in the area investigated. The structure of mesozooplankton was dominated by the small copepod Acartia tonsa, which accounted for 92% of the zooplankton community and 78% of its biomass.Conclusion. The size structure of the B. ovata population with a predominance of larvae and small individuals indicates a recently completed breeding cycle and adaptation of the ctenophore to the conditions of the Caspian Sea. The first impacts of the new invasive ctenophore on the population of M. leidyi were demonstrated. This event may be the beginning of a new stage in the evolution of the Caspian Sea ecosystem and the restoration of its bio resources affected by the invasion of Mnemiopsis leidyi. The structure of mesozooplankton with total dominance, in abundance and biomass, of the small copepod Acartia tonsa did not differ from that in the previous period, indicating that the Caspian zoocenosis did not respond to the short-term reduction of the impact of M. leidyi. A brief analysis of the history of the introduction of ctenophores to the Black and Caspian Seas is presented and their impact on ecosystems and biological resources of these seas is studied. Based on longterm observations of the invasive ctenophores' interactions in the Black Sea, the possible outcomes of the penetration of Beroe cf. ovata in the Caspian Sea are discussed.
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Ariyunita, Selvi, Yeny Dhokhikah und Wachju Subchan. „The First Investigation of Microplastics Contamination in Estuarine Located in Puger District, Jember Regency, Indonesia“. Jurnal Riset Biologi dan Aplikasinya 3, Nr. 1 (31.03.2021): 7. http://dx.doi.org/10.26740/jrba.v3n1.p7-12.
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Microplastics are harmful to the ecosystem and need to solve immediately. Detection of microplastic contamination is the first step to reduce plastics pollution. Estuarine in Puger has a high potential for microplastic pollution related to the multifunction of waters as ports, tourism, fish market, fish processing, and human settlements. However, there are no studies related to microplastic contamination in the area. The objectives of this research were to determine microplastic contamination in the estuarine located in Puger District, Jember Regency, Indonesia. The research results were the first evidence to inform the society and local government about the actual condition of plastic pollution, especially in the aquatic ecosystem. The sampling sites were determined by purposive sampling. Fifty liters of water from each station (with three repetitions) were taken using a 24V water pump and then filtered using stainless steel filter (mesh 5 mm and 0.2 mm). The filtered samples were placed in a sterile bottle sample, stored at 4 ± 20C. Microplastics were counted and categorized according to size, color, and type under a microscope stereo. Microplastic abundance was calculated based on the number of microplastic particles identified per liter of sample water (particle/liter). The result showed that the study area was contaminated by microplastics throughout site sampling, with abundances varying from 0.03 particles/liter to 0.19 particles/liter. The highest microplastic abundance found near the fishery market. The microplastics also vary in size, color, and type. According to characterization, the sources of microplastic contamination come from human-based activities.
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Hadisusanto, Suwarno, Dwinda Mariska Putri, Puguh Sujarta, Raditia Nugraha, Qisti Fauziyah, Riska Putri Asmawati, Annisa Mawarni, Firda Nabila Nur Azizah und Muhammad Rifqi. „Macroinvertebrate benthic community as rapid quality assessment in Winongo, Code, and Gajahwong Streams inside Yogyakarta City, Special Region of Yogyakarta Province“. E3S Web of Conferences 76 (2019): 02004. http://dx.doi.org/10.1051/e3sconf/20197602004.
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Streams in Yogyakarta City are classified as an urban river, they receive huge amount of organic matter daily from anthropogenic waste. Growing urbanization affected water ecosystem causing water quality and benthic community changes. Macroinvertebrate benthic immediately respond to physic-chemical changes of the stream. Aims of this study are studying urbanization alter macroinvertebrate benthic community, and water quality in Winongo, Gajahwong, and Code streams of Yogyakarta City. Samples were collected at December 2015 and January 2017 in Winongo, Gajahwong, and Code streams inside the administration area of Yogyakarta City using sediment Dredge. Collections perform by dividing each stream into three parts with five replications. Macroinvertebrate benthic were filtered using stratified filter mesh 60, 40, and 20 results showed that macroinvertebrate benthic diversity decreasing from 2015 to 2017 in these three urban streams. There were not much species founded in Yogyakarta City Streams, indicates riparian ecosystem lack of natural habitat. All riparian zone are damage by anthropogenic activities. Their density is also decreasing probably because riparian floodplain embankment caused water velocity faster, leave little sediment for benthic organism. Chironomids larvae dominate in all stations in each river, and the most abundant in Code. They were abundant because streams in Yogyakarta City accept high input of organic matter. They classified as tolerate groups where their abundance indicates water pollution. High waterfall during 2016 most probably caused water quality better in 2017 than 2015. Dissolved oxygen was higher, and water ph is closer to neutral. Thus it cannot be used as an indicator.
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Hatake, Shuhei, Yuki Kohori und Yasushi Watanabe. „DISASTER PREVENTION COASTAL MAP PRODUCTION BY MMS & C3D“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (03.06.2016): 595–99. http://dx.doi.org/10.5194/isprs-archives-xli-b1-595-2016.
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In March 2011, Eastern Japan suffered serious damage of Tsunami caused by a massive earthquake. In 2012, Ministry of Land, Infrastructure and Transport published “Guideline of setting assumed areas of inundation by Tsunami” to establish the conditions of topography data used for simulation of Tsunami. In this guideline, the elevation data prepared by Geographical Survey Institute of Japan and 2m/5m/10m mesh data of NSDI are adopted for land area, while 500m mesh data of Hydrographic and Oceanographic Department of Japan Coast Guard and sea charts are adopted for water area. These data, however, do not have continuity between land area and water area. Therefore, in order to study the possibility of providing information for coastal disaster prevention, we have developed an efficient method to acquire continuous topography over land and water including tidal zone. Land area data are collected by Mobile Mapping System (MMS) and water area depth data are collected by interferometry echo sounder (C3D), and both data are simultaneously acquired on a same boat. Elaborate point cloud data of 1m or smaller are expected to be used for realistic simulation of Tsunami waves going upstream around shoreline. Tests were made in Tokyo Bay (in 2014) and Osaka Bay (in 2015). The purpose the test in Osaka Bay is to make coastal map for disaster prevention as a countermeasure for predicted Nankai massive earthquake. In addition to Tsunami simulation, the continuous data covering land and marine areas are expected to be used effectively for maintenance and repair of aged port and river facilities, maintenance and investigation of dykes, and ecosystem preservation.
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Eisner, Lisa B., Elizabeth C. Siddon und Wesley W. Strasburger. „Spatial and temporal changes in assemblage structure of zooplankton and pelagic fish in the eastern Bering Sea across varying climate conditions“. Izvestiya TINRO 181, Nr. 2 (30.06.2015): 141–60. http://dx.doi.org/10.26428/1606-9919-2015-181-141-160.
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Zooplankton and pelagic fish samples collected on the eastern Bering Sea shelf in late summer 2003-2010 were used to evaluate spatial and temporal changes in the plankton and nekton community structure. The zooplankton were sampled by vertical towing of a Juday net (168 μm mesh) and oblique towing of a Bongo net (505 μm mesh), and pelagic fish were caught by midwater rope trawl. The communities were compared across climate regimes (in relatively warm and cold years), by latitude (in the northern and southern parts of the shelf), and by water depth (in the inner, middle, and outer domains of the shelf). Zooplankton were dominated by the small copepod Oithona spp. in warm years but relatively larger copepods Pseudocalanus spp. and Acartia spp. in cold years. Notably, the large copepod Calanus spp., an important energy-rich prey for fish, were more abundant in cold years than warm years. Age-0 walleye pollock Gadus chalcogrammus were more abundant in warm years, while capelin Mallotus villosus were abundant within cold-year communities over the northern shelf. Latitudinal variations in communities were more prominent in the cold years, particularly in 2007 and 2010. Cross-shelf variations were evident, particularly for large zooplankton and fish, with communities corresponding to specific oceanographic domains. Outer shelf communities varied less than inner and middle shelf communities between warm and cold periods, suggesting that this region may be less impacted by climate variability. An understanding of the overlap of zooplankton (prey) and fish communities within specific shelf regions or climate regimes may provide information for ecosystem-based approaches to fisheries management.
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Tumewu, Novia, Munirah Tuli und La Nane. „Species composition and abundance of fishes in seagrass meadow ecosystem in tontayuo village and lamu village, batudaa pantai subdistrict, gorontalo regency, tomini bay area.“ Tomini Journal of Aquatic Science 3, Nr. 1 (20.05.2022): 28–37. http://dx.doi.org/10.37905/tjas.v3i1.16999.
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The objective of this research was to determine the species composition and abundance of fishes in the waters of Tontayuo Village and Lamu Village, Batudaa Pantai Subdistrict, Gorontalo Regency. This research was conducted from April to May 2022. The data collection of this research was carried out using a net with a length of 50 m, a widh of 2 m, and a mesh size of 1.5 cm drawn in the seagrass meadow, and it was replicated three times at each station, namely station I (Tontayuo Village) and station 2 (Lamu Village). The findings denoted that the highest species composition was found at station I with 34 species, while at station 2, there ware only 11 species. At the same time, the highest abundance value found at station 1 was Piotosus lineatus species, and the highest abudance at station II was Caranx melampyus species. Overall, the finding signified that the composition and abundance of fishes at station I and station II ware highly different due to the different water condition and fishing times.
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Munawar, Ali, Indarmawan und Hery Suhartoyo. „Litter Production and Decomposition Rate in the Reclaimed Mined Land under Albizia and Sesbania Stands and Their Effects on some Soil Chemical Properties“. Journal of Tropical Soils 16, Nr. 1 (28.06.2013): 1–6. http://dx.doi.org/10.5400/jts.2011.v16i1.1-6.
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Vegetation establishment is considered as a critical step of mined land rehabilitation. The growing plants do not only prevent soil erosion, but also play important roles in soil ecosystem development. Their litterfall is the main process of transferring organic matter and nutrients from aboveground tree biomass to soil. Thus, its quantification would aid in understanding biomass and nutrient dynamics of the ecosystem. This study was aimed to investigate the litter production and its decomposition rate in a reclaimed mined land using albizia and sesbania, and theireffects on some soil properties. The litter under each stand was biweekly collected for four months. At the same time litter samples were decomposed in mesh nylon bags in soils and the remaining litters were biweekly measured. Soil samples were taken from 0-15 cm depths from each stand for analyses of soil organic C, total N, and cation exchange capacity (CEC). The results demonstrated that total litter production under albizia (10.58 t ha-1 yr-1) was almost twice as much as that under sesbania stands (5.43 t ha-1 yr-1). Albizia litter was dominated by leaf litter (49.26%) and least as understory vegetation (23.31%), whereas sesbania litter was more evenly distributed among litter types. Decomposition rates of all litters were fastest in the initial stage and then gradually decreased. Sesbania leaf litters decomposed fastest, while albizia twigs slowest. Differences in the litter production and decomposition rates of the two species had not sufficiently caused significant effects on organic-C, total N, and CEC of the soilsafter one year of revegetation.Keywords: Albizia (Paraserianthes falcataria), decomposition rates, litter, mined land, Sesbania grandiflora
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Fithria, Dewi, Hairul Basri, Indra Indra und Zainal A. Muchlisin. „The Species Composition of Phytoplankton and Nutrient Content in the Nipa Nypa fruticans Ecosystem on the West Coast of Aceh, Indonesia“. International Journal of Design & Nature and Ecodynamics 17, Nr. 6 (31.12.2022): 967–72. http://dx.doi.org/10.18280/ijdne.170619.
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Nipa Nypa fruticans grows in estuaries that are affected by sea waters and freshwater. Therefore, the Nipa habitat develops into an area of water mass circulation and becomes rich in nutrients that trigger the growth of phytoplankton as the primary producer in the aquatic ecosystem. This study aimed to examine the species composition and distribution of phytoplankton and nutrient content in the nipa ecosystem on the west coast of Aceh, Indonesia. It was conducted from July 2018 to September 2019 and sampling was carried out in two areas, namely Kuala Bubon Aceh Barat district and Kuala Tadu, Nagan Raya district. A total of 100L of surface water samples was taken from three points at each location. Subsequently, the water was filtered with a plankton net mesh No. 25 and preserved with a 4% Lugol solution. The water sample from both locations was also analyzed for nitrogen and phosphorus contents. The results showed that there were 20 species of phytoplankton in both sampling locations, with Kuala Bubon consisting of 13 species with density of 160.87 cells L-1, and 15 species in Kuala Tadu with density of 273.64 cells L-1. Haramonas sp. was the dominant species in Kuala Bubon, while Amphisolenia bidentata was dominant in Kuala Tadu. Based on the nutrient content (nitrate+nitrite and phosphate), the average nutrient content in Kuala Bubon was 1.31 mg L-1 (mesotrophic) and 0.12 mg L-1 phosphate (hypertrophic). Meanwhile, Kuala Tadu had 1.078 mg L-1 nitrate+nitrite (mesotrophic) and phosphate, 0.22 mg L-1 (hypertrophic) waters. These findings are an early indication that the estuary of Kuala Bubon and Kuala Tadu have been contaminated by organic matter.
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Andino, Patricio, Rodrigo Espinosa, Verónica Crespo-Pérez, Sophie Cauvy-Frauníe, Olivier Dangles und Dean Jacobsen. „Functional Feeding Groups of Macrofauna and Detritus Decomposition along a Gradient of Glacial Meltwater Influence in Tropical High-Andean Streams“. Water 13, Nr. 22 (22.11.2021): 3303. http://dx.doi.org/10.3390/w13223303.
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Tropical Andean glaciers are retreating rapidly, with possible consequences for trophic structure and ecosystem processes in high Andean meltwater streams. Here, we measured the environmental characteristics, quantified pools of particulate organic matter (POM) and periphyton (Chl. a), sampled benthic macroinvertebrates, determined functional feeding groups (FFG), and performed mesh bag decomposition experiments with Calamagrostis grass detritus at 17 stream sites along a gradient of glacial influence (GI) with 0–23% glacier cover in the catchment at 4050–4200 m a.s.l. in the Andes of Ecuador. POM was unrelated to GI while Chl. a. showed a weak (non-significant) negative relationship to GI. The macrofauna abundance decreased while taxon richness and the number of FFGs per site showed a hump-shaped relationship with increasing GI. Taxa with an opportunistic and generalist feeding mode generally dominated benthic assemblages and were related to high GI levels and low Chl. a. Only shredders were negatively related to GI, but unrelated to POM. Decomposition rates were comparable to those found in temperate alpine streams, and for both fine (0.0010–0.0065; median 0.0028 d−1) and coarse (0.0019–0.0088; median 0.0048 d−1) mesh bags, peaked at intermediate GI values, while the difference between bag types was small and almost constant along the GI gradient. This indicates an overall minor effect of macroinvertebrate shredders compared to that of microbes, in particular at high GI. It also suggests that the relatively high average temperature of these high-altitude equatorial streams (7–10 °C) does not produce higher decomposition rates than those in comparable but colder streams at temperate latitudes. The results suggest that, at the lower end of glacier cover, tropical glacier loss will not change the dominant microbial role in detritus decomposition, but that part of the physical abrasion could be partially replaced by biological shredding.
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Schourup-Kristensen, V., D. Sidorenko, D. A. Wolf-Gladrow und C. Völker. „A skill assessment of the biogeochemical model REcoM2 coupled to the Finite Element Sea Ice–Ocean Model (FESOM 1.3)“. Geoscientific Model Development 7, Nr. 6 (25.11.2014): 2769–802. http://dx.doi.org/10.5194/gmd-7-2769-2014.
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Abstract. In coupled biogeochmical–ocean models, the choice of numerical schemes in the ocean circulation component can have a large influence on the distribution of the biological tracers. Biogeochemical models are traditionally coupled to ocean general circulation models (OGCMs), which are based on dynamical cores employing quasi-regular meshes, and therefore utilize limited spatial resolution in a global setting. An alternative approach is to use an unstructured-mesh ocean model, which allows variable mesh resolution. Here, we present initial results of a coupling between the Finite Element Sea Ice–Ocean Model (FESOM) and the biogeochemical model REcoM2 (Regulated Ecosystem Model 2), with special focus on the Southern Ocean. Surface fields of nutrients, chlorophyll a and net primary production (NPP) were compared to available data sets with a focus on spatial distribution and seasonal cycle. The model produces realistic spatial distributions, especially regarding NPP and chlorophyll a, whereas the iron concentration becomes too low in the Pacific Ocean. The modelled NPP is 32.5 Pg C yr−1 and the export production 6.1 Pg C yr−1, which is lower than satellite-based estimates, mainly due to excessive iron limitation in the Pacific along with too little coastal production. The model performs well in the Southern Ocean, though the assessment here is hindered by the lower availability of observations. The modelled NPP is 3.1 Pg C yr−1 in the Southern Ocean and the export production 1.1 Pg C yr−1. All in all, the combination of a circulation model on an unstructured grid with a biogeochemical–ocean model shows similar performance to other models at non-eddy-permitting resolution. It is well suited for studies of the Southern Ocean, but on the global scale deficiencies in the Pacific Ocean would have to be taken into account.
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Vostokov, S. V., A. A. Gadzhiev, E. N. Lobachev, A. S. Vostokova, N. I. Rabazanov, R. M. Barkhalov, Ph V. Sapojnikov, B. Abtahi und M. G. Shojaei. „Development and interaction of ctenophores <i>Beroe ovate</i> Bruguière, 1789 and <i>Mnemiopsis leidyi</i> A. Agassiz, 1865 in the coastal zone of the Middle Caspian Sea“. South of Russia: ecology, development 17, Nr. 4 (28.12.2022): 8–15. http://dx.doi.org/10.18470/1992-1098-2022-4-8-15.
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Aim. Analysis of the distribution and status of ctenophores Вeroe ovata and Mnemiopsis leidyi, and assessment of the parameters of their interaction in the Middle Caspian Sea.Material and Methods. The material was obtained in the western and eastern parts of the Middle Caspian Sea in September–October 2022. Large ctenophores were collected using a big cone plankton net with a 0.5 m2 opening and a 500 μm, mesh size. The number and size of large ctenophores were determined immediately after collection, larvae and eggs were counted in samples fixed with formalin to a final concentration of 4%. Zooplankton samples were collected by the Juday plankton net (0.1 m2 opening, 180 μm mesh size).Results. In September‐October 2022, a developed population of Вeroe ovata with active reproduction was recorded in the waters of the Middle Caspian Sea. The habitat area of B. ovata has significantly expanded to the north compared to 2021. Complete suppression of the Mnemiopsis population by the Beroe was observed on most of the western and eastern shelf, as well. The total number of Beroe reached 48 ind/m2, biomass – 12 g/m2. Single large individuals were found in the north of the Middle Caspian Sea at salinity 5.7 psu. The structure of mesozooplankton was still dominated by the small copepod Acartia tonsa.Conclusion. New data indicate the active development of the Вeroe ovata in the Caspian Sea, which presents a fundamental challenge for the restoration of the Caspian ecosystem. The progressive adaptation of Beroe to the conditions of the Caspian Sea has led to its expansion to the north of the Middle Caspian Sea in areas with low salinity. A complete suppression of the M. Leidyi population by the new alien noted on most of the shelf indicates an increase in its pressure on the Mnemiopsis population compared to the corresponding period of 2021.
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Weber, M. G. „Decomposition, litter fall, and forest floor nutrient dynamics in relation to fire in eastern Ontario jack pine ecosystems“. Canadian Journal of Forest Research 17, Nr. 12 (01.12.1987): 1496–506. http://dx.doi.org/10.1139/x87-232.
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Decomposition, litter fall, and nutrient and organic matter turnover rates were determined in five eastern Ontario jack pine (Pinusbanksiana Lamb.) stands having various burning histories, including wildfire. The stands included a 65-year-old age-class (stand No. 1), two stands within this age-class that were treated with nonlethal understorey fires in 1962 and 1963 (stand Nos. 2 and 3, respectively), a 21-year-old age-class (stand No. 4), and an 8-year-old age-class (stand No. 5) created by experimental burning plots within the 21-year-old age-class. Overstorey and understorey litter decomposition was assessed separately using the litterbag (1-mm mesh size) technique over a 2-year period. Overstorey litter weight loss did not vary among stands and understorey litter lost significantly more weight (P < 0.05) in the older age-classes (stands 1,2, and 3) compared with the younger stands (stands 4 and 5). Litterbag nutrient dynamics between overstorey and understorey were significantly different (P < 0.05) for P, K, and Cain all stands. Magnesium and N dynamics were the same in both litter types on all treatments, as was Fe, except in the 65-year-old stand where significantly more Fe was accumulated in understorey litter (P < 0.04) at the end of the litterbag exposure period. Three-year averages of annual litter fall ranged from 119 kg•ha−1•year−1 in the 8-year-old age-class to 4182 kg•ha−1•year−1 in the older stands. Nutrient inputs through litter fall reflect the developmental stage occupied by the younger stands along a continuum leading to equilibrium conditions of the 65-year-old age-class. Forest floor nutrient and organic matter residence times (or annual fractional turnover) were longest (least amount cycled) in the 8-year-old stand (57.6 years for organic matter), indicating harsh environmental controls over nutrient dynamics. Recovery for the 21-year-old age-class to turnover rates approaching equilibrium conditions (10-year residence time for organic matter) was rapid, demonstrating ecosystem stability in its interaction with fire. Detrimental effects on ecosystem processes can be expected if a stand-replacing fire recurs during early stages of jack pine ecosystem development.
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Chowdhury, AA, MY Hossain, FA Rima, M. Ashekur Rahman, Z. Mawa, MA Islam, M. Ataur Rahman et al. „Morphometric and Meristic Characteristics of Walking Snakehead Channa Orientalis in a Wetland Ecosystem (Northwestern Bangladesh) Using Multi-Linear Dimensions“. Journal of Bio-Science 29, Nr. 2 (04.08.2021): 53–60. http://dx.doi.org/10.3329/jbs.v29i2.54954.
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The present study is illustrated complete morphometric and meristic characteristics of fresh water fish, walking snakehead, Channa orientalis (Bloch & Schneider 1801), using nine linear dimensions and covering different fin-rays (i.e., dorsal fin, D; pectoral fin, P1; pelvic fin, P2; anal fin, A and caudal fin,C) from the wetland ecosystem Gajnar Beel in northwestern (NW) Bangladesh. Total 230 specimens of C. orientalis were collected from the Gajnar Beel in the time of January to December 2018 by several local fishing gears (e.g., cast net, gill net and square lift net (mesh size ranges: 1.5 - 2.5 cm, 1.5 - 2.0 cm, & ~2.0 cm, respectively). Different morphometric lengths were measured to 0.01 cm, and whole body weight (BW) was estimated 0.01 g for each individual. Fin rays and scales (including lateral line scale) were computed by a magnifying glass. All LWRs were highly significant (p<0.0001) with the r2 values ≥0.978. Based on r2 value, LWR by BW vs. TL was the best fitted model among nine equations. However, the LLRs were also significant with r2 values ≥0.992. According to r2 value, LLR by TL vs. SL (TL = a + b × SL) shown the best fitted model among eight equations. The fin formula of C. orientalis is: dorsal: D. 29-35; Pectoral, P1. 12-14; Pelvic, P2. 5-6; Anal, A. 20-22; Caudal, C. 12-14. A double lateral line is present which continued with 12-13 scales in the first line and 26-28 scales in other line. The present study will be helpful for the species identification and resource management of C. orientalis in the Gajner Beel NW Bangladesh and other sub-tropical countries. J. Bio-Sci. 29(2): 53-60, 2021 (December)
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Santana, Claudeilton Severino de, Ralf Schwamborn, Sigrid Neumann-Leitão, Manuel de Jesus Flores Montes und Simone Maria de Albuquerque Lira. „Spatio-temporal variation of planktonic decapods along the leeward coast of the Fernando de Noronha archipelago, Brazil“. Brazilian Journal of Oceanography 66, Nr. 1 (März 2018): 1–14. http://dx.doi.org/10.1590/s1679-87592018147206601.
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Abstract Tropical island environments are considered hotspots due to their high diversity, endemism and ecological importance. However, reports that discuss the composition and ecology of planktonic decapods in these environments are still very few. In order to ascertain the composition, abundance and spatial-temporal distribution of planktonic decapods, zooplankton samples were taken by means of sub-surface hauls with a standard plankton net of 300 µm mesh size. Sampling was carried out at five stations in the nearshore leeward area of the Fernando de Noronha archipelago, in July and December 2013 and June and November 2014. A total of 22 decapod taxa were recorded, among which the most abundant were Brachyura (zoeae), Clibanarius sp., Caridea and Callianassidae. Characteristic annual distribution and temporal tendencies were observed for the larvae of the hermit crab Clibanarius sp. and for the larvae of burrowing shrimps (Callianassidae). Some taxa showed differences between sampling stations. In general, higher abundances were observed in the southern (downstream) stations of the island (Baía dos Golfinhos and Cacimba do Padre), and lower abundances in the northernmost (upstream) station (Porto de Santo Antônio), indicating the existence of larval retention in the nearshore coastal zone of this oceanic island ecosystem.
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Kouassi Alain, Kouadio, Yao Stanislas Silvain, Kamelan Tanoh Marius und Konan Yao Aristide. „Length-Weight Relationship And Condition Factor Of Mangrove Fish Species In Azagny National Park (Grand-Lahou Department, Ivory Coast)“. European Scientific Journal ESJ 18, Nr. 8 (28.02.2022): 158–71. http://dx.doi.org/10.19044/esj.2022.v18n8p158.
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The length-weight relationship and condition factor of mangrove fish species in Azagny National Park (ANP) were studied, to provide baseline data of the impact of mangrove disturbances on ichthyofauna. Specimens were captured from March 2019 to February 2020 using gillnets and mesh traps. After identification, each specimen was weighed to the nearest gram and measured to the nearest millimeter. Twenty-eight species belonging to 17 families and 24 genera were selected based on their numbers (only species with at least 10 specimens were considered). Most of these species have a negative allometry (22 species, 78.57%). 14.28% species showed positive allometry and 7.14% species showed isometry. The length-weight regressions are significant with a coefficient of determination (r²) varying between 0.115 for Chrysichthys maurus and 0.936 for Labeo coubie. The coefficient of allometry b varies from 0.413 for Chrysichthys maurus to 4.272 for Labeo coubie with a mean value of 2.384 ± 0.810. The condition factor ranged on average from 0.935 ± 0.966 for Schilbe mandibularis 113.3 ± 10.644 for Chrysichthys maurus. This study provides information on the effects of mangrove disturbance on the growth of species of the said ecosystem and contributes to the management of the ichthyofauna of the ANP.
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Linares, Marden Seabra, Gregorio Guirado Faccioli und Liriane Monte Freitas. „Benthic macroinvertebrate community structure and seasonal variation in a neotropical stream in the State of Alagoas, Brazil“. Biota Neotropica 13, Nr. 3 (September 2013): 50–54. http://dx.doi.org/10.1590/s1676-06032013000300006.
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This paper presents a study on the macrobenthic community in the Salvia stream, a headwater stream that runs through a conserved Atlantic forest fragment in the state of Alagoas, Brazil, and identifies the environmental factors that most influence the community structure. Ten sampling sites were chosen, conducting each collection during the rainy season of 2010 and the dry season of 2011. At each site the macroinvertebrates were collected using a D net (0.250 mm mesh). Water samples were collected and taken to the laboratory to analyze Dissolved Oxygen, Conductivity, pH and Alkalinity. Water temperature, surface current speed and depth were measured at the site. Canonical Correspondence was used to analyze the effect of environmental factors on the macroinvertebrate community. All the environmental factors measured showed significant variation between seasons, showing the seasonality effects on the stream environment. Eighteen taxa were identified, with predominance of Palaemonidae (Decapoda) and Chironomidae (Diptera), respectively, during the rainy and dry season. The results showed that the macroinvertebrates were more correlated to pH, Alkalinity and Dissolved Oxygen, indicating that this ecosystem variation is mainly based on the organic matter decomposition process.
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Liñero Arana, Ildefonso, Víctor H. Balarezzo, Héctor Eraso, Francisco Pacheco, Carolina E. Ramos, Ruth G. Muzo und Carla J. Calva. „Water quality of an Ecuadorian Andean stream with the use of aquatic macroinvertebrates.“ UNED Research Journal 8, Nr. 1 (10.06.2016): 69–75. http://dx.doi.org/10.22458/urj.v8i1.1225.
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Ecuador is crossed by a network of rivers that originate mainly in the high Andean reliefs and pour into two basins: Amazon and Pacific. Many suffer from severe human impact. The main objective of the present study was to assess water quality of Mojarrero stream using biotic indices (BMWP/Col. and Shannon-Wiener index) as a tool to evaluate ecosystem health. During June, August and October 2014, bottom samples were taken at three stations. Each month and season three replicates of benthic aquatic invertebrates were taken on sandy-stony bottoms with a 0,3 mm mesh “D-net”. The fauna was represented by eleven orders and 29 families. The most abundant order was Coleoptera, representing 42,70% of total collected organisms, followed by Diptera (19,01%) and Ephemeroptera (11,38%). The most abundant family was Elmidae, with 568 individuals, (37,37% of total organisms), followed by Chironomidae (11,38%) and Baetidae (7,24%). Shannon diversity values ranged between 0,98 bits/ind. (June, EST. 2) and 2,23 bits/ind. (October, Est 1). The BMWP/Col. index values indicate that the river has a good environmental health on the high and low sections. The median section has some pollution, particularly during August and October.
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Zhou, Lei, Dingli Guo, Lei Zeng, Peng Xu, Qindong Tang, Zhi Chen, Qiaoying Zhu et al. „The structuring role of artificial structure on fish assemblages in a dammed river of the Pearl River in China“. Aquatic Living Resources 31 (2018): 15. http://dx.doi.org/10.1051/alr/2018003.
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To address the fish use patterns of artificial structures mimicking floating macrophytes deployed in a impounded tributary of the Pearl River, China, field experiments were performed from December 2014 to June 2016 using multi-mesh gillnet. The fish assemblages using artificial structures differ in terms of species richness, abundance, body size, diversity indices, and ecological traits from fish assemblages on natural barren habitats of this river. Overall, fish abundance, species richness, Shannon diversity index, and functional richness were higher at the artificial structures than at the control sites, while fish length and functional evenness was greater at the control sites in comparison to artificial structures. The introduction of artificial structures did not result in statistically significant effects on fish biomass as artificial structures attracted more individuals with smaller size. Seasonal changes of chlorophyll-a and transparency may affect the efficiency of artificial structure in harboring fishes. This study revealed that artificial structures, as synthesized habitats, are effective in acting as a “fish attractor” and an alternative tool to provide new habitats for smaller individuals in a dammed river like the Youjiang River which is a structure-less ecosystem.
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Darlis, Denny, Dion Saputra Parulian Sirait und Dimas Bayu Maulana. „Sustainable smart forest monitoring system for burning forest and deforestation detection“. MATEC Web of Conferences 197 (2018): 13023. http://dx.doi.org/10.1051/matecconf/201819713023.
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Forests sustain the planet and provide air, soil, climate cycles. These ecosystem services enable economic sectors. Forests are under threat, last decade about 13 million of hectares of forests were deforested. A system to provide monitoring and prevention are needed to sustain the forest but only a few countries have implemented a smart forest system alike. By utilizing sensors, minimum wireless system and renewable energy will provide more accurate, real time, efficient energy and easy to maintain compare to the conventional conservation. Our proposed system will consist of low power camera and grid of fire and smoke detectors, humidity and temperature sensors connected each other as a mesh network and each powered by a solar panel and lithium battery processed by microcontroller then send data periodically to the monitoring server and gives precaution information when some case happened. The system use environment disguise and periodically maintain to ensure it works. While precaution information can be shared and access by government or even public, human act are needed to solve it. Thus it could assist the already implemented system and utilize the available resources as possible.