121 resultados para Cyanobacteria communities


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EXTRACT (SEE PDF FOR FULL ABSTRACT): The 1977 climate shift was characterized by low chlorophyll a concentrations and a shift in phytoplankton community composition throughout the upper San Francisco Bay estuary. ... For climate to be a driving force in phytoplankton communities, it must affect mechanisms that control biomass and community composition. The influence of climate on environmental conditions and phytoplankton community composition among water-year types was examined using 19 years of physical, chemical, and phytoplankton data collected monthly at 15 stations throughout the estuary.

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This is the first in a series of case studies undertaken by the International Collective in Support of Fishworkers (ICSF) to document the traditional knowledge of fishing communities dependent on marine and coastal resources in protected and conserved areas in different parts of the world. The study, done with the support of the Bay of Bengal Large Marine Ecosystem (BOBLME) project, documents the traditional knowledge of fishing communities in the Gulf of Mannar in the state of Tamil Nadu. It focuses on two fishing villages, Chinnapalam and Bharathi Nagar, whose communities have traditionally depended on Krusadai and Appa Islands for their livelihood. Traditional knowledge relating to oceanographic, meteorological, biological, ecological and navigational aspects of fisheries was documented. The study will be useful for researchers, students, scientists, policymakers, fishworker organizations, NGOs and anyone interested in the traditional knowledge of local fishing communities related to marine biodiversity and the customary use of fisheries resources and fishing practices.

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In preparation for the Workshop and Symposium on “Asserting Rights, Defining Responsibilities: Perspectives from Small-scale Fishing Communities on Coastal and Fisheries Management in Asia”, held in Siem Reap Cambodia, from 3 to 8 May 2007, case studies were undertaken in six countries in Asia—Bangladesh, Cambodia, India, Indonesia, Philippines and Thailand. Among other things, the studies aimed to document and explore the understanding that fishing communities have about their rights to fisheries and coastal resources, as well as the obligations and responsibilities associated with these rights, and to document and discuss their initiatives to assert these rights and fulfill their responsibilities. The studies formed the basis for discussions at the Workshop and Symposium. This case study from Cambodia will be found useful by NGOs, regional and national organizations of artisanal fishworkers, and anyone interested in fisheries and fishing communities in Cambodia.

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In preparation for the Workshop and Symposium on “Asserting Rights, Defining Responsibilities: Perspectives from Small-scale Fishing Communities on Coastal and Fisheries Management in Asia”, held in Siem Reap Cambodia, from 3 to 8 May 2007, case studies were undertaken in six countries in Asia—Bangladesh, Cambodia, India, Indonesia, Philippines and Thailand. Among other things, the studies aimed to document and explore the understanding that fishing communities have about their rights to fisheries and coastal resources, as well as the obligations and responsibilities associated with these rights, and to document and discuss their initiatives to assert these rights and fulfill their responsibilities. The studies formed the basis for discussions at the Workshop and Symposium. This case study from the Philippines will be found useful by NGOs, regional and national organizations of artisanal fishworkers, and anyone interested in fisheries and fishing communities in the Philippines.

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This report on the “Sub-regional Dialogue on Labour, Migration and Fisheries Management”, held at Chulalongkorn University, Bangkok, Thailand, from 11 to 13 December 2013, highlights the issue of migrant labour on board fishing vessels and the problems migrant workers face in their workaday lives. This report will be useful for students, researchers, activists and anyone else interested in matters related to fisheries and small-scale fishing communities.

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Small-scale and artisanal fisheries contribute about two-thirds of the global fish production destined for direct human consumption. They also accommodate over 90 per cent of those who make their living from fisheries. Women comprise at least half the workforce in small-scale fisheries. Despite the important contributions made by small-scale fisheries to poverty eradication and food security, small-scale fishers and fishworkers continue to be marginalized at different levels. It is in this context that the Committee on Fisheries (COFI) of the Food and Agriculture Organization of the United Nations (FAO) has developed the Voluntary Guidelines for Securing Sustainable Small-scale Fisheries in the Context of Food Security and Poverty Eradication (SSF Guidelines).

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The fishery sector in Uganda has seen important changes in the last two decades. Among the changes registered, is the expansion of fish markets locally, regionally and internationally. Upon which, remarkable benefits have been realized at local and national levels, for instance, it is estimated that an average of 40m$ is being earned annually as foreign exchange. Besides, presently fish accounts for over 50% of total animal protein in take. However, it is argued that sustaining these gains has become an up hill task due to failure to maintain fish quality as a result of the rudimentary and inappropriate sanitary, fish handling and artisanal fish processing practices that both directly and indirectly affect the quality of fish and fish products. Therefore, against this background, a study of 507 respondents was undertaken among the Lake Victoria Communities specifically in Wakiso, Mayuge and Mukono districts. The study examined the perceptions of fishers on the social cultural practices of sanitation, fish handling and artisanal fish processing and consequently identified factors that influenced these practices.

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postive transformation of the fisheries sector in Uganda has of recent been scatted by failure to mountain fish quality and safety,akey prerequiste for retaining and gaining fish markets. The social cultural study established the extent to which social cutural practices had affected the levels and the use of sanitation facilities,fish handling facilities and artisanal fish processing techniques and the factors that influenced these practices in the fishing communities of lake victoria. This information is of significance for the purpose of advocacy and mobilization of fishers in order to improve sanitation, fish handling and artisanal fishing processing situation in the fishing communities.

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Phytoplankton (52 species; Bacillariophyceae>Chlorophyceae>Cyanophyceae> Euglenophyceae=Dinophyceae) of Samuajan beel, a tropical floodplain lake, registered identical mean annual richness (30+4 species) in littoral and limnetic regions and depicted 33.3-77.2% and 31.4-81.1% community similarities respectively. Their abundance ranged between 137+54 n/l in littoral (Bacillariophyceae>Chlorophyceae) and 122 ± 45 n/l (Chlorophyceae>Bacillariophyceae) in limnetic communities, comprised about 46% of net plankton and indicated winter peaks. This study depicted moderate species diversity, high evenness and low dominance of phytoplankton; species diversity showed significant direct correlation with richness and evenness and an inverse relationship with dominance. Phytoplankton showed significant positive relationship with transparency and silicate and negative with water temperature, rainfall, chloride and nitrate. Multiple regression revealed that ten abiotic factors accounted for >80-98% of density variations of phytoplankton and the dominant groups. ANOVA depicted trends of significance in abundance of the biotic communities analysed.

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The mobile water hyacinth, which was produced in growth zones, especially Murchison Bay, was mainly exported to three sheltered storage bays (Thruston, Hannington and Waiya). Between 1996 and May 1998, the mobile form of water hyacinth occupied about 800 ha in Thruston Bay, 750 ha in Hannington Bay and 140 ha in Waiya Bay). Biological control weevils and other factors, including localised nutrient depletion, weakened the weed that was confined to the bays and it sunk around October 1998. The settling to the bottom of such huge quantities of organic matter its subsequent decomposition and the debris from this mass was likely to have environmental impacts on biotic communities (e.g. fish and invertebrate), physico-chemical conditions (water quality), and on socio-economic activities (e.g. at fish landings, water abstraction, and hydro-power generation points). Sunken water. hyacinth debris could also affect nutrient levels in the water column and lead to reduction in the content of dissolved oxygen. The changes in nutrient dynamics and oxygen levels could affect algal productivity, invertebrate composition and fish communities. Socio-economic impacts of dead sunken weed were expected from debris deposited along the shoreline especially at fish landings, water abstraction and hydropower generation points. Therefore, environmental impact assessment studies were carried out between 1998 and 2002 in selected representative zones of Lake Victoria to identify the effects of the sunken water hyacinth biomass

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The study objectives are to describe seasonal and successional variation in rocky intertidal community structure; determine the response of rocky intertidal communities to natural and human-induced disturbances and correlate these responses with successional, seasonal, and latitudinal variation; and correlate life history information and oil toxicity data with data from this and other relevant studies. The Year III and IV report is for the third (1987) and fourth (1988) years of a five-year field experimental study investigating two biological assemblages, the Mytilus assemblage and the Endocladia/Mastocarpus papillatus assemblage, that are being studied at six sites along the California coast. Volume I includes the report, Appendix A, and Appendix B. Volume II includes Appendix C. Volume III includes Appendix D. Volume IV includes Appendix E and Appendix F. Volume V includes Appendix G, Appendix H, and Appendix I.

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The configuration for the eastern side of the Gulf of Suez was studied over 241 km from Ras Mohammed to Ras Sudr including 35 station. Litters, tar balls and aged oil patches aggregated in considerable amounts on the beach and shore line of the middle part due to the oil spills from off-shore oil wells. A large reef flat in the shallow intertidal waters exists at stations 1 and 2 (Ras Mohammed, Protected area) and spars coral patches are less frequent at the Stations from 7 to 13. Density and diversity of marine benthos were higher on hard and cobble bottoms compared to muddy sand and sandy substrates. The assemblages of the benthic fauna are dominated by the gastropod Courmya (Thericium) vulgata; the bivalve Brachiodontes variabilis, and the barnacles Chthamalus stellatus, Balanus amphitrite and Tetraclita rubescens. The distribution of the algal cover in the intertidal region shows high abundance of the brown algae, Sargassum latifolium; padina pavonica and Cystoseira trinodis rather than the green and red algae. These species are found in both polluted and unpolluted areas. The changes in benthic structures in the study area depend not only on the state of pollution but also on the type of substrates.