91 resultados para stream invertebrate

em Aquatic Commons


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This is the Evaluation of the impact of cypermethrin use in forestry on Welsh streams from the University of Plymouth, published on September 2010 by the Environment Agency South West. The report focuses attention on Cypermethrin, a highly active synthetic pyrethroid insecticide effective against a wide range of pests in agriculture, public health, and animal husbandry. It is also used in forestry to control the pine weevil, Hylobius abietis. Cypermethrin is very toxic to aquatic invertebrates and fish at nanogram per litre concentrations. This project checks the effectiveness of current best practice measures in minimising the risk of pollution associated with the use of cypermethrin in forestry in Wales. Chemical results from the intensive studies show that cypermethrin entered minor watercourses draining treated areas at two of the eight sites. In one of these cases the level was well in excess of the short-term Predicted No Effect Concentration. The absence of a buffer area at the other site resulted in the cypermethrin reaching a main drain. However dilution appeared to be sufficient to prevent any impact on water quality or on the invertebrate community in the main stream. Invertebrate and chemical data from the extensive survey showed little evidence of pollution due to wider use of cypermethrin in Welsh forestry. Finally, a number of recommendations are made for further tightening controls on forestry practice to minimise the risk of cypermethrin entering the aquatic environment.

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Upland stream systems have been extensively investigated in Europe, North America and Australasia and many of the central ideas concerning their function are based on these systems. One central paradigm, the river continuum concept is ultimately derived from those North American streams whose catchments remain forested with native vegetation. Streams of the tropics may or may not fit the model. They have been little studied. The Amani Nature Reserve in the East Usambara Mountains of north-eastern Tanzania offers an opportunity to bring these naturally forested systems to the attention of the ecological community. This article describes a comparison made between two lengths of the River Dodwe in this area. The work was carried out by a group of postgraduate students from eighteen European and African countries with advice from five staff members, as part of a course organised by the Tropical Biology Association. Rigorous efforts were made to standardise techniques, in a situation where equipment and laboratory facilities were very basic, through a management structure and deliberate allocation of work to specialists in each area.The article offers a summary of invertebrate communities found in the stream and its biomass. Crabs seem to be the key organism in both sections of the streams.

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This is the episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystems, with particular reference to fish populations in North West England produced by the North West Water Authority in 1985. This report looks at the biological, physical and chemical information collected over a five year period from over 100 sites on upland streams in the North West Region of which drained rocks of low buffering capacity. In both Lake District and South Pennine sites striking differences were found between the composition of invertebrate communities inhabiting acid-stressed and less acid-stressed streams. Electric fishing surveys showed that acidic streams (geometric mean pH <5.5) generally had abnormally low densities of salmonids ( < 0 .2m2) and that 0+ fish were very few or absent. The latter indicates recruitment failure. Salmon were more sensitive than trout to low pH.

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CONTENTS: Learning from each other about conflict, by Ronet Santos. E-learning to support knowledge sharing in aquatic resources, by Robert T. Raab and Jonathan Woods. Livelihood strategies, gender and participation in aquaculture: findings from participatory research in northwestern Sri Lanka, by Lindsay J. Pollock and David C. Little. Farming of giant tiger shrimp in northern central Vietnam, by Jesper Clausen. Interacting with stakeholders and policy-makers, by To Phuc Tuong. The role of nutrition communications in meeting the nutritional challenges of the Asia-Pacific region, by Georgina Cairns. (PDF has 16 pages.)

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CONTENTS: Efforts of a farmer in fish seed production for self-employment, by Ras Behari Baraik and Ashish Kumar. Remembering: the missing capacity, by Terrence Clayton. Measuring the process, by Nick Innes-Taylor. Women’s fish farmers group in Nawalparasi, Nepal, by S.K. Pradhan. Periphyton-based aquaculture: a sustainable technology for resource-poor farmers, by M.E. Azim, M.A. Wahab, M.C.J. Verdegem, A.A. van Dam and M.C.M. Beveridge. Unlocking information on the Internet: STREAM media monitoring and issue tracking, by Paul Bulcock (PDF has 16 pages.)

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CONTENTS: From resource user to resource manager: a significant change story, by Ruperto Aleroza as told to Jocel Pangilinan and Ronet Santos. Significant change with Cambodian provincial livelihoods study teams, by Bun Hay Chheng, Tan Someth Bunwhat, Mey Chanthou and Bun Puthy. The Community Fisheries Development Office: one year on, by Matt Fox. CFDO open for business, by Louise Mackeson-Sandbach. Stakeholders and institutional involvement in aquaculture management and development, by M. Krishnan and Pratap S. Birthal. Fish seed production for aquaculture in southeast Cambodia: decentralization, the way to go, by Olivier Delahaye Gamucci, Graham C. Mair and Harvey Demaine.

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CONTENTS: Hon Mun MPA Pilot Project on community-based natural resources management, by Nguyen Thi Hai Yen and Bernard Adrien. An experience with participatory research in Tam Giang Lagoon, Thua Thien-Hue, by Ton That Chat. Experiences and benefits of livelihoods analysis, by Michael Reynaldo, Orlando Arciaga, Fernando Gervacio and Catherine Demesa. Lessons learnt in implementing PRA in livelihoods analysis, by Nguyen Thi Thuy. Lessons learnt from livelihoods analysis and PRA in the Trao Reef Marine Reserve, by Nguyen Viet Vinh. Using the findings from a participatory poverty assessment in Tra Vinh Province, by Le Quang Binh.

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CONTENTS: Learning insights from the Fisheries Resource Management Project, by Tee-Jay A San Diego. An orientation on the SIAD approach and participatory local development planning, by Elizabeth M. Gonzales. Group-building, production success and the struggle to prevent capture of the resource, by B.K. Sahay, K.P. Singh and S.N. Pandeya. Urban agriculture, water reuse and local economies: case study of coastal riverine Settlements of Ondo State, Nigeria, by Yemi Akegbejo-Samsons. Livelihoods analysis: actual experience from using PRA, by Pham Minh Tam and Trinh Quang Tu. A sustainable livelihoods approach to fisheries development for poverty alleviation in southeastern Vietnam, by Nguyen Van Tu and Nguyen Minh Duc

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There is strong evidence to suggest that ground-water nitrate concentrations have increased in recent years and further increases are expected along portions of the central Gulf coast of Florida. Much of the nitrate enriched groundwater is discharged into surface waters through numerous freshwater springs that are characteristic of the area and the potential for eutrophication of their receiving waters is a legitimate concern. To test the potential effects of elevated nutrient concentrations on the periphyton community an in situ nutrient addition experiment was conducted in the spring-fed Chassahowitzka River, FL, USA, during the summer of 1999. Plastic tubes housing arrays of glass microscope slides were suspended in the stream. Periphyton colonizing the microscope slides was subjected to artificial increases in nitrogen, phosphorus or a combination of both. Slides from each tube were collected at 3- to 4- day intervals and the periphyton communities were measured for chlorophyll concentration. The addition of approximately 10 μg/L of phosphate above ambient concentrations significantly increased the amount of periphyton on artificial substrates relative to controls; the addition of approximately 100 μg/L of nitrate above ambient concentrations did not. The findings from this experiment implicated phosphorus, rather than nitrogen, as the nutrient that potentially limits periphyton growth in this system.(PDF contains 4 pages.)

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CONTENTS: Livelihoods and languages: a SPARK-STREAM learning and communications process, by Kath Copley and William Savage. Towards broader contextual understandings of livelihoods, by Elizabeth M. Gonzales, Nguyen Song Ha, Rubu Mukherjee, Nilkanth Pokhrel and Sem Viryak. Using tools to build shared understandings, using a sustainable livelihoods framework to learn, by Nuchjaree Langkulsane. Learning about rattan as a livelihood, by Mariel de Jesus and Christine Bantug. Meanings of “community-managed area,” by Arif Aliadi. Lessons learnt about processes for learning and communicating, by Graham Haylor and Ronet Santos.

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CONTENTS: Livelihood Improvements through fisheries in the Pode community in Pokhara, Nepal, by Tek Bahadur Gurung and Jay Dev Bista. Women’s participation in coastal resources management and livelihoods in Khanh Hoa Province, Vietnam, by Nguyen Thu Hue, Than Thi Hien, Pham Thi Phuong Hoa, Nguyen Viet Vinh and Dao Viet Long. Supporting people’s efforts and interactions in coastal resources management in Indonesia, by Tabitha Yulita. Planning for a community fisheries M&E system, by Heather Airlie and Haiko Meelis. Identifying needs and recommendations for efficient stakeholder communications through an information access survey, by Elizabeth M. Gonzales, Malene Felsing and Erwin L Pador. IEC seminar-workshop in support of fisheries ordinance implementation in Roxas City, Philippines, by Belinda M. Garrido and Elizabeth M. Gonzales.

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CONTENTS: An experience with group formation in Jabarrah, West Bengal, by Amar Prasad, Virendra Singh, Binay Sahay and Gautum Dutta. Aquaculture self-help groups in rural West Bengal, by Satyendra Tripathi, Graham Haylor and William Savage in consultation with Jagdish Gangwar, Virendra Singh, Gautam Dutta and Prabhat Pathak. Lessons learned for Fulwar Toli from an exposure visit to Jabarrah Bhim Nayak and Rubu Mukherjee. Livelihood intervention by Fish Farmers Development Agency: a success story from Mayurbhanj, Orissa, by G.B. Parida. Understanding of assets-based livelihoods through participatory rural appraisal to eliminate hunger, by Binay Sahay. Poverty ranking tools in PRA: experiences of EIRFP in addressing vulnerability, by Binay Sahay.

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CONTENTS: Creating understanding and ownership of collaborative research results through ‘learning by doing,’ by Robert Arthur and Caroline Garaway. Fish culture, farming, markets and promotion: an integrated, sustainable approach to aquaculture and rural development, by Pen Rotha and Brendan Boucher. Fisheries policy reform impact assessment in Cambodia: understanding policy and poor people, by Philip Townsley and Sem Viryak. “Shrimp Hero” Phan The Phuong, by Ngo Minh Khoi. Coral farming in Vietnam, by Nguyen Viet Vinh. The global fisheries market: can rural poor people benefit? Issues raised by STREAM Media Monitoring Reports, by Paul Bulcock.

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CONTENTS: BFAR moves on in Region 6, by Janice N. Tronco. Livelihoods initiatives in Sapian Bay, by Tee-Jay A. San Diego. Improving access to information through Barangay Learning Resource Centers, by Elizabeth M. Gonzales. The Philippines Fisheries Information System, by Agnes C. Solis. The contributions of planning activities in the participatory process, by Rommel P. Guarin. Inter-LGU alliance building: a key to sustaining the Integrated Fisheries and Aquatic Resource Management Council (IFARMC), by Josephine P. Savaris.