Ecosystem study Altenwoerth: impacts of a hydroelectric power-station on the River Danube in Austria

The aim of this article is to briefly describe the effects of the Altenwoerth Barrage, on the River Danube, on some physical variables and their consequent effects on water chemistry and the biota of the river. The methods used for biological sampling are summarised, especially those used in the limnological part of the study, and the macroinvertebrate and fish fauna listed. Comparisons are then made between the impounded section of river immediately above the dam and two unimpounded free-flowing sections of the river. Further developments on the Danube are considered.

The contrasting invertebrate fauna of freshwater habitats in the Swavesey fens of East Anglia

During July and August 1988, 21 ponds and 33 ditch sites were sampled at Swavesey fens in East Anglia. Water from each site was collected and analysed at monthly intervals in the year preceding faunal sampling. Temperature and oxygen were measured on site. The "quality" of the faunal community was assessed by three approaches: a modification of the BMWP scoring system (Biological Monitoring Working Party); faunal richness was calculated as the number of faunal "groups" at each site; and by using Simpson's index of diversity. Statistical analysis was carried out to explore the relationships between sites, environmental variables and faunal diversity. The survey clearly showed the detrimental effects of elevated nitrate and phosphate from agricultural sources and the localised impacts of treated sewage effluent on invertebrates in ditches.

Strengthening governance across scales in aquatic agricultural systems

Aquatic agricultural systems in developing countries face increasing competition from multiple stakeholders operating from local to national and regional scales over rights to access and use natural resources—land, water, wetlands, and fisheries-essential to rural livelihoods. A key implication is the need to strengthen governance to enable equitable decision-making amidst such competition, building capacities for resilience and transformations that reduce poverty. This paper provides a simple framework to analyze the governance context for aquatic agricultural system development focused on three dimensions: stakeholder representation, distribution of power, and mechanisms of accountability. Case studies from Cambodia, Bangladesh, Malawi/Mozambique, and Solomon Islands illustrate the application of these concepts to fisheries and aquaculture livelihoods in the broader context of intersectoral and cross-scale governance interacti

Aquatic Agricultural Systems: Annual report

The program on aquatic agricultural systems (AAS) aims to change the way the CGIAR engages with aquatic agricultural systems and the poor and vulnerable communities who depend upon them. To do so the program has focused on three primary lines of work in its first six months: (i) preparing for implementation of the program in focal countries and geographical hubs; (ii) harnessing the best of earlier and ongoing research that contributes to the science themes of the program and which we wish to see expanded and integrated into the program as it develops; (iii) establishing innovative governance and management arrangements that will guide and implement the program. This report summaries the achievements and reviews the progress of the AAS program.

Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance

We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively, were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas (ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs.

Impacts of climate change and variability on fish value chains in Uganda

This study examines the vulnerability of fish pr oduction in Uganda, particularly as it r elates to the predicted impacts from climate change, using the concept of the value chain. The value chain approach has been recommended as a useful tool to study specific challenges facing a sector resulting from various drivers of change, including climate. Critically, such analyses can reveal context-specific response strategies to enhance a sector (Jacinto and Pomer oy 2010). The specific purpose of the study was to identify curr ent and potential impacts of climate change and corresponding adaptation strategies in fish value chains. The study builds upon information fr om earlier value chain analyses on fisheries and aquaculture production in Uganda to provide a more in-depth understanding of issues facing the fish industry, in particular, those to be incorporated in the CGIAR Resear ch Program Livestock and Fish.

Assessment of the impact of aquatic resources research by ICLARM: scope and methodologies

The importance of quantifying the economic returns to investments in aquatic resources research together with the social, environmental and institutional impacts of such investments is widely recognized among ICLARM's donors, trustees and beneficiaries. As with other Consultative Group on International Agricultural Research (CGIAR) centers, ICLARM is being asked to provide specific accounts of the outputs of its research and their impact on farms and on fisheries, including their socioeconomic impact. Such impact information has become a necessary, though not sufficient, basis for setting priorities and allocating resources for research for the CGIAR centers. This paper discusses the types and methods of impact assessment relevant to ICLARM's work. A three-pronged assessment approach is envisaged to capture the full range of impacts: 1) ex ante assessment for research priority setting; 2) assessment prior to dissemination or adoption along with monitoring and evaluation; and 3) ex post impact assessment. It also discusses the objectives and scope for operational impact assessment of ICLARM's research.

Anticipated impacts of recent political changes on fisheries management in South Africa

South Africa's marine resources are essentially fully exploited and in some cases over exploited. The Government of National Unity has embarked on the ambitious Reconstruction and Development Programme (RDP) to: meet the basic needs; develop the country's human resources; build economy; and democratize the state and society. Although fisheries can only be expected to play a minor role in contributing to RDP, the Programme have a role to play in managing South Africa's living marine resources. The role of RDP in fisheries management is presented together with fisheries management approaches to help achieve the aims of the RDP.

A global experiment on tilapia aquaculture: impacts of the Pond Dynamics/Aquaculture CRSP in Rwanda, Honduras, Philippines and Thailand

The Pond Dynamics/Aquaculture Collaborative Research Support Program (PDA/CRSP) is a global research network to generate basic science that may be used to advance aquaculture development. One of a family of research programs funded by the United States Agency for International Development (USAID), the CRSP focuses on improving the efficiency of aquaculture systems. The PDA/CRSP began work in 1982 in Thailand, and subsequently in the Philippines, Honduras, the US and, until recently, Rwanda. At all the sites, the goal is the same: to identify constraints to aquaculture production, and to design responses that are environmentally and culturally appropriate. The research network's global experiment has focused on tilapia (Oreochromis niloticus), although some sites have devoted attention to marine shrimp and other locally significant species. Impact of the network's investigations with tilapia is examined in this article.

Extending the Bajo de Sico, Puerto Rico, Seasonal Closure: An Examination of Small-scale Fishermen’s Perceptions of Possible Socio-economic Impacts on Fishing Practices, Families, and Community

Despite considerable conservation efforts, many reef fish fisheries around the world continue to be in peril. Many are vulnerable to overexploitation because they have predictable and highly aggregated spawning events. In U.S. Caribbean waters, fishery managers are increasingly interested in advancing the use of closed areas as a means for rebuilding reef fisheries, protecting coral reef habitats, and furthering ecosystem-based management while maintaining the sustained participation of local fishing communities. This study details small-scale fishermen’s views on the Caribbean Fishery Management Council’s proposals to lengthen the current Bajo de Sico seasonal closure off the west coast of Puerto Rico to afford additional protection to snapper-grouper spawning populations and associated coral reef habitats. Drawing on snowball sampling techniques, we interviewed 65 small-scale fishermen who regularly operate in the Bajo de Sico area. Snowball sampling is a useful method to sample difficult-to-find populations. Our analysis revealed that the majority of the respondents opposed a longer seasonal closure in the Bajo de Sico area, believing that the existing 3-month closure afforded ample protection to reef fish spawning aggregations and that their gear did not impact deep-water corals in the area. Whilst fishermen’s opposition to additional regulations was anticipated, the magnitude of the socio-economic consequences described was unexpected. Fishermen estimated that a year round closure would cause their gross household income to fall between 10% and 80%, with an average drop of 48%. Our findings suggest that policy analysts and decision-makers should strive to better understand the cumulative impacts of regulations given the magnitude of the reported socio-economic impacts; and, more importantly, they should strive to enhance the existing mechanisms by which fishermen can contribute their knowledge and perspectives into the management process.

Transforming aquatic agricultural systems towards gender equality: a five country review

Aquatic agricultural systems (AAS) are systems in which the annual production dynamics of freshwater and/or coastal ecosystems contribute significantly to total household income. Improving the livelihood security and wellbeing of the estimated 250 million poor people dependent on AAS in Bangladesh, Cambodia, the Philippines, the Solomon Islands and Zambia is the goal of the Worldfish Center-led Consortium Research Program (CRP), “Harnessing the development potential of aquatic agricultural systems for development.” One component expected to contribute to sustainably achieving this goal is enhancing the gender and wider social equity of the social, economic and political systems within which the AAS function. The CRP’s focus on social equity, and particularly gender equity, responds to the limited progress to date in enhancing the inclusiveness of development outcomes through interventions that offer improved availability of resources and technologies without addressing the wider social constraints that marginalized populations face in making use of them. The CRP aims to both offer improved availability and address the wider social constraints in order to determine whether a multi-level approach that engages with individuals, households and communities, as well as the wider social, economic and political contexts in which they function, is more successful in extending development’s benefits to women and other excluded groups. Designing the research in development initiatives to test this hypothesis requires a solid understanding of each CRP country’s social, cultural and economic contexts and of the variations across them. This paper provides an initial input into developing this knowledge, based on a review of literature on agriculture, aquaculture and gender relations within the five focal countries. Before delving into the findings of the literature review, the paper first justifies the expectation that successfully achieving lasting wellbeing improvements for poor women and men dependent on AAS rests in part on advances in gender equity, and in light of this justification, presents the AAS CRP’s conceptual framew

Resilient livelihoods and food security in coastal aquatic agricultural systems: Investing in transformational change

Aquatic agricultural systems (AAS) are diverse production and livelihood systems where families cultivate a range of crops, raise livestock, farm or catch fish, gather fruits and other tree crops, and harness natural resources such as timber, reeds, and wildlife. Aquatic agricultural systems occur along freshwater floodplains, coastal deltas, and inshore marine waters, and are characterized by dependence on seasonal changes in productivity, driven by seasonal variation in rainfall, river flow, and/or coastal and marine processes. Despite this natural productivity, the farming, fishing, and herding communities who live in these systems are among the poorest and most vulnerable in their countries and regions. This report provides an overview of the scale and scope of development challenges in coastal aquatic agricultural systems, their significance for poor and vulnerable communities, and the opportunities for partnership and investment that support efforts of these communities to secure resilient livelihoods in the face of multiple risks.

Economic and social impacts of Integrated Aquaculture-Agriculture technologies in Bangladesh

This study estimated the adoption rate of integrated aquaculture-agriculture (IAA) technologies in Bangladesh and their impact on poverty and fish and food consumption in adopting households. We used a novel, simulation-based approach to impact assessment called Tradeoff Analysis for Multi-Dimensional Impact Assessment (TOA-MD). We used the TOA-MD model to demonstrate how it is possible to use available data to estimate adoption rates in relevant populations, and to quantify impacts on distributional outcomes such as poverty and food security, thus demonstrating ex ante the potential for further investment in technology dissemination. The analysis used baseline and end-of-project survey data from WorldFish-implemented Development of Sustainable Aquaculture Project (DSAP), promoting IAA. This dataset was used to simulate adoption and assess its impacts on poverty and food security in the target population. We found that, if adopted, IAA had a significant positive impact on reducing poverty and improving food security and income.

Ex-ante assessment of integrated aquaculture-agriculture adoption and impact in Southern Malawi

There are increasing requirements for impact assessment by development partners in order to increase the accountability and effectiveness of research and development projects. Impact assessment research has been dominated by conventional economic methods. This context challenges agricultural research organizations to develop and apply alternative impact assessment methods incorporating economic, social, and environmental impact components. In this study, we use the Tradeoff Analysis for Multi-Dimensional Impact Assessment (TOA-MD) model to evaluate the impact of integrated aquaculture-agriculture (IAA) adoption in Malawi. The study demonstrated that with a minimal data set, the TOA-MD model can be applied to predict and assess the adoption rates of new technologies and practices as well as their economic and non-economic impacts.

Acid waters in North West England. The effect of liming agricultural land

This is the Acid waters in North West England: The effect of liming agricultural land on the chemistry and biology of the River Esk, North West England report produced by National Rivers Authority in 1992. This report focuses on the study of Acid Waters in the North West Region of England, UK, which began in 1982 and sampling was completed in October 1990. This work was initiated because of the observation of the simultaneous mortality of adult and juvenile salmon and sea-trout in both the River Esk and adjacent River Duddon in June 1980. Investigations at that time indicated that an "acid episode" was the most likely cause of this mortality. A land use study indicated that a reduction in agricultural liming may have been a major factor in the development of acid episodes and consequent fish kills in the River Esk and River Duddon. However there was no evidence that the mortalities of salmonids in the early 1980's were due to a reduction in agricultural liming. They were due to some other phenomenon such as a period of intense acid deposition.