| 英文摘要: | Pollution, habitat degradation, and harvest have resulted in dramatically reduced freshwater fish stocks and diversity around the world. For many people, especially those in developing countries, fish constitutes a critical source of daily nutrition. In marine ecosystems, to increase fish abundance and diversity, large areas have been set aside as marine protected areas. Previous research has shown that by restricting harvest in areas containing important fish habitat, fish abundance and diversity generally increases compared to adjacent unprotected areas. This in-creased number of fish inside the reserves also results in a greater number of fish entering fished areas, and can increase local harvest rates overall. To date, however, this research has not been applied to freshwater systems. This research project will explore a network of protect-ed areas in northern Thailand in order to test the effectiveness of river protected areas in in-creasing the abundance and diversity of fish in rivers. Additional information regarding the age of the reserves and level of protection will also be collected. Finally, the researchers will map river habitats and measure fish movement in and out of reserves. Results will be shared with government officials, academics and resource managers. This research will provide new in-sights into new ways of conserving global freshwater biodiversity, and potentially increase the ability of rivers to continue to provide important nutrition to people globally.
This research project will apply the body of theory developed for marine protected areas (MPAs) to a network of freshwater protected areas in the Ngao River, northern Thailand. Previous meta-analyses of MPAs has suggested that factors including duration of protection, size, spacing, and dispersal are key to predicting MPA success. Researchers will use extensive fieldwork to map an existing network of over 40 small, local community-initiated no-take reserves within a 1,000 square kilometer watershed. Fish densities and species richness will be measured for paired reserve/non-reserve areas using a variety of visual census methods. Additionally, side-scanning sonar will be used to generate accurate habitat maps of both reserve and non-reserve areas and to track dispersal of fish out of reserve areas. Researchers will use generalized linear mixed-effects models to test for significant relationships between dependent variables (species-specific reserve response factors, trophic group response factors, and Bray-Curtis community dissimilarity indices) and the measured characteristics of RRs listed above (e.g., reserve size, age, habitat composition, etc.). The results of this study will inform future freshwater conservation strategies and may also reciprocally inform marine protected area theory as well. |