No abstract

Summary Habitat segregation has been recognized as an important means of resource partitioning in river fish assemblages. Association between river fishes and habitat features were identified through principal component analysis (PCA). Fish and habitat data were collected in the Kaoping, Tsengwen, Choshui, and Tatu rivers from July 1997 to June 1999 in western Taiwan. Electrofishing was used to collect fishes in grids, and environment variables in the sampled areas were measured immediately after sampling. The first four PCs of depth, velocity, cover, substrate and water temperature variables explained 92.3% of the total variance in habitat characteristics. Varicorhinus barbatulus, Acrossocheilus formosanus and Tilapia mossambica in the upper right quadrant, indicated preference for deep‐water habitat. Species usually associated with shallow water habitat include several minnow species. Rhinogobius brunneus, Hemimyzon formosanum, Sinogastromyzon puliensis and Crossostoma lacustre distribution is centred in the upper and lower left, indicating preference for shallow water. Principal component (PC) scores on Zacco pachycephalus, Abbottina brevirostris and Hemiculter leucisculus appeared to have no special preference. Differences in habitat use exhibited by these species may be related to success in finding food and avoiding predators.

The objective of the present study was to determine diel and seasonal patterns of fluvial fish composition and abundance. Electrofishing grids were used to collect fish in the Platte River at North Bend, Nebraska, USA. Sampling was started at 12.00 h and continued every 3 h for a 24‐h period. More species were taken during the day than at night in the spring. In contrast, more species were taken at night than during the day in summer. In the fall, equal numbers of species were caught during the day and night. Comparisons of fish densities showed significant differences among the three seasons. Major taxa were significantly more abundant in spring, but river shiner Notropis blennius and western silvery minnow Hybognathus argyritis were more abundant in the fall. The greater nocturnal abundance of fish in summer and fall than in the spring may be due to changes in the physical and chemical characteristics during the study periods. The significance of seasonal difference in abundance of fish assemblages may indicate a response to changes in available habitats.

The ancient fishing methods include stone fish weir, beach seine and baulk net, but the fish catches of the stone fish weir is the most abundant. The stone fish weirs not only constitute important landscape, but also are representative of the fishery culture in Penghu, because they are fishing ground built by ancient people to take advantage of natural environment and resources. The objectives of this study is to understand the relevance of stone fish weirs in Penghu and to preserve biological diversity, as well as the value of stone fish weirs in Penghu fishery culture, and further make suggestions on the stone fish weirs. According to the present study, the marine species around the stone fish weirs tend to be diversifying, and in the future the region's economy can be revitalized by sightseeing, which may promote the ecotourism, and also volunteer tourism. In the future, stone fish weirs must be promoted as a sightseeing destination. Also, by taking into consideration the experience of the Jibei stone weir protection team, the local communities of Penghu can have their own protection team to revitalize the stone fish weirs for sustainable operation and management.

A major challenge for fisheries management lies in how to strike a balance between the livelihoods of fishermen and sustainable operation of the fishing industry under the impact of climate change. In the long term, important marine habitats need to be designated as marine protected areas and prevent destructive man-made activities through appropriate legislation and law enforcement to promote marine resource conservation and ecological protection. Furthermore, marine protected areas have been recognized as the simplest, cheapest and most effective way in which to restore fishery resources and protect marine biodiversity in the future. However, the competent authorities have been unable to achieve co-management of the environment and partnerships for many years, and continue to rely on extensive integration and collaboration between governments and non-governmental organizations or individuals due to implementation-related factors such as the island society, the multiple social relationships of fishermen or residents in fishing villages, the closely related place attachment, and general xenophobia. The National Penghu University of Science and Technology established marine protected area community patrols in 2018. The patrols not only protect marine resources but also allow community residents and fishermen to build consensus among communities and reduce class discrimination against fishermen, which is in line with the sustainable planning and management strategy in fisheries of the blue economy and with the spirit of sato-umi. Sato-umi is a coastal area where biological productivity and biodiversity has increased through human interaction. In this study, social network analysis was used to systematically analyze the process of stakeholder engagement in the co-management of conservation areas, link cross-domain recreational resources amongst fishing villages, and cultivate regional revitalization in fishing communities through the visualization of participants’ locations, interactions, and relative influence.