Biogeographic freshwater fish pattern legacy revealed despite rapid socio‐economic changes in China

Abstract

Understanding drivers of freshwater fish assemblages is critically important for biodiversity conservation strategies, especially in rapidly developing countries, which often have environmental protections lagging behind economic development. The influences of natural and human factors in structuring fish assemblages and their relative contributions are likely to change given the increasing magnitude of human activities. To discriminate natural and human drivers of fish diversity and assemblage patterns in developing countries with rapid socio‐economic development, a dataset of 908 freshwater fish species and 13 metrics including three categories of both natural (i.e., biogeographic) and human drivers (i.e., economic growth, inland fisheries) in China were analysed with machine learning algorithms (i.e., self‐organizing map, random forest). Here, we found that biogeographic drivers explained 21.8% of the observed fish assemblage patterns in China and remained stronger predictors when compared to human drivers (i.e., 15.6%, respectively). Freshwater fish species richness was positively correlated to rainfall, air temperature, surface water area and inland fisheries production but negatively correlated with urbanization. In addition, the strong structuring effects of climatic variables on Chinese fish richness patterns suggested that the fish assemblages could be particularly vulnerable to climate change. Our results showed that natural biogeographic factors still dominate in driving freshwater fish assemblage patterns despite increased human disturbances on aquatic ecosystems in a rapidly developing country. These findings consequently suggested that we should consider both natural (e.g., climate) and human (e.g., urbanization, inland fisheries) factors when establishing aquatic conservation strategies and priorities for developing countries that are experiencing rapid socio‐economic changes.

Model‐based decomposition of environmental, spatial and species‐interaction effects on the community structure of common fish species in 772 European lakes

“…However, the approach as demonstrated here elucidates that there are strong hints for a significant effect of species interactions on the assembly of lake fish communities. The comparison of p/a, biomass and mean mass datasets did not produce erratic patterns, but confirmed information that we have assembled from several earlier studies comparing lake fish communities across large spatial scales (Brucet et al., 2013; Griffiths et al., 2014; Guo et al., 2019; MacDougall et al., 2018). We agree that mechanistic experiments at ecosystem scales would be the preferred option to support the correlative evidence accumulated here.…”

“…We found a dominant effect of temperature, precipitation and elevation on the large‐scale occurrence of fish species, whereas ecosystem size, expressed as lake area or depth, and productivity were strong predictors of species biomasses and average mean masses. These environmental filters have been identified in previous studies on lake fish communities in Europe, North America and China (Brucet et al., 2013; Griffiths et al., 2014; Guo et al., 2019; MacDougall et al., 2018; Trochine et al., 2018). Temperature again emerged as the main driver of continental‐scale differences in fish species occurrences, with lakes at higher latitudes and elevation harbouring primarily fish species of the cold‐ and coolwater thermal guilds (genera Coregonus , Lota and Osmerus ), whereas the warmwater thermal guild encompasses mainly the species of the family Cyprinidae (Brucet et al., 2013; Emmrich et al., 2014).…”

Fish Diversity, Endemism, Threats, and Conservation in the Jinsha River Basin (Upper Yangtze River), China

“…2011; Guo et al. 2019). Based on the geographic characteristics of the JRB, fish data were collected from 31 sites (Tables 2, 3).…”

“…Therefore, identifying areas of remaining high fish diversity may be useful to determine areas for protection (Guo et al. 2019). The Jinsha River basin (JRB) in the upper subbasin of the Yangtze River has the highest species richness compared with the other Yangtze River subbasins, and more than half of the species are endemic to China (Ye et al.…”

“…Thus, the JRB is an important region for fish diversity conservation in the Yangtze River basin (Guo et al. 2019). However, the upper Yangtze River basin has received critical impacts from multiple stressors, such as hydropower developments, sand mining, loss of riparian vegetation, and soil and river bank erosion, among others (Park et al.…”