Fish diversity and use of nearshore and open‐water habitats in terminal lakes

Abstract

Terminal lakes face conservation challenges due to consumptive water use and changes in climate. We quantified the extent of the littoral and open water zones in 18 terminal lakes spanning five continents and show that lake level declines produce variable changes in littoral zone surface area. While littoral zones account for a small portion of the habitat in these lakes, 77% of the fish species inhabit these zones and 87.5% consume littoral–benthic organisms. We found that littoral zone surface area correlates with littoral zone fish species richness (P < 0.01; R2 = 0.47) as well as the number of species relying on benthos (P < 0.01; R2 = 0.44). However, we found (1) no correlation between the percent of the lake’s surface area that is littoral and the percent of the fish community that inhabits the littoral zone (Pearson’s r = 0.3; P = 0.3), and (2) no correlation between the percent of the lake’s surface area that is littoral and the percent of the fish community that consumes benthic organisms (Pearson’s r = −0.1; P = 0.8). Because many terminal lakes are desiccating, conservation of biodiversity in the nearshore zones of these lakes may be warranted.