Measuring ecosystem degradation through half a century of fish species introductions and extirpations in a large isolated lake

Seventy‐five years of biodiversity decline of fish assemblages in Chinese isolated plateau lakes: widespread introductions and extirpations of narrow endemics lead to regional loss of dissimilarity

“…This means that the anthropogenic changes experienced by the Yun-Gui plateau lakes were so harsh that they erased the distance decay of similarity, a general biogeographic trend known for almost all organisms and ecosystems on earth (Nekola & White, 1999;Soininen et al, 2007). In addition to the changes in species composition, a recent study reported the dramatic changes in functional and phylogenetic diversity of fish assemblages in one of the studied lake under long-term introduction pressures (Jiang et al, 2015). Moreover, the distance decay reported when considering the entire fauna was only attributable to the differences in exotic species established in the different lakes, that likely refers to the strength in introduction pressure in each lake (Leprieur et al, 2008b).…”

“…However, compared to the abundant literature on islands, studies examining the effects of human disturbances on the change in dissimilarity in isolated lakes remain scarce (Lopes et al, 2014). During the past 75 years, these lakes have experienced drastic changes in fish assemblages because of intensive introductions of exotic fishes and extirpation of native endemic species (Chen et al, 1998;Kang et al, 2013;Jiang et al, 2015). During the past 75 years, these lakes have experienced drastic changes in fish assemblages because of intensive introductions of exotic fishes and extirpation of native endemic species (Chen et al, 1998;Kang et al, 2013;Jiang et al, 2015).…”

Fish Assemblage Shift after Japanese Smelt (Hypomesus nipponensis McAllister, 1963) Invasion in Lake Erhai, a Subtropical Plateau Lake in China

“…This lake also has experienced a series of fish species invasions and loss of native fish diversity in recent decades [23]. Commercial fish such as four major Chinese carp had been introduced successively in Lake Erhai since the 1960s, and the main fishery had gradually shifted from native fishes to artificially introduced non-native fish [21]. In addition, due to the introduction of commercial fish, the fish production in Lake Erhai increased from less than 2500 tons in 2001 to more than 5000 tons in 2009 [40].…”

“…Afterwards, production of Dali schizothorax dropped sharply, and most native fish such as the Yunnan schizothorax (Schizothorax yunnanensis) and Erhai carp disappeared. In the mid-1980s, icefish was introduced, and it quickly became a dominant species [18][19][20][21][22], so much so that in 1985 the Dali Erhai Conservation Administration was prompted to start compiling long-term fishery catch statistics to evaluate changes in annual yield. In the 1990s, the production of icefish soared, and the average annual yield rose to 3880.4 t.…”

“…From 2000 to 2010, several fish researchers conducted a detailed survey of the fish composition of Lake Erhai [21,23] and found that the Japanese smelt (Hypomesus nipponensis) arrived in 2010. We then conducted annual samplings for nearly a decade (2011-2019) to observe variations in its population.…”