Basin-specific effect of global warming on endemic riverine fish in Korea

Abstract

The differences in geographical setting among basins create variation in regional climate and local assemblages. Global warming might induce varying degree of changes in the biodiversity and distribution of freshwater fish through water temperature increase in each basin. We investigated the effect of global warming on the thermal habitat suitability of endemic riverine fish in the basin scale and the relationship between change in species loss rate and altitude within a basin. Surface air temperature projections based on A1B emission scenario were used to estimate water temperatures in the major basins of South Korea in the future decades. The thermal tolerances of 39 endemic fish species were estimated from water temperatures and abundances in the habitats using the weighted average regression model. The minimum water temperature was compared with the maximum thermal tolerances to simulate the change in thermal habitat suitability of each species in a basin. Global warming is expected to drive 2-20 species to the risk of removal at 4.3-35.5% of their thermal habitats during 2060-2080s. The effect was variable according to the species' thermal tolerances and the level of basin-specific water temperature increase. The correlation between species loss rate and altitude was positive only when the relationship was considered separately for each basin. The results implied that global warming would greatly affect the suitable habitats of endemic fish before 2060s in Korean rivers. It was suggested that the biodiversity conservation efforts needs to incorporate the spatial heterogeneity in thermal regime among the basins.

Aquatic ecosystem assessment and management

“…Results of species turnover and spatial autocorrelation confirmed changes in the fish community near the dam, suggesting that the habitat alterations due to the dam construction have caused fragmentation of fish communities. Chung et al (2016) studied the effect of global warming on the thermal habitat suitability of endemic riverine fish and the relationship between change in species loss and altitude within a basin. The results showed that global warming is expected to negatively affect 2-20 species in 4.3-35.5% of their thermal habitats from the 2060s to 2080s.…”

Predicting the Impact of Climate Change on Freshwater Fish Distribution by Incorporating Water Flow Rate and Quality Variables

“…These values were much greater than those for the Han, Nakdong, and Yeongsan river basins, which are expected to decline 9.5, 11.09, and 13.37, respectively. Chung et al [59] also reported that endemic fish species in the Geum and Yeongsan-Seomjin river basins will be more severely affected by climate change than those in the Han and Nakdong river basins, resulting in larger decreases in SRI in the Geum and Yeongsam-Seomjin river basins.…”

“…In general, Korean spotted barbel inhabits where the water temperature is relatively cool (13 • C in average) [65]. Chung et al [59] also showed that the optimum temperature for Korean spotted barbel was relatively low, at approximately 9.2 • C, compared with 39 endemic fish species (8.75-11.86 • C) in Korea. The probability of presence was high from 200 to 300 m (Figure 3b).…”

Thermal landscapes in a changing climate: biological implications of water temperature patterns in an extreme year

“…Heterogeneous patterns were predicted across salmon rivers in eastern Canada (Daigle et al 2015). Chung et al (2016) predicted variable water temperature increases leading to differential effects of warming temperatures on thermal habitat suitability by river basin in Korea. Chen et al (2016) also observed heterogeneity of warming rates across seasons and river reaches in China, with more pronounced climate effects for lower-flow rivers and during the dry season; and an east-west gradient of thermal change over time was observed across Poland (Marszelewski and Pius 2016).…”

“…Increasing frequency of extreme events, e.g., very warm years and droughts, puts existing native species at a competitive disadvantage (Diez et al 2012). More generally, researchers from around the world, including Iran (Morid et al 2016), Korea (Chung et al 2016), Canada (Daigle et al 2015), and central Europe (Hardenbicker et al 2017), have estimated losses of thermally suitable habitats for endemic fishes as a result of climate change.…”