Life histories determine divergent population trends for fishes under climate warming
Hui-Yu Wang, Sheng-Feng Shen, Ying-Shiuan Chen, Yun-Kae Kiang, and Mikko Heino
Dr. Hui-Yu Wang (IO NTU), Dr. Sheng-Feng Shen (AS BRC), and Dr. Mikko Heino (UiB, Norway) have conducted the first assessment of warming-induced effects on various types marine fishes in the Indo-Pacific. Their findings reveal that warming impacts are not uniform; instead, warming impacts are contingent on life histories of fishes. Their study was published in Nature Communications on Aug 14, 2020.
The research team investigated temperature effects on fish populations based on life history and temperature data from publicly-available sources. Using meta-analysis, they show that rising temperature leads to overall increased growth rates, earlier maturation, reduced asymptotic length, and elevated natural mortality. Accounting for these life-history changes, population growth rates for about 41% of the Indo-Pacific fishes are predicted to decrease under warming. Moreover, there are divergent trends in population growth rates between fishes: the slow life-history species (such as bathydemersal and elasmobranch fishes) may benefit from rising temperature, while the fast life-history ones (mainly pelagic and reef fishes) may experience reduced population growth rates under warming (Figure 1). Together, these results suggest that life histories mediate differential population growth trends in the face of ocean warming.
Implications for resources management of climate impacts
To evaluate the impacts of climate change on marine resources, the Food and Agriculture Organization of the United Nations (FAO UN) has adopted models that assume a uniform warming effects for all fishes. Results from this research will allow to relax this assumption and advance precision of assessment on the impacts of climate change on living marine resources. Furthermore, these findings provide insight into optimal policy making for marine management – to prioritize conservation on the fast life-history fishes stressed by ocean warming.
Figure 1. The effects of ocean warming on fishes are divergent, contingent on their life histories. Fast life-history fishes will undergo life-history changes to a greater extent under warming compared to slow life-history ones. Furthermore, warming will benefit slow life-history fishes but may impair population growth rates for fast life-history ones.
Reference
Wang, H.-Y.*, S.-F. Shen, Y.-S. Chen, Y.-K. Kiang, and M. Heino. 2020. Life histories determine divergent population trends for fishes under climate warming. Nature Communications 11:4088. https://doi.org/10.1038/s41467-020-17937-4