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) conduct 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 is published in Nature Communications on Aug 14 2020.
The research team investigates temperature effects on fish populations based on life history and temperature data from publically-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) will benefit from rising temperature, while the fast life-history ones (mainly pelagic and reef fishes) will have reduced population growth rates under warming (Figure 1). Together, these results suggest that life histories mediated 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) adopts 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 marine biological 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. Divergent effects of ocean warming are contingent on life histories of fishes. 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.