title: Large but uneven reduction in fish size across species in relation to changing sea temperatures.
abstract: Ectotherms often attain smaller body sizes when they develop at higher temperatures. This phenomenon, known as the temperature-size rule, has important consequences for global fisheries, whereby ocean warming is predicted to result in smaller fish and reduced biomass. However, the generality of this phenomenon and the mechanisms that drive it in natural populations remain unresolved. In this study, we document the maximal size of 74 fish species along a steep temperature gradient in the Mediterranean Sea and find strong support for the temperature-size rule. Importantly, we additionally find that size reduction in active fish species is dramatically larger than for more sedentary species. As the temperature dependence of oxygen consumption depends on activity levels, these findings are consistent with the hypothesis that oxygen is a limiting factor shaping the temperature-size rule in fishes. These results suggest that ocean warming will result in a sharp, but uneven, reduction in fish size that will cause major shifts in size-dependent interactions. Moreover, warming will have major implications for fisheries as the main species targeted for harvesting will show the most substantial declines in biomass.
authors.affiliation: School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Itai
authors.identifier: 0000-0002-3617-3099
authors.initials: I
authors.lastname: van Rijn
authors.affiliation: School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yehezkel
authors.initials: Y
authors.lastname: Buba
authors.affiliation: School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
authors.forename: John
authors.initials: J
authors.lastname: DeLong
authors.affiliation: Department of Life Sciences, Ben-Gurion University, Be'er Sheva, Israel.|The Interuniversity Institute for Marine Sciences of Eilat, Eilat, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Kiflawi
authors.affiliation: School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.|The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Belmaker
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D018533:Biomass; D049628:Body Size; D057231:Climate Change; D017753:Ecosystem; D005399:Fishes; D008522:Mediterranean Sea; D013696:Temperature
keywords: climate change; ectotherms; fish growth; fisheries; temperature-size rule