Top Fish Predators Could Suffer Wide Loss of Suitable Habitat by 2100 Due to Climate Change
Published:13 Sep.2023    Source:Woods Hole Oceanographic Institution
A study of 12 species of highly migratory fish predators -- including sharks, tuna, and billfish such as marlin and swordfish -- finds that most of them will encounter widespread losses of suitable habitat and redistribution from current habitats in the Northwest Atlantic Ocean (NWA) and the Gulf of Mexico (GOM) by 2100. These areas are among the fastest warming ocean regions and are projected to increase between 1-6°C (+1-10°F) by the end of the century, a sign of climate-driven changes in marine ecosystems. In some cases, these iconic, and economically and ecologically important species, could lose upwards of 70% of suitable habitat by the end of the century, and in most cases, the impacts of these climate-induced changes are already observable." The ongoing and projected effects of climate change highlight the urgent need to adaptively and proactively manage dynamic marine ecosystems," according tothe study, "Widespread habitat loss and redistribution of marine top predators in a changing ocean," published in the journal Science Advances.
The study, led byCamrin Braun, an assistant scientist and marine ecologist at the Woods Hole Oceanographic Institution (WHOI), identified areas offshore of the Southeast U.S. and Mid-Atlantic coasts as predicted hotspots of multi-species habitat loss. The researchers studied the impacts on three shark (blue, porbeagle, and shortfin mako), five tuna (albacore, bigeye, bluefin, skipjack, and yellowfin), and four billfish (sailfish, blue marlin, white marlin, and swordfish) species. Although the researchers' model framework could not account for potential adaptability or thermal tolerance by species, the results "suggest predominant and widespread habitat loss for nearly all [highly migratory species] studied." Scientists used three decades of satellite, oceanographic model, and in situ biological data to develop dynamic species distribution models to assess how climate change has already and will continue to impact the fish species in the NWA and GOM.
The shifts in the habitat and distributions of these species "raise concerns for associated fisheries and the socioeconomic impacts of climate change on fishing communities," according to the article. The concentrated changes in species distribution also "highlight the need for adaptive management approaches that can respond to expected changes." "Our results suggest static fishery management measures will continue to lose ecological relevance and economic efficacy as species redistribute under climate change." Braun said the motivation for the research is not only to better understand the fish and marine ecosystems, but also to understand how changes affect people, their livelihoods, coastal communities, and commercial fisheries.