A brand-new research study led by researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science exposed that the areas and timing of tiger shark motion in the western North Atlantic Ocean have actually altered from increasing ocean temperature levels. These climate-driven modifications have actually consequently moved tiger shark motions beyond secured locations, leaving the sharks more susceptible to industrial fishing.
The motions of tiger sharks, (Galeocerdo cuvier) the biggest cold-blooded pinnacle predator in tropical and warm-temperate seas, are constrained by the requirement to remain in warm waters. While waters off the U.S. northeast shoreline have actually traditionally been too cold for tiger sharks, temperature levels have actually warmed substantially over the last few years making them ideal for the tiger shark.
“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” stated Neil Hammerschlag, director of the UM Shark Research and Conservation Program and lead author of the research study. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”
Hammerschlag and the research study group found these climate-driven modifications by evaluating 9 years of tracking information from satellite-tagged tiger sharks, integrated with almost forty years of standard tag and regain details provided by the National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program and satellite obtained sea-surface temperature level information.
The research study discovered that throughout the last years, when ocean temperature levels were the hottest on record, for each one-degree Celsius boost in water temperature levels above average, tiger shark migrations extended further poleward by approximately 250 miles (over 400 kilometers) and sharks likewise moved about 14 days earlier to waters off the U.S. northeastern coast.
The results might have higher environment ramifications. “Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” stated Hammerschlag.
Reference: “Ocean warming changes the distributional variety, migratory timing, and spatial defenses of a pinnacle predator, the tiger shark (Galeocerdo cuvier)” 13 January 2022, Global Change Biology
DOI: 10.1111/ gcb.16045
The research study’s authors consist of: Neil Hammerschlag, Laura McDonnell, Mitchell Rider, Ben Kirtman from the UM Rosenstiel School; Garrett Street and Melanie Boudreau from Mississippi State University; Elliott Hazen, Lisa Natanson, Camilla McCandless from NOAA Fisheries; Austin J. Gallagher from Beneath the Waves; and Malin Pinsky from Rutgers University.
The Batchelor Foundation, Disney Conservation Fund, Wells Fargo, Guy Harvey Ocean Foundation, the Herbert W. Hoover Foundation, the International Seakeepers Society, Oceana, Hoff Productions for National Geographic, and the West Coast Inland Navigation District supplied assistance for the research study.