Shifting Habitats in Warming Waters
As the world prepares for Shark Week 2026, which begins Sunday, July 26, marine biologists are documenting significant shifts in shark behavior and distribution driven by climate change. According to the National Oceanic and Atmospheric Administration (NOAA), the world’s oceans have absorbed more than 90% of the surplus heat in the climate system over the past decade. This historic warming is fundamentally altering the ecosystems that sharks rely on for feeding, breeding, and nursery development.
Shannon Barry, a researcher at the Florida Institute of Technology, highlights that these temperature increases are pushing species toward higher latitudes. In a recent study, Barry’s team identified that bull sharks are establishing new nursery populations as far north as North Carolina. Bull sharks typically prefer water temperatures between 26°C and 30°C (78.8°F to 86°F). As near-shore habitats move into these preferred temperature ranges, the species is expanding its range poleward.
New Insights into Great White Migration
While bull sharks are shifting their coastal nurseries, other apex predators are also changing their seasonal habits. A peer-reviewed study published in Wildlife Research has challenged long-held assumptions regarding great white shark migration. Utilizing satellite-linked smart position and acoustic tags on 92 white sharks, researchers involved in an OCEARCH-led effort tracked these predators from Nova Scotia, Canada, to the Gulf of Mexico.
The data confirms that the Gulf of Mexico serves as a regular winter habitat for many great whites, particularly from December through May. Chris Fischer, founder of OCEARCH, noted that this connectivity between the Atlantic and Gulf ecosystems is more profound than previously understood. This shift in understanding is critical for conservation efforts and public safety, given that these waters host millions of beachgoers annually.
Public Safety and Ecosystem Health
Despite the heightened attention to shark sightings, experts emphasize that shark attacks remain extremely rare. Data from the Florida Museum of Natural History places the odds of a shark attack at 1 in 11.5 million. To minimize risk, researchers recommend that swimmers avoid entering the water at dawn or dusk when visibility is low, steer clear of areas where fishing activity is occurring, and avoid wearing shiny jewelry that may mimic the appearance or movement of prey.
Understanding these migration patterns is also vital for the broader marine ecosystem. As noted during the Calvert Marine Museum’s ‘Sharkfest’ in Maryland, sharks act as critical scavengers that maintain the health of the food web. With approximately 25% of the 500 known shark species currently threatened or endangered, the impact of climate change on their ability to find suitable habitats represents a significant conservation challenge.