Great white shark activity surge in the North Atlantic

Marine biologists reported a record number of shark sightings along both the U.S. East and West coasts in the summer of 2026, attributing the trend to rising ocean temperatures tied to El Niño and broader climate warming. A notable case was the 1,400‑pound great white “Breton,” originally tagged off Nova Scotia in 2020, which migrated south and was detected off Florida’s coast where surface waters hit 87 °F. Researchers highlighted that while great whites prefer cooler depths, they can dive deep to follow prey, and the shark’s unusual movement underscores how warming seas may be reshaping predator patterns.

Following that surge, scientists led by Dr. Neil Hammerschlag intensified efforts to track large great whites in the North Atlantic. During Discovery Channel’s Shark Week they deployed tuna bait and satellite tags near Mud Island, tagging several sizable individuals, including a 16‑foot female “Sweetheart.” Their focus turned to a giant, 20‑foot female dubbed “Big Rose,” thought to be one of the largest recorded in the region and possibly over 50 years old. Although “Big Rose” evaded capture, the expedition documented a sharp rise in sightings of massive whites between Cape Cod and Nova Scotia over the past decade, reinforcing scientific interest and highlighting the challenges of studying highly mobile apex predators in deep Atlantic waters.