Author: Allie Wilkinson / Source: Science News
Far from their usual tropical waters, some 200 bottlenose dolphins and about 70 false killer whales have been spotted off the western coast of Canada’s Vancouver Island.
Over on the Atlantic coast, bull sharks have turned a North Carolina estuary into a nursery — a sight more familiar in Florida, until now.Two new studies highlight the unusual northern sightings of these three ocean predators.“Alone, these sightings could be seen as accidental, or vagrancies,” says marine ecologist Luke Halpin of Halpin Wildlife Research in Vancouver and part of the team tracking the dolphins sighting. “But we’re seeing a lot of warm-water species ranging into historically cold North Pacific waters.” Those include dwarf sperm whales (Kogia sima), pygmy sperm whales (Kogia breviceps) and short-finned pilot whales (Globicephala macrorhynchus) documented by other researchers.
The results suggest that these marine species will increasingly migrate outside of their typical range as climate change increases ocean temperatures, researchers say. In just the last century, average sea temperatures have risen every decade by 0.07 degrees Celsius, though temperature changes can vary widely by location.
The eastern North Pacific Ocean had experienced a three-year period of warming from 2013 to 2016, and by July 2017, water temperatures about 180 kilometers offshore of Vancouver Island hit 16.
5° C. That’s smack in the middle of the range that common bottlenose dolphins (Tursiops truncatus) prefer and at the…The post Bull sharks and bottlenose dolphins are moving north as the ocean warms appeared first on FeedBox.