Climate Change Forces Tiger Sharks to Move 250 Miles Up North, Become More Vulnerable to Commercial Fishing

A study led by researchers from the University of Miami (UM) found that tiger sharks are traveling 250 miles poleward due to warming oceans caused by climate change. MailOnline reported that the team has recorded the warmest water temperature on record over the past 10 years, which may have pushed tiger sharks to migrate 14 days earlier to waters long the US northeastern coast.

The new study noted that oceans in the north were historically too cold for the sharks, but climate change is changing it all. These changes do not only pose threat to human safety, but to the sharks, too, because they venture to unprotected areas where they could be subjected to commercial fishing.

 Climate Change Forcing Tiger Sharks to Move 250 Miles Up North, Becoming More Vulnerable to Commercial Fishing
Climate Change Forcing Tiger Sharks to Move 250 Miles Up North, Becoming More Vulnerable to Commercial Fishing Unsplash/Jeremy Lanfranchi


Tiger Sharks Population Have Extended to the North

Over the past four decades, wildlife experts noticed that the distribution of the tiger sharks population has already extended further poleward along with warming waters, says UM Shark Research and Conservation Program director Neil Hammerschlag in a statement.

He added that the northeast portion of the US was thought to be historically too cold for tiger sharks but now has warmed, making it a suitable environment for tiger sharks. Hence, the increased sightings of tiger sharks in those areas.

Hammerschlag and his colleagues sought to uncover how warming waters affect tiger sharks. So, they tagged 69 of these sharks found off the southeast and southwest coasts of Florida as well as the northern Bahamas to monitor migration patterns for nine years that started on May 2010 to January 2019.

They generated 5,227 locations coming from the 47 tiger sharks and concluded that for every one degree Celsius (1.8 degrees Fahrenheit) increase of water temperature during the warmest months, tiger sharks also moved toward the north by nearly four degrees latitude.

Migration of Tiger Sharks to the North May Have Greater Ecology Implications

Hammerschlag said their findings may have greater ecological implications given that tiger sharks are apex predators. According to Science Daily, these changes in the movements of tiger sharks could change predator-prey interactions that may lead to imbalances in the ecosystem and more frequent shark-humans encounters.

In the study, titled "Ocean Warming Alters the Distributional Range, Migratory Timing, and Spatial Protections of an Apex Predator, the Tiger Shark (Galeocerdo cuvier)" published in the journal Global Change Biology, researchers wrote that implications of the study could also include the conservation of the species.

As more tiger sharks move outside of their protected areas, the more they are at risk of commercial fishing. If that happens, it could drastically change their ecology, especially since tiger sharks reproduce and grow slowly, making them vulnerable to threats.

Smithsonian Magazine reported that tiger sharks prefer the balmy temperatures of ocean waters, so they arrive earlier in the year and even extend farther north than they did four decades ago.

Check out more news and information on Sharks in Science Times.

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