Is Climate Change Increasing the Risk of Shark Attacks?


Sofia Adelsberg, Staff Writer

Every time we swim in the ocean, we lay our lives at the mercy of fate. Each time, we run the risk of death: by riptides, jellyfish, or most gruesomely, by sharks. The odds of suffering from an attack or death by shark are extremely low, however these risks have been increasing in recent years, most likely from the effects of global warming.

The U.S had the highest amount of unprovoked attacks in 2021, yielding 47 out of the 73 attacks globally, with one even being fatal. Though these numbers are still very low, reason for concern spiked last summer, when five unprovoked attacks were reported off of Long Island, thought to have been caused by sand tiger sharks, and with victims reporting bites on their hands.

 It has been theorized that new increases in shark attacks globally could be from the runoff caused by agriculture. This leads to an overwhelming amount of nutrients like nitrogen in the ocean. Eutrophication, which is the buildup of too much organic materials, can occur from this excess nitrogen. This leads to the acidification of the oceans which results in insufficient amounts of oxygen which can have consequences on the patterns of marine life, including sharks. In the most recent 50 years, oxygen levels are thought to have decreased by 2%. Zones with low oxygen levels are known as dead zones and are often identified and documented by scientists.

From this, studies have shown that sharks and fish tend to prefer these areas. However, this is problematic because the location of these dead zones are very close to the coast. A map created by Bob Diaz, from the Virgina Institute of Marine Science, shows studies on the location of dead zones globally. It demonstrates that most dead zones are located right off the coast, with a large amount occurring on the eastern coast of the U.S.

This means that fish, and therefore sharks, may be coming closer to the coastline following these dead zones. With more sharks closer to the coast in waters where humans swim, conflict is inevitable. Instances such as last summer could continue to increase, but only time will tell.