Posted June 30, 2024
Once a rare sight in Cape Cod, great white sharks have started to return in record numbers each summer to the Cape Cod National Seashore, where they reside from June to October. Drawn by the rebounding populations of several seal species these top predators have been seen hunting in the swells along roughly 40 miles of the coast and they are here to stay. With them comes concerns for public safety. The National Parks Service, MA Division of Marine Fisheries, Atlantic White Shark Conservancy, and other members of the Regional Shark Working Group have collaborated on shark research, knowledge, and safety efforts to mitigate and prevent harmful interactions between the members of the natural and wild marine ecosystem and the humans who recreate in this environment.
The white sharks’ return comes on the heels of another population rise, that of gray seals. To protect the interests of commercial fisheries in the late 1800s and early 1900s, seals were culled with a bounty program that incentivized their eradication from the area. By the 1960s seals were virtually absent on the Cape. The bounty program ended in the late 60s and in 1972 the Marine Mammal Protection Act was enacted formally protecting seals from taking and harassment. Today the population found on the Cape now numbers between 30,000 and 50,000. As an excellent source of fat and nutrition, seals are preferred prey for sharks. The rebound of the Cape Cod seal population has led to sharks returning to hunting in the waters closer to shore where the seals congregate.
A key word here is that these sharks are “returning” to these waters after many years of exile. Many species of shark have long called the waters of Cape Cod home, including dogfish, thresher, sand tiger, basking, and, of course, great whites. All are descendants of a lineage stretching back 400 million years. That kind of pedigree usually comes with an ecological purpose; as top predators, sharks are responsible for influencing many factors that go into marine health including abundance, distribution, and diversity of species. Sharks regulate populations of other marine animals and also increase the health of these populations by preying on sick or weak individuals. Their importance was recognized with designation as a protected species in federal waters in 1997, followed by state designation in Massachusetts in 2005.
With protections in place sharks and seals have been free to live in their natural habitat. This has come with some significant concerns for public safety as the Cape Cod National Seashore draws millions of tourists and beachgoers each summer when shark activity is at its peak. The members of the Regional Shark Working Group have and continue to conduct research on shark behavior and movement which has allowed them to form new safety efforts and increase public knowledge through educational programs and outreach. These include:
- Purple shark flags to remind beachgoers sharks frequent the area
- “Stop the Bleed” first aid training which teaches participants relevant techniques for shark bite victims
- The Sharktivity App, which provides live updates on shark sightings and pings from tagged sharks.
- Shark Centers in Chatham and Provincetown which provide an interactive educational experience for all ages.
If you find yourself in the waters off the Cape this summer, first remember that you are entering a wild habitat — the same as if you were to trek into bear or rattlesnake country — and take the necessary precautions. Sharks, as well as many other wild animals, live in and frequent these waters and there is an inherent level of risk to be aware of in addition to the usual risks of swimming. Be mindful of advisories, look for the purple shark flag, and follow any guidance from lifeguards. General shark safety also advises:
- Be aware sharks hunt for seals in shallow water.
- Stay close to shore where rescuers can reach you.
- Swim, paddle, kayak and surf in groups – don’t isolate yourself.
- Avoid areas where seals are present.
- Avoid areas where schools of fish are visible.
- Avoid murky or low visibility water.
- Limit splashing.
Lastly, remember that unprovoked shark bites occur at an extremely low instance rate. Sharks do not hunt humans despite what JAWS has to say about it. The International Shark Attack File 2023 Yearly Shark Attack Report found 69 unprovoked shark bites, with 10 fatalities resulting worldwide. Don’t let fear stop you from enjoying sunny beach days OR these fascinating marine animals in our ocean.
Written by Julia Ledo, Terracorps Service Member