On July 1, 2010, SFGate relayed a Bloomberg News report: "Great White Shark Warning Issued for Massachusetts Holiday". The Coast Guard in Boston had warned of a sighting of a seven-foot-long great white shark in the last week of June, 2010. This follows on previous reports of sharks as large as fifteen feet. Sharks this large could capsize a kayak or small boat.
Greg Skomal, of the Division of Marine Fisheries, speculated that the sharks are coming to Cape Cod because of a growing seal population. Harbor seals are the most common seals found in this area of New England.
Expect Annual Incursions of Great White Sharks off Cape Cod
(Updated Nov. 3, 2011). Further reports of great white sharks off Cape Cod surfaced in the summer of 2011. Molly Line's report for Fox News, "Great White Sharks Pose Danger and Discovery Off Cape Cod Beaches" was one of many to sound the alarm. So long as seals thrive in this region, the sharks will continue to use Cape Cod as a seasonal hunting ground.
Introduction to the Great White Shark
The great white shark is the world's biggest predatory fish. Individuals can reach over 20 feet in length and over 4,000 pounds in weight.
They are found in coastal waters, if the temperature is right. They tolerate a range from 54 to 75 degrees Fahrenheit, but prefer 59 to 67 degrees. In the summer, the Cape Cod coast is a nearly perfect fit for their temperature preference. They probably winter further south near Florida. They swim in fairly shallow water where sunlight easily penetrates. Besides haunting the eastern seaboard, great white sharks also are common off California, Mexico, Australia and South Africa.
The scientific name is "Carcharodon carcharias", which means "sharp tooth". Each triangular tooth is well designed for slicing meat. With many teeth and terrific biting strength, the great white shark is well deserving of its scientific name.
The Diet of the Great White Shark
Great white sharks eat large fish, such as tuna; marine mammals including porpoises and dolphins, sea lions, and of course seals; and sea birds. In addition to their famous ability to "smell" blood in the water, they can sense the small electrical currents that animals emit. Sharks often attack from below, to avoid being noticed and to make it difficult for their prey to flee.
While they are certainly dangerous to individual swimmers or kayakers, they do not especially prefer humans as food. Whether people do not have the right flavour, or wet suits and snorkels have the wrong textures, sharks just do not pursue homo sapiens as their main prey.
Concerns for Conservation
The International Union for Conservation of Nature (IUCN) considers the great white sharks to be "vulnerable" - likely to become "endangered" unless conditions improve. From this perspective, these sharks are to be protected rather than to be feared or hunted.
Seals: The Cape Cod Connection
The Cape Cod hotel industry encourages every tourist to view the harbor seal colonies off the coast of Chatham, Monomoy and South Beach.Not surprisingly, these are the very areas where great white sharks have been sighted.
Harbor seals are the most common in this area. They are up to six feet long and weigh up to 200 pounds.On some sunny afternoons, perhaps 1,500 seals can be sighted basking on Monomoy Island alone.
The larger grey seals - actually more of a silver or brown color - may reach eight feet in length, with the females weighing in at about 700 pounds. The males are considerably lighter, at perhaps 400 pounds.
Seals are, themselves, predators: they eat fish, shrimp and squid. Seals are simply not at the top of the food chain: they are outranked by sharks.
Great White Sharks: the Expected Guests
So the return of the great white shark to the Cape Cod coast was not a surprise...except possibly to the occasional tourist, and certainly to any seals who became meals for this amazing piscine predator.
References:
Susan Milton, CapeCodOnline.com, published July 13, 2010, referenced July 14, 2010.
(Editors: Charlotte Porter, Richard Stubbe), SFGate.com, published July 1, 2010, referenced July 14, 2010.
Wikipedia.org, referenced July 14, 2010: Great White Shark article.
(Added Nov. 3, 2011) Molly Line, Fox News, "Great White Sharks Pose Danger and Discovery Off Cape Cod Beaches", published Aug. 4, 2011, referenced Nov. 3, 2011.
Mike DeHaan - Copyright (c) Mike DeHaan, B. Math., of DeHaan Services. Well written and well researched freelance articles; ghost writing for clients.
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