Over the past decade white sharks (Carcharodon carcharias) have been observed more frequently in the waters of coastal Massachusetts. Often referred to as ‘great whites,’ the white shark is well known for its size and power; the largest recorded individuals have approached or exceeded 20 feet in length and 2 tons in weight and are arguably the world’s largest extant macro-predatory fish and primary marine mammal predator. However, most sharks observed in Massachusetts have been between 8-15 feet long, with estimated weights less than 2,000 pounds.
Most observations of white sharks in the waters of Massachusetts have come from areas east of Chatham’s Monomoy Island. This 8-mile long spit of sand extends southwest from the Chatham mainland and is home to the Monomoy National Wildlife Refuge. The refuge was established in 1944 to provide a resting, nesting and feeding habitat for migratory birds. More than ten species of seabirds, shorebirds and waterbirds nest on the island, including the second largest nesting colony of common terms on the Atlantic seaboard, as well as colonies of the federally protected piping plover and roseate tern.
Monomoy Island’s inlets and sand deposits are also a haven for thousands of gray and harbor seals. Monomoy’s seal population has been steadily growing for the past few decades with many thousands observed, a result of their protected status under the 1972 Marine Mammal Protection Act. This large and increasing population of marine mammals is likely a primary reason for the amplified shark activity off Chatham.
The white sharks in this area actively swim back and forth along the eastern shoreline of Monomoy Island in an apparent search for feeding opportunities. Their distance from shore could be as little as 25 yards, but most often they have been sighted ¼ - ½ mile or more offshore. Despite their size white sharks are difficult to spot as they are a deep water species; their characteristic dorsal fin is usually not visible above the waterline.
For the past 25 years the Massachusetts Division of Marine Fisheries (MarineFisheries) has been studying the habits of more than a dozen species of coastal sharks that frequent the Commonwealth’s waters. In 2009 senior shark biologist Dr. Greg Skomal began a white shark tagging program using electronic PSAT tags. The program was recently endowed with a $25,000 grant from the Sacco Foundation to continue on-going research.
In early September 2009 Dr. Skomal, working with local fisherman Bill Chaprales and spotter pilot George Breen, tagged 5 sharks off the eastern shore of Cape Cod. These were the first successful tags deployed in the western Atlantic. These tags collected and recorded water temperature, depth and light level data. Once dislodged from the sharks the tags transmitted the information, via satellite, back to MarineFisheries scientists who were able to determine the sharks’ possible movements and migrations. To date all 5 of these transmitters have surfaced, with 4 providing valuable data. The tags indicate that the sharks stayed in Massachusetts’ coastal waters through September before moving south and west. While in the waters of the Commonwealth’s the tagged white sharks moved from shallow waters to depths of 50-100 feet, demonstrating that they remained close to Monomoy Island. Four of the sharks were found to leave the coastal waters of Massachusetts in the fall and head for the waters of the southeastern United States where they stayed from January through March (click for shark migration map).
This season Dr. Skomal and his team have successfully tagged three additional white sharks. These tags will provide data that furthers ongoing shark location and migration research. This website will be periodically updated with new research findings.
The eastern coast of Monomoy is a known seal hunting ground for the white shark. When feeding they are less likely to distinguish human activity from that of their principal prey; therefore any commotion in the vicinity of their prey could provoke an attack. While shark attacks are extremely rare and fatalities even rarer, MarineFisheries urges all beach goers to look for beach postings and heed all warnings issued by municipal officials. We strongly recommend that the public use extreme caution when utilizing the coastal waters east of Monomoy Island (red shaded area); especially swimmers, kayakers and surfers. If you go in the water, maintain distance from seals. If you notice that seals remain in shallow water there may be nearshore presence of white sharks.
2010 White Shark Sighting and Tagging Updates
September 1, 2010 Single great white shark tagged off of Chatham, MA with a pop-up satellite tag. Seventh white shark tagged this summer.
August 27, 2010 Single great white shark tagged off of Chatham, MA with a pop-up satellite tag. Sixth white shark tagged this summer.
August 21, 2010 Single great white shark tagged off of Chatham, MA with a pop-up satellite tag. Two basking sharks were also tagged with pop-up satellite tags off of Chatham. Fifth white shark tagged this summer.
August 12, 2010 Single great white shark tagged off of Chatham, MA. Fourth white shark tagged this summer.
August 7, 2010 Single Great White shark tagged off the shores of eastern Monomoy. Third shark tagged this summer.
August 3, 2010 Single Great White shark spotted by spotter pilot George Breen in the early morning off south Beach Chatham.
July 31, 2010 The team tagged the second shark of the season with a pop-up satellite tag. This shark was estimated at 10 feet long. Over the course of the day, six different white sharks were seen in the area by the spotter pilot- all within 1 mile from shore. One of the sighted sharks was a re-sighting of the previously tagged white shark from July 27.
July 30, 2010 After 3 white sharks were sighted off South Beach in Chatham, town officials closed the east facing beaches of Monomoy until further notice.
July 27, 2010 Spotter pilot George Breen spotted seven white sharks east of South Beach near Chatham. Estimated length ranged from 10-18 feet. One female white shark (14 ft.) was tagged with a pop-up satellite tag about 150 feet from shore.
July 25, 2010 Three great white sharks sighted, one off the tip of Monomoy Island and the other two near the north break of Chatham Harbor.
July 20, 2010 Spotter pilot George Breen observes a great white shark stalking seals south of Lighthouse Beach, on the Eastern side of Monomoy Island.
EOEEA Press Releases:
June 28, 2010: Catch and Release of White Shark on Stellwagen Bank
March 3, 2010: Two More White Sharks Tracked to North Coast of Florida
January 20, 2010: First White Shark Tag Surfaces off Florida Coast
Sharks in the News:
August 27, 2010: Basking Sharks Commonly Mistaken for White Sharks
August 26, 2010: Beaches are Safe Despite Rise in Shark Sightings
August 13, 2010: Shark Sightings on the Rise
July 29, 2010: White Shark Tagging Efforts