The Orleans Conservation Trust (OCT) hosted a lecture entitled “Great White Sharks, Our New Neighbors” on Tuesday, April 16th as part of our Third Tuesday Winter Lecture Series. More than 90 people of all ages came to hear Dr. Gregory Skomal, Senior Marine Biologist for the State of MA Division of Fisheries and Project Supervisor of the MA Shark Research Program, speak about the recent insurgence of Western Atlantic Great White Sharks off the coast of Orleans and beyond.
Skomal explained that his primary focus this past summer was in our backyard where he explored the Great White’s feeding behavior as it relates to the gray seals that inhabit the Cape Cod region. This nutritional food source is attracting the sharks and represents an opportunity to understand their localized behavior. Skomal shared some very exciting videos of himself and other professionals within the field successfully tagging a number of Great White sharks along the eastern seaboard. In total, Skomal was able to tag more than 30 sharks this past year using a variety of techniques, which was more than double the total from the previous year.
The acoustic tags will be able to detect a signal from a tagged shark, and will record the time the shark entered the area, how long it stayed, and when it left. This information will be used to see if there are repeat patterns of entry into specific coastal waters for individual sharks, and to determine if environmental factors such as weather and water temperature play a role in their movement.
These tags have also allowed Skomal and other shark scientist to get a better understanding of where the sharks travel on a yearly basis. In 2009 Skomal had the opportunity to film and tag a large, 17-foot 3,000 pound great white named Curley, whom was feeding on a dead whale carcass off the coast of the Cape. After being tagged, Skomal found, to his surprise, that Curley traveled north to Sable Island, an area with a large seal population off the outer banks, and then quickly back down southeast to the Sargasso Sea. It is still a mystery as to why the shark was there, however, it is thought that the Sargasso Sea may be an area where some great white sharks go to have their young.
At the end of the presentation Skomal teased the audience by flashing a picture of his most recent project with the Discovery Channel. Skomal said he has been working to modify an autonomous underwater vehicle to link to the existing acoustic tags, allowing scientists to remotely follow a shark’s movements for extended periods of time underwater.
If you missed this talk, we hope you can come to our next presentation, “The Symbiotic Relationship between Humpback Whales and Marine Birds,” which will be held on Tuesday, May 21st at the Orleans Yacht Club. The talk will be given by Peter Trull, a local naturalist and science teacher at the Lighthouse Charter School. Doors open at 6pm, with the lecture beginning at 6:30pm. We hope to see you there!