White Shark Research
|Photo courtesy of Matt Davis, Maine DMR|
Sharks in New England
The Northwest Atlantic Ocean is home to a variety of marine species, and sharks are no exception. From the large filter-feeding basking shark to the small bottom-dwelling spiny dogfish, sharks of all shapes and sizes can be found inhabiting the waters of New England. Perhaps the most notorious and charismatic of these fishes, however, is the white shark.
White sharks are classified as a highly migratory species, traveling large distances in search of optimal foraging and mating opportunities. Their presence in New England is historically documented, and they are most often observed during late spring, summer, and fall months. White sharks are considered an apex predator of their ecosystems, meaning they exist at the top of the food web with few predators. Young white sharks predominantly prey on bony fish, but as they grow and mature, the primary source of food transitions to marine mammals.
Concerning their populations, the management of white sharks in the Northwestern Atlantic could be considered a conservation success story. Research suggests that abundance has increased following the implementation of conservation measures in the 1990’s, and protection of marine mammals in the 1970’s has resulted in recovery of seal populations, which are a major prey of white sharks. However, according to the International Union for the Conservation of Nature (IUCN), as of 2019 the white shark remains a globally vulnerable species, threatened by fishing and harvesting in parts of the world.
This summer, Maine DMR has unveiled a new resource for people on the water or on the shore to confirm if what they see is a white shark. A form is now available online, that provides a convenient way to submit photos and a description of what you see to the Maine DMR science bureau. Visit here for more information and a link to the form.
Ongoing Research and Collaboration
In 2020, the Maine Department of Marine Resources, in collaboration with Massachusetts Division of Marine Fisheries, the Atlantic White Shark Conservancy, and James Sulikowski of Arizona State University, initiated efforts to monitor the presence of white sharks in southern Maine waters. With the placement of acoustic monitoring devices (or “receivers”), which record signals from acoustic transmitters (or “tags”) attached to sharks by researchers outside the DMR, the DMR and its collaborators monitored trends in coastal shark activity. Results from this preliminary survey are being used to expand the survey’s scope in 2021. As of June this year, DMR has successfully deployed 32 passive acoustic receivers across southern and Midcoast Maine.
To further improve the management and scientific knowledge of white sharks in the Northern Atlantic, Maine DMR has partnered with several regional organizations to form the New England White Shark Research Consortium (NEWSRC). With access to a large variety of resources and knowledge, the DMR and NEWSRC aims to further our understanding of white shark ecology, distribution, and habitat use. Members of the NEWSRC include: Atlantic Shark Institute, Atlantic White Shark Conservancy, Center for Coastal Studies, Canada Fisheries and Oceans, Massachusetts Division of Marine Fisheries, New England Aquarium, New Hampshire Department of Natural and Cultural Resources, National Oceanic and Atmospheric Administration Apex Predators Program, Rhode Island Department of Environmental Management and Division of Marine Fisheries, Sulikowski Shark Lab of Arizona State University, University of Maine, Bigelow Laboratory, University of Massachusetts (Amherst and Dartmouth), and University of New Hampshire.
The department deployed 11 receivers between Wells and Popham Beach State Park in 2020.
All sites were chosen to ensure that data supports efforts to protect public safety and to provide important information about migration and habitat use of great white sharks in the Gulf of Maine.
Receivers deployed in 2020 were retrieved in the fall and data was downloaded by DMR Science Bureau staff. It has been shared wit the New England White Shark Research Consortium, which will incorporate it into its ongoing research.
Data from the acoustic receivers has been uploaded to the Atlantic White Shark Conservancy Sharktivity app. The app provides users with a recap of shark activity detected by receivers, in addition to shark sightings information and alerts. The app also allows users to upload their own photos and locations of sharks they spot. Information and app downloads can be found at https://www.atlanticwhiteshark.org/sharktivity-app.
2020 Acoustic Receiver Array Details
- Receivers deployed: 11
- Depths range: 27’ to 55’
- Total fish detected: 45
- Non-shark fish: 29
- Total transmitter pings: 20,244
- Non-shark pings: 19,000+
Shark Species Observed
- White Shark (Carcharodon carcharias): 14
- Blue Shark (Prionace glauca): one
- Sand Tiger Shark (Carcharhinus taurus): one
- Earliest detection: “Lockjaw” on Jul 25th at Stratton Island
- Latest detection: “White Shark 2020_07” on Nov 8th at Wells
- Largest shark: “Gillie” – 15’ female white shark tagged in 2015
- Smallest shark: unnamed 4.5’ female white shark tagged in 2017
- Sharks detected by two or more receivers: “Joanie”, “Salty”, “White Shark 2020_07”, and one unnamed
- Most mobile shark: “White Shark 2020_07” - detected at six receivers from Aug 20th (Popham) to Nov 8th
- Most active months: August (seven white sharks) September (five white sharks, one blue shark)
- Most active receivers: Bailey’s Island (four white sharks) and north Wood Island north (four white
sharks, one blue shark)
Plans for 2021
Maine DMR has deployed 32 acoustic receivers in 2021 in collaboration with partners in the New England White Shark Research Consortium. The receivers will continually log and store data until they are retrieved and data is downloaded. DMR plans to retrieve the receivers and download data at least once during 2021 and again when they are pulled for the winter.
The receiver array was made possible in 2020 thanks to members of the New England White Shark Research Consortium, with special thanks to Massachusetts Division of Marine Fisheries, Atlantic White Shark Conservancy, and the Sulikowski lab. Transmitters detected by this array originate from regional collaborators both within and outside the consortium.
About the New England White Shark Research Consortium
Maine DMR, in collaboration with members of the New England White Shark Research Consortium, aims to characterize the presence and habitat use of white sharks in coastal Maine waters. Established in 2020, the consortium continues to expand its monitoring coverage within the northern Gulf of Maine and throughout the region.
- Sharks belong to a group of animals called Elasmobranchii – fish that have bones made of cartilage. Stingrays and skates belong to this same group!
- Sharks are old – the first is thought to have originated over 400 million years ago!
- Not all sharks are apex predators – some smaller species, like the spiny dogfish, are prey for larger species.
- Some sharks give live birth, while others produce eggs. In very rare instances, scientists have observed parthenogenesis; that is, a female shark reproduced without male contact!
- Sharks are important – whether big or small, sharks help to regulate prey populations and transfer energy within their ecosystem. This is important in sustaining marine environments.
- Shark attacks are extremely rare – more people succumb to injury from lightening strikes than they do shark attacks.
- Though rare, attacks are recorded – reported attacks are tracked globally and publicly compiled in the International Shark Attack File (https://www.floridamuseum.ufl.edu/shark-attacks/)
- If you choose to swim, surf, or paddle, be aware of your surroundings
- Stay close to shore
- Swim, paddle, and surf in groups
- Avoid areas where there are seals or schooling fish
- Avoid murky, or low visibility water
- Limit splashing
- Avoid swimming at dawn/dusk when lighting is low
- Adhere to all signage at beaches and follow lifeguard instructions
- Additional advice is available at https://www.floridamuseum.ufl.edu/shark-attacks/reduce-risk/swimmers/
Seasonal Distribution and Historic Trends in Abundance of White Sharks, Carcharodon carcharias, in the Western North Atlantic Ocean Movements of the white shark Carcharodon carcharias in the North Atlantic Ocean
Also see the Species Info page for more general information for many species.