Eight shark species are known from Maine waters, according to the state’s Department of Marine Resources (DMR). The one that makes the news is the great white, which DMR scientists track every summer. Here is what is known about each shark, what the state’s numbers show, and where sources disagree.
The 8 shark species in Maine
DMR lists these sharks as found in Maine: basking, blue, common thresher, porbeagle, sand tiger, shortfin mako, spiny dogfish and white. Bangor Daily News and the Island Institute also say eight.
- White shark (great white). An apex predator that DMR says is most often seen in July, August and September. More below.
- Basking shark. A large shark that the Island Institute calls harmless.
- Spiny dogfish. The smallest of the eight, per the Island Institute.
- Porbeagle. In 2010, as Down East tells it, an 8-foot porbeagle charged a commercial diver, who was not injured.
- Blue shark, common thresher, shortfin mako and sand tiger. All listed by DMR as found in Maine.
Great white sharks in Maine
According to DMR, white sharks are most often seen along Maine’s coast in July, August and September. DMR says western North Atlantic populations appear to be slowly recovering, which it links to shark conservation measures from the 1990s and marine mammal protections from the 1970s.
Since 2020, DMR, the Massachusetts Division of Marine Fisheries and the Atlantic White Shark Conservancy have monitored white sharks in southern and mid-coast Maine. Acoustic receivers along the coast pick up sharks that carry tags, and DMR says about 300 white sharks carry them.
The state’s yearly counts:
- 2023: DMR’s report recorded 29 white sharks, 81 since monitoring began in 2020, with 1,700 detection events.
- 2024: DMR’s report detected 19 white sharks, 93 since 2020, with 26 sighting records. August and September were the peak months.
These counts are not a headcount. DMR says only some white sharks are tagged, receiver coverage is sparse, and in 2023 nine of its 26 receivers were not recovered, so the totals likely understate activity. It also says 2024 was markedly lower than the 2021 to 2023 averages, partly because fewer receivers were deployed, and that the cause is unclear.
The Island Institute reports that great whites have long lived in the Gulf of Maine but have moved closer to shore as seal populations have grown. DMR also runs a public data portal for white shark activity, at mainedmr.shinyapps.io/IWSM.
The 2020 shark attack on Bailey Island
On July 27, 2020, a shark attacked a 63-year-old woman swimming near Mackerel Cove on Bailey Island in Harpswell, and she died at the scene. A tooth fragment recovered by the state medical examiner was identified by regional shark experts as a great white, according to Down East magazine, which called it the first confirmed shark-related death in Maine’s history.
Down East adds that colonists recorded multiple shark interactions, including an attack on three fishermen in a dory off Damariscotta, without a count or date. It says that before 2020, Maine had recorded one shark attack report since colonial times, the 2010 porbeagle incident.
Reporting a shark sighting
DMR asks people to report white shark sightings through the Atlantic White Shark Conservancy’s Sharktivity app. Its shark research page also lists how to contact the DMR scientist who tracks them.
Why the sources disagree
- Eight species. DMR, Bangor Daily News and the Island Institute all say eight. The Island Institute adds that hammerheads and whale sharks seen off Cape Cod in 2020 are normally found farther south or offshore, so eight is the regular list, not every shark ever seen.
- Why sightings are up. DMR credits conservation measures for slowly recovering white shark numbers. The Island Institute says warming water is slowly shifting some species north and that seal growth brought whites closer to shore. Down East says most scientists do not believe warming has significantly changed shark concentrations.
- Which year was busier. DMR counted 29 white sharks in 2023 and 19 in 2024, but says receiver numbers changed, so the years are not directly comparable.
- First fatal attack. Down East calls 2020 the first confirmed death in Maine’s history while noting colonial-era accounts of attacks that were never counted.
Sharks in Maine: FAQ
Are there sharks in Maine?
Yes. DMR lists eight species found in Maine: basking, blue, common thresher, porbeagle, sand tiger, shortfin mako, spiny dogfish and white.
Are there great white sharks in Maine?
Yes. DMR says white sharks are most often seen along Maine’s coast in July, August and September, and its acoustic receivers detected 19 of them in 2024.
Has anyone been killed by a shark in Maine?
Down East reports one confirmed fatal attack, in July 2020 off Bailey Island in Harpswell, which it calls the first confirmed shark-related death in the state’s history.
When are sharks in Maine?
Mostly July through September, with August and September the peak months in DMR’s 2024 report.
How do I report a shark sighting in Maine?
Through the Atlantic White Shark Conservancy’s Sharktivity app, according to DMR.
Our details come from DMR’s shark research page, DMR’s 2023 and 2024 white shark reports, Down East magazine, the Island Institute and Bangor Daily News, republished by RESTORE. We have not independently verified each statement, and counts change as DMR publishes new reports.