At least one scientist believes that hundreds of great white sharks may be in Passamaquoddy Bay each season as they may be looking to establish courtship and mating areas, but other scientists, including shark experts, are skeptical of the hypothesis. However, last year acoustic receivers in the region of the bay did pick up signals from between 36 and 46 great whites that have been tagged, and interest in the large, aggressive sharks has been increasing. Later this month, National Geographic reportedly will be in the Passamaquoddy Bay area to film a segment on great white sharks.
      Steve Crawford, a fish ecologist at the University of Guelph in Ontario, has been in the area for the past few weeks to gather reports and information from local knowledgeable people about great whites in the bay. The Jacques Cousteau television series had hooked him as a child to learn about the sharks, and after he read the book Jaws on a trip with his parents to Florida, "My toes never touched the water." The section of the book from the shark's perspective sparked his interest in animal behavior. When he worked with Indigenous peoples around the Great Lakes for 25 years gaining knowledge from the people who lived there, he began knowledge system research, realizing that local people are a good source of reliable information about local environments.
      In 2015, while interviewing people in New Zealand about great white sharks, he spoke with a man who was the first person to see two white sharks mating, which was in 14 feet of water in the middle of a harbor. Crawford notes, "It's what scientists should be doing -- talking with people who spend their lives on the water."
      Now in the Passamaquoddy Bay area, Crawford is conducting the same type of research here. "I'm going on both sides of Passamaquoddy Bay to find the most knowledgeable people, who spend time on the water." Over the next few years, he hopes to eventually interview perhaps 150 people from Key West to Labrador about their experiences seeing the sharks.
      Crawford notes that many great white sharks have been tagged with either satellite tags or acoustic telemetry pingers. There was already an array of acoustic receivers in Passamaquoddy Bay, along with ones around Deer Island, Campobello and Grand Manan, and last year signals from nearly 50 different sharks were picked up through the season in Passamaquoddy Bay. Adding in the many sharks that are not tagged, Crawford claims, "We're talking on the order of hundreds of great white sharks in Passamaquoddy Bay through the season, and at any time there could be between 50 and 100 individuals."
      Crawford notes that about two years ago a woman saw a great white shark taking a porpoise off Todd's Point, St. Stephen, and a few years ago a woman kayaking off Deer Island was chased by a great white shark. Also, two years ago Kingsley Pendleton and his family of Deer Island saw a great white that was approximately 20 feet long, one of the largest ever documented, in the waters just north of St. Andrews. And in just the past week, two seals were seen being taken by great whites in Passamaquoddy Bay.
      Crawford is hypothesizing that great white sharks are not just feeding in the area but may be establishing courtship and mating territories for enticing large females to Passamaquoddy Bay, particularly around sandy bay areas that are near seal colonies. The males would also patrol their territory and chase off any intruding males. "We should leave them alone, if they are setting up territories," Crawford says, "and not have people putting themselves at risk." He says people who are on or near the water need to keep an open eye out for sharks, although he notes they are not "man-eaters" and rarely engage with people. The Maine Department of Marine Resources (DMR) also advises that, while the relative risk of a shark attack is very small, the risks should be minimized.
      Crawford points out that he is not the only scientist who has put forward this suggestion about the activities of white sharks in the area. In 1998 a journal article by Paul Mollomo in the Northeastern Naturalist hypothesized that there were more great whites in the waters off Maine and Atlantic Canada than people thought. And Mollomo mentions a female great white shark that was found dead on a beach near Deer Island that had numerous nipping lacerations that it may have received when it was impregnated by a male. The article mentions numerous other shark encounters, including a reported 37-foot shark found in a herring weir on White Head Island in June 1930, which would be the largest white shark ever reported.
      As for the great white shark attack on a woman who was swimming off Bailey Island in southern Maine in July 2020, Crawford says it might have been a case of the shark mistaking the woman for a seal, as has been speculated, but he believes that the shark may have been acting in a territorial manner and chasing her out of the cove. He believes that there is enough uncertainty that more details need to be released about the attack.
      Crawford believes that great whites have been in the Passamaquoddy Bay area for a long time, noting that pre-contact, Indigenous peoples in the areas of Maine and New Brunswick had a tradition of burying their dead with great white shark teeth. "They're not rare; they're just not seen very often," he notes. Crawford believes they regularly migrate into Passamaquoddy Bay and may also be doing so off Cape Breton and Sable Island, N.S. "It's not the only area, but it's a major one and appears to have been for eons."
      Noting there is still much that is unknown about the behavior of great white sharks, Crawford says, "We are ecological detectives," like those who come onto a crime scene and try to figure out what has happened.
      Crawford has been issuing an open call to hear from people who have had interactions with great whites to contact him. They can reach him at scrawfor@uoguelph.ca. The Maine DMR also is collecting data on sharks, which will be shared with the Atlantic White Shark Conservancy to be uploaded to their Sharktivity app. The app provides users with a recap of shark activity detected by acoustic receivers, in addition to shark sightings. Information and app downloads can be found at www.atlanticwhiteshark.org/sharktivity app.

Researchers urge caution on estimating numbers
      Other scientists, including shark experts, are unconvinced about some of Crawford's hypotheses. Marc Trudel of the Department of Fisheries and Oceans' (DFO) St. Andrews Biological Station reports that last year they deployed approximately 160 acoustic receivers in the Passamaquoddy Bay area, including around Campobello, Grand Manan, Cobscook Bay, Back Bay and Maces Bay. While the main purpose of the work was to investigate the migration of Atlantic salmon and alewife and the extent of their interactions with aquaculture fish, they also documented species tagged by other researchers that migrate into the area, such as white shark, sturgeon and striped bass. The researchers detected 36 white sharks, with 10 additional tag codes that are suspected to be from white sharks.
      Trudel notes that the technology "can be our ears to observe the ocean in a different way, and at times, they will pick up things that we don't always see with our own eyes, because these animals are not always at the surface or not at the time of the day when we can see them."
      Heather Bowlby, research lead at DFO's Canadian Atlantic Shark Research Laboratory, says the number of detections in Passamaquoddy Bay is consistent with research that suggests approximately 20% of the wider population in the northwest Atlantic is expected to move northward in any given year. While not able to speculate on how many white sharks would be in the Bay of Fundy at any one time, she notes that it is important to recognize that the receivers in Passamaquoddy Bay weren't picking up 36, or possibly 46, individual white shark tag codes at the same time, but that the detections were spread over the months of June to early November. The highest number of tag codes detected in a single week was around 10 and in most weeks was around two to four. She notes, "Individuals are continually moving into and out of the bay, possibly travelling farther along the Canadian coastline or possibly returning to U.S. waters."
      As for Crawford's suggestion about mating in the bay, Dr. Bowlby states that there is "nothing in the acoustic or satellite tag monitoring data that supports this hypothesis." Juvenile white sharks are nearly five times more likely to come to Canada than adults and would not yet be concerned about mating. "The behaviour exhibited by white sharks along the Canadian coastline is consistent with searching and foraging behaviour rather than aggregation behaviour associated with mating," she says. "There is no data that suggests white shark are born in Canadian waters, and individual animals spend the majority of their time in habitats along the continental U.S."
      The acoustic monitoring strongly supports that sharks in this area are seasonal visitors, and Bowlby adds, "I don't have any evidence that white sharks are increasing occupancy in Canadian waters." She says that a relatively consistent proportion of the tagged population, about 20% since 2016, comes to Canada each year, and that doesn't suggest their presence in Canada is increasing. "What we have seen is that as more animals are tagged and as we increase monitoring effort, we detect more animals."
      Greg Skomal, a senior fisheries biologist at the Massachusetts Division of Marine Fisheries, has studied sharks for more than three decades and is considered the North Atlantic's go to guy for information about white sharks. He says there is no way to extrapolate the number of tagged sharks picked up by the acoustic receivers to the total number of sharks in the bay. "I think the term 'hundreds' is unrealistic and, to my knowledge, there is no evidence of courtship and mating in Passamaquoddy Bay."
      Skomal says it is very difficult to say whether white shark numbers are increasing in Passamaquoddy Bay. "We can look at raw numbers and probably see more detections each year, but we have to take into consideration that more white sharks are tagged each year." In recent years about 40 to 50 sharks have been tagged per year.
      However, he says it appears that the western North Atlantic population of sharks is rebounding from high levels of exploitation and therefore increasing. He adds, "With the growing abundance of seals over the last two decades, it is reasonable to conclude that more white sharks are likely to be moving into the Gulf of Maine to take advantage of this resource."