The new study has revealed that white sharks are increasingly frequent visitors to the waters along Maine’s coastline, particularly in the northern Gulf of Maine. Researchers have been tracking them using acoustic telemetry data from 2012 to 2023, to shed light on their movements and habits.

From 2012 to 2019, researchers deployed 11 acoustic receivers on average each year to monitor white shark activity. After a fatal shark incident in Maine in 2020, the effort was ramped up, with 40 receivers being used annually from 2020 to 2023. Over the years, 107 white sharks were tagged and tracked, with most of the sharks found in shallow waters less than 50 meters deep.

Most are young individuals

The sharks detected ranged in size from 2.1 to 4.9 meters, with the majority being juveniles or subadults. Most detections occurred between May and December, peaking between July and September. The sharks were spotted in several areas near Maine's western beaches, as well as in eastern Casco Bay, where higher concentrations were noted.

Although the number of detections is low compared to shark aggregation sites, this study provides valuable baseline data on the increasing presence of white sharks in this part of the world. Researchers suggest that more work is needed, including expanded receiver coverage in eastern Maine and the use of additional tagging technologies to provide more data.

Their protection is crucial

These findings offer important information that could help with marine spatial planning and conservation efforts in the region. With white shark numbers increasing in Maine's coastal waters, this study is a crucial step toward better understanding and protecting them. 

More about white sharks

White sharks are apex predators and their diet consists primarily of marine mammals including seals and sea lions. They also eat large fish and smaller sharks. 

Behaviour

They frequently approach their prey unseen from below, an ambush-style strategy. Their powerful upward lunge often brings them through the surface with explosive force, their prey grasped in their powerful jaws. They will often take a single bite and then retreat, allowing the prey to die from blood loss before they eat it.

They will also mouth objects to see if they are edible. Unfortunately, this mouthing can result in a terrible wound to a person. But, the shark moves away instead of feeding because white sharks do not eat people.

White sharks will congregate around areas where there is abundant prey, such as seal colonies. At such times, their interactions with each other have been seen to be much more complex than scientists expected. Their social lives are still not well known nor understood.

Migration

The great white shark undertakes long-distance migrations, often travelling thousands of miles across oceans. Tracking studies have found that sharks off the coast of South Africa, for example, migrate to the waters of the Indian Ocean and even to the coast of Australia.

White sharks have also been found to move between the shallower waters off the coast and the deep ocean, possibly for reasons linked to mating or feeding. They can regulate their body temperature to stay active in colder waters, which helps them hunt in deep, nutrient-rich waters. Some studies suggest that white sharks exhibit vertical migrations, diving to deep water during the day and coming closer to the surface at night. This behaviour may be linked to hunting patterns, as some prey species, like squid, are more active at night.

Protection needed

White sharks are considered vulnerable due to overfishing, habitat destruction, and by-catch in commercial fisheries. They are protected in many parts of the world, and various conservation efforts aim to preserve their populations and prevent further declines.

Conclusion

White sharks are complex and fascinating animals, with behaviour patterns that have been shaped by their status as apex predators. While much is known about their hunting and migration patterns, there is still much to learn about their social interactions, reproductive habits, and overall ecology. As research continues, scientists are uncovering more about how these remarkable animals navigate and thrive in the world’s oceans.