Many people commonly believe sharks are creatures of warm, tropical waters, not found in chilly, northern oceans. This misconception often surprises people when sharks in Alaska are mentioned. However, Alaska’s diverse marine ecosystems host various shark species, challenging the idea they are absent from cold environments. Their presence highlights shark adaptability and their integral role in these unique aquatic habitats.
Sharks Found in Alaskan Waters
Alaskan waters are home to several shark species, with the Pacific sleeper shark (Somniosus pacificus), salmon shark (Lamna ditropis), and spiny dogfish (Squalus suckleyi) being the most commonly encountered. The Pacific sleeper shark is the largest, potentially reaching lengths of up to 7 meters (23 feet) and weighing hundreds of kilograms. These sharks are generally dark gray to black with a cylindrical body and a short, rounded snout.
The salmon shark, a relative of the great white shark, is known for its robust, spindle-shaped body, dark gray to black on top, and a white underside. They typically grow between 2 and 2.6 meters (6.6 to 8.6 feet) long and can weigh up to 220 kg (485 pounds). Spiny dogfish are smaller, usually reaching about 0.9 to 1.2 meters (3 to 4 feet) in length. While these three are common, other species like blue sharks and even great white sharks are occasionally sighted in Alaskan waters.
Habitats of Alaskan Sharks
Sharks in Alaska inhabit various marine environments, from deep-sea continental shelves and slopes to coastal and even intertidal areas. Pacific sleeper sharks, for instance, are large deep-water species, often found at depths of 2,000 meters (6,600 feet) or more in lower latitudes, but can be found closer to the surface in colder, higher latitudes. Their adaptations to frigid depths include specialized liver oils that remain fluid at low temperatures, aiding buoyancy.
Salmon sharks are primarily pelagic, meaning they live in the open ocean, but are also found in coastal waters and can dive to depths below 150 meters (500 feet). They prefer cold boreal to cool temperate waters. This species is notable for its ability to maintain a body temperature warmer than the surrounding water, a trait known as homeothermy, which is unusual among fish. This physiological adaptation allows them to thrive in cold North Pacific waters, including areas with seasonal salmon runs.
Interactions with Humans
Interactions between sharks and humans in Alaska are infrequent, and aggressive encounters are rare. Many of the shark species in Alaskan waters, especially the Pacific sleeper shark, primarily inhabit deep, offshore environments, limiting their overlap with human activities. The lethargic nature of Pacific sleeper sharks also contributes to their low threat perception.
Despite the presence of various shark species, there have been no reported fatal shark attacks on humans in Alaska. While some incidents of unusual injuries to seals and sea lions have been attributed to sharks, direct aggression towards humans remains uncommon. Shark experts emphasize that most shark-human interactions resulting in bites are often due to mistaken identity or curiosity rather than predatory intent, and sharks generally do not view humans as prey.