The Puget Sound, a complex network of waterways, harbors diverse marine life. While many associate sharks with warmer waters, a surprising number of species call the cool, deep waters of the Sound home. These aquatic predators play a role in the local ecosystem.
Resident Species: Common Sharks
The bluntnose sixgill shark is among the most commonly encountered species in the Puget Sound, reaching lengths of 16 to 20 feet. These deep-water sharks enter shallower areas of the Sound, which may serve as important pupping grounds for young sharks. While typically found in oceanic depths, their presence in the Sound’s shallower waters is notable.
The Pacific spiny dogfish is another abundant resident, a smaller shark measuring up to 4.3 feet. These sharks are widespread in cold waters and frequently found in large schools within the Puget Sound. They migrate seasonally, moving into shallower coastal waters during summer and retreating to deeper areas, sometimes up to 3,900 feet, in winter.
The Pacific sleeper shark also inhabits the Sound’s deep environment, though less frequently observed. This species can grow to 14 feet long and resides in depths reaching 6,480 feet. The broadnose sevengill shark has also been confirmed as a resident, particularly in the South Puget Sound. These sharks, growing to 8 to 10 feet, were previously considered rare but are now known to be present.
Occasional Visitors: Rarer Sharks
Beyond common residents, several other shark species are occasional visitors to the Puget Sound, often entering for reasons like following prey. The salmon shark is a rare visitor that can reach 10 feet in length and may enter the Sound, possibly following salmon runs. These sharks consume a variety of fish, squid, and marine birds.
The blue shark, a pelagic species, is another rare sight within the Sound, though it may be found near its entrance. Growing up to 12 feet, blue sharks feed on fish and squid. Other less frequent visitors include the leopard shark, reported in recent years, which forages in shallow waters for clams, crabs, and small fish.
The critically endangered soupfin shark has also been documented in the South Puget Sound. These sharks can grow up to 6.5 feet. Historically, the basking shark, the world’s second-largest fish, was more common in the Salish Sea but is now a very rare visitor to the Sound, known for filtering plankton at the surface.
Life in the Sound: Habitat and Diet
The Puget Sound’s unique characteristics create a suitable environment for various shark species. As a deep estuary, the Sound averages 450 feet in depth with a maximum of 930 feet, providing extensive deep-water habitats for species like the bluntnose sixgill and Pacific sleeper sharks. This complex system of interconnected waterways is fed by freshwater from numerous rivers, mixing with nutrient-rich saltwater from the Pacific Ocean.
The Sound’s diverse marine ecosystem offers an ample food supply, supporting these shark populations. Sharks in the Sound feed on a variety of prey, including schooling fish like herring and sandlance, as well as crustaceans such as crabs and shrimp. Larger species may also prey on squid, octopus, and marine mammals like seals.
Sharks integrate into the local food web, with species like the spiny dogfish shaping prey populations. Varied habitats, from deep basins to shallower areas with eelgrass and kelp, contribute to the biodiversity that sustains these predators.
Human Encounters: Safety and Rarity
For humans, encounters with sharks in the Puget Sound are infrequent, and the species present are not considered a threat. The risk of a shark attack in Washington state, particularly within the Sound, is low. Most resident sharks are deep-dwelling or naturally shy, preferring to avoid human interaction.
Despite the presence of several shark species, very few shark attacks have been recorded in Washington, with none inside the Puget Sound. This low incidence is due to the sharks’ typical behaviors. For those engaging in recreational activities, basic awareness, such as avoiding swimming at dawn or dusk when some sharks are more active, is advisable.