Lurking far below the surface of Puget Sound is one of Washington’s most ancient and mysterious residents: the bluntnose sixgill shark (Hexanchus griseus). With six gill slits instead of the usual five and a lineage that dates back more than 200 million years, sixgills are living fossils. While they may look intimidating, these sharks play a quiet but critical role in keeping Washington’s marine ecosystems healthy.
But out of sight shouldn’t mean out of mind. Sixgill sharks have been here since before the dinosaurs—and with the right choices, they’ll remain a vital part of Washington’s marine future.
Washington already has a state fish (steelhead), a state marine mammal (orca), and a state bird (the goldfinch). But we lack another major symbol of our marine heritage—a state shark. And no shark represents Washington waters better than the six-gill. Also, no other state has an official shark - here’s why Washington should lead the way:
1. They’re uniquely Pacific Northwest.
Six-gills are found worldwide, but the Salish Sea hosts one of the largest known urban shark populations on Earth. Few other big sharks spend so much time close to major cities.
2. They highlight the importance of deep-water habitat.
From the deep fjords of Hood Canal to the canyons off the Olympic Coast, six-gills depend on the very habitats Washington is working to protect.
3. Protecting six-gills means protecting the whole ecosystem.
Designating a state species often sparks conservation funding, education, and research.
Sixgill sharks are typically deep-water dwellers, spending their days hundreds or even thousands of feet below the surface before sometimes rising into shallower waters at night to feed. Puget Sound is one of the few places in the world where researchers can regularly observe sixgills relatively close to shore, making Washington a globally important place for studying this elusive species.
Sixgills are one of the largest sharks in the world, growing up to 20 feet long, but despite their size, they are not a threat to humans. Sightings are rare, and interactions even more so. For most Washingtonians, sixgills remain an unseen presence—doing essential work out of sight.
Sixgill sharks are apex predators. That means they help regulate populations of fish, rays, and smaller sharks, preventing any one species from dominating the ecosystem. This balance is crucial for maintaining healthy food webs throughout Puget Sound and Washington’s offshore waters.
When top predators disappear, ecosystems can unravel. Overpopulation of certain species can lead to habitat degradation, loss of biodiversity, and cascading impacts that affect everything from kelp forests to commercially important fish species. By keeping prey populations in check, sixgills help sustain the overall resilience of Washington’s marine environment. Sixgills also play a vital role as scavengers, helping to clean up the ocean floor.
Because sixgills live so long—possibly up to 80 years—and sit high on the food chain, they are particularly vulnerable to pollution, toxic runoff, and bioaccumulation of contaminants. Changes in sixgill populations can signal deeper problems in water quality and ecosystem health. In this way, sixgill sharks are living indicators of how well we’re caring for Puget Sound. Protecting clean water, reducing plastic pollution, and preventing toxic discharges doesn’t just benefit people—it helps safeguard species like sixgills that rely on a healthy marine system to survive.
Despite their ancient resilience, sixgill sharks face modern threats. Bycatch, vessel traffic, underwater noise, habitat degradation, and pollution all pose risks. Climate change adds another layer of uncertainty, altering ocean temperatures and oxygen levels in the deep waters sixgills depend on. Because sixgills reproduce slowly and have relatively few offspring, population declines can take decades—or longer—to recover from. That makes proactive conservation especially important.
Sixgill sharks are part of what makes Washington’s waters unique. Few places on Earth can claim a resident deep-sea shark living so close to urban shorelines. They are a reminder that Puget Sound is not just a backdrop for recreation or commerce—it’s a living, breathing ecosystem connected to the deep ocean. Protecting sixgill sharks means protecting clean water, intact marine habitats, and balanced ecosystems. These are the same values that support surfing, fishing, wildlife watching, and coastal communities across Washington.
Everything that flows into our waterways eventually reaches the sea. Efforts to reduce plastic pollution, improve stormwater management, protect nearshore habitats, and address climate change all contribute to a healthier home for sixgill sharks. By standing up for clean water and thriving oceans, we’re not just protecting what we can see—we’re safeguarding the ancient life forms cruising quietly beneath the surface.
Six-gill sharks embody everything powerful and wild about Washington’s waters: depth, mystery, resilience, and beauty. They are ancient guardians of the Salish Sea, quietly shaping our marine ecosystems while remaining almost entirely invisible to the public eye.
It’s time to bring them into the spotlight.
Washington is a state defined by water: the Pacific, the Salish Sea, the Strait of Juan de Fuca, and thousands of miles of coastal habitat. A state shark is a natural fit.
And let’s be honest—choosing a giant, ancient, curious deep-water shark as a state symbol is undeniably cool.
A short PBS documentary on the Six Gill Shark in Puget Sound