How big is “big”?
The Beringraja binoculata, or big skate, is found along the Pacific Coast—including in the waters of Puget Sound and the Salish Sea—and is the largest skate species in North America. They’ve been recorded up to eight feet long and weighing 200 pounds, with the average falling under six feet long and 110 pounds. They live along the sandy seafloor from the intertidal zone to a depth of 390 feet, eating shrimp, worms, clams and some fish.
Breathing top to bottom
Big skates are typically found hidden in the sand and mud on the seafloor, with only their eyes protruding. So how do they breathe? They take water in through spiracles (modified gill slits) on the tops of their bodies, then push it out through gills on the bottoms of their bodies—which also aids in the burying process. It’s a win-win system!
The word “binoculata” from its scientific name comes from the Latin “bi,” meaning “two,” and “oculatus,” meaning “eyed.” This refers to the two large eyespots on the big skate’s fins, which resemble eyes. Scientists think these "eyes" might confuse predators or make a smaller skate look bigger, and therefore less vulnerable to a predator, such as a shark. Plus, not only do they bury themselves on the seafloor, but their mottled gray bodies serve as camouflage, and spines along their upper bodies offer protection as well.
The dangers of late maturity
Big skates live on average between 15 and 26 years, and they mature later in life (after 12 or 13 years for females, seven or eight years for males). This leads them to produce fewer offspring than other kinds of fish, which makes them especially vulnerable to overfishing. And, because they spend so much time on the seafloor, they’re at risk of being taken as bycatch by bottom trawlers.
It's a family (conservation) affair
Big skates are elasmobranchs—related to rays. Unfortunately there are many species of rays and skates that are considered threatened and endangered. One example, the common skate (Dipturus batis) is now considered critically endangered by the World Conservation Union (IUCN). In fact, the IUCN Red List includes 547 species of elasmobranchs, of which at least 20% are in danger of extinction.
How we can help
Big skates, as well as every other living thing in Puget Sound, the Salish Sea and our one world ocean, rely on a healthy environment to thrive. When we do our part to preserve and protect the marine environment, we’re also helping to care for the big skate.