PORTLAND, Ore. (KOIN) -- For the first time, researchers at Oregon State University have documented two shark species that are new to the Puget Sound, including one critically endangered species.
During 10 days of fieldwork in 2022 and 2023, researchers caught 10 sharks belonging to the broadnose sevengill and the endangered soupfin species near Olympia.
According to the researchers, the find could mark changes in the "economically, culturally, and ecologically valuable" waterway.
Working with the National Oceanic and Atmospheric Administration, researchers confirmed the sevengill -- which can grow nearly 10 feet long -- now live in the heavily urbanized south Puget Sound, which stretches to the Salish Sea.
“Understanding the sevengill presence in this new habitat is crucial for understanding the food webs of the Salish Sea, and it highlights the need for continued monitoring and research – including their relationship with other species of conservation concern, such as salmon,” said OSU researcher, Jessica Schulte, a lead author on a recently published sevengill paper.
Broadnose sevengill sharks live in temperate waters around the world, including off the west coast of North America, and from southern Alaska to Baja California.
Before 2021, only one sevengill shark was confirmed in the Salish Sea at Point Roberts, Washington, near the Canadian border, OSU said.
That changed in August of 2021 after reports that several sevengill sharks were caught in the South Puget Sound.
The scientists caught nine sevengills nearly 200 miles away from their previously documented range.
Eight of those sharks were males, with the largest measuring just under seven feet, and the female was around four feet, six inches.
“Our continued research on this species in Oregon and Washington waters will allow us to have a better handle on its role in our valuable marine ecosystems,” Schulte said.
During the concurrent fieldwork with the sevengill project, researchers caught one soupfin shark, a male that measured over five feet.
The soupfin shark is the largest species of hound shark and can grow as big as 6.5 feet, the researchers said, noting the shark got its name because of its use as a key ingredient in shark fin soup.
“Soupfin sharks were relentlessly exploited during the 1930s and 1940s, including for their livers, which are rich in vitamin A,” said OSU Graduate Student Ethan Personius. “Despite lower fishing pressure the species has not been able to recover and is currently under consideration for federal protection under the Endangered Species Act.”
Similar to the sevengill, soupfin sharks are found in temperate waters and are top predators in any ecosystem they inhabit.
The researchers noted that during an extreme marine heat wave in 2014 and 2015, known as "The Blob," anchovies became a dominant forage fish in the Salish Sea after they were previously uncommon in the area. According to the research team, soupfin sharks are a known predator to anchovies.
“The Salish Sea has experienced pervasive shifts in species abundance and composition along with industrialization and significant habitat degradation,” Personius said. “The appearance of soupfin sharks may be a result of climate change and changes in prey availability.”
