CLACKAMAS, OR – Scientists hope to shed new
light on an ancient fish in a study taking place at multiple
locations along the Pacific coast.
Biologists from the Oregon Department of Fish and Wildlife, in
collaboration with their counterparts from Washington, are trying
to gain a better understanding of one of the region’s unique and
poorly understood fish – green sturgeon.
Green sturgeon, which are listed as “threatened” under the
federal Endangered Species Act (ESA), are known to inhabit waters
from Northern California to Alaska. Beyond that, scientists don’t
know much about what they do through much of their life cycle.
“There’s not a lot of population information about green
sturgeon,” said Erick Van Dyke, leader of ODFW’s green sturgeon
Funded by a grant from the National Marine Fisheries Service,
Van Dyke and his team will spend the next two years tracking
sturgeon as they move up and down the Pacific coast and into
estuaries along the way. Through their research they hope to gain a
better understanding of abundance, distribution, critical habitat
needs, spawning activity, and other factors key to the survival of
For the next two months scientists, aided by commercial
fishermen, will collect green sturgeon at the mouths of the Umpqua
and Columbia rivers as well as Gray’s Harbor and Willapa Bay. Using
commercial fishing boats and 600-foot gillnets, they will catch and
tag up to 525 green sturgeon a year. Tags will be implanted using
surgical methods and thus will not be visible to plain view. Tagged
fish will provide information needed to more effectively estimate
population size and to track their movement and use of estuaries
along the Pacific coast line. Scientists want to find out when the
fish enter the river from the ocean, how far up the river they
move, how long they stay there and when they leave. They know that
green sturgeon spend time in the brackish water of the river mouths
but at some point move upstream to spawn in fresh water.
Scientists already know green sturgeon spawn in the Sacramento,
Klamath and Rogue rivers and they suspect the fish may also be
using other water bodies, like the Umpqua River, for this
Ultimately biologists are looking for information that will lead
to better management and, ideally, delisting of the species,
according to Van Dyke.
Green sturgeon are found only on the Pacific coast of North
America. As an ESA-protected species, retention of green sturgeon
is not allowed and, if caught, they must be released unharmed.
Unlike the more abundant white sturgeon, green sturgeon are less
likely to bite traditional fishing baits, which is why researchers
are using gillnets to collect their sample populations.