OLYMPIA – When a species that supplies the diet for a host of marine fish and animals runs into trouble, biologists are doubly concerned.
That's the scenario facing herring at Cherry Point in North Puget Sound, which are spawning at such low numbers that scientists question whether the stock will survive.
On-going efforts by Washington Department of Fish and Wildlife (WDFW) scientists to determine the reasons for the decline of Cherry Point herring are described in a new article in Fish and Wildlife Science, WDFW's on-line magazine.
"When a unique population is in trouble that's always cause for concern; when that stock is a key link in the Puget Sound food web we feel even more urgency," said WDFW Director Jeff Koenings, PhD., about the Department's studies of herring at Cherry Point.
"Besides continuing our own research efforts, we're hopeful by working with scientists from other states and Canada we can determine the precise causes of the herring decline and take steps to reverse it."
Pacific herring (Clupea pallasi) as a species are believed to comprise some 71 percent of the diet of lingcod, and 62 percent of the food source for chinook salmon. In addition, other species such as coho salmon, Pacific halibut, and a number of seabirds and marine mammals feed heavily on herring.
Commercial harvest of Cherry Point herring was sharply reduced in 1981 and closed completely in 1996. Despite the closure, the Cherry Point stock has continued to decline.
Koenings said WDFW will host a workshop this fall in the Bellingham area for scientists from Canada and the Pacific states, as well as scientists representing Cherry Point industries, to discuss the latest findings in herring research.
The herring article details efforts to identify Puget Sound's genetically separate stocks of Pacific herring, and to determine the causes for the steep decline in the stock that spawns at Cherry Point, near Bellingham.
The Pacific herring is a species of small, schooling fish found throughout Puget Sound and the northeast Pacific Ocean. Herring spawn at 20 distinct locations in Washington. Not only are the spawning grounds highly specific, but so are the spawning times, with the peak of spawning rarely varying more than seven days from one year to the next.
Cherry Point herring, once the most prolific stock in Puget Sound, have declined 94 percent from historic spawning levels. That drop, which is causing scientists to question the ability of the stock to sustain itself, takes on added significance in light of the fact that the Cherry Point stock is the Sound's only spring-spawning stock.
Cherry Point is one of 20 distinct herring spawning grounds in Puget Sound and Washington coastal waters. The Cherry Point area also is the site of some of the largest industrial plants in the state.
WDFW biologists have been studying the Cherry Point herring stock since the mid-1970s. Research efforts now underway include genetic stock identification of herring from Cherry Point and other spawning grounds; an investigation of lipid (fat) levels, an indicator of food abundance and likely survival rates, and mortality studies investigating chemical contamination and other factors. Preliminary results indicate that Cherry Point herring may be genetically separate from other Puget Sound herring stocks, and that herring there have very low lipid levels.
The electronic magazine, which was launched in April, showcases the department's scientific research efforts. Recent articles highlighted Puget Sound's underwater marine reserves, Eastern Washington mule deer studies and bat roost site surveys.
Persons who do not have access to the Internet may request a printed copy of the article by contacting WDFW Public Affairs at (360) 902-2258. Further information on the planned fall herring science workshop is available by contacting Greg Bargmann at (360) 902-2825.