After finding the abundance of exploitable razor clams on the Ninilchik beach had plummeted to the lowest records seen in recent memory, the Alaska Department of Fish and Game implemented widespread harvest restrictions on Monday.
Fish and Game reduced the bag and possession limit of razor clams harvested on eastside Cook Inlet beaches from the mouth of the Kenai River south to the end of the Homer Spit to 25 clams per day and 25 clams in possession.
The limits are set to begin Thursday and will continue through the rest of the year. Previously, residents were limited to 60 clams per day, 120 in possession.
In a news release, Fish and Game said that exploitable razor clams — which are greater than 3.14 inches — decreased on the Ninilchik Beach from about 1.5 million clams in 2011 to about 79,000 clams in 2013. That number is the lowest on record based on periodic surveys conducted since 1990, according to the release.
Fish and Game wrote that the cause of the decline is unknown, but could have resulted from poor spawning or settling success.
Carol Kerkvliet, assistant area management biologist in Fish and Game’s Homer office, said the department first started studying the Ninilchik beach after observing a “high-mortality clam event” where an alarming amount of dead razor clams washed up in 2010.
Kerkvliet said clam abundance was still high then, but it was mainly one age group.
“So we’ve been tracking that age group over these past three years and basically they are growing and getting old and disappearing from the beach, which is not unexpected, but we are looking for a younger group of clams to replace them,” she said. “So the number of small clams that we are seeing, they are definitely there, but the overall total abundance has dropped. So we are just being cautious.”
Kerkvliet said a number of conditions could affect clam spawning, including unfavorable ocean currents, habitat, food and temperatures. She said it is a complex system of reproduction and it’s hard to tell what the problem might be.
“One thing could be temperature, another thing could be the proximity of the males and females together,” she said. “... Once they are fertilized they are in this larval state and the larvae are transported with the currents. They are free-floating larvae. So they spawn in July and August and settle down into the sand and grow into the larger sized clams.”
Large clam population swings aren’t unheard of, Kerkvliet said, but numbers can recover just quickly as they drop off.
“Some years conditions are just right for spawning and settling success,” she said. “Other years they are not as favorable.”
Although the population estimates are reserved to the Ninilchik beach area, the restriction covers the entire Peninsula as to not shift the harvest too heavily on other beaches. She said recent digging surveys on other beaches, like Clam Gulch, haven’t given off any red flags and have healthy populations.
Brian Smith can be reached at firstname.lastname@example.org.