Creature Feature: Euchalon, Jun/Jul 2016

June, 2016

 Eulachon (Thaleichthys pacificus) are small, silvery fish within the smelt family. Eulachon are anadromous, meaning that like salmon, they breed in freshwater but spend most of their adult lives in the ocean. After three to five years in the sea, eulachon return to spawn from late-winter through mid-spring. Hatchlings born in freshwater are carried by swift flowing waters back to the ocean. Historically, eulachon could be found along the coast from the southern Bering Sea to Northern California. Here in Northern California, eulachon were commonly found in the Smith River, Klamath River, Redwood Creek and Mad River, although they are nearly extinct in California today.

The eulachon goes by many names (savior fish, quat-ra, hooligan, oolichan) but is perhaps best known as the “candlefish,” because if dried and strung on a wick, the fatty fish can burn like a candle. The eulachon is prized by indigenous communities of the Pacific Coast for its high oil content. Processing the oil is an art form, one that is handed down through generations. The length of time the fish is left to decompose determines the flavor of the oil.The oil was a historic trading good for coastal tribes who would transport the oil across well-worn paths, known as “grease trails,” to interior tribes.

Eulachon are a forage fish—a common prey species for nearly all predatory creatures along the coast. They provide important ecosystem functions by transferring energy from primary or secondary producers, such as plankton, to higher trophic levels, like larger fish, coastal seabirds, sea lions and whales.

Not all is well for the eulachon. Eulachon have historically had unpredictable boom-and-bust cycles. Local newspaper accounts indicate that 1919, 1963, 1967-69, and 1973 were banner years for eulachon in the Klamath River and Redwood Creek.

Because of these large population swings, it took a while before anyone noticed that the fish were not bouncing back as they once had. Today, populations in the Klamath River, Redwood Creek and the Mad River are likely close to extirpated.

It was native tribes who first took notice. In 2008, the National Marine Fisheries Service received a petition from the Cowlitz Tribe—which takes its name from the Salish word for eulachon—to list the Washington, Oregon and California populations of eulachon under the Endangered Species Act. In 2010, the Service listed the species under the Act.

What happened to the eulachon is a matter of debate. Because eulachon have never been an important commercial fishery outside of tribal uses, there has been little research. Climate change has likely played some part, changing the ocean and river conditions that the eulachon depend on. Poorly managed ocean shrimp fishing may have played a role too, killing large numbers of eulachon as an accidental bycatch, tipping the species in steep decline.

Human mismanagement of habitat also likely played a role. Sediment pollution, which in coastal waters is often caused by poorly maintained forest logging roads, likely affects eulachon by smothering eggs. Runoff and chemical pollution affect eulachon mortality. Dams have blocked off habitat and have changed flows and sediment patterns. Locally, levees in lower Redwood Creek and sedimentation are thought to have negatively altered the habitat to the point that eulachon may no longer be able to live in its waters.

Will eulachon return to Northern California? Listing the eulachon under the Endangered Species Act has resulted in new interest and funding for research. New technologies, like LED lights strung on trawl fishing lines, reduced eulachon bycatch by 90 percent in experimental trials. The removal of the Klamath dams  will help return natural flow regimes to the Klamath River. Many salmon habitat restoration projects, like removing forest roads and properly sizing culverts, are likely to help the eulachon as well.