A Time to Look for Smelt
by Anne Murphy, Executive Director PTMSC
Among the many animals that migrate through Port Townsend Bay each year there is one fish population that routinely uses the Marine Science Center pier as a resting place. For several weeks each fall, dock-walking enthusiasts have the opportunity to enjoy the intriguing, sometimes aimless, sometimes purposeful, always graceful swimming patterns of surf smelt, Hypomesus pretiosus. These smelt live their entire lives in schools. They hatch, feed, travel and spawn en masse.
The north eastern Pacific is home to seven varieties of smelt. Some varieties live their entire lives in the ocean, spawning either in open water or on coastal beaches. Others migrate to inland coastal waters such as Puget Sound to spawn on beaches, while other smelt varieties migrate into river systems to spawn in river gravels. The surf smelt and Eulachon, Thaleichthys pacificus, are probably the most common local smelt. Eulachon, anadromous smelt that migrate into the Columbia and Fraser river systems, is also called candlefish because of the Native American practice of drying the fish and burning the preserved fish as a candle.
The Marine Science Center has underwater video footage, taken in the fall of 1993, of a school of surf smelt biding their time under the pier, waiting for the "message" to move on or to start the spawning ritual. Thousands of fish are in this group; however they move and respond to stimuli as a single organism. One moment they're in a loose ball with only the ambient weavings of the outer fish noticeable. Then something, a shadow or movement in the water, causes them to pull in tightly. Light pulses off their bodies, a submerged flashing silver strobe. It's a time when humans utter "wow. "
These fish, captured on PTMSC video tape, could have been the stock that spawns on Fort Worden Beach or, they could have been on their way to one of the known surf smelt spawning areas such as Kilisut Harbor, Old Fort Townsend Beach, Port Gamble Bay, Liberty Bay, South Hood Canal, South Puget Sound or Sinclair/Dyes Inlet where smelt spawn on a varying schedule from October to March. Surf smelt populations west and north of the Port Townsend Bay area spawn earlier in the year from May to September. On-going exploratory surveys continue to discover new, unreported surf smelt spawning areas.
Surf smelt spawn in the upper intertidal during high tides. Females glue their eggs to coarse sand or fine gravel as males swim through, fertilizing the eggs. Incubation takes two to five weeks depending on water temperature. Hatching most likely occurs at high tide too, so that the newly hatched fish are carried off the beach by the ebb tide into the cover of eelgrass or algae beds. Their average age is two to three years, five years maximum.
Fisheries biologists are learning that stocks of surf smelt are similar to salmon and other extensively studied fish stocks in that each stock is believed to be genetically distinct with it's own set of biological variables, including dependence on a specific spawning location. This means that faced with a loss of habitat, the local Kilisut Harbor stocks most likely would not re-establish in another location. Surf smelt are especially susceptible to environmental damage due to the location of their spawning areas so high up on the beach. The use of rip-rap, bulk heads or any type of shoreline fortification is prohibited in documented surf smelt spawning areas.
Washington Department of Fish and Wildlife classify marine food fish into two categories - groundfish and baitfish. Groundfish refers to marine fish that reside and/or are caught primarily on the bottom, although they may be migratory or travel near the surface. Baitfish are small, schooling fish living close to the surface. Smelt are in the baitfish group along with herring, sandlance and northern anchovy. Baitfish represent a critical connection in food webs in that they are the link between plankton and predatory fish, birds and mammals. Smelt feed on a wide variety of small crustaceans including copepods, amphipods, crab and shrimp larvae. They also feed on marine worms, insects, combjellies and some larval fish. In turn they may be eaten by any of the numerous piscivores: spring salmon, sturgeon, pigeon guillemots, harbor seals or humans.
People often confuse the baitfish, especially since they do resemble each other. They're all silver and about the same length. However, the similarities end there. Stop in, and Marine Center staff will be happy to show you the difference. We do not keep surf smelt, or any of the baitfish, with the exception of occasional sandlances, in our tanks at the Marine Science Center because they survive best in schools and a small school requires larger tanks than we currently have. But please ask us about them. We've got some good anecdotal stories and excellent underwater video footage.
Notes:
Surf Smelt, Hypomesus pretiosus. Scientific name from the Greek roots hypo (below) and mesos (middle - position of pelvic fins); and Latin pretiosus (precious).
Eulachon, Thaleichthys pacificus. Scientific names from Greek roots thalea (rich), ichthys (fish) and Latin pacificus (referring to the Pacific Ocean).
Reference:
J.L. Hart: Pacific Fishes of Canada, Ministry of Supply and Services Canada, 1980.