From Sand Grains to Salmon – Why Forage Fish Matter!

  • Jun. 17, 2009 1:00 p.m.

Submitted by Ramona de Graaf and Haida Fisheries Program–You have heard it before – all things are connected. Have you imagined how to connect beach sand grains to the food chain of Pacific salmon, blue herons or killer whales? Salmon, great blue herons, eagles, sea lions, humpback and killer whales are some of the hundreds of predators that depend on the “forage fishes” of the sea. We are most familiar with herring but in our home waters, the surf smelt, Pacific sand lance (needlefish) and capelin are three marine forage fish species that spawn on certain sand/gravel marine shores. Let me lead you on an exciting discovery of connections from the sand grains along your favourite beach to the salmon on your barbeque. Perhaps you have seen silvery surf smelt leaping at high tide along quiet shores? Using the beach surf, ripened female smelt rush to release their eggs just a few feet above the beach surface. The 1 mm eggs produce a marvelous invention-an anchor-grabbing membrane that catches small pea-sized pebbles. This ‘weight belt’ tumbles the egg between larger pebbles to incubate within humid nurseries a few centimeters below the beach surface. In winter, Pacific sand lance move to fine gravel/sand beach areas for spawning. Sand pits filled with eggs are made by wriggling spawning females. Small eggs (0.6-0.8 mm) become sand-coated and buried within the surface layer of sands and pebbles. After weeks below the surface, these tiny beach babies, only 3 mm long, swim out with the ebbing tide and feed among the eelgrass beds and kelp forests in our inland bays and inlets. From these little fishes, big things grow! The year round abundance of forage fish determines the survival of larger predators. Forage fish are the cornerstone of the marine food web. Pacific sand lance alone make up 10-50% of the diet of rockfish and salmon species, including adult Chinook diets that can contain over 50% sand lance! BC’s endangered marbled murrelets hunt at dusk to feed their hungry chicks with a diet of 85% sand lance and other seabirds such as the puffins and auklets also heavily rely on sand lance. Humpback whales gorge on herring and Pacific sand lance. Harbour porpoises, cutthroat trout, salmon and others prey on surf smelt-many of these predators are listed as species at risk. Beach-spawning forage fish that begin their lives near our doorsteps are right in the path of many human activities that negatively impact their critical spawning and rearing habitats. Shoreline alterations to make way for roadways, ports, seawalls, marinas, boat ramps and other developments can result in the loss of critical fish habitat areas. Without these little fish, larger predators may face food shortages, making recovery for salmon, rockfish, and killer whale populations even more difficult. Recently, local communities have begun sampling beaches to document and protect these critical habitats.To learn more and help us map and protect the spawning habitats of surf smelt and Pacific sand lance, please contact Sharon Jeffery at the Haida Fisheries Program at 250-626-3302. Haida Fisheries and World Wildlife Fund Canada are sponsoring public presentations in Skidegate and Massett and training workshops in Tlell this coming week, June 20 and 22, in cooperation with biologist trainers Ramona de Graaf from the Bamfield Marine Sciences Centre and Dan Penttila from Washington State Department of Fish and Wildlife. Ramona is working with communities throughout BC to protect shore spawners’ habitats and improve the health of the marine food web, and Dan has been studying forage fish for over 30 years.