Forage fish vital for sea food web
Sunday, November 11, 2012
Sometimes, the environmental challenges facing our oceans seem so large that it's hard to know where to start solving them. Changes in climate, degradation of habitat and rising demand to feed an ever-growing world population are just a few of the daunting ocean-related problems.
In the past several months, however, a collection of conservationists, anglers and others have come together to urge federal policymakers to safeguard the species that serve as the foundation for a healthy marine ecosystem. And, to their credit, regional fishery managers on both coasts heeded the message these advocates delivered: If we want to protect the oceans, it makes sense to start small.
Species such as menhaden, sardines and herring — commonly known as forage fish — are the lifeblood of a healthy ocean. Swimming together in dense schools, these oil-rich fish feed on microscopic plants and animals, then become nourishment for larger wildlife as a crucial link in the marine food web. These fish account for more than a third of all ocean species caught around the world, but unlike catches of cod or tuna, most of the forage fish that is caught is not consumed by people.
Take menhaden, for example. Giant schools once ranged along the Atlantic coast, feeding whales and seabirds, and commercially important fish. But menhaden populations have plummeted 90 percent in the past 25 years and remain at a record low. Despite declining numbers, hundreds of millions of menhaden are still hauled in and ground to be used in fertilizer, pet and livestock feed, and dietary supplements for people.
This removal of forage fish can have significant impacts on coastal ecosystems. Studies have found that the amount of menhaden in the diets of striped bass, ospreys and bluefish has declined. And on the Pacific Coast, the decrease of forage fish has been linked to diminished salmon runs, losses in seabird populations and the unnecessary death of marine mammals. In 2009, scientists documented 80 percent mortality among pups in a population of sea lions off of the coast of California when females left them for a week in search of food. Locally, Columbia River salmon depend on forage fish as food while they're in the ocean and as cover for juvenile salmon running against a gauntlet of predatory seabirds, seals and larger fish where the river flows into the sea.
Appeal to federal help
According to a recent report by 13 eminent ocean scientists, forage fish are twice as valuable left in the water as they are caught because of the vital role they play as food for commercially valuable predators such as tuna and cod. In other words, it's important for federal fishery managers to ensure there are enough of them to feed everything else in the sea.
That's why conservation and fishing organizations — including the Pew Environment Group — have urged the federal government to step up protection of forage species in the Atlantic and the Pacific. In the Atlantic, we call on the National Oceanic and Atmospheric Administration to follow the expressed will of regional fishery councils,and implement protections for menhaden and river herring. On the West Coast, we ask NOAA officials to fulfill the Pacific Fishery Management Council's June commitment to forestall fishing for certain forage species until there is proof that catching such forage fish will not harm the overall ecosystem.
Even though the regional fishery councils endorsed these common-sense objectives and earned broad public support, those commitments mean nothing until NOAA implements the policies.
Unfortunately, agency officials have been slow to embrace the councils' direction.
America's oceans offer a tremendous economic asset and cultural legacy. Whether you enjoy fishing on the water, eating seafood or watching whales and seabirds, all of these activities depend upon a thriving and healthy marine ecosystem.
If we're going to protect our oceans, we must make sure healthy populations of smaller prey species remain to support the entire food web.
Peter Baker and Paul Shively work for the Pew Environment Group. Paul Shively lives in Portland and directs the Pacific campaign and Peter Baker directs the Northeast campaign on Cape Cod, Mass.