April 2, 2012
Task Force: Throw The Little Fish Back!
New analysis by an international group of scientists specializing in everything from fish ecology to marine mammals highlights the importance of preserving the seas´ smallest fish species that serve as an important food for larger marine animals.
The Lenfest Forage Fish Task Force -- a consortium of 13 scientists from around the world -- reported that forage fish populations such as anchovies, herring and sardines are being affected by commercial fishing. The group recommends that fishing of these important food staples should be halved for some fisheries to protect the populations of both the forage fish and the natural predators that depend on them.
The 120-page Lenfest report -- “Little Fish, Big Impact: Managing a crucial link in ocean food webs” -- is the most comprehensive worldwide analysis of the science and management of forage fish populations to date. The analysis concludes that in most ecosystems at least twice as many forage fish should be left alone by commercial fisheries.
“The message is, if you cut back on harvesting of forage fish, there will be benefits,” Ellen K. Pikitch, director of the Institute for Ocean Conservation Science at Stony Brook University and chairwoman of the task force that produced the report, told Henry Fountain of the New York Times.
Forage fish account for 37 percent of the world´s commercial fish catch, with an annual value of more than $5.5 billion. The report finds that nearly 90 percent of the fish caught are processed into fish meal and fish oil that end up in feed for livestock and farmed fish; only 10 percent of these fish caught are eaten by humans.
The task force concluded that forage fish support $11.3 billion worth of commercial fish by serving as their prey, nearly double their worth as a catch. The analysis did not include the value forage fish provide to sea birds or marine mammals, many of which are also highly dependent on them.
Dee Boersma, a conservation biologist at University of Washington, and one of the task force members, said studies she has conducted on the breeding success of Magellanic penguins showed that they relied heavily on the supply of forage fish within their range. If these penguins could find food within 50 miles of their colony they typically produced two chicks, but if they had to travel more than 125 miles outside of their colony, they generally had no chicks.
A thriving marine ecosystem is highly dependent on forage fish. They are a critical link in the ocean food chain because they eat tiny plants and plankton, and then are preyed upon by larger animals such as penguins, whales, seals and puffins. They are also the primary food sources for many commercially and recreationally valuable fish found in North America, such as tuna, salmon and cod.
Boersma also noted that many seabirds were traveling farther for less food. “Suddenly, instead of 90 percent, you´re settling for 10 percent. That´s what´s happening to seabirds. When fish is not there, they don´t do as well,” she told the Washington Post in an interview.
Pikitch said that society may need to reassess its reliance on small marine species to sustain the growing aquaculture trade. Farmed fish accounts for roughly half of the world´s commercially sold fish.
“People don´t understand how massive this fishery is,” Pikitch said, referring to how many forage fish are processed. “It seems we may be on a collision course at some point, where increased demand is going to pull the rug out from under the ocean ecosystem.”
“Sometimes the value of leaving fish in the water can be greater than taking it out,” Pikitch said.
Because of the growing concern that some fish species could be suffering, fishery managers in the mid-Atlantic voted in November to cut the amount of menhaden being harvested annually from 183,000 metric tons to 174,000.
One company, Omega Protein, took 160,000 metric tons of menhaden -- about a 20 percent cut from its 2010 haul -- off the coast of Virginia, the only state that allows industrial fishing of menhaden.
Task force member Edward D. Houde, professor at University of Maryland´s Center for Environmental Science at the Chesapeake Biological Laboratory, said fishery managers should be leaving at least 40 percent of adult forage fish in the sea. Menhaden, for instance, support a range of species in the Chesapeake Bay and Atlantic Ocean, including osprey, bald eagles, pelicans and striped bass.
The Atlantic States Marine Fisheries Commission is crafting new rules on menhaden limits, which should be finalized sometime next year. The rules will ensure at least 15 percent of adult menhaden, and perhaps as much as 30 percent, are left to spawn in the ocean and its tributaries after the yearly harvest. Currently, fisheries are only forced to leave 8 percent.
“That would not be as precautionary as we´re recommending in the task force,” Houde told Washington Post's Juliet Eilperin, though he said it was a step in the right direction. “It´s still very hard for them to reduce fishing, which means reducing catches and reducing profits. It´s not easy for them to take these precautionary steps that are important for the environment.”
“Around the globe, we´ve seen how removing too many forage fish can significantly affect predators and people who rely on that system's resources for their livelihoods," said Houde. “We need to be more precautionary in how we manage forage fish in ecosystems that we know very little about.”
“The Lenfest Forage Fish Task Force has provided guidance on how to prevent overfishing of these small prey species,” said Boersma. “Our hope is that fishery managers will put our recommendations into action to protect penguins, cod, whales, and a whole host of other creatures that need them to survive.”