Smaller Fish Should Stay Fish Food, Say Experts
April 2, 2012
FISHING for prey species such as herring and anchovies should be cut in half globally to protect creatures that eat them, such as puffins, whales and penguins, an international team of experts has argued.
The team warns that the increasing use of herring and anchovies to feed farmed fish, pigs, chickens and as nutritional supplements for humans is putting wild species that rely on them at risk.
The Lenfest Forage Fish Task Force, which includes a St Andrews University marine biologist, carried out the most comprehensive analysis of the science of “forage fish” populations to date.
Its report, Little Fish, Big Impact: Managing a crucial link in ocean food webs, published today, concluded that in most ecosystems at least twice as many of these species should be left in the ocean as conventional practice.
As the fish are key food sources for commercially valuable fish such as salmon, tuna, bass and cod, the task force estimated they were twice as valuable in the water as they were if they were caught.
Using modelling, they calculated that forage fish contribute £7 billion by serving as food for other commercially important fish, compared with £3.5bn they generated as direct catch.
Professor Ian Boyd, director of the Sea Mammal Research Unit at the University of St Andrews, said: “Our analysis found that the best way generally to ensure there’s enough food for dependent predators is to reduce fishing for their prey.
“We need to start to understand that leaving some types of fish in the water in greater numbers is not just good for ecosystems, but it is good economics too.”
The Lenfest Forage Fish Task Force, made up of 13 scientists, was established to generate advice to support better management of forage fish around the world.
It highlights that a thriving marine ecosystem relies on plenty of forage fish, which are a crucial link in the food chain.
They eat plankton and are preyed upon by animals such as penguins, whales, seals, puffins and dolphins, which are important for tourism.
However, they are also in increasing demand for use as fish meal to feed farmed fish, pigs and chickens. They are also used to produce omega 3 oils, used in food supplements for humans.
“Traditionally we have been managing fisheries for forage species in a manner that cannot sustain the food webs, or some of the industries, they support,” said Dr Ellen Pikitch of the Institute for Ocean Conservation Science at Stony Brook University, who led the Lenfest Forage Fish Task Force.
“As three-fourths of marine ecosystems in our study have predators highly dependent on forage fish, it is economically and biologically imperative that we develop smarter management for these small but significant species.”
Dr Edward Houde, a professor at the University of Maryland’s Center for Environmental Science, added: “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.
“We need to be more precautionary in how we manage forage fish in ecosystems that we know very little about.”
Lenfest Forage Fish Task Force news release