Cutbacks of small fish catches will yield big gains
August 23, 2012
Environmental Industry Magazine
Ellen K. Pikitch, Ph.D.
Lenfest Forage Fish Taskforce
A recent report authored by 13 preeminent scientists from around the globe shows that some of the smallest fish swimming in the seas play a disproportionately large role in ocean food webs. Often referred to as “bait fish,” these small, schooling fish, which include anchovies, herring, menhaden and sardines, are also called forage fish because so much ocean life depends upon them for food. More than half the diet of many types of seabirds, marine mammals and larger fish such as tuna, cod and salmon, consists of forage fish. These and other species that depend heavily on forage fish as prey occur commonly throughout the world’s oceans.
The report also reveals that the value of forage fish left in the ocean to support production of larger, commercially important species is twice their value in a net. Overall, forage fish provide nearly $US17billion per year to commercial fisheries production. Yet alarmingly, in many places, these fish and the services they provide are in jeopardy because they are being pulled from the ocean at an unsustainably high rate. Forage fish now make up more than one-third of the world’s marine fish catch. With price and demand skyrocketing, it’s time to hit the brakes, and implement smarter management policies to avert further damage.
Despite their vital role in maintaining healthy oceans and their high economic value, only in recent years have these small fish begun to garner the attention they deserve. Part of the reason for this is that our encounters with forage fish are most often indirect and inconspicuous. Only 10 percent of the forage fish catch is directly consumed by people, while the majority of the catch is processed into fishmeal and fish oil, and used in agriculture and aquaculture. Some of the oil, valued for its rich supply of heart-healthy omega-3 fatty acids, is used in nutritional supplements.
Unsustainable exploitation of forage fish would negatively affect not only the animal species but also the industries that depend on them. However, prior to the formation of the Lenfest Forage Fish Task Force, specific scientific guidance for managing forage fish in a holistic manner that recognizes their vital ecological roles was generally lacking. Following three years of intensive work involving both synthesis of existing information and development of new science, the task force recommended specific goals, targets and thresholds for forage fish management that are designed to sustain both forage fish and their predators.
In developing its advice, the task force drew upon lessons learned from past examples of forage fish management. The consequences of ignoring interdependencies in marine ecosystems are illustrated in the case of the Barents Sea where collapses of the forage fish, capelin, due to fishing and other causes, resulted in nutritional stress and cannibalism in cod, a predator fish, with consequent economic losses to the cod fishery. Additionally, starving mammals and sea birds died or left the area. However, this situation was addressed, and the “capelin rule” was put into place, which prohibits fishing of capelin if the biomass of the population falls below a certain level. Since this rule has been implemented, there have been no additional collapses of the capelin fishery, and the cod population in the Barents Sea is the healthiest in the world.
After comparing conventional and precautionary management strategies, the task force found that only precautionary management protects both the fish and the predator species that depend on them. The task force determined that the amount of information available about the ecosystem and the forage fishery should establish, in part, the level of precaution managers should apply. In circumstances where basic information is lacking, the task force advises that no new forage fish fisheries should be initiated. Conversely, where there is abundant clear, and reliable information about the consequences of forage fish fishing, higher exploitation rates may be applied. Most fisheries now considered well-managed from a conventional, singlespecies perspective will likely fall within the “intermediate” information tier defined by the task force. For intermediate tier fisheries, it is recommended that catches be halved, and the amount of forage fish left in the ocean should be doubled, compared with conventional management.
The cutbacks in fishing recommended by the task force could significantly reduce catches for some ongoing forage fisheries. However, the benefits of implementing the task force’s advice should far outweigh these short-term costs. The expected benefits include more robust forage fish fisheries less subject to boom and bust cycles, healthy oceans with a full complement of marine life and an increase in the economic value of global commercial fisheries. Overall, these are mighty hefty gains to be achieved from more conservative management of some very small fish.
Read the article in Environmental Industry Magazine online.