What are Forage Fish?
Forage fish are small schooling fishes that feed on plankton and occupy an important place in marine food webs. Generally, these species eat herbivorous or carnivorous plankton (primary and secondary producers), and are eaten by larger predators that are higher on the food chain. They play a fundamental role in marine ecosystems by converting energy from lower trophic levels into food for larger fish, marine mammals, and seabirds.
Types of Species
Forage fish and other “prey” species include sardines, herring, anchovy, menhaden (all of which are commonly referred to as baitfish), and krill (an invertebrate). In some cases, such as with menhaden in Chesapeake Bay, forage fish perform an additional role in the ecosystem, acting as filter feeders that maintain water quality and help prevent the formation of algal blooms.
Forage species tend to be high in abundance and influenced by changing environmental and oceanographic conditions. The systems that forage fish dominate can change in response to fishing, climate, predator/prey dynamics or a combination of these and other factors. The Task Force took these considerations—and the potential for uncertainty—when developing their recommendations.
How Forage Fish Are Used
Forage fish are a fundamental part of marine food webs, but are also used by humans for a variety of purposes. 90 percent of the forage fish catch is “reduced” to fishmeal or fish oil for use in the agriculture, aquaculture, pet food, and other industries. Forage fish are also caught for use as baitfish in commercial fisheries and to a limited extent for human consumption. In recent years, the extraction of forage fishes from the ocean has escalated enormously, and these species currently comprise approximately 37% of the global wild marine fish catch with further increases likely. Unsustainable exploitation of forage fish populations can impact the marine food web, cause declines in seabird and marine mammal populations, and even threaten food security in some countries by diverting forage fish from use as food for humans.
The ecological and economic importance of forage fish, along with their tendency to react in unexpected ways to fishing pressure, require that forage fish exploitation be carefully managed to sustain predators and support ecosystem functions. Even in cases where forage fish are well-managed from a single species perspective (i.e., a particular fish species is not overfished), removals may negatively affect the ecosystem as a whole. It is widely acknowledged that the interconnected nature of marine populations requires a multispecies approach where populations are managed in a broader context.
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