Some of the world’s largest fisheries are for small, short lived species such as menhaden, anchovies and sardines. While some of these fish are consumed directly by humans, most of these fisheries reduce their catch to fish and animal feed and fish oil for everything from vitamins to cosmetics. Some of these species are managed and have sufficient data to assess the health of stocks and determine how much fish can be harvested. Others have little to no data, making sustainable management difficult.
However, these small fish also have another important role in nature. They represent a critical link in ocean food webs because they feed on plankton, which produce energy from the sun, and they transfer this energy to seabirds, marine mammals, and larger fish such as tuna, salmon, and cod. As such, fisheries managers need to consider not only how many of these “forage fish” can be extracted from the ocean for human use, but also how many fish need to be left in the water as food for other fish.
New and emerging science has demonstrated that these little fish have a big impact, indeed. One studyi reported that, of all the ecosystems studied, 75% had at least one key predator species whose diet consisted of at least 50% or more of forage fish. 29% of the ecosystems studied had at least one major predator that had a diet that consisted of 75% or more of forage fish species. Therefore, when forage fish stocks decline from overfishing so do predatory species that feed heavily on them.
Globally, commercial forage fish fisheries have an economic impact of $5.6 billion dollars, annually. However, the supportive value of forage fish—or their subsequent benefit to larger, commercially important fish when left in the water—is $11.3 billion. In other words, forage fish have a higher economic value when left in the water as forage for larger predators. We have no idea what their economic contribution is to important recreational fisheries?
It’s time that these little fish were recognized for the big impact that they have on other recreational and commercially important species. Fisheries managers need to take into consideration their natural role in marine ecosystems to ensure that we are not robbing the ocean of food for its larger predatory species. IGFA has begun working with a number of other organizations to highlight new science on forage fish and to elevate their importance to fisheries managers so that they can be better conserved and managed.