January 22, 2013 –At first glance, the menhaden is not a glamorous fish, and not one that you would find on a restaurant menu. Also known as bunker, pogy, or bugmouth, the bony, oily fish, which is silver with black spots on its sides, is a humble fish. But there’s more than meets the eye when it comes to the menhaden. For countless creatures under the sea, the menhaden plays several critical roles, leading some to refer to it as “the most important fish in the sea.”
Menhaden are an indispensible part of the Atlantic Coast food chain. Not only does the menhaden serve as the primary diet of numerous fish and aquatic birds, including rockfish, bluefish, herons, egrets, and ospreys, the fish also eats phyto- plankton, doing the essential job of cleansing ocean waters. Adult fish filter an incredible 4 gallons of water per minute!
However, the menhaden are severely threatened. According to the Pew Environment Group, the population of Atlantic menhaden surviving to one year has plummeted to less than 10 percent of historic levels and is now at record lows. Despite this, hundreds of millions of menhaden are still hauled in and ground up, removed from the ecosystem each year, mostly to be used in feed for agricultural animals and farm-raised fish, pet food, fertilizer, and dietary supplements for people.
By weight, more menhaden are caught than any other fish along the Eastern seaboard. A single company in Reedville, Virginia, catches about three-quarters of the entire East Coast catch—more than 410 million pounds annually. Most of that catch comes from the Chesapeake Bay, an important habitat for the juvenile menhaden.
In a Conservation Magazine article titled “The Oiliest Catch,” Richard Conniff writes that executives at this Virginia menhaden facility argue that menhaden produce 18.4 trillion eggs annually. This certainly sounds like a lot of eggs. But as Conniff points out, this number is actually down from a peak of 117 trillion in 1961. And while 18.4 trillion eggs should be enough to maintain the species at target levels, it doesn’t. This means that regardless of the number of eggs produced annually, the process of transitioning those eggs into grown-up fish has gone awry, and conservationists cite overfishing as the likely culprit.
Analysis: In his January 22 A Blue View podcast on Baltimore NPR affiliate WYPR, National Aquarium CEO John Racanelli discussed menhaden, which he described as “the most important fish in the sea,” a description not based in science, originally coined by Rutgers English professor H. Bruce Franklin.
Mr. Racanelli, when describing menhaden’s role in the ecosystem, stated that menhaden consume “phytoplankton, doing the essential job of cleansing ocean waters.” He further claimed that menhaden can filter four gallons of water per minute. A 2010 study by the Virginia Institute of Marine Science found that juvenile menhaden consumed mostly phytoplankton, but consume less of it as they age. Adult menhaden consume mostly zooplankton. The study found that the rate of phytoplankton consumption was not enough to significantly improve water quality.
Mr. Racinelli also claimed that menhaden have “plummeted to less than 10 percent of historic levels,” further noting that the number of menhaden eggs being produced has declined from recorded highs in the early 1960s, and that “regardless of the number of eggs produced annually, the process of transitioning those eggs into grown-up fish has gone awry.”
Historical evidence indicates that environmental factors, rather than pressure from fishing, have the most impact on menhaden recruitment (the number of menhaden successfully born in the fishery), and with it menhaden population growth. Menhaden have historically followed a cyclical pattern of abundance and decline, a cycle that is evident when examining the history of data from the fishery, which dates from the late 1950s. There have been periods of high abundance, like the late 1970s and early 1980s, and periods of low abundance, like the mid 1960s and today. These cycles have little connection to fishing, but have a strong relationship to prevailing climatic regimes and environmental conditions. This link has been recognized by NOAA, which has stated that “menhaden recruitment appears to be independent of fishing mortality and spawning stock biomass, indicating environmental factors may be the defining factor in the production of good year classes,” and the Atlantic States Marine Fisheries Commission (ASMFC), which concluded that fluctuations in menhaden abundance may be, “almost entirely driven by non-fishery sources.”