November 2, 2012 — Sometimes the environmental challenges facing our oceans seem so large that it’s hard to know where to start solving them. Changes in climate, degradation of habitat and rising demand to feed an ever-growing world population are just a few of the daunting ocean-related problems our nation faces.
Over the past several months, however, a collection of conservationists, anglers and others have come together to urge federal policymakers to safeguard the array of species that serve as the foundation for a healthy marine ecosystem. And, to their credit, regional fishery managers on both coasts heeded the message these advocates delivered: If we want to protect the oceans, it makes sense to start small.
Species such as menhaden, sardines and herring — commonly known as forage fish — are the lifeblood of a healthy ocean. Swimming together in dense schools, these oil-rich fish feed on microscopic plants and animals and then become nourishment for larger wildlife as a crucial link in the marine food web. These fish account for more than one-third of all ocean species caught around the world. But unlike catches of cod or tuna, most of the forage fish that is caught is not consumed by people.
Take menhaden, for example. Giant schools once ranged along the Atlantic coast, feeding whales and seabirds and commercially important fish. But menhaden populations have plummeted 90 percent in just the past 25 years and remain at a record low. Despite their declining numbers, hundreds of millions of menhaden are still hauled in and ground up to be used in fertilizer, pet and livestock feed and dietary supplements for people.
Analysis: Pew Environment Group's article, which mentions claims previously seen in similar Pew articles and petitions on menhaden, is full of selective quoting of menhaden science. Examining all relevant information on menhaden reveals a situation that is much less dire than Pew suggests.
The article's claim that menhaden biomass has declined 90 percent in 25 years is particularly selective, because it does not examine the whole time series of available data. The length of time cited in the article (the last 25 years) begins during a period (the early-to-mid 1980s) when menhaden biomass was particularly high. Over the 50-plus years that data on menhaden biomass has been recorded by the Atlantic States Marine Fisheries Commission (ASMFC), biomass has fluctuated based on the strength of menhaden recruitment (the number of menhaden that are born), and current biomass figures are similar to the levels seen in the late 1960s, when biomass was lower. During the late 1970s and early 1980s, several years saw especially strong recruitment, which were followed by years of high biomass. The decline that the petition cites is part of an alternating cycle of strong and weak recruitment.
But the article does not discuss the role of climate and environment, two major influences on recruitment. While the commercial fleet has declined by about 79% since the mid 1980s (from 38 vessels in 1984 to 8 vessels in 2012), environmental conditions have fluctuated widely, producing circumstances that are alternately favorable and unfavorable for menhaden recruitment. Conditions in the late 1970s and early 1980s proved favorable, during a period when the menhaden industry was significantly larger than it is today; conditions since have been considerably less so. The relationship between menhaden and climate is recognized both by NOAA, which concludes, “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 ASMFC, which concluded that fluctuations in menhaden abundance may be, “almost entirely driven by non-fishery sources.”