For hundreds of years, fueled by humans' rapacious appetite for fresh seafood and false notion that stocks were inexhaustible, fish and shellfish have been pulled out of bays and oceans at an unsustainable rate. Cod, striped bass, sturgeon, and oysters headline the list of species that at some point have been fished to near zero. Unless things change, and fast, add menhaden to that list.
A key food for rockfish, birds and sea mammals, menhaden are in trouble. The most recent stock assessment by the Atlantic States Marine Fisheries Commission revealed overfishing has occurred in 32 out of the last 54 years. Even scarier is that East Coast menhaden populations are estimate to be only 8 percent of its historical abundance. Today, one-fifth of the bunkers caught are used for bait by sport and commercial fishermen. The rest – about 150,000 tons – is caught by reduction fishery, run by Omega out of its Reedville plant. There, this key forage is cooked down into industrial oils for cosmetics and vitamins or ground into chicken feed or meal for farmed fish.
The fight to get the ASMFC's attention regarding menhaden's downward spiral goes back at least to the late 1990s. Although he wasn't quite the lone voice in the wilderness, Jim Price of the Chesapeake Bay Ecological Foundation didn't have a full chorus behind him when he expressed concerns that something was wrong with bay stripers and that perhaps a lack of menhaden in their diet might be a contributing factor. Early on, some scientists scoffed, but today his initial premise has proven to be spot on.
Virginia Institute of Marine Science researchers have since discovered that Mycobacterium shottsii, a new species of bacteria, is largely responsible for an outbreak among Chesapeake stripers causing lesions and early mortality. These findings only strengthen the argument that bay rockfish aren't getting nearly enough protein. Historically, rockfish primarily ate protein-rich menhaden. Today, bunker makes up less than 10 percent of bay stripers diet. That insufficient numbers of menhaden translates into a less-than-healthy rockfish population is a logical correlation.
In 2006, a bay-wide cap on the Chesapeake menhaden harvest went into effect with great fanfare and optimism. Part of that plan was to use LIDAR, the acronym for ''light detection and range'' in which pulses from a laser measure the properties of a target, to try and determine how many bunker were in the bay. But LIDAR didn't work; bay waters were too deep and particulate matter presumably skewed the laser's effectiveness.
Read the full article at The Capital.
Analysis: The article makes several misleading claims about the health of the menhaden fishery. While the article worries that menhaden are one of the species being fished at an "unsustainable" rate and that menhaden could soon be fished to "near zero" the recent history of the fishery does not provide any evidence of overfishing. The fishery is overseen by the Atlantic States Marine Fisheries Commission (ASMFC); in their last assessment of the fishery in 2010, the ASMFC concluded that menhaden are not overfished, and that overfishing had only occured once in the last ten years.
The claim that "menhaden are only at 8% of their historical abundance" is also misleading. Menhaden are currently fished to 8% of their Maximum Spawning Potential (MSP), which, rather than being a historical number as claimed in the article, is a population estimate of a theoretical unfished population. An 8% MSP is not unusual or a sign of an overfished population; menhaden have rarely exceeded 10% MSP in the past few decades, and the population hasin the past been able to rebuild itself at that level.
The article's assertion that a low menhaden population is responsible for mycobacteriosis in sea bass is not unanimously supported. The cause of mycobacteriosis in bass has likely more to do with environmental factors than to the presence of menhaden, such as the "thermal niche/oxygen squeeze" theory. Currently, large amounts of run-off in the Bay have created areas with low levels of oxygen, called hypoxia, in cold waters that bass traditionally inhabit. Because the waters that they are most suited to are uninhabitable, bass spend more time in warmer, shallower waters. The temperature of these waters are too high for the bass to feed properly, leading to a variety of health problems, including susceptibility to mycobacteriosis.