Two important decisions emerged from the recent meeting of the Atlantic States Marine Fisheries Commission that should have a positive impact on the Chesapeake Bay's striped bass (rockfish) industry. The first was a decision not to restrict the harvest of striped bass, the other to significantly curb the Atlantic menhaden catch.
How could a decision to leave alone rockfish, a species highly prized by commercial fishermen and recreational anglers alike, while restricting the harvest of the lowly menhaden, an oily little fish that no self-respecting hook-and-line fisherman would use for anything other than bait, be a win for conservationists and the fishing industry?
It's a lesson of the food chain — and a victory for science over politics and short-sighted commerce. The decision not to reduce the striped bass catch by 50 percent in 2012 was voted down chiefly because striped bass landings are still near record-highs and recruitment in the Chesapeake Bay this year was robust as well — the fourth highest number of baby fish on record.
Meanwhile, menhaden stocks are thought to be at all-time lows. Studies suggest that heavy fishing — primarily by one company — has depleted the menhaden spawning population to just 8 percent of its potential.
Menhaden may seem inconsequential to the seafood-lovers among us, but to striped bass they are a delicacy beyond compare. The fates of the two species are thought to be closely intertwined. Since the 1990s, scientists have found evidence that problems in the Chesapeake Bay striped bass population — poor nutrition and a prevalence of a bacterial infection called mycobacteriosis — are linked to a depletion of young menhaden in the bay.
So it's not too great a stretch to suggest that restricting the menhaden catch by 37 percent — as the commission has decided — could boost rockfish prevalence (and lower natural mortality rates) as well. And that's a big victory for advocates, including Gov. Martin O'Malley and officials at the state Department of Natural Resources, who spent years lobbying for this.
But the fight is far from over. Officials in Virginia, home to Omega Protein, Inc., the company responsible for an estimated 80 percent of the East Coast menhaden catch, are likely to resist the restrictions, which won't go into effect for two years. The Virginia legislature would have to approve of them in 2013, and Omega may take the matter to federal court before then.
Read the full article at the Baltimore Sun.
Analysis: The article says that "heavy fishing" has led to an unsustainably low menhaden population, with the population of the fishery at "8 percent of its potential." However, it ignores the most recently available scientific data, and misrepresents some key facts about the fishery.
The most recent stock assessment from the Atlantic States Marine Fisheries Commission (ASMFC) concluded that menhaden are not currently overfished. Slight overfishing did occur in 2008, but it was the only year in the last decade where overfishing occurred and was not sufficient to declare the fishery overfished.
The article also is misleading when it claims menhaden are at 8 percent of their potential. Menhaden are currently fished to around 8 percent of their Maximum Spawning Potential (MSP), which is an estimate of a theoretical unfished population. However, this is not by itself a sign of overfishing, as menhaden have previously been able to rebuild themselves at that level. There is also a poor correlation between MSP and menhaden recruitment.
Finally, while the article claims that current health problems in bass such as mycobacteriosis are the result of a lack of menhaden, there are several other more likely causes, such as the "thermal niche/oxygen squeeze" hypothesis. Currently, large amounts of run-off into the Chesapeake Bay have created areas with low levels of oxygen, called hypoxia. These hypoxia zones are in the deeper, colder waters that bass usually inhabit. With their usual territory rendered inhospitable, the bass migrate to shallower, warmer waters for which they are ill-suited. As a result of the stress caused by higher-than-normal water temperatures, the bass don't feed properly, and are susceptible to a variety of diseases, such as mycobacteriosis.