June 20, 2012 – A report released this week by the Sustainable Fisheries Partnership gives the Atlantic menhaden fishery a grade of “C,” the lowest score.
The report analyzed reduction fisheries in the Atlantic and South America, and graded them in five different categories, including precautionary management, how well fisheries managers follow science advice, whether fishermen comply with regulations.
Reduction fisheries target mackerel, herring, anchoveta, and other forage fish like menhaden, which form the base of the ocean food web. In 2010 alone, 11 million metric tons of forage fish from the Atlantic and South America were transformed into industrial products such as fish oil and fishmeal for aquaculture. Seven of the top ten fisheries in the world target forage species.
According to the Sustainable Fisheries Partnership, fishery managers are following scientific advice, and fishermen are complying with regulations in many of these fisheries.
However, the fishing mortality for Atlantic menhaden was three times above the target level, and “better progress [is] needed,” the report stated. Atlantic menhaden “has not been effectively managed and significant improvements are required.”
The Atlantic States Marine Fisheries Commission (ASMFC) determined last year that menhaden are subject to overfishing, and the Commission implemented new reference points for judging the health of the stock. However, the agency has yet to reduce the menhaden harvest.
Read the full story at the Public Trust Project.
Analysis: A new report by the Sustainable Fisheries Partnership (SFP), as reported by the Public Trust Project, graded the sustainability of several North and South American reduction fisheries, and asserted that the Atlantic menhaden fishery has room for improvement in this area. The report, “Global Sustainability Overview of Fisheries Used for Fishmeal and Fish Oil”, gave the Atlantic menhaden fishery, along with more than half of the other fisheries examined, a letter grade of “C”, the lowest on the scale.
However, the SFP’s choice of data used to evaluate the fishery is flawed. In calculating its score for the future health of the Atlantic menhaden stock, SFP used the fishing mortality level from the 2010 assessment, which is based on fishery data through 2008, while using the reference point (the level of fish removal that can’t be exceeded) from 2011. A new, stricter reference point was established in 2011, which the SFP fails to properly take into account.
The menhaden reference point, which determines when overfishing is occurring, is in terms of percentage of Maximum Spawning Potential (MSP), an estimate of the size of a theoretically unfished population. The value of this reference point represents the total population that must remain in the water at the end of a fishing season. In the 2010 assessment, the reference point was equal to around 9 percent MSP. At that level, the menhaden fishery was only .4 percent above the limit. However, due to the slight overfishing observed in the assessment released in 2010, the reference point was raised to 15 percent MSP in 2011. The SFP uses this 2011 reference point in its analysis, instead of using the reference point for the same year as the catch data.
The Atlantic menhaden fishery was given scores above 6 out of 10 for all categories that factored into the grade but one. Menhaden received a value of “Zero” for the Sustainability Overview’s “future health of the stock biomass” category, dragging down the overall grade to the “C” level. As the SFP’s website states, the scores “do not define a fishery as ‘good’ or ‘bad’.” Instead, they only provide suggested improvements to achieve maximum sustainability. Although the Atlantic menhaden fishery received a grade of “C”, the score does not come with a recommendation to withdraw from using menhaden as a source of fishmeal and fish oil.
The fishery made its 2008 catches (with this data being released in the 2010 assessment) to correspond with the reference point of that time, not the increased limit of 2011. By using the 2010 assessment's catch estimates and the 2011 reference point, SFP is penalizing the fishery for failing to fish to a limit that did not yet exist. When the 2010 mortality rate is judged against the more conservative 2011 reference point, the population appears to be experiencing heavy overfishing. Yet it is inaccurate to use these two points of data together, as it was not possible for the 2008 fishing mortality (from the 2010 assessment) to follow the 2011 reference point. Until the results of the update menhaden stock assessment that is occurring this year are made public, it is impossible to know how the current status of the stock compares to the newly established reference points.