The environmental oceans advocacy group Oceana has published a blog post about the Gulf of Maine Cod situation that states the following:
Rebuilding fish stocks to healthy levels ensures that fish will be at robust levels to allow commercial fishing to continue on these stocks well into the future. For Gulf of Maine cod, the rebuilding deadline is 2014. The 2008 assessment indicated that the stock was well on its way toward meeting that deadline, so the New England Fishery Management Council set annual catch limits under that assumption and fishermen fished according to the law.
In a startling reversal, scientists have now determined that the picture in 2008 was flawed and the stock is nowhere near as healthy as they initially thought. In fact, they have found that the stock is only 20 percent of its rebuilt size and is being fished roughly five times the level it can sustain.
Even more troubling, scientists say that even if all fishing of cod ceased, the species will still not recover by the 2014 deadline. NMFS has said that even under the best case scenario, the stock would not be rebuilt until 2018. The assessment is currently under peer review and the results will be released later this month.
No one knows exactly why the 2008 assessment was so far off the mark, but all evidence seems to suggest that the 2011 assessment is more robust and thus more accurate. Fisheries science is based on many assumptions – it uses data, modeling and estimates to try to assemble an accurate picture of how a species is faring. Short of draining the oceans and counting every single fish, the science used to manage each species and set catch limits will require some element of uncertainty. More frequent assessments would help address some of this uncertainty, but this requires resources that are scarce in these challenging economic times.
So what is to be done? Unfortunately, there is no way to create more fish in the Gulf of Maine, so any solution will require significant sacrifices by key stakeholders.
ANALYSIS:
This blog post states "all evidence seems to suggest that the 2011 assessment is more robust and thus more accurate." In fact, there are legitimate reasons to question the accuracy of the 2011 assessment.
The 2008 (GARM III) and 2011 (SAW 53) Gulf of Maine cod stock assessments diverge widely and present two contrasting pictures of the health of Gulf of Maine cod. While the 2011 assessment is the most recently completed, several methodological problems and new uncertainties in the assessment cast doubt on whether it is more accurate than the 2008 assessment.
While there is always a measure of uncertainty in measuring and assessing fish stocks, the 2011 assessment introduces two new potential sources of error, whose effect on the reliability of the results is undetermined. The new research vessel used to collect data used in the 2011 assessment, the Bigelow, has several important differences from the previous research vessel, the Albatross. Most importantly, the Bigelow is significantly bigger than the Albatross; it’s big enough that it can’t navigate the shallower waters in the region that Gulf of Maine cod inhabit and both commercial and recreational cod fishermen fish. As a result, it was unable to include the abundant cod that swim in the shallower waters in the assessment.
The differences between the Bigelow and the Albatross can affect the accuracy and reliability of the survey in other ways. NOAA scientists estimated that the Bigelow can catch twice as many large cod and six times as many small cod than the Albatross. NMFS used this estimate in catch difference to calibrate its assessment. However, whether or not the estimates and resulting calibrations are accurate is a reasonable point of debate, and introduces even more uncertainty into the 2011 assessment, particularly taking into account the fact that the Bigelow could not operate in the shallow waters.
In addition to a change in research vessels, an anomalously high estimate of recreational catch also provides a new source of potential error in the 2011 assessment. There is a legitimate question in whether the measurement of the size of the recreational fishery is an accurate representation of recreational fishing activity. The 2011 assessment concluded that half of all 2010 recreational fishing activity occurred in just a two-week period in the spring. Further, it concluded that 60% of the recreational catch came from private day boats. Both results are eyebrow-raising, and more likely reflect errors in the methodology and uncertainty in the data than they do an accurate picture of recreational fishing activity.
Some information that was not considered in the 2011 assessment, but was included in the 2008 assessment, indicates an increasing stock. For example, measurements of catch-per-unit-of-effort (CPUE) in both the recreational and commercial fisheries show an increase since the 2008 assessment, which potentially indicate an increase in available catch. Combined with potential sources of uncertainty introduced in the 2011 assessment, statistics such as these indicate that the most recent assessment may be much more inaccurate than the previous 2008 assessment.
Read the complete blog entry from Oceana