In a recent article published in Marine Ecology Progress Series the German scientists Rainer Froese and Martin Quaas suggest that current exploitation levels should be kept for several years, or alternatively that the fishery is closed for 2 years in order to achieve MSY by 2015.
The article summarises a study which explores three different management options for rebuilding the eastern Baltic cod stock to the biomass that can produce Maximum Sustainable Yield (MSY). The first option incorporates the fishing mortality decided upon in the current management plan, 0.3. The second option further includes the harvest control rule of a maximum increase in TAC of 15% until a fishing mortality of 0.3 is reached, also as stipulated in the management plan. The third option freezes the 2010 TAC for two years before allowing a linear increase in fishing mortality with spawning stock biomass towards 90% of MSY.
None of the three options manages to rebuild the stock to MSY levels (Bmsy) by 2015 and therefore fail to deliver on the UNCLOS and the 2002 Johannesburg WSSD commitments. In order to achieve this, the fishery must be closed for either 2 years or maintained at current levels for several more years (the report does not specify for how many years, but 2015 is quickly approaching), according to the report. The third option achieves MSY at 2021 and maintains SSB at Bmsy thereafter. The second option which is following the approach determined by the management plan reaches Bmsy at 2017, but then drops below Bmsy after some years and stays below thereafter.
According to the study the third option will already from 2014 produce the highest economical profits.
It has to be noted though that the study uses a rather high estimation of Bmsy, close to 1 million tonnes, which is higher than any SSB level ever recorded of the eastern Baltic cod stock. However, the authors argue that if fishing pressure would have been lower during the 80’s when the SSB reached historically high levels, the SSB would have surpassed 1 million tonnes, and that the stock currently shows a strong growth potential, indicating that the chosen Bmsy candidate would be realistic.
Interestingly, none of the options explored by the authors would result in any cuts in TAC from current levels (except for the option to close the fishery for two years, which could be replaced by keeping current levels for an unspecified number of years) rendering a rather bright future for both Baltic cod and the industry.
The full article can be downloaded below.