Let’s imagine a hypothetical tuna stock. The stock assessments indicate that its stock level has declined continuously during the latest decade. The current level of the stock biomass is well below that of MSY (maximum sustainable yield). Despite past management measures that were intended to limit the fishing mortality coefficient (F) at the level at that time, F has increased substantially; the current level being excessive for making a sustainable yield. In other words, this stock has been over-fished (or in an overfished condition) and is still being overfished. The future projection analysis indicates that the stock would keep declining, if the current fishing level continues. However, if the fishing mortality level is reduced to the previous level which the past management intended to maintain, the stock would recover gradually.”
Let’s assume that we have to advise managers to take some actions for this hypothetical stock at the scientific meeting of a RFMO. There could be quite different opinions during the drafting process. Two examples of possible opinions on this stock could be: 1) “The stock is deteriorating rapidly in recent years, being overfished and could be extinguished in a few years. We must recommend very strict regulations to reduce catch significantly and/or reduce the efforts on this stock, immediately”’; and 2) “The stock has been overfished but if we comply with past conservation measures, it will recover”
These are extreme examples from pessimistic and optimistic points of view. Both state some facts which are not incorrect. However, a part of the findings is deliberately excluded in either of these examples. The first one does not state that the reduction of effort is required only to the level of the first recommendation. The second view ignores the fact that the compliance of the recommended management requires a considerable reduction of effort from the current level. As a result, the impressions they give are quite different.
While drafting the final text of advice to the Commission, scientists have to work out a way to keep a very delicate balance, between maintaining the precautionary approach, and minimizing the unnecessary sacrifice by fishers. The final advice of the Scientific Committee would be something like: ‘The stock biomass level is below the MSY level and recent fishing mortality (effort) is above the level corresponding to MSY. If the current effort level is reduced and maintained at or below the level at the time when the past regulatory measures had been taken, the stock would recover. Also, the managers should consider the possibility to restrict catches as well as or instead of effort restriction.” Unfortunately, such advice often turns out to be a little ambiguous as nothing can be stated with hundred-percent certainty. However, scientists have to be so careful in ensuring that their words are not misunderstood, accidentally or deliberately.