There’s “Overfishing”, then there’s “Overfishing”

22nd July 2009 in Sustainability / Environment

“Overfishing” is a widely used phrase, especially in the media. But it doesn’t always mean the same thing.

Over the last ten years or so the term has changed its meaning quite radically. It has moved from a term suggesting a practise that if not halted will lead to the extinction of a species, or at the very least the collapse of a commercial fish stock. It is now being used, most recently in the Commission’s “Communication on Fishing Opportunities for 2010” as any level of fishing that is inconsistent with a stock at maximum sustainable yield – somewhere close to the Nirvana of fisheries management. For those who are confused, a simple guide to the different definitions of “overfishing” is laid out below:

  1. “Overfishing” in perhaps its original sense, means irresponsible excess out-take of a stock that will lead inevitably to the extinction of that species, or sub species. This meaning dwells more in the media than with serious fisheries scientists but it is very common in the former and may be said to be the everyday understanding of the term.
  2. “Overfishing” in this sense is where the out-take from the stock can lead to a population collapse of the fishery so that it is no longer capable of sustaining a commercial fishery. The collapse of the Newfoundland cod fishery in 1995 is the case quoted most frequently. Although there are now signs of recovery in that stock, it has taken many years to rebuild. A similar collapse was seen in the 1970s with North Sea herring. Although this stock recovered quite quickly after a total ban on directed fishing was it took years for the market to recover.
  3. “Overfishing” meaning fishing outside precautionary limits (reference points) set by fisheries scientists as part of the precautionary approach. This approach has been in place since the mid 1990s. If the spawning biomass of any stock is outside its precautionary limit or fishing mortality (% of the stock estimated to be removed by fishing each year) is above the prescribed level the stock is said to be overfished in terms of its precautionary limits. In other words, if fishing continues at the current level there is a high probability that in the event of a series of poor recruitment years, the stock and therefore the fishery could face serious problems.
  4. “Overfishing” in relation to maximum sustainable yield. As the term suggests, this is the out-take that is consistent with delivering the maximum output of an individual stock over time. As a principle of fisheries management it rose to prominence in the Johannesburg Summit on Sustainable Development in 2002 but even before this, informed commentators had questioned its validity. Even for those, like the NFFO, who favour movement towards a large stock strategy, it has to be recognised that it is not possible, not least because the species predate on each other, to hold all commercial stocks at MSY all the time. A theoretical construct has been adopted as a practical management tool backed by heavyweight political commitment.

It is this last definition of “overfishing” that allows the European Commission, and a whole array of alarmists in the environmental media, to claim that 86% of EU stocks are seriously “overfished”. A more sober view would take into account the changing definition of overfishing over the last decade and recognize that although there are serious problems with a minority of stocks, most are stable and many are improving, in spite of rather than because, of the Common Fisheries Policy.

The NFFO falls neither into the camp that says there is no problem with European fisheries, nor the doomsayers with their alarmist cries of imminent environmental catastrophe. The latter is just a distraction from the serious work that needs to be done.