IPSO facto? oh no…
Posted by Philip MacMullen on 02 October 2013
Seafish, and the whole UK seafood industry, have broadly welcomed the recent report from IPSO, the International Programme on the State of the Ocean. It very sensibly identifies ocean warming and acidification as critical threats to the future functioning of marine ecosystems. Our own Paul Williams has blogged on this previously and one of the co-authors of the report is Chris Reid, known to many of us as an eminent expert on plankton who ran the Continuous Plankton Survey for some years. This survey has been sampling plankton in the North Atlantic, North Sea and Baltic for 80 years and gives us by far the longest time series of its kind in the world.
So we know about the evidence base for much of what IPSO is claiming.
When it comes to fishing however, I feel the commentary moves on to less firm ground. Dr Cheung, from the University of East Anglia writes an overfishing 'case study' about a ponderously enormous fish, the 'bahaba', found in major estuaries in south east China.
The piece opens by telling us that 'a recent study showed that 63% of the assessed stocks worldwide are over-exploited or depleted' and that 'overfishing is now estimated to account for over 60% of the known local and global extinction of marine fishes'.
In actual fact, the FAO series 'State of World Fisheries and Aquaculture', (aka 'SOFIA'), has been plotting the status of more than 520 stocks since 1974 and their 2010 report shows us that just about 30% fall into the 'over-exploited, depleted or recovering' category; the rest being either underexploited or giving their maximum yield. Clearly, there is no cause for complacency, but this does produce a rather different picture, especially as Dr C produces no references for his assertion.
And when Greenpeace tried to persuade the Women's Institute in 1996 that trawling was responsible for 'mass extinctions of marine species' I queried that and couldn't find a single species that we had lost. Again Dr C gives no references and doesn't name even one of the victims but does, later in his piece, name a few species suffering from depletion.
So here's the challenge: - if you're going to talk about extinctions, name that species! I'm always content to accept evidence-based material but sweeping statements don't get us anywhere.
And, by the way, that 'bahaba' is a bit of a cross between a dodo and a bluefin tuna. They grow up to 2m/100kg and their swimbladder is worth $20-70k/kg. I feel sorry for such a creature in our materialist age.
Philip MacMullen, Head of Environment