Lies, damned lies and fisheries statistics

'Bystander' questions the validity of the science that underpins fisheries management.


Much of what is good in life today came about through the work of scientists. Science is a honourable profession. It enjoys that reputation because throughout history scientists have been extremely careful in the way that they research, experiment and present their discoveries. Their work is based on valid, factual evidence; unless proven otherwise theories remained theories, leading to reputations founded on honesty, truth and exactitude.

Even so, there is a long list of self-serving individuals masquerading under the banner of science who seek to pervert the cause of science; men who see what is not there, who seek to twist statistics to pursue egocentric fame or push dubious, unpopular agendas.

'If the industry is to survive it is vital that the scientific
statistics used to advise and frame policy are accurate.'

But genuine scientists know this, which is why the standards of proof required by the scientific world are high. For instance, in medicine a double-blind system is operated so that the scientist testing a new medicine or drug does not know which of his patients is taking his drug or a placebo, thereby ensuring that his own desires do not innocently influence the result, such is the care taken to ensure accuracy.

How would the scientific community view the methods and results of the scientists who, in the course of advising the EU Commission that frames legislation on fish TACs and quotas, seek to quantify the fish stocks in the seas surrounding Great Britain?

This legislation that has great bearing on the livelihood of those who make their living from the sea and has already had catastrophic effects on the industry, being responsible for the decimation of the fishing fleet and the unemployment of thousands of workers.

If the industry is to survive it is vital that the scientific statistics used to advise and frame policy are accurate - it is impossible to justly shape and police the industry unless they are.

We hear of lengthy reports being written; statistics, records and details of research being collected, collated and studied; graphs, bar and pie charts are compiled, committees are assembled - while fishermen wait with bated breath as policy, restrictions and quotas are decided.

But how can these committees be sure that the decisions they make are based on accurate statistics and projections? How can they be sure - when their evidence conflicts with the experience of fishermen who have spent most of their adult life at sea? Only a fool would ignore the knowledge and sage counsel of skippers, realistically the only true experts.

I am not a scientist, I haven't been to university nor do I have letters behind my name, but I am reasonably confident that I could calculate the number of blades of grass in a ten acre field within a couple of percentage points. And given a map of the coastline, the apparatus to measure the depth of sand to the bedrock and a fixed tidal line, I could calculate the total weight of sand on a mile long beach - I would even be able to calculate the total number of grains of sand on that beach to the same degree of accuracy.

But ask me to calculate the number of fish in our harbour to within ten percentage points (a spread of 20%), and I couldn't do it.

Even if I had the numbers of anglers and fishing boats operating in the harbour, a record of every fish caught during the past ten years, and extensive readouts of sonar equipment taken over every square yard of the harbour, I still wouldn't have a clue.

I'll go further: make available to me all the expertise of every scientist, mathematician and statistician and university graduate currently employed by the agencies involved in calculating the bio-mass of the seas around our coastline, add the services of every research vessel and I still couldn't guarantee that the result would be anywhere near accurate - not even if the harbour was sealed so that there is no migration. To come up with figures that are anywhere near accurate would be impossible.

If however, I worked for one of those agencies and the onus was on me to quantify the biomass of fish stocks in the harbour, then, in the sure knowledge that it would be impossible to contradict my figures, I could produce a leather-bound, fully illustrated, multi-colour report full of market returns, statistics gleaned from the fishing records of research vessels, graphs, bar charts, sonar readouts, photographs and supporting bibliography.

It would be a report that would knock your eye out, a report that any publicity-seeking, self-serving politician would be proud to publicly brandish aloft in his aim to become known as a firm and fair administrator.

Our harbour covers about 20 square miles and has an average depth of about 40-50ft - a drop in the ocean you might say compared to the total area of the seas around Britain. So if it is so difficult to quantify the number of fish in such a small body of water, how much more difficult would it be to quantify the biomass in all British waters - which, it should be noted, are not ring fenced?

Taking into consideration climate change, changing currents, weather, industrial fishing, fish feed, predators, disease and a hundred other variables that can and do affect the fish population, I can unequivocally state that it is impossible to quantify stocks in the sea with anything like reasonable accuracy. Any claims to the contrary would owe more to alchemy than science. Interviewing fishermen and checking catches landed is the only way that any reasonable and acceptable indications of the state of fish stocks can be obtained. But even recording catches is of limited use, for substantial distortions creep in when one considers the number of over-quota fish caught and thrown over the side; for they are no longer part of the stock, nor are they recorded as catch - they just disappear from the radar screen. All the thousands of tons of fish dumped overboard makes nonsense of biomass estimates.

So how do you estimate fish stocks? The answer is that you cannot: it is impossible. Think of the care taken by real scientists, the double-blind testing of chemical products, and compare that degree of care with the methods used by fishery scientists to evaluate stocks: research vessels with sloppily rigged trawls and the counting of floating eggs and spat - it doesn't actually fill one with confidence.

I go along with comparative results; comparisons are fine, being especially useful when used to check the efficacy of one trawl against another, or the ability to conserve using different types of escape panels, but to use hopelessly inefficient gear, trawling areas forsaken by other fishermen and expecting to come up with accurate figures of fish stocks by comparing the contents of codends is arrant nonsense.

That is not to say that no research should be done - the more we know about everything to do with fish stocks the better. But based on the vastness of the sea and sheer numbers of fish it would be foolish to believe or claim that any estimates were anything other than pure speculation.

Yet these infinitesimal specifics - quotas for non-sector boats are calculated down to as little as 250kg a month in some cases - we know for sure are being used to decimate fishing fleets, empty once crowded ports, ruin businesses and put thousands on the dole. This is more than nonsense - it's criminal.

But there is something to be gained, something to be learned from this whole experience. This is that a policy of returning over-quota fish to the sea chosen by politicians to aid conservation, which has proved to be such a depressing, dismal failure, is a realistic indicator of the knowledge and intellect of those responsible for making the policy.

And the fact that as the policy remains in place, continuing to damage both the fishing industry and fishing stocks, with no indication of its early removal, is evidence of the intransigence and arrogance of those who initiated the policy in the first place - of that we can be sure. . .

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