- A self description of a modern fishery scientist -

Below is a question that regards fishing mortality: Despite severe cuts in fishing activity, there is no rebound for the cod stock. Could there be other factors than fishing that affect the stocks? The postings were on FishFolk internet list.


From: William Silvert <ciencia@SILVERT.ORG> 15 Apr 2006:

Mike Flaherty posted a question on the FISH-SCI list which generated an interesting reply from Les Kaufman, who is not so far as I know a subscriber to FF. I thought his reply was very good, and so I am taking the liberty of forwarding it to FF. If you want to reply to him, please use reply-all since if he is not a FF subscriber he will not see messages posted to the list:

The question from Mike:

Hello All, Attached is an editorial written by Jerry Fraser of "National Fisherman" (NF) magazine. It came across on NF's weekly emailed newsletter yesterday. Personally, I disagree with many of the points he makes. However, I'll try to keep this subject of this post related to the science of the matter unless others feel comfortable enough discussing policy matters here. For purposes of discussion on for FISH-SCI, I am looking for some input on Mr.Fraser's following assertion...

NMFS knows the truth but does not utter it: Whatever is going on with cod, whose stubborn resistance to rebuilding efforts is at the heart of Yankee woes, it isn't fishing mortality that is keeping stocks down.

For those familiar with the situation in New England, scientifically speaking, is that statement true?

If I read Mr. Fraser correctly, I think he is basing his assertion on the fact that fishing Days-At-Sea (DAS) have been cut time and time again for cod fishermen. So, in his view, if cod stocks haven't rebounded then it certainly can't be the fishermen's doing.

However, as it was explained to me, with input controls like DAS, a day of fishing has become so valuable that fishermen learn to make the very best of the days available for them to fish. The result is yet even more improved effiency (Remember, the New England fleet is dealing with some 60% overcapacity). On the flip side though, it is my understanding that collectively about 1/3 of the alloted DAS are not even being used (perhaps good for a discssuion on cause vs effect) - so a further cut in DAS isn't necessarily going to result in a 1:1 cut in fishing effort.

Undertandably, there are numerous factors that are not helping cod rebuild and some of them have been discussed on this list before (pollution, climate, etc). However, I have to think that when it comes to codfish, one of the largest impacts determining the chances of success in their rebuilding has to do with the level of targeted fishing effort on them (comm and rec). Also the regulatory dead discards associated with catching too many of them at once (whether directed or not) isn't helping either. Am I incorrect?

Scientifically speaking would cod stocks (and axiomatically, current fishermen) be better or worse off if the environmental groups that Mr. Fraser mentions did not get involved to help stop overfishing (which is still occurring by the way)?

Thanks,Mike Flaherty Wareham, MA. A recreational fisherman from Wareham, MA

Answer from a scientist involved in management

From: "Les Kaufman" <lesk@bu.edu> To: <FISH-SCI@SEGATE.SUNET.SE> Saturday, April 15.

Subject: Re: New England Cod

Hi, Mike. This is Les Kaufman, a scientist with the Boston University Marine Program and active in cooperative fisheries research and fisheries management in New England.

The statement that you quoted by Mr. Fraser is, to the best of my knowledge, not true either entirely or mostly. Fishing mortality over centuries and over decades are closely (but inversely) related to cod stocks in New England. This must have a strong causal element. I say this because fishing removes a large proportion of the population of cod, because it is especially effective in removing the larger, older cod, because fishermen know extremely well how to continue to find cod as they get fewer and fewer, and because fishery reductions (however harsh on an industry that of course wants to survive and grow) have failed to achieve some effects that biologically are extremely important to stock rebuilding and fishery sustainability.

Among these are:

Fishery management has lately been focussed on reducing cod mortality. Fishermen have really felt this pinch, of course. There are three related problems with the approach that has been taken to management (of simply reducing mortality in a very general way), at least if you are looking for the huge cod rebound in the last few years that has failed to happen.

Fishermen are right to point to the climate and pollution as things likely to be contributing to this poor resiliency. It would be very good if we stopped polluting the world and changing the climate and we should anyway. But if I had to make an investment in rebuilding New England cod and my life depended upon it, which it sort of does professionally, I would get much more serious about reducing mortality, holding it really low, and not letting up at all until several very strong year classes had progressed into their second decade of life. I would also establish a system of no-take areas in New England across all habitat types (but especially in rocky areas- not so hard to do at this point except for opposition, ironically, from the recreational and lobster fisheries), put hard clamps on the sea herring fishery, restore river herring populations, and insist on a hard TAC (total allowable catch) both for individual species and groups of ecologically similar species. I would also switch fishery management from single species to an ecosystem-based approach, focus on really understanding why the ecosystem does the crazy things it does, and manage people so they don't "make it mad"- you know, extreme precautionary management- the old "it isn't nice to fool with Mother Nature" deal. Having done all of this, I would then devote all my remaining energies to watershed restoration and reversing climate change. There is every reason to believe that cod would then return to New England in very large numbers...eventually. Perhaps in several decades.

The science indicating that if we want cod back we should do all of the stuff above, is very strong. But it doesn't guarantee results, because nature is not a simple machine. Extreme patience, a small, nimble fishery, and great caution are the most important general elements of any realistic strategy to restore cod to New England. Fisheries in general do not have good track records of patience, modesty, or caution. The New England Fishery Management Council is, in this respect, very typical in its behavior. It also has people on it who would rather have lots of herring or lobster, than lots of cod. Everybody is entitled to their opinion.

What I have just said would make me sound like a nutty environmentalist to some fishermen I know. However, I am not saying it AS a nutty environmentalist. I am saying it with my scientist hat on, the same way that a judge might say things with his or her black robes on or a doctor with a white doctor get up and stethoscope on. They are reasonably objective statements based on a lot of hard science, much about New England, and a lot from the rest of the world. It is a crucial part of science for scientists to challenge each other constantly...but I'd wager that what I wrote above reflects a consensus among fishery scientists and marine ecologists. In other words, it means something that you would have to search had to find another qualified scientist who would have really major disagreements with the sum of what I said. Some of the folks who might join this consensus do work for environmental organizations, and yes, some of them work for NMFS, but a few like me work for universities. Although I have a nine-month salary from teaching, I do take research grants from both federal and environmental organizations, and some of the money that I get from both places was originally made by drilling for oil, or by fishing for that matter; the grants are drawn off federal taxes or off the interest on money that was made a long time ago. Those are my disclaimers.

So in brief, fish stocks and fishermen will both be much better off, at least eventually, if people accept what science and good judgement have to say about proper behavior. The fact that environmentalists all seem to be agreeing with science and good judgement, is not a reason to abandon science and good judgement, even if you dislike environmentalists. It is also true that "eventually" may not be soon enough for many good folk who still tie up today in places like Gloucester, Chatham, and New Bedford.

For perspective, try this. I also work on coral reefs, and in my own short lifetime I have watched the coral reefs of the entire world, but especially those in the Caribbean, take a dive unprecedented except if you look back thousands (more likely hundreds of thousands) of years in the fossil record. We know a lot about that one. Overfishing definitely puts coral reefs on the edge of a precipice and stopping fishing definitely helps them to get healthy again, but climate change and pollution threaten to throw them into the abyss and keep them there for as long as people behave the way that they've been doing for the past couple of hundred years. And once everybody comes to their senses, it will still take centuries- CENTURIES- to repair all the damage. Now, THAT is a bummer for you.

Compared to restoring the coral reefs of the world, getting cod back in New England will be easy. - I say, not as a scientist but as a recreational fisherman with commercial fishermen friends... let's do it. - Les

Response from Bob McDonald

Bob has for a long time criticised the orthodox fishery biologists and his answer below describes that very well.

From: Bob McDonald <parrot@JEACK.COM.AU> , 17 Apr 2006

Subject: A lack of Competition for Scientists

Hi Folks and Bill: Les succinctly puts the prevailing point of view of almost every fisheries scientist I have met. In summary, first we cut catches - and when we cut these catches across many fisheries and protect habitat that trawling interacts with and then it is called ecological management. A bit short by any definition of ecology - but avoids sea temperature and current changes as 'watershed managment' neatly.

He also states that some fishermen seem to be able to find good catches of cod regardless of what the stock assessment is - and remain a threat to the fishery. This is because various parts of the fishing ground have different production at different times that have nothing to do with total numbers of fish. If fishermen can still get good catches of Cod within the same fishing ground then the abundance of Cod cannot be measured by changes fishing catches and effort can it?

I await the lead to get interested in climate change and watershed/catchment management after fisheries have been closed. Good one - and how pray tell are we to know the impact of spending billions on these activities if there is no fishing?? How are we to justify it financially - to help the 'marine ecology' - the neo cons will love that - not. This is a cop out. The dismissal of a significant challenge to the assumptions that underpin stock modelling. And despite what this author falsely states - concern over pollution and habitat change does not come just from fishermen 'making excuses'.

No mention of seismic testing on the Canadian side? No mention of large scale changes in currents and sea temperature that have cyclic impacts on catches as shown by other scientists? So we have our science objective except when - what - the assumptions that underpin the models used are challenged. By definition this science is not objective.

What is the problem seismic testing anyway - we almost all drive cars - pay an arm and leg for petrol and would not notice a fish friendly tax to cover the cost of modifying seismic testing and studying its impact objectively so it can be reduced. Of course it is easier to do fish counting science if you just ignore it. Slack - slack as.

Oh, the weary tone - if only people would listen to scientists......

It reads like another learned tome from the 'Church of Cod' - the belief in 'hundreds of years of overfishing'. It really is an act of faith with and again very little to do with objective science. The only answer to the problem this scientist has described - but carefully not mentioned - is ITQs - a management method that guarantees employment of scientists forever. This is not the sole approach available to fisheries management.

Why not keep the fleet and manage the fishing grounds, the gear used - not the number of fish that can landed per boat, week or fishing days at sea? Manage the catchments that feed them and study the impact of seismic testing and monitor it. Look harder and further for historic Cod nursery areas inshore as well as offshore and the factors that compromise them. Archival tag more fish and work out where they go. There is plenty to do if the fleet is quarantined from catch management.

It is mathematically impossible for fishermen to catch a greater proportion of the fish if they are becoming less abundant - efficiency x efficiency???. I will bet the author a slab of bear that the fishermen who keep catching cod have not got the newest boats or the latest equipment. The model has failed and manipulating the truth regarding fishing is just a 'patch' that relies on mythology.

Scientist may be very proficient at modelling stocks, but like economists, if their models are wrong the management they recommend is too. Now who can tell/show them that the assumptions that underpin their models are wrong that they will listen too? How do we test the models independently from those whose livelihood is dependent on them?

The fishing industry has to be able to employ and train its own scientists and economists if there is to be any kind of scientific rigor. This preaching comes from a lack of any kind of meaningful challenge - a lack of competition in science. There should be scientists challenging these views, harder than I do, nipping at their heals and keeping them keen, sharp and challenged. Perhaps the last word should go to a scientist:

From 'Consilience', by the biologist and philosopher E. O. Wilson:

Biologists, it is said, suffer from physics envy. They build physics-like models that lead from the microscopic to the macroscopic, but find it difficult to match them with the messy systems they experience in the real world. Theoretical biologists are nevertheless easily seduced (I confess to being one, and having been responsible for more than my share of failures).

Armed with sophisticated mathematical concepts and high-speed computers, they can generate unlimited numbers of predictions about proteins, rain forests, and other complex systems. With the passage to each higher level of organisation, they need to contrive new algorithms, which are sets of exactly defined mathematical operations pointed to the solution of given problems. And so with artfully chosen procedures they can create virtual worlds that evolve into more highly organised systems.

Wandering through the Cretan labyrinth of cyberspace they inevitably encounter emergence, the appearance of complex phenomena not predictable from the basic elements and processes alone, and not initially conceived from the algorithms. And behold! Some of the productions actually look like emergent phenomena found in the real world.

Their hopes soar. They report the result at conferences of like-minded theoreticians. After a bit of questioning and probing, heads nod in approval: 'Yes, original, and exciting, and important - if true.' If true . . . if true. Folie de grandeur is their foible, the big picture their illusion. They are on the edge of a breakthrough! But how do they know that nature's algorithms are the same as their own, or even close?

Many procedures can be false and yet produce an approximately correct answer. The biologists are at special risk of committing the fallacy of affirming the consequent: it is wrong to assume that because a correct result was obtained by means of theory, the steps used to obtain it are necessarily the same as those that exist in the real world.

Cheers Bob Mac

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