Almost sounds like a Lotka-Volterra model of predator prey interaction.

Not really. To decreasing fishing mortality it is necessary decreasing the fishing  effort. So the revenue of fishermen decreases and the quality of life of the fishermen worsens i.e. increases the fishermen mortality.

But if stocks are low, fishermen mortality would decease the fishing effort.  The question is if the reduction in fishing effort is a planned & controlled reduction a la government, or an uncontrolled one by way of free open access....that's where the social policy fits in. And here's where the L-V relationship seems to fit in   But the problem is on the supply and demand end for marketing the caught fish.  Scarce fish supply means you can come home with less fish catch but haul in more money...putting even more pressure on the already scarce stocks.

Leonardo, I think you are approaching important questions that go to the heart of the failure of conventional fisheries management but you are over simplifying -- perhaps deliberately, as you make your point.

It is not, of course, necessary for fishermen to die in order to reduce fishing mortality. Even non-human predators can switch their prey resources to some extent and fishermen can shift between fisheries, emigrate to fish new regions of the ocean or even leave the sea to work ashore. The converse is part of the problem: Whenever a resource recovers, there are many fishermen and potential fishermen waiting to enter the newly-prosperous fishery. Such complexities of human behaviour are what make attempts to model human/fish interactions in terms of predator/prey relationships futile: Fishermen are only the "tentacles" by which the human "super organism" obtains its fish. Consumers are the "stomach" and the demography of the consuming populations operates through their economic relations with food harvesters of all kinds to determine the pressures placed on food sources -- agricultural soils as much as seafood resources. Most of those same consumers are also parts of the "super organism's" "brain", influencing the "tentacles" through politics and regulation. That system can be modeled but models which capture the behaviour of the system are likely to be far more complicated than ecologists' predator-prey equations.

I think the solution to the conundrum that you have raised is quite different: To frame the issue in terms of excessive fishing mortality, reductions in effort and the tempering of such reductions through concerns over fishermen's interests is to perpetuate the idea that fisheries management is a conflict between fish conservation and fishermen. That has been the experience of managing offshore fisheries for the past 150 years or so but it was not the basis for the management of near-shore fisheries over the previous 100,000 (or maybe 1,000,000). I think we need a recognition that fisheries management is a matter of balance, not conflict: Take no fish this year and you do not have a fishery. Take too many this year and you will soon not have a fishery. Take an intermediate amount and you have the basis for lasting prosperity, balancing the taking with the leaving. The primary beneficiaries of that balance should be the fishermen and the fishing communities, so they should be the primary supporters of fisheries management. The attempts of governments to address the problems of 20th Century offshore fisheries, however, proceeded through top-down, command-and-control approaches, creating conflict where there should have been support -- conflict which then progressed into management of coastal fisheries, where it was never necessary. Backing out of the resulting mess won't be easy but I think it is necessary before we will see truly successful fisheries management.

In short, I suggest that we need to re-arrange the way that people see fish/human interactions and the accompanying human/human interactions. If that can be achieved, your question (and much else in the fisheries debates of the past 70 years) would come to seem irrelevant. 

Dear Trevor, the core of the question is: Wisely, many policy makers take into account the mortality of the fishermen through measures such as "loss of income" (that means pay fishermen to reduce fishing effort). Unfortunately policymakers, pressed by the fishermen’s lobby, often excessively favour the fishermen in fear of losing electoral support.

And the twin cores of the mistake are (1) that policy makers seek to set the limits on the size of fisheries and (2) that the fishermen's lobby presses for those limits to be relaxed.

The now-conventional management system (the one that was developed for the great offshore fisheries during the second half of the  20th Century and which is now being applied to so many fisheries worldwide) is internally consistent. Among its consistencies, it expects the fishing industry to always seek to expand effort. It expects that government agencies will cap that effort at a level that the resource will support. Given those two expectations, it is logical that fishermen will oppose the limits, creating the conflicts that we see in so many fisheries. Each part of that management system is fully sensible and all parts interact with one another in fully understandable ways. Within that frame of reference, your question is eminently sensible.

Unfortunately, that 20th Century approach to management is an abject failure. I hope that somebody can point me to at least one fishery where it has worked (and worked over a long enough time that we can expect continued success -- 20 years might be a suitable minimum). Sadly, I do not know of even one. Not one, anywhere on the planet.

We need a different way to manage fisheries and I will suggest that one of the things that needs to change is fishermen's resistance against conservation limits. We need a fishing industry that recognizes wise use of resources as being to its own benefit, hence fishing communities which set those limits for themselves. (Which means that we also need rights-based management, so that those who limit themselves get to enjoy the fruits of their restraint.) To those who refuse to recognize the failure of the 20th Century way, fishermen embracing their own limitation looks like utopian nonsense but it was the way that fisheries were managed (very successfully) for a very long time -- and continue to be where nobody has sought to impose a "modern" but ineffective alternative. The challenge before us is to figure out how to reconstruct a desire for self-limitation in fisheries that are embedded in modern economies.

It won't be easy but it is essential that we succeed.

Dear Leonardo,   I suppose the politicians would need some sort of political calculus to figure if the fishermen's lobby is worth worrying about.  The fishermen's lobby can be noisy and active, but in lots of places there is not that many of them in relation to other voters.   Might politicians ignoring the fishermen's lobby actually be doing the industry a service in the long run?   I sure don't know.

As for managing loss of fishermen's  income, we've seen instances where boat buyback programs have proven to be problematic, with some fishermen getting rid of their older inefficient boats and taking the proceeds to invest in bigger & faster boats to get out to the fish ahead of the others.  So there's a game in that regard.  Paying fishermen to stay home has been discussed frequently, but when that sort of thing hits the newspapers, many in the general public balk at the public expense.  And Ironically, often the fishermen's lobby groups themselves are mistrusting of government management of the fisheries in general, so they tend to vote for politicians promising to limit the power of the management agencies (e.g. there are bumper stickers on fishermen's trucks locally that proclaim "National Marine Fisheries Service: Destroying Fishermen & Their Families Since 1976").  But then again there are just about as many differing opinions as there are fishermen!

Often it is the environmental NGOs are playing the major role around here of pressuring for the strictest fisheries management by the fisheries management agencies.  Their mantra is "advocacy for the fish".   And they will sue in court to assure that the state and federal management agencies are following the strictest interpretation of the conservation laws, so they are frequently at odds with the fishermen...that's an important dynamic.

Michael: One of the oddities of most democratic systems is that they respond to the few people who care enough about one issue to change their vote on that point alone, rather than responding to the views of the majority, whose level of concern over the issue in question does not rise to the point of a changed vote. (Maybe that's not a bad thing:  When a minority is pressed hard, it should generally be listened to and not simply be subjected to the dictates of the majority.) A lot of us would probably change our votes if our primary source of income was under threat. A fair number of sport fishermen also seem to care that much about their fishing, even though it isn't a job for them. That makes politicians generally responsive to the fishermen's lobby.

There can be complications. In Canada in the 1980s, fishing interests were concentrated on the Atlantic coast and could have affected enough votes in enough ridings to swing a federal election. It was a whole lot easier to prop up the fishing industry using wealth derived from Ontario than to annoy the fishing communities by applying some "tough love". Doubly so since giving a fishermen what he expects will only be seen as just, earning no political reward, whereas taking away what he wants will be seen as an evil to be punished at the ballot box. (And fishing families have long memories for such evils.) Meanwhile, in Australia the few fishing votes were too scattered to have much electoral impact. No surprise which of the two nations saw its principal fisheries collapse in the early 90s. (Not that the electoral differences were the only causative factor, of course.)

Trevor, I think you are spot-on with the politics of the organized  minority, that's why the 'best' legislators really are good at the political calculus.  From my point of view, the massive investment in mussel farming in PEI was one of the best silver linings of a mostly ugly situation.

An interesting question, and I guess the income and employment of fishermen is affected by fishing opportunities. I management works well (F = FMSY or F=FMEY)  however, in currently depleted stocks there could be more fish at lower fishing mortality, simply due to the rebuilding of the stock. This is because fishing mortality is a relative, catch an absolute metric. But I presume, that was not the point of the question ;-)

However, the gap between short-term (economic gain) and long-term interests (high fish stock) of fishermen is often not closed by politicians. In order to rebuild a stock, fishermen would have to agree on reduced catches for 1 or 2 years, which they cannot afford due to financial short-term obligations. Political solutions should help fishermen to compensate the short-term losses to allow them to agree to the long-term benefits.

Dear Wolfgang, I completely agree with your answer. But this is only the first part of the question "with wisdom, for some years, political solutions should help fishermen to offset losses in the short term." Sometimes the compensation becomes "forever". Because fishermen often perceive "compensation" in the form of a grant. So the unions of fishermen push politicians to institutionalize the compensation by threatening to remove the political consensus. Many policymakers, with the complicity of their scientific advisors, too often favour the fishermen in the fear of losing support.

Wolfgang: Fishermen's objectives, and those of the rest of the seafood industry, are far more complex than your words suggest. Too many of our fishery resources are badly depleted and it will take much more than a year or two of reduced catches to rebuild them. Even if people in the industry are persuaded by the numbers (and there is a huge credibility gap between the fishing industry and fisheries scientists), individuals face massive problems in surviving through long periods of very low fishing effort -- especially when sustaining the high catches of the future means keeping effort down and so cutting capacity below past levels. Present pain is not welcomed if the future gain will go to other people! There are also serious questions about whether the industry could re-expand after prolonged periods of near-zero fishing. Fisheries have to draw labour (fishermen) from communities with rather unusual characteristics. If fishermen's children find work ashore, fishermen's families get used to having their breadwinners home every evening, boat yards close, waterfront land is developed for hotels, consumers develop a taste for other foods, can a new fishery emerge when resources are finally rebuilt? In Norway and Newfoundland, probably yes. In Florida, very likely no.

Where resources are currently at levels that can sustain harvests of optimum yield, the interests of the seafood industry and the individuals within it are _long_ term: As the economists say, fisheries capital is non-malleable -- fishing boats have little value outside the fishery for which they were built. Fishermen's lives are even less malleable. Once a teenager leaves school early to fish with his or her father, the young fisherman's options outside fishing get very constrained. Many a fisherman, as he approaches old age, has been concerned to see his way of life passed on to his grandchildren. Thus, if a fishery is anywhere near long-term stability, everyone within it should be looking decades ahead. Politicians' interests are much shorter-term, not often stretching even as far as the next election. We should be asking why people in the fishing industry press their politicians for short-term responses instead of demanding effective long-term management.

The answers probably lie in social psychology but I'll take a guess that they include distrust of the numbers generated by fisheries scientists, perceptions built around the variability of fish availability (which hides trends from anyone who does not have access to statistical analyses), a view from the wheelhouse that is very local combining with an understanding that the ocean is vast, and life experience built around success (e.g. high catches) coming from effective utilization of opportunities to fish -- the latter making fishermen uncomfortable with anything that constrains future options.

I think that we need to change the way that we conceive of fisheries management, so that the industry sees fisheries science as being supportive (not confrontational) and so that the industry can take charge of its own destiny. If management (including long-term resource conservation) was something that fishermen do, rather than something done to them, I think the resistance would fade away and the industry's long-term interests come to the fore. _How_ to structure management to achieve that, and especially how to make the transition when the current generation of fishermen has been raised on confrontation with management, are the challenges.

@ Trevor: Of course You are right, things in reality are more complicated than in scientific models and overfishing raises as much social and economic issues as biological ones. The loss of knowledge and people being able to fish will be substantial if fishing is reduced.  

You seem to favor a strong self-responsibility of the fishing industries in managing fishing resources, which is good. Hover, I think national (UK, Germany, Denmark, Netherlands, etc.) and regional governments (e.g. EU, US Federal government, etc.) are the only institutions that can balance the interest of resource users (fishers) and the common public. Nobody else can do this, this is the very essence of fisheries management institutions. At its best, these institutions would  be populated by people with a long-term perspective i.e. professional managers, and not only politicians with an election back ground. And also in an ideal case, science, the industry, other stakeholders (NGOs like WWF or Greenpeace)  and the management institution would cooperate in a transparent process to achieve societal consensus on what, how and how much to fish. Therefore stakeholder participation has to be more formalized into the management process, the RCA within the EU CFP are a first step in this direction. Let's see more of this.

Hi Wolfgang: Reality is always more complex than anyone's model. That is inevitable and proper. Trouble arises when the simplifications in models lead to conclusions that are the reverse of those we would draw if we could contemplate the full complexity of reality. Nothing new in that but we must always guard against that problem. My conclusion, after 30+ years of studying the issue, is that the simplifications underlying the post-1945 approach to fisheries management have led us to failure. I think we need to shift to a different set of simplifications and, from them, build a different way of managing fisheries. That makes me sensitive to colleagues who trot out the same old assumptions as through they were empirical truths.

You say that I favour strong self-responsibility for the fishing industry. That is not my goal but I have concluded that sustained prosperity throughout the seafood production system (which requires sustained marine ecosystems and resource productivities) is unlikely to be achieved without a large measure of self-responsibility. Thus, I do favour it but as a necessary means to the end that is broadly (though usually not explicitly) defined by the public policy of most fishing nations. As a fisheries scientist, it is not my place to dictate the goals but rather to explain to decision-makers what will be needed if their goals are to be achieved.

I see two roles that can only be filled by "higher powers" -- which usually mens governments but, for one role, could be "councils" empowered by governments but made up of non-governmental people. The first is the role that you mention: Only the processes of government can ensure that the interests of the general public are given full consideration in policy-making and policy-implementation. (Easier to understand in a democracy than in a military dictatorship, of course, but the role is still there.) Back when I was a member of two Australian Management Advisory Committees, in the mid-80s, it was evident that the then-Minister's preference to delegate fisheries-management decisions to the MACs made his on-going role one of representation of the general public's interest. I think that is healthy: governments should speak for the mass of the citizenry. That, however, is true of the public's interest in every industrial sector. It is reason for governments to set standards that fisheries management must achieve but does not justify governments dictating the details of how those standards are to be met. The attempt at detailed management of fishing is (almost) unmatched in governmental regulation of other industries. Since it hasn't worked, we should re-think current approaches.

The second role for a "higher power" in fisheries management comes from questions of spatial scale. Fishermen (either captains of big trawlers or the collective agreements  of small-boat fishermen working out of one harbour) are capable of managing their own fishing but not (usually) of addressing the overall impacts of the fishery on even one resource of immediate interest. Some form of collective decision-making and decision-implementing structure is essential. In the post-1945 version of fisheries management, that role has been filled by governments or inter-governmental organizations. There have been various attempts at involving the managed in the management, of course, with varied degrees of success. It is likely that many fisheries would benefit from more involvement of the fishing industry at that level but it is also likely that other fisheries could do with less of it. (Such is the diversity of fisheries around the world.) 

The important point, I think, is this: While fishermen are usually not able to make and implement the large-scale decisions (except perhaps through structures and mechanisms supported by governments), governments are usually quite incapable of making the small-scale decisions. Fisheries vary but fishermen usually place their gears with spatial precisions of centimetres to kilometres and temporal precisions of seconds to (at most) a few days. Government agencies (fortunately!) have not even attempted to manage across such scales. Instead, there is an unstated assumption that fishery resources do not have fine-scale structure within the management units mis-named "stocks", hence fine-scale targeting is irrelevant to the aims of management. In reality, fishermen (like non-human predators) would starve to death if they did not exploit the fine-scale structure in their resources. The failure of the post-1945 form of management (one of the failures?) is that emphasis on large-scale conservation restraints drives fishermen to exploit small-scale structure in an attempt to advance their individual goals. As the approach has matured, we have ended up with fisheries managers pursuing one set of goals across large scales while "fishing managers" pursue a different set over fine scales. Failure should not be a surprise.

Only "the man in the pilot house" (as my friends in New England would say) can manage over small scales. Thus, societal goals for fisheries cannot be achieved until he (and everyone else in the seafood industry) has a central role in the overall management process.

And that is why I appear to favour "strong self-responsibility".

Hi. I think it dhould be directly proportional and not inversely proportional.