Newlyn Fish Market - boats due to land.

Thursday, 28 June 2012

Overfishing : what everyone needs to know. Ray Hilborn



In 2006, a study on the state of global fisheries created a sensation in asserting that more and more species would vanish and were to disappear by 2048 if we extended the trends in abundance of fish stocks as well as the fishing effort. This study  was questioned particularly by Ray Hilborn, who suggested to one of the authors of this study, Boris Worms, to reconsider the data which had led to such catastrophic conclusions. This work ended up in a publication that largely questioned the analysis and conclusion of the previous study, but the media and environmentalNGOs ignored it, and still go on spreading alarmist conclusions. The height was reached at the beginning of June 2012, before the decisive meetings on the CFP and the Rio+20 Summit ( articles in Paris Match and daily papers, news on the Web, press releases, and TV programs, screening of the film « The End of The Line »). 

Ray Hilborn is one of the top scientists on fishing in the US. Contrary to 'aquacalypse' prophets, he is working at improving the fisheries situation in a pragmatic and successful way. His experience covers industrial as well as artisanal fishing, in the North as well as in the South. He is one of the specialists on Pacific salmon. In an attempt to give an end to this utterly pessimistic  « pensée unique », he published a book in March 2012 - a pedagogical book meant to review the situation of overfishing and the management problems – a simple approach, with questions and answers, so as to clarify a complex issue.

Overfishing, a complex notion

Overfishing is a complex, multifaceted reality. There are various types of overfishing. "Yield overfishing prevents a population from producing as much sustainable yield as it could if less intensively fished" the stock is not necessarily threatened of collapsing. This yield overfishing itself also presents different aspects. It can be recruitment overfishing: "there are no longer enough spawning fish to produce enough recruitment". It can be growth overfishing : "it has to do with how old a fish is when captured relative to its size". 

In this case, overfishing concerns mainly young fish, but in compensation, those which are left have generally a quicker growth since they enjoy more food if natural conditions are normal. Yet, there is a loss of potential biomass because the fishing pressure is too high. Finally, a stock that is being overfished may also be in a restoration phase if catches allow the maintenance of a surplus generating the stock growth. 


For example, it is the case at the moment for sole in the Bay of Biscay. This yield overfishing concerns about 30% of well-known stocks in the world. It is mainly true of fisheries in  developed countries. There are stocks that are not well-known, but which are not threatened and major stocks are better known and monitored. The tendency in developed countries is toward a reduced fishing pressure and the number of overfished stocks is quickly diminishing even in Europe. Ray Hilborn reminds us that we can’t trust catches data to estimate a stock because some stocks are under-fished and conversely, there are discards. Then we are far from catastrophic data of 75% of overfished stocks and that are threatened or being depleted. 


The other aspect of overfishing is that of economic overfishing : « More fishing pressure than would make the most profit…Fishing for profit requires less effort than fishing for highest biological yield ». 60% of the well-known stocks in the world are in this situation according to the database established by Ray Hilborn and other scientists. The problem then is economical and non biological, there is no threat of collapse linked to fishing, nor general depletion of the seas. 15% of the well-known stocks are depleted, among which some are in the process of being restored. The constant onslaught of the media announcing the threat of the depletion of oceans is hardly justified, given the actual data that rather show a tendency toward a restoration of stocks. Above all, it reveals a will to get out of economic overfishing so as to obtain a maximal profit. It is a possible choice, but it isn’t the only one, and this deserves a real debate on society rather than the diktats of lobbies that are founded on unreliable data.

Management : variable objectives.

What is a well-managed fishery ?

The answer to this is complex, because management objectives can be different, and consequently, imply totally variable fishing pressures. « To some, well managed means very little fishing and largely intact ecosystems. To others, well managed fisheries should produce near maximum economic value to an individual nation or the world. Others might consider well managed to ensure food security, and then again it might mean maintenance of traditional fishing communities and employment » Today, all those who spread pessimistic estimates, in reality aim at either securing the integrity of ecosystems, and currently a slight fishing pressure, or a maximum profit, because there is no risk of a generalised biological collapse of stocks, even if there are some cases of depleted or threatened stocks.

Two phenomenons make management problems more complicated : the natural variability of stocks, and the diversity of species in multi-specific fisheries. A drop or a collapse in catches is not necessarily linked to overfishing, but to natural variability.

In this way, pelagic fish like sardines in California or North Sea herring fluctuate in abundance from 1 to 100. The biomass of Alaska pollock, one of the most important fisheries in the world, has gone from 12.8 million tons in 1995 to 4.8 million in 2008, then to 9.6 million tons in 2011. Overfishing can’t be blamed for it, because catches are limited and controlled to an average of 15% of the biomass.

The standard management by TACS and quotas applies to  industrial stocks, whereas the ecosystem is made of a diversity of species which interfere between themselves. It is difficult to reach a maximal yield stock by stock, even if today efforts are made to develop an ecosystem management approach : one stock can be healthy, when another is weakened in the ecosystem. Generally speaking, the ecosystem biodiversity is far richer when we move from the Poles towards the Equator, and a management by quotas is then less adapted when moving from the North to the South in our hemisphere. Finally, threats on the ecosystem do not come only from fishing, but also from climate changes, pollution, currents, etc…

The role of decadal oscillations of currents in the Pacific and the Atlantic is more and more acknowledged and these considerably influence the evolution of stocks such as salmon, cod, sardine, anchovy, hake etc…
Which management tools ?
For Ray Hilborn, as for most people in charge of fisheries management, the key to management is to be found in the control of access to fishing. Such limitations to access are obtained by the granting of exclusive rights. These can be private (ITQs) or granted to organisations or communities to be managed collectively. For Ray Hilborn : "It is best to provide direct incentives to the fishing fleet by assigning them collective or individual shares of the catch, let them find ways to catch their share of each species, anf give the fleet the choice of where to fish, when to fish, and what gear to use"

His choice, (at least for industrial fishing) goes to a management founded on maximum profit below the maximal biological yield. For coastal and artisanal fishing, the approach by collective rights (on such territories as those in Chile) seems to him better adapted. He also agrees with the pertinence of Eleanor Ostrom’s approach for collective rights. We may question his praise of New Zealand, Icelandic, North American models. In Iceland, ITQs have not led to an optimal management of cod stocks, and have favoured the birth of a speculative bubble. In all countries, New Zealand included, the privatisation of fishing rights has had negative social impacts. Entry costs are prohibitive, and amount to 9 times the value of annual catches for halibut in Alaska. For Ray Hilborn, it is still possible to support fleets with on-the-water boat owners on condition that restricting rules are clearly set so as to avoid concentration.

In his pragmatic, rather liberal way of looking at things, he is opposed to any subsidy (for fuel, credit, research, control), considering that a high profit makes it possible for fishermen to finance all this. But, he doesn’t believe in another liberal approach, in the consumer action, impossible apart from some developed countries, mainly Anglo-Saxon or Nordic, and often pernicious, because a stock in a bad state can even be moderately fished if it is in the process of being restored . Everything depends on at which speed its restoration is expected. A boycott may uselessly penalise fishermen who have to bear severe constraints. The setting up of reserves may be useful to fishermen, and they have created a few, but it may also lead to a higher fishing pressure outside the reserve, and thus create problems in the access to fishing zones. MPAs are mainly tools for the conservation of biodiversity. The choice of MPAs, of their numbers, their size, their location, their functioning, has more something to do with political and social choices than fisheries management. One of the most difficult problems to overcome is that of mixed fisheries, it is difficult to protect the most feeble species when others are healthy. There are three possible solutions :

  • temporary closures in the zones where the weakened species concentrate
  • the change of fishing gear so as to make it more selective
  • give the fishermen the possibility to adapt in case of excessive catches of the species to be sustained (which entails an observation system aboard).

Fishing and biodiversity

Fishing has an impact on ecosystems and on biodiversity. It modifies the size and abundance of stocks : generally, an ecosystem subject to fishing reaches : 20 to 50% of the unfished abundance. Fishing also modifies the balance prey / predator, because it aims at some species, it can favour others that are not aimed at, since there is competition for food. Fishing modifies the food web : for example, fishing carnivores helps the development other fish consuming the zooplankton, which in turn can favour the phytoplankton and lead to the ecosystem saturation.

Such extreme evolutions are not frequent, there are often many species at the same trophic level, and species adapt themselves to food availability.
Of course, the more overfishing, the more modifications of the ecosystem, but the wish of a maximal conservation of the ecosystem ends up in a reduction of the fishing pressure and a reduction of food production. This reduced production is transferred to other productions that may even be more harmful to the environment. Here again, the level of protection of the environment has to do with political and social choices. 

All things considered, fishing is one of the rare human activities that little affects the primary productivity : the plankton, at the basis of marine production . It is pollution that destroys the plankton, as well as the destruction of the sea floor by extractions or sprawls of concrete buildings and infrastructures. Yet, fishermen have to bear constraints that are stronger than those imposed on other activities.

Among the fishing gear accused of destroying the ecosystem, are the trawlers and dragnets. These gears modify the sea floor, but they do not destroy all of it, particularly if it is sandy or muddy.  Globally, where trawlers and dragnets are used, zones remains quite productive if the effort is adapted. A storm may also disturb the habitat. Reconstruction is sometimes very quick. For Ray Hilborn : The extreme claim that trawls catch all marine life and kill all habitats is certainly not true for most of the ocean that is trawled".

There are often alternative techniques, but not always, and technical changes are far from being easy to do. Trawling is not as destructive of ecosystems as farms can be,  on a cleared ground or a ploughed meadow, even if they are organic. It is true that fishing is energy consuming : 10 times more energy consuming than the food energy produced, but such costs in energy to produce animal proteins remain inferior to those used in animal raising, and moreover, fishing doesn’t require many other inputs ( water, pesticides etc.. .) Ray Hilborn multiplies examples to show the extreme complexity of fishing and of its management : complexity of objectives, of scientific approach, of management systems, of natural uncertainties. He is strongly influenced by the very liberal frame of American fisheries, but remains pragmatic and supports Eleanor Ostrom’s propositions for a collective management of the common goods. In any way, the management should be legitimated by the fishermen, so as to be efficient.

His work has the virtue of clarifying concepts, and some diagrams or graphs would have helped to an even better understanding. He questions the pessimistic vision of fishing evolution, and demystifies easy slogans on (foretelling) the general depletion of oceans, which first serve the interests of lobbies that want to impose their diktats while pretending to represent society’s interests, but without letting a real political debate to take place on their objectives.

Ray HILBORN, with Ulrike HILBORN.


With thanks to Alain Le Sann
(Translated by Danièle Le Sann)