Depleted stocks recovery: a challenging necessity
Fishermen in the Baltic sea haul a catch of herring which are caught in wicker traps for more eco-friendly fishing
During the eighteenth and nineteenth century, thinkers such as Jean-Baptiste de Lamarck and Thomas Huxley assumed that the size of the oceans and the high fecundity of commercially exploited fish and shellfish meant that, under the conditions prevailing at that time, the risk of extinction of fishery resources was low. These scientists overestimated the ocean's resilience to fishing and underestimated both the future demand and the potential progress in fishing efficiency. However, the fact that local natural renewable resources could be depleted through wasteful competition and lack of ownership has been known literally for centuries, and by the end of the 1960s the "tragedy of the commons" was already common knowledge.1
The problem of overfishing was already recognized by the first FAO Fisheries Technical Committee in 1946 and was flagged recurrently in the successive FAO fisheries conferences, for example in Vancouver (1973), Rome (1984) and Reykjavik (2002), to cite just a few major events. The depletion issue was flagged again at the start of the twenty-first century in The State of World Fisheries and Aquaculture 2002 , which indicated that "An estimated 25 percent of the major marine fish stocks … are underexploited or moderately exploited … About 47 percent of the main stocks or species groups are fully exploited … 18 percent of stocks or species groups are reported as overexploited … The remaining 10 percent have become significantly depleted, or are recovering from depletion."
Among the stocks considered depleted, the Northeast Atlantic and the Mediterranean and Black Seas are the areas with stocks having the greatest need for recovery, followed by the Northwest Atlantic, the Southeast Atlantic, the Southeast Pacific and the Southern Ocean areas.
The depletion of stocks contravenes the basic conservation requirement of the 1982 UN Convention on the Law of the Sea and of sustainable development. It is also contrary to the principles and management provisions adopted in the 1995 FAO Code of Conduct for Responsible Fisheries. It affects the structure, functioning and resilience of the ecosystem, threatens food security and economic development, and reduces long-term social welfare. The demand for fish as human food may reach around 180 million tonnes by 2030 and then neither aquaculture nor any terrestrial food production system could replace the protein production of the wild marine ecosystems.
The Plan of Implementation of the World Summit on Sustainable Development specifically urges the need to "Maintain or restore stocks to levels that can produce the maximum sustainable yield with the aim of achieving these goals for depleted stocks on an urgent basis and where possible not later than 2015." Considering the trends since 1946, this time-frame certainly represents a high-order challenge.
While stock recoveries from stocks driven to 10 percent of their unfished biomass level have been documented, it is advisable to develop an explicit recovery plan before they fall below 30 percent of that level and, preferably, as soon as resources appear to be clearly below their long-term maximum average yield.
The measures needed for stock rebuilding are no different, in essence, from those needed to avoid its depletion, namely:
Under the ecosystem approach to fisheries, stock rebuilding is a prerequisite for ecosystem rehabilitation. In the last issue of this report it was stated that "recovery usually implies drastic and long-lasting reductions in fishing pressure and/or the adoption of other management measures to remove conditions that contributed to the stock's overexploitation and depletion". The explicit adoption of a rebuilding strategy, however, implies that rebuilding be adopted as an explicit objective in a formal stock rebuilding plan, including target reference values, specific management measures and performance assessment. It emerges from available examples that a successful recovery plan needs most, if not all, of the following basic components, in some order of priority:
1. A "rule-based" precautionary management framework providing non-discretionary measures incorporated into overriding legislation.2 Subsidies and other measures that allow participants to continue to fish a depleted stock will compromise recovery.
2. A proper institutional set up with: (i) teams of experts to take responsibility for recovery plans; (ii) a participatory process involving fishers in all operations to promote transparency; (iii) public information and education programmes; and (iv) integration of goals, strategies, measures and data among jurisdictions. In the case of shared resources a cooperative management regime would be needed in most situations.
3. Mandatory limitation of access to the resource and reduction of capacity and exploitation rates to levels compatible with recovery conditions. This may involve closing all or critical parts of the stock range and allocation of explicit fishing rights. In multi-species fisheries, tradeoffs may arise between attaining recovery of the depleted stock and continued harvesting of other, healthier, stocks.
4. Provisions for compensation for definitive or temporary loss of rights and livelihood in the form of alternative employment. These may not be required if alternative resources are available but may be essential in the case of poor, rural or disenfranchised communities.
5. Ex-ante assessment of the consequences of the planned measures, for example in terms of bioecological as well socio-economic impacts, the transfer of excess capacity to other areas or resources, and a likely time-frame for recovery. This assessment should offer an analysis of cost-benefits of various options with different grades of severity for the people involved.
6. A system for monitoring stock, people's/communities' status and fleet activities using indicators of fishing pressure, economic well-being, recruitment and environmental conditions and, if affordable, a fishery-independent monitoring of stock biomass by regular research vessel surveys.
7. A system of indicators with target reference points and limit reference points representing agreed "dangerous" stock conditions, unsustainable levels of exploitation of the stock, or deterioration of critical habitats for the resources in question.
8. Tight enforcement of the recovery plan until there is a high probability that the stock spawning biomass is above the level corresponding, at least, to the one that provided the maximum sustainable yield or equivalent prior to collapse. In particular, the occurrence of a good year class should be seen as a rare opportunity to rebuild stock biomass and not an excuse to increase quotas or prematurely terminate a rebuilding plan.
9. The elaboration of post-recovery management plans avoiding significant new increases in effort and incorporating aspects of recovery planning into routine, post-recovery management.
Even the best planned recovery may be inhibited by one or more of the following factors:
All of the above factors could be aggravated by loss of genetic diversity.
Because of the costs involved and the essentially uncertain nature of the recovery process, the number of fisheries to be included in recovery plans and the time-horizon for recovery will need to be carefully considered. Recovery times vary according to the resource, the scale of the intervention and the socio-economic and climatic environments. If a large proportion of stocks are depleted and overcapacity is high, the process may need to be drastic, and hence costly, if any impact is to be made in a reasonable time. The reproduction of depleted stocks consisting of young fish is unlikely to give optimal results, and rebuilding the older age groups requires that the recovery time extends beyond a single generation to rebuild the stock capability to "bridge" across medium-term climatic oscillations.4 Impacts may be felt in the target fishery as well as in other fisheries connected to it, for example through bycatch or predator-prey relationships.
Because of their potential social costs, the development of recovery plans needs the close involvement of the communities concerned.5 The plans may not be very popular but, as shown by past examples, the cost of laissez-faire policies is likely to be much higher in the medium to long term.6 Rebuilding may require a permanent reduction in fishing capacity and may also lead to the displacement of fishing crew. In most countries, some form of compensatory measures will be needed for both the vessel owners (e.g. vessel buy-back) and the fishing crew (e.g. unemployment insurance, soft loans, retraining, alternative employment). Buy-back programmes have led to mixed results and care must be taken that the financial support provided is not reinvested in more powerful vessels.
Recovery of a collapsed fish stock, such as the Atlantic cod in Canada, requires the explicit adoption of a solid rebuilding strategy
During the recovery plan, enforcement and monitoring are of key importance. When recovery begins to be obvious, pressure from the sector to resume or increase fishing rises drastically and strict management will be needed to avoid a repetition of the problem.
Curbing fishing effort has been the main measure for recovery when the stock has been depressed by overfishing - combined or not with unfavourable climatic conditions. The progressive reduction of fishing, for example through a reduction in total allowable catches, has generally been the first choice in order to limit the need to address social and economic consequences. However, because of the cost and difficulty of reducing fishing capacity to the level of harvest compatible with stock recovery, the action has often been "too little and too late". Allocating the residual effort among the artisanal, industrial and recreational segments of the fishery is a difficult task and rarely attempted. In addition, the fact that catchability tends to increase exponentially with some stocks as abundance decreases seriously complicates the control of fishing pressure. Effort may therefore have to be eliminated abruptly, for ecological or economic reasons; indeed, most of the abrupt fishing closures in the past have been forced by the economic collapse of the fishery.
Seasonal closures (e.g. "biological rest") have also often been proposed as "soft" rebuilding measures. These have been shown to be ineffective if the overall fishing capacity remains excessive.
Moratoria have generally been called for following failed attempts to curb fishing pressure progressively. They have often been imposed as a result of the economic demise of the fishery. No-take sport fisheries may have a similar effect if all individuals caught and released survive. Moratoria were relatively successful in restoring herring fisheries in the North Atlantic and Northeast Pacific. Such closures are more easily implemented and hence acceptable for selective pelagic fisheries than for demersal multispecies multigear fisheries; the latter require an integrated recovery plan that addresses all segments of the fisheries affecting the resource in the area and pose a more complex challenge to a wide range of interest groups. There is no guarantee that the success of total closures will be rapid or even certain, as evidenced by the very slow recovery of the Canadian cod fishery after a decade of efforts.
Areal closures, either permanent (sanctuary), temporary or seasonal, aimed at protecting nursery or spawning habitats and concentrations of spawners or juveniles, have also been used for some time. They may be introduced to protect critical habitats in rivers and streams, mangroves, seagrass meadows, algal beds and coral reefs. Their efficiency depends on the level of overcapacity and degree of enforcement or compliance. Marine protected areas, if adequately located, may be useful in this respect. The closure of a 17 000 km2 reserve on the United States side of George's Bank to haddock and flounder trawl fisheries demonstrated, after five years, a significant recovery of the two target species as well as some recovery of cod and a large-scale build-up of scallop stocks. However, the results of a closed area or closed fishery are not always entirely predictable, as demonstrated by the rise of lobsters, snow crabs and shrimp landings in the Northwest Atlantic and Scotian Shelf following the cod fishery closure. The high value of these landings might generate pressures against the original recovery plan objective.
Although not uniformly successful, experience shows the importance of a "harvest control rule" specifying the conditions under which rebuilding is obligatory and its strict enforcement for as long as rebuilding is not completed. A rule-based approach requires precautionary or limit reference points to be defined (e.g. for spawning biomass and fishing capacity) and non-discretionary action must be decided in advance and taken if and when these limits are reached. Action should continue until the spawning stock is restored to some predetermined level - possibly higher than that formerly supporting the maximum sustainable yields. A lack of capacity control will then result in the fishery oscillating dangerously around the boundary of the overfished condition.
Proactive recovery planning is recent. The majority of proper recovery plans relate to waters adjacent to developed countries and have less than 10-20 years of track record. Their success has been limited and many plans are still underway. If such a plan is considered successful when an upward trajectory of biomass is registered some time after a plan has been initiated, past experience shows that recovery has been successful in 12 (46 percent) of the cases for groundfish, 8 (67 percent) of them for pelagic fish and 10 (71 percent) for invertebrates, possibly related to reduced predation by collapsed groundfish stocks. These statistics suggest that groundfish stocks recovery has been less successful than for other resources, except for some local area closures in the tropics. It has also been shown that many small pelagics recovered five years after the major decline, while 40 percent of the groundfish stocks continued to decline even 15 years after the period of largest decline in the stock history was over.
Can we meet the Johannesburg directive?
The review provided above and the results experienced to date illustrate both the major scale of the task called for in the Plan of Implementation of the World Summit on Sustainable Development, the time frame of which results from political bargaining more than any scientific analysis of recovery times. Recovery will inevitably have a high cost, although the alternative (taking no action) can only be more costly. From the few successful recovery plans located, restoring demersal stocks is a much more difficult task than for pelagic fish and invertebrates, especially on high-latitude fishing grounds. Rapid recovery will also be compromised if environments are unfavourable, or stocks reduced to much below 30 percent of the unexploited stock size. Local recoveries of mainly tropical shallow shelf resources have been achieved relatively rapidly by closing areas to fishing, but it is expected that recovery of high-latitude demersal stocks will require rebuilding periods of 15 years or more, and will probably need to be supplemented by large closed areas and technical measures. Unfortunately, relatively few large-scale closures of demersal fisheries have been attempted in temperate zones, although this mechanism seems to offer chances of success over a decadal time frame.
A negative sign is given by the slow progress achieved in adjusting fishing capacity to biological productivity since the problem was first recognized at least 50 years ago. Awareness is now extremely high and pressure from both fisheries and environmental quarters is growing. However, capacity to fulfil this task is still very unequal and often insufficient, particularly in developing countries. In addition, the concept that without allocation there will be no conservation - a concept reaching back to Greek civilization - has still to be accepted in the modern political arena, jeopardizing the process in many areas.
1 G. Hardin. 1968. The tragedy of the commons. Science, 162: 1243-1248.