You are here: Marine Issues / Marine Fisheries / Overfishing
Marine Issues
The Marine Environment Marine Fisheries Marine Aggregates Climate Change
Healthy Seas and Society Marine Aquaculture Coastal Development Nuclear and Sellafield
Policy and Governance Offshore Oil & Gas Maritime Transport Other Issues
Marine Protected Areas Offshore Renewables Marine Pollution  
Marine Fisheries
Introduction Fisheries Management Overfishing Marine Litter
Fishing Sectors Deep-sea Fisheries Bycatch and Discards Online Resources
Irish Fleet Fisheries Ecology Habitat Degradation  


The majority of the world’s fishery resources are being subjected to overfishing as stocks* are reduced to below safe levels associated with long-term, sustainable and efficient production. Stocks exploited beyond maximum sustainable limits are at high risk of depletion and collapse.

* The elements of world fishery resources that we call "stocks" are generally conglomerates of stocks (and often of species). Stocks may be classified as underexploited, moderately exploited, fully exploited, overexploited, depleted or recovering, depending on how far they are — in terms of biomass and fishing pressure — from the levels corresponding to full exploitation.

Of course, overfishing is not just a case of depleting the natural renewable capital on which commercial marine capture fisheries depend. The removal of huge quantities of fishes from the oceans has both direct and indirect impacts on entire marine ecosystems, for example, by altering predator-prey relationships, food web structures, nutrient cycling, marine mammal survival, seabird breeding success, and so forth. (See Fisheries Ecology).

Overfishing is not a recent phenomenon. It was recognised in the North Atlantic as long ago as the early 1890s and was the subject of the London Conference on Overfishing in 1946. It has since become prevalent in most of the world's fishing areas, affecting marine capture fisheries in developing and developed countries alike. It is usually most severe adjacent to densely populated coastal zones and in biologically productive offshore areas.

Situation worldwide

The majority of the world's fishery resources are being subjected to exploitation at or above their capacity to produce maximum sustainable yields (MSY). About 75% of the world's most valuable marine fish stocks are either fished to the limit or else overfished.

Looked at another way, about 28% of the world's fish stocks are below the level of abundance represented by the MSY level of biomass and require fisheries management action aimed at rebuilding them to at least the MSY level.

The Food and Agriculture Organization of the United Nations (FAO) has estimated that the maximum production for world marine capture fisheries, under the present overall fishing regime (generally characterised by capture of small juvenile fish and significant discards), corresponds to about 82 million tonnes per year (FAO 1997a). An additional 20 million tonnes of annual landings might be obtainable worldwide, provided that 1) depleted resources are rehabilitated, 2) under-developed resources are exploited further, whilst avoiding their overfishing and the overfishing of fully exploited resources, and 3) discarding and other wastage are reduced (FAO 1997a).

However, the 1999 world marine capture fisheries production was in fact about 84 million tonnes. In 2002 this had risen to 93.2 million tonnes (FAO 2004).

According to the FAO (2004), among the world's major marine fish stocks or groups of stocks for which information is available, in 2003:

  • An estimated 3% are underexploited and 21% moderately exploited. These stocks may have the potential to produce more under increased fishing pressure.

  • About 52% of stocks are fully exploited and, therefore, are producing catches that have either reached or are very close to their maximum limits, with no room expected for further expansion. Stocks that are fully exploited are considered as being exploited at levels close to their MSY. These stocks are in need of (and in some cases already have) effective measures to control fishing effort.

  • Another 16% are overexploited (i.e. clearly fished beyond their MSY) and have no potential for further increase. Moreover, there is an increasing likelihood that catches from overexploited stocks will decrease if remedial action, such as capacity reduction, is not taken to reduce or revert overfishing conditions.

  • About 7% of stocks have been depleted (by exploitation beyond their MSY). The remaining 1% are recovering from depletion. Such stocks have potential for recuperation and stock rebuilding, provided that drastic management measures are adopted in order to revert uncontrolled and excessive fishing pressure as well as any other condition that could have contributed to the stock's overexploitation or depletion.

Even where directed fishing pressure on recovering stocks may have been reduced (by management or lack of profitability), these stocks may still be under excessive fishing pressure, including as a result of their exploitation as bycatch in another fishery.

Situation in the North-East Atlantic

Over a thousand species of fish have been recorded in the North-East Atlantic (i.e. the OSPAR marine area) — with some 700 species occurring in the waters around Ireland and adjacent seas (OSPAR Region III Celtic Seas).

About 5-10% of these species are either targeted directly by the commercial fishing industry or otherwise caught incidentally as bycatch. The biodiversity of the open ocean west of the European continental shelf (OSPAR Region V Wider Atlantic) is less well quantified, particularly in deeper waters, but fewer species are likely to occur than over the continental shelf.

OSPAR Commission management regions

The 1998 stock status of the main commercially exploited species around Ireland are given in Table 1.

The larvae of many commercially important fish species disperse into the open ocean from their spawning grounds over the continental shelf and in estuarine areas. Some fish species perform long annual migrations between the feeding, spawning and overwintering areas. Variability in stock recruitment is related to both the size of the parental stock and to a number of factors, including environmental variability and predation, which affect egg and larval survival.

Many deep-water species have an extensive geographical distribution owing to the small environmental variations of their habitat. In the Wider Atlantic, top predators such as sharks probably play an important role in maintaining the structure and diversity of fish assemblages. Large pelagic predators, such as tuna and marlin, are highly migratory, ranging far beyond the boundaries of the OSPAR region.

OSPAR 2000

It is thought that the maximum potential annual production for marine capture fisheries in the North-East Atlantic (FAO Statistical Area 27) is about 12 million tonnes. During the late 1980s and early 1990s annual catches in the region were approximately 10 million tonnes. The 1998 catch was 10.9 million tonnes.

Since the 1950s the proportion of the total North-East Atlantic catch that is made up of historically valuable or traditional species such as cod, haddock and herring has declined, while catches of many formerly lower-valued species such as sandeels and blue whiting have increased.

In 1997 the FAO reported that most of the traditional fishery resources of the North-East Atlantic were fully exploited or overexploited, with several stocks in a depleted condition. "The root cause of this poor situation within European waters has been the inability of the member states within the European Union (EU) to control and reduce fleet capacity within the Common Fisheries Policy" (FAO 1997a).

In its Quality Status Report 2000 of the North-East Atlantic, the OSPAR Commission states that many target species are now outside their "safe biological limits" [1]. Fishing is particularly intensive in the North Sea, with around 50-60% (but up to 60-70% in some cases) of the total biomass of the main commercial stocks removed each year. Fishing on this scale is clearly unsustainable and threatens the integrity of the marine ecosystem, resulting in, for example, the modification of predator-prey relationships.

In 1999 the International Council for the Exploration of the Sea (ICES) reported that 40 out of 60 major commercial stocks in the North-East Atlantic were outside safe biological limits or, in other words, heavily overfished (OSPAR 2000). In the same year a scientific assessment of EU fish stocks judged 67% to be overfished, 40% depleted, and 37% of species suffered from both problems (CEC 2000). ICES has also estimated that mature demersal fish (i.e. fish living close to the seabed) decreased by about 90% between the early 1970s and late 1990s (CEC 2001).

In the North-East Atlantic about 83% of stocks are consistently being exploited at or beyond MSY levels [2] Perhaps the most severely struck species has been cod. In the EU the average yearly landings over the period 1995-1999 were down 65% compared to 1978-1982. Numbers of larger, mature cod (vital for spawning to replenish stocks) have fallen by 73% in the same period (CEC 2001). One of the areas in which the situation is worst is in the Irish Sea.

As a consequence of continuous overfishing, total allowable catches (TACs) for northern hake have been slashed from 21,120 tonnes in 1997 to a little over 7,000 tonnes in 2001; while quotas for herring off Western Scotland have been cut from over 83,000 tonnes in 1998 to just above 30,000 in 2001.


It is highly likely that squid are vulnerable to pressure from exploitation. The biology of squid is not well known despite being very abundant, especially in the Wider Atlantic. Only a few species are exploited commercially, but squid are of considerable ecological importance as predators, and as the food of some whales, fish and seabirds.

OSPAR 2000

Fish stocks in OSPAR Region III (Celtic Seas)

Stock assessment is designed to improve understanding of the dynamics of exploited species and involves the estimation of parameters such as mortality rates (due to fishing and other causes), numbers in age groups (year classes) and recruitment, growth rates and spawning stock biomass.

The state of the main commercially exploited stocks of fish and shellfish in OSPAR Region III (Celtic Seas) is assessed annually by scientists in the bordering countries, under the coordination of the ICES Advisory Committee on Fisheries Management (ACFM). For some stocks and/or sub-areas, sampling levels are generally too low for reliable assessments to be made.

In 1997 seven stocks were considered by ICES to be "close to or outside safe biological limits" and consequently their status is a matter of concern. These were: cod in division VIa, whiting in divisions VIIe-k, northern hake in all divisions, saithe in sub-area VI, plaice in VIIf+g and sole in VIIa and VIIf+g [3]. ICES ACFM has also recommended significant reductions in the exploitation rates of salmon stocks.

In 1997 the FAO reported that:

  • Cod stocks of the West of Scotland, Rockall, Irish Sea and Celtic Sea are all considered to be outside safe biological limits to varying degrees. FAO experts advised reductions in fishing mortality.

  • The West of Scotland and Rockall saithe stock is considered outside safe biological limits, with spawning stock biomass (SSB) close to the record low level of 1992. FAO experts advised the maintenance of low levels of fishing mortality.

  • Catches of Irish Sea plaice have generally been below advised TACs since 1988, but the SSB declined below average levels in 1990 and has yet to recover significantly.

  • FAO experts advised a 20% reduction in fishing mortality of Irish Sea sole.

  • The Celtic Sea plaice and sole stocks are considered to be near safe biological limits. FAO experts advised a 20% reduction in fishing mortality.

  • Mackerel may be outside safe biological limits and FAO experts advised a significant reduction in fishing mortality.

  • The Northern hake are found from the Bay of Biscay to the Celtic, Irish and North Seas. The stock is considered to be outside safe biological limits and FAO experts advised a 30% reduction in fishing mortality and improved enforcement of mesh size and minimum landing size regulations. ICES recommended a significantly reduced fishing mortality since stock rebuilding is urgently required, especially in the southern region. A large number of under-sized fish are caught and these are usually discarded (FAO 1997a).

It is very important that fishing is managed in a sustainable way to avoid overexploitation of the fish stocks and to rebuild those stocks that are believed to be overexploited today.

OSPAR 2000

In 2000 the OSPAR Commission stated that many of the commercial fish stocks within Region III are heavily exploited. Of the 35 stocks assessed in the region, the spawning stocks of 13 are low compared to their averages over the periods for which data are available. Of these, five stocks show a downward trend and the remainder have been stable over recent years. The stock size and recent trends of nine stocks are unknown.

OSPAR (2000) adds that: "Poor catch statistics and a lack of biological data severely hamper assessment of the horse mackerel stock and there are uncertainties about its current status. Underreporting and misreporting in division VIa, whereby fish caught in the assessment area are reported as being caught in another, affects the reliability of assessments of the cod fishery."

In 2001 the European Commission reported on the state of the European Union's fishery resources and their expected development in its Green Paper on the future of the Common Fisheries Policy (CEC 2001):

  • The Irish Sea (ICES area VIIa): The Irish Sea cod stock is an "emergency situation" and strong management action was imposed in 2000. The whiting stock is also in a "critical state". The flatfish stocks have stabilised "but at a lower level than in the past" and fishing mortalities have been reduced.

  • Celtic Sea, West Channel and the northern part of Bay of Biscay (ICES areas VIIf-k and VIIIa+b+d+e): Cod in area VIIe-k "will approach a critical state" if fishing mortality is not reduced. Whiting in area VIIe-k appears to have an improvement in spawning stock biomass (SSB) with decreasing fishing mortality, but fishing mortality seems to have increased in recent years. Almost all flatfish stocks such as plaice VIIf+g and sole VIIf+g are "heavily exploited" but some stocks such as anglerfish and megrim are stable or fluctuating. Most of the herring stocks in this area are increasing or stable such as herring in Celtic Sea.

  • Widely distributed stocks (ICES areas II to IX): Stocks such as mackerel, blue whiting and northern hake straddle several of the above-mentioned areas. Among these stocks the development for northern hake and recently blue whiting "is of most concern". Mackerel, as most other pelagic stocks, shows a stable and possibly a sustainable trend.

In regions where commercial stocks have been overexploited, fishing pressure is often switched to stocks in other areas, including deep-sea populations. The slow growth rates and low fecundity of many deep-sea fish makes them especially vulnerable to overexploitation. Evidence is beginning to emerge that deep-sea trawling inflicts damage upon some of the deeper ecosystems. These impacts may already be quite extensive and recovery can be relatively slow.

OSPAR 2000

Recent status of Europe's stocks

Regarding the current state of the main European Union (EU) fish stocks, Annex 1 of the European Commission's May 2002 "roadmap" on the reform of the CFP (CEC 2002) states:

The quantities of mature demersal fish in the sea, as assessed by ICES, have in many cases "declined significantly" over the last 25 years. On average, these quantities were about 90% greater in the early 1970s than in the late 1990s. The general decline in landings is similar. "For some stocks such as cod even more drastic reductions in mature fish have occurred". The biomass of pelagic and industrial species increased by, on average, 20% since the late 1970s and mid-1980s at least in part following the recovery of herring from the low levels of the late 1970s.

The overall trend is of an increased proportion of the stocks being taken each year, which has led to the "erosion of the quantities of mature fish". In recent years for many stocks the quantities of mature fish in the sea have been "below or very close to the minimum levels required to provide high probability of sustainability (precautionary levels of stock biomass)," whereas historically they tended to be above such levels. Similarly, many stocks have been subject to a level of fishing mortality rate "in excess of precautionary levels" whereas, historically, the fishing mortality rate was less than the precautionary level.

"From a biological point of view, the sustainability of a high number of stocks will be threatened if the current levels of exploitation are maintained and, at present, this risk is highest for demersal round fish stocks which are of high commercial value." The situation is better for pelagic stocks. Stocks of small pelagic species (herring, sprat, mackerel, horse mackerel, anchovy, sardine) and species which support industrial fisheries (Norway pout, sandeels) have generally not deteriorated over the last 20 years and especially not over the 10 ten years.

In the case of benthic resources (Nephrops, flatfish) "a general economic overexploitation pattern can be observed" but at the biological level the situation cannot be considered as systematically serious.

Finally, there are also resources such as skates and rays, and the minor flatfish species (including turbot, brill, lemon sole, witches, dabs) that are not subject to detailed scientific follow-up "but which may also be overexploited". The situation varies from one zone to another, especially in terms of apparent evolution of fishing mortality in the mid- to long-term.

"In the Baltic, the current situation does not seem to be sustainable. In the North Sea, it has not been possible to reverse the decline of round fish stocks nor to ensure in the case of sole and plaice a security margin in accordance with the precautionary principle which would have also improved the economic situation for these fisheries. In Western waters, fishing mortality rates have been increasing catching up with and often exceeding historical levels observed in the North Sea. In the Mediterranean, the available scientific data are less complete but there is a large consensus that many important stocks are being over-fished."

To sum up, the Commission states that: "many stocks are at present outside or almost outside safe biological limits. They are too heavily exploited or have low quantities of mature fish or both. At present, the situation for most stocks is not catastrophic. If current trends continue, however, many stocks will collapse. Improvement in the state of many fish stocks is urgent."

Stocks for which scientific advice recommends recovery plans include:

  • Blue whiting (combined stock, I-IX, XII and XIV)
  • Northern hake in Western waters (Vb, VI, VII, XII, XIV)
  • Cod in North Western waters (Vb, VI, XII, XIV)
  • Cod in the Irish Sea (VIIa)
  • Cod in western waters (VIIb-k, VIII, IX, X, CECAF)
  • Whiting in the Irish Sea (VIIa)
  • Haddock in the Irish Sea (VIIa)

Other stocks outside safe biological limits include:

  • Anglerfish in western waters (Vb, VI, XII, XIV)
  • Anglerfish in the West of Ireland (VII)
  • Horse mackerel in the West of Scotland, West of Ireland and Bay of Biscay (Vb, VI, VII, VIIIabde)
  • Sole in the Celtic Sea (VIIfg)
  • Plaice in the Celtic Sea (VIIfg)

Root causes of overfishing

The problem of overfishing typically arises in the economic and political environment provided by open, market-driven economies. The FAO states that: "An essential characteristic of most fisheries, and of some aquaculture production systems, is that they make much use of common, non-priced resources, the access to which is not effectively limited. As a result, fishermen and aquaculturists often exploit the commonly held resources beyond what would be efficient in the long run for the community as a whole. In the process, they impose — often unknowingly — costs on others, both inside and outside the fishery sector, including leisure fishers and non-consumptive users of the marine environment. This latter category of users is becoming increasingly vocal in its advocacy that capture fisheries, and aquaculture when relevant, should be made accountable for the costs they impose on others through their impact on the environment" (FAO 1997b).

Clearly, governments must intervene to provide guidance to fishermen and aquaculturists on what constitutes economically and socially efficient, long-term levels of fisheries effort. "This is a difficult task because fishermen and aquaculturists see themselves as being asked to bear the immediate costs, with little prospect of sharing in the long-term benefits; that is, they perceive guidance by government as an attempt to reallocate their income to others" (FAO 1997b).

Safe biological limits

Consistent with a precautionary approach to fisheries management, the ICES ACFM sets precautionary levels (reference points) for fishing mortality rates and spawning stock biomass, beyond which the stock is considered to be outside "safe biological limits" and the fishery to be unsustainable.

One such reference point is the "minimum biologically acceptable level" (MBAL). This is the level of spawning stock biomass below which the probability of poor recruitment (i.e. the production of offspring/recruits) increases as the spawning stock decreases. MBAL is not a target for management but rather an indicator of a situation that may threaten the future sustainability of the stock.

Other criteria that indicate when a stock is outside safe biological limits include the age structure and distribution of the stock (a decrease in stock size may be accompanied by a decrease in the area occupied by the stock) and exploitation rates. A fishery that maintains stock size within a precautionary range (a range within which the probability of reaching any limit is very small) would be expected to be sustainable. It should be noted, however, that the numerical values of the reference points used to define safe biological limits may change as biological characteristics of the stock change, or as new information becomes available (OSPAR 2000).

Exceeding the TAC

Agreed annual catch limits, known as the "Total Allowable Catch" (TAC) for a fish stock, are the principle means by which commercial fishery resources have been managed in EU waters under the Common Fisheries Policy (CFP) framework (see How are TACs and quotas set?). However, many fisheries experts believe the TAC system contributes to long-term overfishing. The FAO has highlighted "the fact that catches often exceed agreed TACs, that agreed TACs often exceed those advised by ICES, and that advised TACs have been based on uncertain, and often optimistic stock assessments" (FAO 1997a). This is corroborated by the European Commission, which stated in its Green Paper on the future of the CFP that: "The current situation of resource depletion results, to a good extent, from setting annual catch limits in excess of those proposed by the Commission" (CEC 2001).

Under the TAC system, the European Commission reviews scientific advice from ICES and proposes TACs for certain commercial stocks. Prior to the anticipated CFP reforms coming into effect during 2003, these proposed TACs were then subject to annual horse-trading by the EU Council of Fisheries Ministers, which is required to take into account economic and social conditions as well as resource status when agreeing the TACs.

The FAO states: "The implications on stock status of considering increased catches based on these factors remains uncertain but is of concern… many past decisions on the setting of TACs (and/or levels of fishing effort) appear inappropriate in light of the biologically based advice. The pattern of agreed TACs exceeding advised TACs has contributed, together with the enforcement problems and stock assessment uncertainties… to the poor long-term performance of TACs as management measures. In contrast, effective management of fishing fleets with reduced capacity could provide many benefits, including increased overall landings and economic yields, increased profitability and increased stability in catches, while reducing the risk of stock collapse" (FAO, 1997a).

In 1997 the FAO stated that the large overcapacity of the European fleet and the poor status of many of the resources have led to agreed TACs being restrictive for an increasing number of stocks. "The difficulties inherent in enforcing output based fisheries regulations such as TACs (rather than input based measures such as limited entry) and the resulting low probability of detecting transgressions creates economic conditions that encourage illegal overfishing. Hence, actual catches exceed restrictive agreed TACs" (CEC 2001). The European Commission's response was to call for cuts of up to 40% in the size of certain national fleets to be included as part of the Fourth Multi-annual Guidance Programme (MAGP IV), which ran from 1997-2002.

The agreed TAC for a particular stock may also be exceeded because fish from the stock are taken as bycatch in fisheries targeting other species.

According to the FAO (1997a):

"Illegal catches are either not reported at all or are reported as different under-quota species, resulting in a deterioration in the quality of fisheries statistics used for stock assessments. This situation is worsening and is a cause for great concern."

The FAO's Advisory Committee on Fisheries Management (ACFM) has warned that, if data quality continues to deteriorate, it will become impossible to monitor certain stocks, particularly with regards to the provision of short-term forecasts used for setting TACs.

"The under-reporting of catches, particularly where the level of under-reporting is unknown and/or fluctuates widely, can result in the under-estimation of stock size, which, in turn, results in larger discrepancies between actual and predicted catch rates. As this discrepancy grows, the incentive for fishers to continue fishing illegally increases and the degree of under-reporting of catches increases. This combination of high exploitation intensities and poor quality data has lead to concerns over the future effectiveness of TAC-based quota management. For instance, the ACFM suggests that stand-alone technical measures or catch controls are likely to be insufficient in reducing fishing mortality on the Irish Sea cod stock such that spawning stock biomass can return to safe biological levels."

Juvenile fish catches and selectivity

Regarding the huge expanse of open ocean that lies to the west of the European continental shelf (OSPAR Region V Wider Atlantic), the OSPAR Commission reports that the impacts of overfishing "are being exacerbated by the general disregard of size restrictions on the fish that may be landed" (OSPAR 2000).

The Worldwide Fund for Nature (WWF) recently stated that the capture of significant quantities of small, immature fish is a general problem, common to many European fisheries, which threatens the integrity of fish stocks and thus seriously undermines the sustainability of fisheries (WWF 2002).

"Selectivity" refers to the variation in the capability of particular types, configurations and deployment of fishing gear to catch individuals of a given species, depending on the size of the fish, which in turn depends on the age. Thus more selective gear or fishing practices result in a higher percentage of individuals of the targeted size/age in the catch. By selectively removing fish of a certain age group from the population — instead of removing a proportion of the overall population that is representative of all age groups — selectivity can result in a significant change in the age structure of the population compared to the unexploited state.

Fisheries that employ low selectivity start by targeting small sized fish, which are of course juveniles. In such cases, the maximum sustainable yield from the fishery is reached with a rather low intensity of fishing or fishing effort, so that higher levels of fishing effort translate into reduced captures as the stock is overexploited. This is known as "growth overfishing", and is particularly prevalent in fisheries capturing long-lived species that usually reach sexual maturity late in life, like hake or cod. Better selectivity (i.e. using gear and practices that start catching fish at much larger sizes, hence older) enables long-term, sustainable and efficient production to be achieved as well as much higher catches, which are obtained through applying equally higher levels of fishing effort (WWF 2002).

Many commercially important species of fish produce large numbers of eggs. Environmental factors such as water temperature, which affect the survival of eggs and larvae, tend to determine how many juvenile fish are recruited into the population as a result of each annual reproductive episode, rather than the size of the mature breeding population (spawning stock biomass).

"However, sometimes fishing is so intense that the adult, reproductive part of the population is pushed below a critical point so that the size of recruitment becomes dependent on the size of the spawning stock. This dangerous situation is called recruitment overfishing, and contrary to the case of growth overfishing (which implies the reduction in the productivity of the fishery, in the mean size of the fish and the in the size of the population), it can cause the complete collapse of the fishery" (WWF 2002).

Although all species are susceptible, it is small, pelagic species such as sardine or anchovy that are characterized by a short life span and an early sexual maturity, that are especially prone to this dangerous type of overfishing.

A typical sequence in many overfished fisheries would be high/excessive fishing effort using low selectivity, followed by growth overfishing, recruitment overfishing and, finally, the collapse of the fishery (WWF 2002).

WWF state that: "Two immediate solutions to avoid any kind of overfishing are 1) capturing fish at the right sizes (= weights) so that the overall productivity of the fishery be kept high and 2) maximizing reproduction by allowing fish to spawn at least once before being caught, all this in the context of a reasonable level of fishing effort. The problem, however, is not so straightforward to remedy once overfishing is reached, since profound changes in the population are inflicted. In this case, improving selectivity alone is no longer a viable solution if it is not accompanied by a drastic reduction of fishing capacity that would allow the population to rebuild and enough fish of the newly targeted size are available to the fleets" (WWF 2002).

Stock recovery

Overexploited, depleted and recovering fish stocks generally have potential to return to historical levels of production provided fishing effort is reduced through — often drastic — measures, such as capacity reduction, aimed at reducing or reverting overfishing conditions and bycatch in other fisheries; and provided that irreversible ecosystem imbalances (changes in population structure, predator-prey relationships, etc.) have not taken place.

Overfishing conditions can be reduced by significantly increasing the age at first capture, prohibiting the exploitation of juveniles, increasing mesh sizes, and temporarily or permanently closing areas where adults spawn and/or juveniles concentrate (i.e. spawning and nursery grounds). Juvenile cod have been successfully protected in Norway through ad hoc area closures. Elsewhere, closed seasons in areas have produced improvements in catch rates.

Effective management of the Arctic cod stock in the Norwegian and Barents Seas has — in contrast to most other Atlantic cod stocks — led to a recovery in spawning stock biomass from a depleted condition to a level not seen since the 1950s following a major reduction in fishing mortality in the late 1980s (FAO 1997a).

There is also a significant potential for improvement from the reduction of bycatch. The FAO has estimated that between 18-39 million tonnes (average 27 million tonnes) of fish are discarded at sea every year (FAO 1997a). This comprises species of low commercial value but also a large proportion of juveniles. The benefits resulting from a reduction of unwanted bycatch through increased survival of juvenile fish can be very significant.

Long-term solutions to overfishing

There are no simple or cheap solutions to the problem of overfishing (FAO 1997b). It is widely recognised that for developed countries, solutions that include market-based strategies for controlling fishing effort tend to be more effective than others — however politically uncomfortable it may be for governments to step-up regulation. "Unfortunately, initial effects of government measures to reduce overfishing are essentially negative: some unemployed fishermen, less fish and higher prices. With time, most of these effects would be reversed: more fish, lower prices and stable, economically attractive employment" (FAO 1997a).

Outside the fishery sector, the growing awareness overfishing and other threats facing fisheries, the resources, and the marine environment in general has led to a number of initiatives by non-governmental and business organisations. In particular, the establishment of the Marine Stewardship Council builds on the assumption that the promotion of fisheries products certified as coming from sustainably managed and environmentally sound fisheries and aquaculture can induce the fishing and aquaculture industries to better manage current fisheries practices, both locally and globally.

In practice, effective management should allow presently overfished resources to recover, thereby increasing fisheries production in the longer-term. The FAO has estimated that better regional management of marine capture fisheries could yield an additional 10 million tonnes worldwide. "The economic benefits from improved management could be as spectacular. As effort limitations become effective, the use of capital and labour will fall (as will annual costs) more rapidly than will income from the fishery. As stocks recover, revenues will grow in absolute terms. These effects will translate into higher disposable income for those fishers who remain, as well as expanding tax revenues" (FAO 1997b).

In 1995, with this in mind, the FAO Conference adopted the Code of Conduct for Responsible Fisheries as guidance for achieving efficient, sustainable and responsible fisheries.

In the medium- to long-term, the major challenge facing marine fisheries is improved and responsible management of stocks. Such management requires the regulation of production in a precautionary manner so that excessive effort, leading to overfishing, is not applied to target stocks. In addition, adoption of an ecosystem approach requires fisheries management processes to take account of fishing impacts on non-target stocks and other components of the marine ecosystem.



1. A stock is considered to be outside, or harvested outside "safe biological limits" when the spawning stock biomass is below the lowest biomass where there is a high probability that the production of offsprings/recruits is not impaired, or when the fishing mortality is higher than a fishing mortality that with high probability is sustainable.

2. i.e. the sum total of those stocks that are fully exploited, overexploited, depleted and recovering.

3. Statistics from 1998 suggested that the situation generally had not improved and, for some species, had deteriorated.


CEC. 2002. Communication from the Commission on the Reform of the Common Fisheries Policy ("Roadmap"). COM(2002)181 final. Commission of the European Communities, Brussels 28/5/02.

CEC. 2001. Green Paper on the Future of the Common Fisheries Policy. COM(2001)135. Commission of the European Communities, Brussels.

CEC. 2000. Report from Commission to Council, Preparation for a Mid-term Review of the Multi-Annual Guidance Programmes. COM(2000)272. Commission of the European Communities, Brussels, 10/500.

FAO. 2004. State of World Fisheries and Aquaculture (SOFIA) 2004. Publishing Management Service, Food and Agriculture Organization of the United Nations.

FAO. 2000. The State of World Fisheries and Aquaculture 2000. FAO Fisheries Department, Rome.

FAO. 1997a. Review of the state of world fishery resources: marine fisheries. FAO Fisheries Department, Rome. FAO Fisheries Circular No. 920 FIRM/C920.

FAO. 1997b. Major Issues in World Fisheries. FAO Committee on Fisheries, Twenty-second Session, Rome 17-20 March 1997.

OSPAR. 2000. Quality Status Report 2000 on the Marine Environment of the North-East Atlantic. OSPAR Commission, London.

WWF. 2002. Baby Fish. By Tudela, S, Aipanjiguly, S, and Remy, A. Worldwide Fund for Nature (WWF), Gland, Switzerland.


Please note: This page will be updated during 2006.


Situation worldwide
Situation in the NE Atlantic
Fish stocks in Celtic Seas
Recent status of EU stocks
Root causes of overfishing
Safe biological limits
Exceeding the TAC
Juvenile fish and selectivity
Stock recovery
Long-term solutions
What does it mean?
Try the pop-up Glossary