Fisheries
3. What is the state of fishery resources?
- 3.1 What is the state of marine fisheries?
- 3.2 How are fishery catches changing?
- 3.3 How may fisheries management affect sustainable development?
- 3.4 What is the state of inland fisheries?
3.1 What is the state of marine fisheries?
The source document for this Digest states:
Figure 18:Capture Fisheries Resources by marine area After increasing from around 79 million tonnes in 1998 to 87 million tonnes in 2000, world marine capture fisheries production decreased to around 84 million tonnes in 2001 and remained at that level in 2002. The decrease of around 2.5 percent in global catches between 2000 and 2002 is mostly due to the declines by 12 percent and 7 percent, respectively, in production from the Southeast Pacific and the Northwest Pacific.
The Northwest Pacific is the most productive fishing area of the world, with nominal catches oscillating between 20 and 24 million tonnes (including China) since the late 1980s. Large catch fluctuations in the area are mainly driven by fisheries for the abundant stocks of Japanese pilchard (or sardine) and Alaska pollock. Both stocks show a declining trend since the late 1980s as a result of the combined effects of overfishing and environmental factors affecting stock productivity. Although there has been an increase in catches of other species, including the Japanese anchovy, it was not enough to compensate for the decline in pilchard/sardine and pollock and to offset the consistent decline in fisheries production in the area of around 3 percent per year since 1998.
In the Southeast Pacific, three species account for around 80 percent of total catches: the Peruvian anchoveta, the Chilean jack mackerel and the South American pilchard (or sardine). Large catch fluctuations are common in the area as a consequence of periodic climatic events associated with the El Niño Southern Oscillation affecting fishing success and stock productivity. For instance, catches of Peruvian anchoveta dropped severely following the adverse El Niño environmental conditions in 1997–98. More favourable climatic conditions in 2000 led to one of the highest catches on record, of around 11 million tonnes, but in 2002 the fishery for Peruvian anchoveta declined to 9.7 million tonnes, causing a net decrease in total fisheries production in the area.
The remaining fishing areas of the Pacific have exhibited increasing trends in catches since 2000. In the Northeast Pacific, fisheries production had been declining since its peak of 3.6 million tonnes in 1987, but made a slight recovery to 2.7 million tonnes in 2001 and 2002. Alaska pollock is the single most important stock in the Northeast Pacific and accounts for most of the fluctuation in total catches. In the Western Central Pacific, fisheries production has been growing steadily since 1950, reaching close to 10 million tonnes in 2001. In the Eastern Central Pacific, total catches have fluctuated between 1.2 and 1.8 million tonnes since 1981. The recent production increase in the area has been influenced by the California pilchard (or sardine), which yielded about 670 000 tonnes in 2001 and 2002 – the highest recorded catch of the species since 1950. Nominal catches in the Southwest Pacific reached a peak of 917 000 tonnes in 1992 and gradually declined to 714 000 tonnes in 2000 before making a slight recovery.
In the Atlantic, catches have increased in the Northwest and Southeast fishing areas. Northwest Atlantic fisheries production reached its lowest level in 1994 and again in 1998 with the collapse of groundfish stocks off Eastern Canada. Catches have since been increasing slowly, from close to 2 million tonnes in 1994 to 2.26 million tonnes in 2002. In the Southeast Atlantic, catches have followed an increasing trend since 1996, with the growth mostly accounted for by small pelagic fish, and reached close to 1.7 million tonnes in 2002. Fluctuations in catch are common in the area in response to the substantial environmental variability of the Benguela Current system. In other areas, such as the Southwest and Eastern Central Atlantic, there has been a noticeable decline in fisheries production since 2000. The 7 percent decrease in total catches in the Eastern Central Atlantic falls within the pattern of catch fluctuation from 2.9 to 4.1 million tonnes observed in the region since 1990. This is a consequence of the combined effect of changes in distant-water fishing effort and environmentally induced changes in the productivity of the abundant small pelagic stocks. In the Southwest Atlantic, the decline in catches can largely be attributed to the fall of around 45 percent in the catches of Argentine shortfin squid from 2000 to 2002. This species made up 33 percent of the total catches in the Southwest Atlantic in 2001 and squid catches have been declining since 1999, when around 1.1 million tonnes were reported.
Monitoring the status of fisheries in the Indian Ocean has been difficult because of a generally poor system of fisheries statistics collection in the region, reflected in the relatively high proportion of catches reported as “miscellaneous marine fishes” in the official statistics. This is also a significant problem in other areas, such as the Southwest, Eastern and Western Central Atlantic and the Northwest and Western Central Pacific. However, both the Western and Eastern Indian Ocean areas show a continuing increase in total reported catches, with fisheries production in 2002 being the highest on record for both areas.
Fisheries production in the high seas is considerably higher in the Pacific, followed by the Atlantic and the Indian Oceans. Tuna comprise the single most important resource exploited in the high seas. In some areas of the Atlantic and Pacific, straddling stocks of jack mackerel and squids and demersal fish on seamounts contribute significantly to production. The contribution of sharks to the total reported catches is minor compared with that of other oceanic resources; moreover, bycatch underreporting and discards are a source of concern when dealing with this species group. The world catches of the seven principal market species of tunas increased from less than 0.5 million tonnes in the early 1950s to a peak of 4 million tonnes in 2002, with a tendency to stabilize since 1998. Skipjack tuna accounts for about 50 percent of this total, with a reported catch of 2 million tonnes, and remains one of the top species in world fisheries production.
Source & ©: FAO "The State of World Fisheries and Aquaculture, 2004"
Part 1: World review of fisheries and aquaculture, The status of fishery resources
3.2 How are fishery catches changing?
The source document for this Digest states:
A recurring pattern in some areas is a long-term change in catch composition following the depletion of more traditional stocks and the targeting of other less-valuable and previously lightly exploited or non-exploited species (Figure 18
). For instance, in the Northwest Atlantic invertebrate catches (molluscs and crustaceans) have increased and those of demersal fish have declined. In the Northeast Atlantic, the continuous decline in cod catches since the late 1960s has been counterbalanced by increasing catches of formerly low-valued fish species such as blue whiting and sand eels. In the Southwest Atlantic, the decline of the Argentine hake has been accompanied by an increasing trend in catches of shortfin squid. The decline in catches of pilchard (or sardine) and pollock in the Northwest Pacific has been partially compensated for by increases in catches of Japanese anchovy, largehead hairtail and squids. These changes in the species composition of fisheries catches can have different causes, including the adaptation of the industry and markets to resources previously considered as low-value, the effect of fisheries on the structure of marine communities, and changes in environmental regimes affecting the stock productivity. These effects are often difficult to discern, particularly in areas where research and monitoring of resources and environment processes are poorly developed. FAO monitors the state of exploitation of the main fish stocks or groups of resources for which assessment information is available. The current global situation follows the general trend observed in previous years.
Figure 19:State of Fish Stocks It is estimated that in 2003 about one-quarter of the stocks monitored were underexploited or moderately exploited (3 percent and 21 percent respectively) and could perhaps produce more. About half of the stocks (52 percent) were fully exploited and therefore producing catches that were close to their maximum sustainable limits, while approximately one-quarter were overexploited, depleted or recovering from depletion (16 percent, 7 percent and 1 percent respectively) and needed rebuilding. From 1974 to 2003 there was a consistent downward trend in the proportions of stocks offering potential for expansion. At the same time there was an increasing trend in the proportion of overexploited and depleted stocks, from about 10 percent in the mid-1970s to close to 25 percent in the early 2000s (Figure 19
). Of the top ten species that account in total for about 30 percent of the world capture fisheries production in terms of quantity (Figure 6
), seven correspond to stocks that are considered to be fully exploited or overexploited (anchoveta, Chilean jack mackerel, Alaska pollock, Japanese anchovy, blue whiting, capelin and Atlantic herring). Major increases in catches cannot therefore be expected from these. Two species could probably support higher fishing pressure in some areas (skipjack tuna and chub mackerel) and the status of the remaining species (largehead hairtail) is unknown. In the Southeast Pacific, a combination of high fishing pressure and adverse environmental conditions, including the severe El Niño event of 1997–98, led to a sharp decline in catches of the two leading species (anchoveta and Chilean jack mackerel) during the late 1990s. While the stock of anchoveta has shown signs of recovery, with catches in the order of 10 million tonnes since 2000, catches of Chilean jack mackerel totalled 1.7 million tonnes in 2002, representing less than 50 percent of the fishery’s historical peak production reached in 1994. In the North Pacific large changes in catches occurred in response to heavy fishing and to natural decadal oscillations in the productivity of pilchard (or sardine), anchovy and pollock. Following record catches in the 1980s, the Japanese sardine (or pilchard) fishery collapsed in the mid-1990s and was followed by a strong rebuild of the anchovy population, which has been supporting catches of close to 2 million tonnes since 1998. This alternation between sardine and anchovy stocks follows a pattern observed in many other regions of the world and seems to be mainly governed by climatic regimes affecting stock production. The stocks of pollock in the Northwest Pacific are considered overexploited, while those in the Northeast Pacific are considered fully exploited. Pollock catches peaked in the late 1980s in both areas and have been declining since then, although a recent modest recovery is evident in the Northeast Pacific. In the Northeast Atlantic, catches of blue whiting reached record levels (1.8 million tonnes) in 2001 and declined slightly in 2002. The stock is currently under heavy fishing and requires more restrictive management measures. Capelin and herring are exploited to their full potential and are currently considered within safe biological limits. Catches of skipjack tuna have increased steadily since 1950 and reached their highest reported value of around 2 million tonnes in 2002, representing about half of the total capture of market tunas. The status of skipjack tuna stocks is highly uncertain but there are indications that some potential remains for increases in catches in the Eastern, Western and Central Pacific and in the Indian Ocean, provided that these increases in skipjack catches will not lead to parallel increases in catches of other species that are presently fully exploited or overexploited, for example bigeye and yellowfin tunas.
Figure 20:Marine Resources Exploitation The percentage of stocks exploited at or beyond their maximum sustainable levels varies greatly by area. In the Eastern Central Pacific, only 33 percent of the stocks for which assessment information is available are recorded as fully exploited, with the remainder being either underexploited or moderately exploited, whereas in the Western Central and Northeast Atlantic and the Western Indian Ocean, all the stocks for which information is available are reported as being fully exploited (73 percent, 59 percent and 75 percent respectively) or as being exploited beyond this level (Figure 20
). In 12 of the 16 FAO statistical regions at least 70 percent of stocks are already fully exploited or overexploited, suggesting that that the maximum fishing potential has been reached and that more cautious and restrictive management measures are needed. This conclusion is also supported by analysis of the trend in fisheries production of the regions. Four of the 16 regions are at their maximum historical level of production, while in 12 regions production has declined slightly and in four the declines have been sharper, including the Northwest Atlantic (50 percent decline from a peak in 1968), Southeast Atlantic (47 percent decline from a peak in 1978) and Southeast Pacific (31 percent decline from a peak in 1994). In most cases overfishing has been a main contributory factor and in some cases this has been associated with adverse or highly variable environmental conditions. All the information available tends to confirm the estimates made by FAO in the early 1970s that the global potential for marine capture fisheries is about 100 million tonnes, of which only 80 million tonnes are probably achievable. It also confirms that, despite local differences, overall, this limit has been reached. These conclusions lend support to the call for more rigorous stock recovery plans to rebuild stocks that have been depleted by overfishing and to prevent the decline of those being exploited at or close to their maximum potential.
Source & ©: FAO "The State of World Fisheries and Aquaculture, 2004"
Part 1: World review of fisheries and aquaculture, The status of fishery resources
3.3 How may fisheries management affect sustainable development?
The source document for this Digest states:
In response to worldwide public concerns, countries have been promoting, through FAO and the World Summit on Sustainable Development held in Johannesburg, South Africa, in 2002, an extension of the usual policies and management focus from single fishery stocks to ecosystems. This implies an increasing demand for better understanding and monitoring of a wide range of processes affecting or affected by fisheries. Some of the most important management concerns today are the effects of fisheries on habitats, marine communities, and ecological interactions (such as predator–prey relationships), as well as the those of land-based activities and climatic changes on fisheries. The lack of selectivity in many fisheries, which leads to bycatch and discards (the unintended catch of non-targeted species and their subsequent discarding) is an additional management concern. Bycatch may increase fishing pressure on resources targeted by other fisheries, possibly aggravating overfishing, and can also have undesirable impacts on endangered and protected species such as sea turtles and certain species of marine mammals, sea birds and sharks. Discards of inedible, non-commercial, or undersized species and individuals represent collateral damage to the ecosystem, a waste of resources and an additional source of overfishing.
Coastal development (including urban and industrial expansion and aquaculture) and industrial activities in the hinterland also pose many threats to the health of marine ecosystems when they pollute and degrade critical coastal habitats. These land-based and coastal alterations adversely affect the livelihoods of coastal fishing communities and industries, for example through a reduction of the sustainable yield of fish stocks; modification of the resource species composition, health and diversity; an increase in ecosystem instability and variability and a reduction of seafood quality and safety. Periodic climatic phenomena such as El Niño can have a drastic impact on fish populations and lead to the collapse of fisheries (e.g. the Peruvian anchoveta in the Southeast Pacific in the early 1970s). Over the longer term, many fish stocks follow decadal fluctuations that seem to respond to natural climatic cycles. The effect of climate on fisheries is exacerbated in a situation of overfishing, when both fish stocks and fishing industries become more vulnerable to the natural dynamics of the environment. The assessment of these and other ecosystem–fisheries interactions is still in its infancy and much more needs to be known about their effects on fishery resources, fishing communities and industries, their causes and trends, and how to deal with and adapt to them. The state of fishery resources and their ecosystems, however, allows little room for delay in the implementation of measures that should have been taken in the last three decades. Therefore the precautionary approach to fisheries, recommended by UNCED, the United Nations Fish Stocks Agreement and the FAO Code of Conduct for Responsible Fisheries needs to be implemented in practice.
Source & ©: FAO "The State of World Fisheries and Aquaculture, 2004"
Part 1: World review of fisheries and aquaculture, The status of fishery resources
3.4 What is the state of inland fisheries?
The source document for this Digest states:
Unlike the major marine fish stocks, inland fish stocks are less well defined and occur over much smaller geographical areas, such as individual lakes, rice fields or rivers, or over vast areas such as transboundary watersheds that are often situated in areas that are difficult to access. These factors make it costly to monitor the exploitation and status of fish stocks and, in fact, very few countries can afford to do so. As a result, the majority of countries report only a small fraction of their catch of inland fisheries by species, further compounding the problem of accurate assessment. Thus FAO is not in a position to make global statements on the status of these resources.
It was reported in The State of World Fisheries and Aquaculture 2000 that inland fishery resources are undervalued and under threat from habitat alteration, degradation and unsustainable fishing activities. This trend unfortunately appears to be continuing. LARS 2, a recent symposium on managing the fisheries of large rivers, noted that the availability of global information on river fisheries is poor, that over 50 percent of inland fish species occur in rivers and that rivers contain a higher proportion of organisms classed as endangered or threatened than do most other ecosystems. Many river basins, especially in developing countries, support intensive fisheries and in many cases catches have increased, although changes in their species composition have occurred as catches of large and late-maturing species have declined. River fisheries continue to provide substantial catches in developing countries, even in the face of intensive exploitation. However, in the Mekong River, for the first time, there is evidence that stocks are being overfished. Numerous lake fisheries are also showing signs of overexploitation. In Lake Victoria, for example, the Nile perch fishery decreased from a record catch of 371 526 tonnes in 1990 to 241 130 tonnes in 2002. Sturgeon fisheries in the countries surrounding the Caspian Sea have also decreased, from approximately 20 000 tonnes in 1988 to less than 1 400 tonnes in 2002, owing to a combination of illegal fishing, overfishing and habitat degradation. Inland fishes in general have been characterized as the most threatened group of vertebrates used by humans.
Nevertheless, the status of some inland fishery resources has been enhanced in many areas through stocking programmes, the introduction of alien species, habitat engineering and habitat improvement. In many developing areas, especially in Asia, rice fields and irrigated areas are enhanced to increase the production of aquatic biodiversity other than rice, and to improve the nutritional status of rural households. Enhancement can make the resources more stable, easily harvested and valuable.
Source & ©: FAO "The State of World Fisheries and Aquaculture, 2004"
Part 1: World review of fisheries and aquaculture, The status of fishery resources
