Source: Frank Spooner Pictures
INTRODUCTION |
The interrelationships between fishing and marine and freshwater ecosystems are complex and often not well understood. This lack of understanding is exacerbated by the sheer complexity of food-chains in these ecosystems. Most concern has been focused on three broad issues:
The interrelationships are complicated by the fact that fishing activities both have an impact on and are impacted by the environment.
This chapter reviews the nature and relative importance of the impacts of fishing and aquaculture on marine and freshwater ecosystems. Those which are of greatest concern are then examined in greater detail, with an assessment of environmental impacts and underlying driving forces. The chapter is concluded with an evaluation of the effectiveness of existing fishing policies.
Box 24A provides definitions of fishing statistics used in this chapter and summarises the availability and quality of fishing data.
AN OVERVIEW OF FISHERIES RESOURCES IN EUROPE |
Marine provinces |
The major European marine provinces are the continental shelf of the northeast Atlantic and the Mediterranean basin, in which several distinct biogeographical regions can be identified (see Chapters 5 and 6). The northeast Atlantic is one of the richest areas in the world, accounting for approximately 10 per cent of the world's marine fish catch. This is the result of a combination of factors including the influence of the warm waters of the Gulf Stream and the extensive continental shelf. The Mediterranean basin has a long coastline, but the continental shelf is generally narrow. This reduces the productivity of the area with the exception of the northern Adriatic. The eastern Mediterranean is also noteworthy in that the diversity of fish is increasing because of fish migration through the Suez canal from the Red Sea (Caddy, 1993).
Attempts have been made to collect existing maps into atlases showing the pan-European extent of the major fish species, but these are unfortunately not always up to date (eg, Couper and Smith, 1989; FAO, 1981). The best coverage is currently for the North Sea (ICES, 1993b). Presented here instead in Map 24.1 are the total nominal catches of fish and invertebrates (including crustaceans and molluscs) by administrative zones.
Figure 24.1 shows total catches for the North Sea over this century. Total catches increased from 1 million tonnes just after 1900 to 2 million around 1960. During the 1960s, the catch increased steeply to almost 4 million tonnes, followed by a gradual decline to around 2.5 million in recent years.
In the northeast Atlantic and the Mediterranean, nominal catches showed a remarkable increase between 1960 and 1980. Since then there has been some decline (see Statistical Compendium). Until recently, the FAO used to produce estimates of the maximum sustainable yield (MSY) for its statistical areas. However, the FAO has recently decided that in the case of marine fisheries this is now a misleading concept, as fish resources are so severely depleted that the issue is now stock reconstruction (FAO, 1992a).
The risks of overexploitation are partly due to the common property status of fisheries resources and of the world need for protein. However, the potential for fisheries to meet the needs for increased world food supply is limited: fisheries currently account for only about 16 per cent of the world's total animal protein for human consumption (FAO, 1991). Further, although global harvests are presently below potential yields, many of the more valuable fish stocks are overfished, and the steady trend towards increased global harvests is partly through exploitation of new and less valuable species and of less accessible species which are costly to exploit.
Trends in fishing pressure vary between Western and Central and Eastern European countries. In Western Europe, rapid increases in production throughout the 1960s were stemmed after the establishment of Exclusive Economic Zones (EEZs) in 1977 (see Box 24B). Since then, nominal catches have remained more steady. For Eastern countries, catches have decreased steadily since the 1970s, following a rapid surge in the 1960s. This is due largely to their exclusion from waters of EU countries, through the establishment of EEZs (and the EC Common Fisheries Policy). Other possible factors include ageing fleets, polluted waters and more latterly the difficulties of embracing free market principles in the fishing industry.
Inland water provinces |
Inland water systems, due to their geographic discontinuity, often develop specific fish populations. The most important freshwater systems of Europe in terms of fish resources are the Danube basin, the Volga basin and the ancient lakes of South Europe, such as Ohrid on the Yugoslav­Albanian border and Lake Balaton in Hungary (which alone harbours 512 species of fish). The numerous small lakes and ponds in areas such as Finland and the Mazurian system in Poland are also important habitats for fish, particularly carp (Cyprinus spp), which are the basis of traditional pond culture (Hollis and Jones, 1991).
ENVIRONMENTAL IMPACTS OF FISHING |
Fishing activities have impacts on, and are impacted by, the environment in a number of ways (see Table 24.1). These can be classified loosely as direct and indirect impacts (ICES, 1992b). The most obvious direct impacts of fisheries arise from the commercial harvesting of fish at sea, impacts on non-target species and impacts arising from aquaculture. The indirect effects of fishing are far less easy to describe, but would include impacts on predator or prey species and disruption of ecological equilibria (Northridge, 1991).
However, it is often difficult to isolate the specific impacts of fishing alone, as the marine environment is also impacted by other human activities, as well as by natural fluctuations of, for example, ocean currents and climate. Further, the lack of knowledge about the impact of fishing on the environment, exacerbated by the sheer complexity of marine ecosystem food-chains (Chapter 6), means that causeeffect relationships between fishing and environmental impact are not well defined.
Impacts associated with harvesting of fish at sea |
Ecosystem effects of fishing may occur at all scales of space and time. Changes in ecosystems may be described and quantified in a variety of ways. In this chapter, the practice used by the International Council for the Exploration of the Sea (ICES) is followed by describing changes in the abundance of individual stocks.
Fisheries exploit species against the background of a variable natural environment. Water temperature is an important influence on fish stocks. A temperature rise or fall of one degree can have significant impacts on fish migration and reproduction patterns. Water currents can have a major effect by changing the drift pattern of fish eggs and larvae, and hence their prospects for survival. The currents can also have an impact on water temperature and salinity, which in turn affect fish populations. Ecological factors such as predation and food supply can influence fish populations, which are known to fluctuate greatly in the long and medium term (Gulland, 1983). Fish stocks can also be prone to outbreaks of disease which can affect populations.
Anthropogenic pressures on the marine environment can come from several sources, only some of which are directly or indirectly related to fishing. It can, therefore, be difficult to separate the long-term effects of fishing from changes due to other human activities.
Being renewable resources, fisheries and aquaculture can provide benefits to humans indefinitely, provided that they are properly managed on a sustainable basis. However, due to the commercial importance of fisheries resources and the limited regulation of catches in the past, many of the marine fish species of Europe are, or have been, overexploited (Gulland, 1983). This is reflected in the estimates of fish stocks for the northeast Atlantic (ICES, 1993a).
A classic example is the Atlantic herring (Clupea harengus), which spawns in the spring in the Norwegian Sea. The herring used to migrate away from these waters after breeding, especially to the sea areas to the north and east of Iceland. In the 1960s herring were fished so intensively in Norwegian and Icelandic waters that the population was virtually eradicated. In 1970, the fishery was almost totally abandoned as it was no longer producing catches. Recruitment remained at a low level until 1986, when a good three-year age class was recorded (ie, spawned in 1983)(see Figure 24.2). The reason for the substantial increase in the spawning stock in 1988 was because the greater part of this year class spawned for the first time in 1988. Fishing of herring was resumed on a small-scale basis in 1984. The estimated spawning stock of 2 million tonnes in 1992 is about three times as large as the spawning stock in 1987 (Central Bureau of Statistics of Norway, 1993). However, the catches are only 15 per cent of those recorded in the 1950s (Bernes, 1993). Nevertheless, this shows that even a severely overexploited fishery such as this one can restore its numbers over time.
In the Mediterranean, stock dynamics are less well understood due mainly to a lack of data, the large number of landing sites used by small vessels (which makes record-keeping difficult), and a wide diversity of species. Nearly all commercial stocks in the Mediterranean basins are considered fully- or overexploited, with the possible exception of lower-value small pelagics such as bogue (Boops boops) and horse mackerel (Trachurus mediterraneus) (FAO, 1993b). Catches of pelagic fish, such as swordfish (Xiphias gladius), bluefin tuna (Thunnus thynnus) and bonito (Sarda sarda), have all increased in the Mediterranean in recent years. The mean size of swordfish has declined, however, and there is concern that all stocks are being exploited too heavily. Despite increased
catches in recent years, bluefin tuna populations in the east Atlantic and Mediterranean have diminished by more than 70 per cent since the 1970s (Lleonart, 1993). Among the small pelagics, anchovy (Engraulis encrasicolus) stocks and catches have declined, whereas the less valuable stocks of sardines (Sardina pilchardus) have increased. Hake (Merluccius spp) catches in the western Mediterranean have declined with decreasing recruitment.
However, in the Mediterranean, despite high exploitation rates, the overall landings for all species continued to rise in the 1970s and 1980s. It would normally be expected that landings would decline as effort further increased and stocks were depleted. Increases in fishing production in the 1970s and 1980s were particularly evident in the semi-enclosed basins such as the Black Sea and the Adriatic, where nutrient-enrichment is more pronounced, than in the more nutrient-poor regions of the eastern Mediterranean (FAO, 1992a). Total catches of small pelagics in the Black Sea are estimated to have risen steadily from a plateau of around 350 000 tonnes in the late 1970s to some 700 000 tonnes in the 1980s, before collapsing to a provisional estimate of close to 100 000 tonnes in 1991. This decline is related to the effect of mesotrophic conditions on food webs in enclosed and semi-enclosed seas (Caddy, 1993). In 1970 there were over 26 species of fish in the Black Sea that could be commercially exploited (Gulland, 1983). By 1990 this had dropped to five, principally as a result of overfishing and habitat degradation. The estuaries on the Black Sea have also undergone a decline in fisheries potential. For example, at the beginning of the century, over 1000 tonnes of sturgeon (Acipenseridae) were caught annually in the Romanian part of the Danube delta, whereas only 20 tonnes were landed in 1989 (Crivelli and Labat, 1992). The anchovy fishery has similarly collapsed in the Black Sea.
Significant declines have been noticed in catches of commercial fish species in the Caspian Sea (eg, sturgeon (Huso huso) and pike (Esox lucius)). This decrease has been attributed in part to overfishing, though habitat degradation is a contributing factor. The total fish catch from the Caspian Sea was 300 000 tonnes per year in the mid-1930s; this had dropped to 100 000 tonnes by 1970. Catches of sturgeon in the Caspian sea area of the former USSR fell from 10 830 tonnes in 1907 to only 850 tonnes in 1953 (Sokolov and Berdichevskii, 1989).
Overexploitation does not normally lead to the extinction of the species. The economics of fishing do not generally allow for a complete elimination of a target species. The only documented case of a marine fish population to have apparently disappeared in Europe due to overfishing is the skate (Raja batis) from the Irish Sea (Brander, 1981). In contrast, freshwater species are more vulnerable to extinction, as they often inhabit smaller ranges and generally have smaller stocks, but the few extinctions recorded (eg, the disappearance of the burbot (Lota lota) from Britain) are probably due to habitat loss.
Overexploitation, however, may reduce genetic diversity. For example, overfishing in the Baltic has led to large-scale salmon stocking schemes, for commercial and recreational fisheries. There are fears that this may cause a depletion of the gene pool of the natural salmon stock in the area. Overexploitation of certain fish species can potentially impact on the natural ecological dynamics of the aquatic environment and therefore can affect the abundance of other plant and animal species in the aquatic food-chain.
The Icelandic Ministry for the Environment has suggested that the fishing industry is being affected by air- and seaborne pollution from the rest of Europe and North America, which could endanger fish stocks and marine mammals by affecting their reproductive capacity (Icelandic Ministry for the Environment, 1992).
Technology has played a part in increased pressure on fishery resources. There has been a general increase in the size of nets used, as bigger and more powerful vessels have been built. Bottom trawls, used for fishing flatfish and benthic molluscs, have been modified to allow increasingly rougher ground to be worked. The development of sonar and echo-sounding equipment has increased the searching power of vessels. Synthetic twines have replaced natural fibres, potentially contributing to solid waste generation since they do not rot. The power block allows the use of larger purse seine nets, and helps in hauling in gill nets used in deeper waters. Sealing and whaling are covered in Box 24C.
Impacts on non-target species at sea |
Fishing, by its nature, removes individuals of a 'target' species from the environment: most fishing methods, however, have also an impact on 'non-target' species. Fishing can impact on non-target species both directly through the entrapment of, or damage to, non-target species in nets or by hooks, or indirectly by possibly depleting stocks of certain fish which represent an important food source to other marine animals.
Non-target species taken by a fishery are of little importance to the fishery concerned. Certain species may be retained for sale (known as 'by-catch species'), even though they are not target species. Other species are discarded at sea. Discarded species are not normally recorded other than by dedicated scientific investigation. The discarding of dead fish and parts of fish are important food resources for scavenging organisms, notably sea-birds. In the North Sea, the populations of the fulmar (Fulmarus glacialis) have increased as they feed on discarded offal from fishing vessels (ICES, 1992b).
Obviously the fishing intensity, the season and area of fishing are important, but the type of impact is determined largely by the type of fishing gear being used. Two major gear types have the greatest impacts on non-target species: heavy dragged gear (such as beam trawls and dredges) used to catch demersal species, and fixed (especially gill nets) or drifting nets to catch pelagic species (Northridge, 1991).
Trawls and dredges generally impact on benthic organisms living on the sea floor. ICES has estimated the total swept areas for the North Sea for various types of trawl. However, it is difficult to relate such statistics to damage, as the fishing effort is very uneven, and thus certain areas will be fished many times while others are missed. Nevertheless, there have been some measures taken to prevent damage to organisms on the sea floor. For example, in the Mediterranean, the seagrasses (Posidonia oceanica and Zostera marina), which are important nursery areas, are destroyed by trawling. Consequently, trawling has been banned in the EU, to a depth of 50 metres or to a distance of 0.5 nautical miles from the coast (the limit of growth for seagrasses). Another secondary effect arising from fishing is that of 'ghost' fishing, where non-target species are caught or killed by lost fishing gear (mainly nets and traps).
Fixed and drifting nets have a greater impact on the vertebrate marine fauna (other than fish), especially those with low reproductive rates. Dolphins, for example, the bottlenose dolphin (Tursiops truncatus), and porpoises (Phocoena phocoena), loggerhead turtles (Caretta caretta) and monk seals (Monachus monachus) (see Chapter 9), are particularly vulnerable to entrapment and damage: furthermore, all are mentioned on the IUCN Red List of Threatened Animals (IUCN, 1990). For example, the number of porpoises taken in Danish fixed net fisheries in the Danish inshore waters may be between 500 and 1000 annually (Northridge, 1991). Despite existing international practice (and EC legislation) limiting the use of surface drift nets to lengths less than 2.5 km, their continuing use creates a major problem in the Mediterranean (legislation does not exist for gill nets). Although there is not much reliable information available, there is some evidence that significant, and for some cetacean species possibly unsustainable, numbers of marine mammals are being killed in the Mediterranean Sea due to unselective fishing methods (Northridge and Di Natale, 1991).
Sea-birds can become entangled in most types of fishing nets, particularly in gill and other fixed nets. It has been estimated that 25 000 sea-birds were killed by drowning in the southeast Kattegat between 1982 and 1988 mainly guillemots (Uria aalge) (Oldén et al, 1988, in ICES, 1992b). In the Baltic, salmon gill net fisheries are known to take at least 20 000 birds annually (Northridge, 1991). However, further investigation is required to prove whether breeding sea-bird decline can be attributed to entanglement (ICES, 1992b).
Impacts of inland fisheries |
Catches from inland waters by capture and aquaculture were about 16 per cent of the total world catch in 1991; of total European catches the figure was just under 6 per cent, and that of the former USSR about 7 per cent (FAO, 1993a) (see Statistical Compendium). In both Western and Central and Eastern Europe (excluding the former USSR) inland aquaculture accounts for the majority of inland catches. In Western Europe most capture is for recreational purposes. On the other hand there is more commercial capture in Central and Eastern Europe, especially in the important inland water resources based mainly on the Danube river system and delta and the Mazurian lakes. The former USSR had well-developed inland fishing resources and more than half of inland catches are through capture (rather than aquaculture). However, severe environmental damage in many river systems through pollution and impoundment led to a small fall in the total catch between 1984 and 1990. High levels of stocking are common in rivers in the former USSR in order to sustain commercially valuable fisheries (eg, sturgeon-stocking schemes in the Volga and Ponto-Caspian rivers) (FAO, 1992b).
As inland catches are still not reported as a separate category in FAO statistics, analysis of data for inland fish catches is still at an early stage of development (FAO, 1992b). For some countries the reporting of fish catches extends back several decades (FAO, 1990; 1993c). Trend statistics for inland water are complicated by difficulties in reporting by countries due to differences between extensive inland aquaculture and intensive management of inland fisheries, and the reporting of diadromous species (even though statistical conventions exist for both of these difficulties) (FAO, 1992b). Recreational fisheries have been consistently difficult to quantify because of economic difficulties in collecting such statistics, and their localised nature.
Freshwater fishing activities may have a considerable ecological impact due to the relatively confined nature of some freshwater bodies. This is caused primarily by habitat degradation brought about by pollution or riparian engineering works resulting in an impoverished fish fauna in many rivers (Backiel and Penczak, 1989; Haslam, 1990). However, in larger European rivers, fishing seems to have little effect.
Somewhat ironically, river pollution can reduce fishing pressure in certain situations. For example, one of the reasons the middle reaches of the Vistula river in Poland support an extensive fish fauna is that the pollution is not severe enough to kill the fish, but nevertheless can taint their flavour and make them unattractive to fishermen (Backiel and Penczak, 1989).
Many of the freshwater fish valued as food occupy the niche of top predator (eg, pike (Esox lucius), zander (Stizostedion lucioperca) and eels (Anguilla anguilla)). The removal of top predators from lakes and rivers may significantly affect the biological community. One of the most important induced effects can be increases in the amount of phytoplankton in lakes (Jeppesen et al, 1990).
Generally, recreational fisheries have less impact on the aquatic environment than commercial operations, due to the small quantity of fish caught and the fact that many fish caught by anglers are returned alive to the water. Where recreational fishing can have a major impact on the environment is when a body of water with a limited population of a species considered good sport is fished out entirely. As mentioned above, such species are often top predators, such as pike, resulting in the previously described knock-on effects (Mann and Penczak, 1984). An example of this has occurred in the river Pilica in southern Poland (Backiel and Penczak, 1989). Abundant populations of barbel (Barbus barbus) or nase (Chondrostoma nasus) found by anglers have often been fished out entirely. Recreational fishing can also impact non-target species. For example, concern has been voiced over the toxic effects of anglers' lead weights on waterfowl, such as swans in the UK.
The impact of fisheries (both recreational and sport) on the populations which they exploit can range from the virtual extinction of populations, to a more or less stable relationship of recruitment and cropping which existed in many long-established fisheries (eg, that formerly true for brown trout (Salmo trutta) in Loch Leven, UK). The essence of success in management is to have a well-regulated fishery where statistics on the catch are consistently monitored and used as a basis for future management of the stock.
Any decline in freshwater fishery numbers may not be due to overfishing but to a variety of unrelated factors, especially pollution by domestic, agricultural and industrial wastewater, the introduction of exotic species, habitat destruction and river and lake engineering (Maitland, 1993). Acidification has been attributed as the cause of the loss of considerable fish stocks in large parts of Scandinavia. For example, it has been estimated that over the last 100 years between 92 000 and 300 000 adult salmon (Salmo salar) were lost each year in 25 southern Norwegian rivers (Hesthagen and Hansen, 1991).
ENVIRONMENTAL IMPACTS OF AQUACULTURE |
Aquaculture is the farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants (FAO, 1993d). It can be either freshwater or marine (mariculture), and is increasingly common throughout Europe. There are currently difficulties in separating out aquaculture from the marine and inland catch statistics, although it is generally recognised that they should not be mixed with traditional data. Current statistics indicate that aquaculture production in Europe and the former USSR accounted for 12 per cent of world aquaculture in 1991 (FAO, 1993d). Total aquaculture production in the EU increased from 755 000 tonnes in 1984 to 884 000 tonnes in 1990. The recent increase in aquaculture activity has been stimulated mainly by the high costs of raised species, which has in turn attracted entrepreneurial interest. Escalating costs of fishing (eg, higher fuel costs) and decreasing wild fish stocks are also important factors. Trends in future production are difficult to forecast due partly to concerns over environmental impacts. However, in the short to medium term, aquaculture production levels in Europe are likely to increase.
Salmonoid rearing mainly Atlantic salmon (Salmo salar) and freshwater, mainly rainbow trout species (Salmo gairdnerii) ­ is the most widespread aquaculture activity in Europe, currently accounting for 35 per cent by weight of total European production. Almost 40 per cent of rearing of salmonoid species takes place in Norway. Non-salmonoid species involved with aquaculture are the eel (Anguilla anguilla), carp (Cyprinus carpio), sea bass (Dicentrarchus labrax), gilt-head sea bream (Sparus auratus), catfish (Ictalurus spp and Clarias spp) and various molluscs.
Aquaculture has the potential to supplement fish catches and help offset the declining stocks of some fish species. Collection of comprehensive, reliable data on aquaculture production is often difficult as many operations are small in scale. In addition, data are not always comparable since some include seaweeds and others may include juvenile specimens which are subsequently released to enhance natural stocks (UNEP, 1989).
Aquaculture can lead to eutrophication caused by discharges of fish-food materials and fish excrements from fish farms. However, to date, evidence for fish farming having brought about changes in the nutrient status and eutrophication of coastal waters is limited and restricted to regions with distinct hydrographic characteristics (limited circulation and mixing due to the sea current regime). Organic fish farm waste has been shown to cause enrichment of the sediment ecosystem in the immediate vicinity of the operation. Enrichment also causes changes in the physical structure of the sediment, some aspects of sediment chemistry and the community structure of the benthic macrofauna. Most studies show that the eutrophication effects are localised to within 30 to 40 m of the fish farm. The few studies undertaken to date show that the sediment ecosystem can recover from the effects of organic fish farm waste, although this can take several years. Large-scale deoxygenation of coastal waters as a result of fish farming is taking place in deep, insolated fjords and inlets such as in Norway (Gowen, 1990). There is increasing concern of eutrophication in the Mediterranean (eg, in enclosed inlets with limited circulation), which can be attributed partly to aquaculture. However, other factors such as tourism and agriculture are also responsible for eutrophication in these waters.
In Denmark, in 60 per cent of aquaculture farms an unacceptable state of pollution was found, with higher degrees of pollution downstream than upstream. Separation of feed waste and fish excrement reduces watercourse pollution. Fodder quotients (kilograms of fodder per kilogram of produced fish) have been introduced and reductions have been observed in discharges of nitrogen and phosphorus to watercourses (Danish Ministry of the Environment, 1991).
The pellets used as feed for intensive salmonid culture are generally made of fishmeal. Organic matter produced by phytoplankton is transferred down the food-chain to industrial fish, which are then converted into food for salmon. It has been estimated that intensive salmon farming requires solar fixation by phytoplankton from a sea surface area approximately 50 000 times larger than the surface area covered by the cages. No matter how humans exploit salmon (fisheries, coastal sea ranching, or fish farming) the required ecosystem support areas is of similar size (about 1 km2 per tonne harvest) (Folke and Jansson, 1992).
One of the most potentially serious effects of aquaculture on the environment is the introduction of exotic species into environments where they may compete with, or replace, native species. Such introductions are generally unintended, though some are the result of deliberate actions. Some countries, such as Denmark, have introduced legislation prohibiting the introduction of non-indigenous species.
For example, when the Virginia or American cupped oyster (Crassostrea virginica) was introduced into Europe, two other American molluscs were accidentally introduced with the oysters: the slipper limpet (Crepidula fornicata), which causes extensive damage by smothering oyster beds, and the oyster drill (Urosalpinx cinera), which preys on European flat oyster (Ostrea edulis) spat. The oyster drill has declined in numbers since the 1960s and is no longer a particular problem (Utting and Spencer, 1992).
A number of diseases of aquatic animals have been introduced to Europe along with imported fish and shellfish. These include the crayfish plague that has decimated European crayfish populations and the sporozoan (Bonamia ostreae) which has been responsible for severe mortalities of European oysters along the Atlantic coast (Utting and Spencer, 1992).
Aquaculture has a range of other impacts on the environment. Increased production through aquaculture is brought about by medical products (antibacterial agents, anti-parasitic agents and sedatives). The treatment of nets with anti-fouling agents can increase water pollution. Aquaculture can occasionally compete with coastal landuse, for example, by blocking access to important recreational or ecologically sensitive areas.
It should also be added that water pollution can have significant impacts on aquaculture. For example, the toxic algae bloom off the Norwegian coast in spring 1988 caused losses to salmon and trout farms totalling about 480 tonnes (OECD, 1991).
FISHERIES POLICY |
Fishing is of varying importance in its contribution to GNP in different European countries. For example, in Iceland in 1992 it comprised 15 per cent of GNP (Icelandic Ministry for the Environment, 1992). However, in most other Western European nations, fishing accounts for less than 1 per cent of GNP on average, ranging from approximately 0.02 per cent of GNP for Germany to 0.4 per cent for Portugal (1987 data) (ERM, personal communication). Although precise data are not available on the contribution of fishing to GNP for Central and Eastern European countries, it is important for employment and human consumption (European Parliament, 1992a).
Whether fishing is a major contributor to GNP or not, it remains a politically sensitive subject in most European countries because of the needs of areas that rely on fishing as the main source of income (eg, the Faeroes, the Shetlands and northern Norway), disputes over fishing areas and practices used, and overexploitation. These factors have led the EC and a number of European countries to develop policies aimed at ensuring the proper management of fisheries activities, which have met with varying degrees of success (outlined in Box 24B). It has been estimated that if the waters of the EU were properly regulated, they could yield a further ECU 300 million per year (CEC, 1991b).
Fisheries policies aim at maintaining the population size of target species at or above a level which is consistent with sustainable fishing and a maximum yield. In this respect fishing policies take account of the environment. However, few fishing policies or marine management regimes address the broad range of environmental objectives. In order to do this a shift of emphasis is needed from a focus on the users of the resource to an 'environmentally orientated' approach, in which policies are consciously designed to optimise sustainable resource use on the basis of sound scientific information about the whole ecosystem.
CONCLUSIONS |