Habitat and Biology
Climatic zone: Polar; Temperate.
Water Area Overview
The total area of the Northeast Atlantic is 14.3 million km2 with about 2.7 million km2of continental shelf. The main oceanographic features in the Northeast Atlantic are a subpolar and a subtropical gyre, which are driven predominantly by the North Atlantic current originating from the Caribbean. It also has an extended shelf area off northern Europe, the semi-enclosed Baltic Sea, and summer upwellings off the coast of Spain and Portugal (Figure B2.1).
|Figure B2.1 The Northeast Atlantic (Area 27) |
Considered a single stock: No
PROFILE OF CATCHES
Total marine catch in the Northeast Atlantic has increased from an average of about 6 million tonnes in the 1950s to an average of about 11 million tonnes in the period 1970–2000. Since 2005, the total catch has fallen to between 8 and 9 million tonnes (Figure B2.2; Table D2).
|Figure B2.2 Annual nominal catches by ISSCAAP species groups in the Northeast Atlantic (Area 27) |
The composition of the total catch has changed over time, smoothing out some of the more dramatic fluctuations. Overall, declines in fisheries for traditional species, such as North Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and herring (Clupea harengus), have been compensated by the development of fisheries for formerly lower-valued species such as sandeels (Ammodytes spp.) and blue whiting (Micromesistius poutassou). In addition, a number of stocks that had previously been depleted have recovered.
Catches of North Atlantic cod made the largest contribution to the total of cods, hakes and haddocks until 1998 (ISSCAAP Group 32). Since then, blue whiting landings have become the most important species in this group (Figure B2.3). A persistent downward trend in cod catches is evident from the peak in the late 1960s. The lower catches in recent years can be attributed in part to the rebuilding programme for North Sea cod, and a small recovery is evident in 2009. Catches of blue whiting have been greater than those of cod since 1999, reaching a peak in 2004. However, the catch has declined in recent years owing to reduced recruitment and lower fishing mortality. The total Northeast Atlantic catches of species other than cod and blue whiting in ISSCAAP Group 32 peaked in the early 1970s and then showed a general decline (Figure B2.4). Saithe (Pollachius virens) and haddock have formed an increased proportion of the catch, whereas whiting and Norway pout have declined alongside cod.
|Figure B2.3 Annual nominal catches of selected species in ISSCAAP Group 32, Northeast Atlantic (Area 27) |
|Figure B2.4 Annual nominal catches of selected species in ISSCAAP Group 32, Northeast Atlantic (Area 27) |
Both North Sea and Norwegian springspawning herring have recovered from overfishing and have sustained the growth in catches of herring through to the mid-2000s (ISSCAAP Group 35; Figure B2.5). The North Sea herring catch has largely stabilized despite low recent recruitment. Catches of European sprat (Sprattus sprattus) have been relatively stable in the last 15 years.
Capelin (Mallotus villosus) catches are affected by environment changes and, thus, show high short-term variability (ISSCAAP Group 37; Figure B2.5). Capelin catches were highest in 1970–1985, fluctuated dramatically between 1985 and 2005, and were at their lowest level between 2005 and 2009. Atlantic mackerel (Scomber scombrus) now makes the largest contribution to ISSCAAP Group 37, and, after a dip in 2006, its catch has returned to around the long-term average maintained since the mid-1970s. Flatfish catches, primarily made up of plaice (Pleuronectes platessa), show a decline since 1990, primarily due to overfishing (ISSCAAP Group 31; Figure B2.6). Atlantic redfish fisheries (various deep-sea and oceanic stocks of Sebastes mentella and S. marinus; ISSCAAP Group 34) are predominantly in international waters in the Irminger Sea. The redfish catches declined overall between 2000 and 2009 partly owing to depletion and partly management action. The small-mesh fishery for sandeels (ISSCAAP Group 33) has expanded substantially since the 1970s, supplying the market for fishmeal.
Catches for 1985–2002 showed no trend and varied between 0.65 and 1.24 million tonnes (Figure B2.6). However, since 2002, sandeel catches have declined to below 500 000 tonnes owing to environmental change and the introduction of management measures. Catches of shrimps and prawns (ISSCAAP Group 45), which include the valuable Nephrops norvegicus fisheries, increased between the early 1980s and 2000 (Figure B2.6). Since then, the fishery has declined to levels observed before 1980. These changes in total catch are mostly attributable to declines in northern prawn (Pandalus borealis) catch. Unlike northern prawn, the combined catches of other shrimp and prawn in ISSCAAP Group 45 species declined slowly from the mid-1950s to 1990s. However, since 2000, their catch has risen to become stable at 40 000–50 000 tonnes.
|Figure B2.5 Annual nominal catches of selected species in ISSCAAP Group 35, 37, Northeast Atlantic (Area 27) |
|Figure B2.6 Annual nominal catches of selected species in ISSCAAP Group 31, 33, 34, 45, Northeast Atlantic (Area 27) |
Management unit: NoFISHERIES UNDER NEAFC JURISDICTION
To access all FIRMS managed fisheries reports available for NEAFC, please look at: NEAFC managed fisheries reports
The ICES provides scientific advice for fisheries in the Northeast Atlantic through its Advisory Committee (ACOM). This committee oversees the production of scientific advice for the management of coastal and ocean resources, and ecosystems on behalf of the ICES. Scientific research is coordinated with ACOM through the Science Committee (SciCOM). The scientific advice is based upon peer-reviewed analyses prepared in the ICES expert groups. The ACOM advice is used by the relevant management authorities, which include government institutions, particularly the European Commission, and multilateral organizations, notably the North East Atlantic Fisheries Commission (NEAFC).
In 2009 and 2010, ICES provided advice on 129 stocks. The majority of larger stocks are assessed annually with age-structured stock assessments. For most other species, the advice is constrained to suggesting limits on catches and identifying further information that is required for more precise recommendations on management measures. Lack of data, or unreliable data, is the main constraint on the precision and accuracy of these assessments. For several stocks, catches have been misreported, and many lack a reliable abundance index to apply standard assessment techniques. Current status of exploitation and trend of catch in the region is shown in Table D2. Through limit and precautionary reference points for SSB and fishing mortality (F), ICES has attempted to implement the precautionary approach in a consistent way. However, for a large number of stocks, reference points remain undefined because the management authority has either yet to agree on the basis for defining them or the necessary data are lacking. More recently, MSY has been adopted as the standard basis for reference points (e.g. Iceland, European Union [EU] Common Fisheries Policy [CFP]) in line with other countries (e.g. the United States of America). In addition, the EU policy paper on fisheries management (COM (2010) 241 Annex III) defines the fishery categories that form the basis for TAC estimation. This is particularly useful where information and stock assessments are lacking. Better definition of fishery categories should lead to improvements over time in standardizing definitions of stock status.
A report by ICES (2010b) outlined the main physical oceanographic events that occurred in 2009:
- The upper layers of the northern North Atlantic and the Nordic Seas were warm and saline in 2009 compared with the long-term average.
- A strong cold anomaly developed in the surface of the central North Atlantic in the summer.
- Warming and salination of deep waters has continued.
Evidence suggests multidecadal changes in ocean climate have been driving changes in recruitment and productivity in the North Atlantic and Pacific Ocean (Klyashtorin, 2001). Long-term climate change may make stocks more vulnerable to fishing by reducing the overall carrying capacity of the stock. This will mean that past exploitation rates might not be sustained (Jennings and Blanchard, 2004) and reference points based on historical data may be invalid. Therefore, s main concern is how climate change affects the way fisheries should be managed (Rijnsdorp et al., 2010).
The effects of climate change are potentially complex and difficult to predict (Rijnsdorp et al., 2010). Climate will affect not only average temperatures, but the frequency of very cold or hot seasons, changes in sea ice cover, CO2 levels, pH, salinity, wind and rainfall patterns. Changes in these can affect physiology, behaviour and population dynamics of species, and hence affect whole ecosystems. Separating these effects from the more direct effects of pollution and fishing is difficult. One of the problems for fisheries science is the complex life history of fishes. They have a factor of ten increase in body size throughout life that leads to major changes in ecology (Rothschild, 1986). Pre-recruits, in particular, may be in life stages that are more vulnerable to changes in climate.
Productivity of fish populations is determined by recruitment, growth and mortality, all of which can be affected by changes in climate. For example, in a comparative study of 15 cod stocks, the large differences in productivity corresponded to differences in water temperature (Dutil and Brander, 2003). In the Bay of Biscay and Mediterranean, changes in river runoff are expected to alter the productivity of sole (Rijnsdorp et al., 2010). Climate change may also affect management controls. Closed areas may not achieve their objectives because species or life stages shift outside the boundaries of the protected area (e.g. the North Sea “Plaice Box” – van Keeken et al., 2007).
Another concern is the effect on benthic habitats of bottom trawls, particularly beam trawls. Beam trawls have been shown to affect the benthic community on sand (de Groot, 1984) and gravel beds (Kaiser and Spencer, 1996). There is little doubt among fisheries managers that many fishing gear types are affecting benthic habitats. The problem facing fisheries managers is to quantify and manage this impact, as the interaction is complex. The primary problem is the physical impact of the gear on the animals on or close to the substrate surface. The degree of impact will depend on the weight and speed of the trawl, frequency of trawling, and the bottom type as well as the characteristics of the animals themselves (OSB, 2002). Management of these impacts involves a multistep process:
- Identifying an acceptable impact as many of the fisheries had been operating for many years before baseline data were collected. This makes the basis for determining the acceptable ecological impact on habitat and the ecosystem unclear.
- Assessing the impact for different gear types and minimizing impacts through technical changes to the gear and the way it is used.
- Controlling the fishery operation over the various marine habitats (the fishery &ldli>quo;footprint”), which involves overlaying the fishery activity on a habitat map, and limiting the area of the fishery or frequency at which specific areas are fished.
- Applying overall control on fishing activity, such as limits on capacity and fishing effort. This forms the more usual fishery management intervention and is necessary to conserve the target stock.
The Marine Strategy Framework Directive (EU, 2008) provides the policy for dealing with this sort of issue in the EU. However, obtaining the necessary information to implement the effective management may still take time. Other environmental concerns arise out of the expansion of mariculture in the Northeast Atlantic region. Extensive farming exists for Atlantic salmon, which may have environmental impacts through local eutrophication. Potential negative impacts on wild populations from salmon farming can occur through interbreeding and introduction of disease.
Until the late 1970s and early 1980s, the principal RFMO in Area 27 was the NEAFC. However, the declaration of 200-mile EEZs and the establishment of the CFP of the EU have changed the management landscape. For fish stocks occurring exclusively within the jurisdiction of the coastal State, it is that State that manages the resource exploitation. This applies to the majority of marine stocks in the region. For States that are members of the EU competency for fishery managements lies with the European Commission and is administered by DG MARE. Fisheries on stocks shared between Norway and the Russian Federation are managed through the Norwegian–Russian Fishery Commission. This means that the role of the NEAFC is now largely confined to shared stocks that also occur in international waters such as mackerel, blue whiting and redfish. The NEAFC recommends and coordinates measures to maintain the rational exploitation of fish stocks in its convention area with scientific advice from ICES. Measures are implemented by the contracting parties that include the EU, as well as Denmark (in respect of Faroe Islands and Greenland), Iceland, Norway and the Russian Federation. The NEAFC not only harmonizes measures in the region, but coordinates the management of shared stocks, and perhaps most importantly, manages fisheries in international waters. If requested, it will also recommend measures for regions under national jurisdiction.
Most fisheries are managed with stock-specific TACs. Therefore, ICES is typically requested to provide catch advice on a stock-by-stock basis. However, other fishery management measures are frequently used as well. Advice is modified to take account of technical interactions (e.g. bycatch in mixed species fisheries) or of biological interactions (e.g. predator–prey) where appropriate.
The majority of the commercial fish resources of the Northeast Atlantic have been overexploited or depleted despite substantial investment in fishery science, monitoring, control and surveillance. Critical components for good management were lacking. These include effective consultation with all stakeholders, enforcement and a clear, understandable process for dealing with risk and uncertainty. However, the signs are positive that management is now improving.
The CFP of the EU, and other fisheries policies in the region, continue to be developed and improved. The latest EU policy is being revised from one that focused on fish production to one concerned much more with sustainable use. This is being complemented with a more effective monitoring, control and surveillance (MCS) system implemented in 2009.
Currently, seven Regional Advisory Councils (RACs) have been established after the revision of the EU CFP in 2002 (EU, 2004, 2007). The objective of the RACs is to work towards integrated and sustainable management of fisheries, based on the ecosystem and precautionary approaches. They provide a way for stakeholders to discuss issues and develop management plans.
Another related and important ongoing development has been the implementation of testable, explicit and transparent harvest control rules. These now form the core of a number of management plans. Fisheries where such management plans appear successful include Northeast Arctic cod and haddock, North Sea herring, sole and plaice. The harvest control rules have aided dialogue between industry (through, for example, the RACs) and ICES (through management plan evaluations). Even where management plans are not being implemented successfully, such as with mackerel, the harvest control rule still provides a clear way to measure management performance and a focus for improvement.
In developing management plans, ICES and relevant management authorities are incorporating MSY as the default basis for reference points, along with ecosystem and precautionary approaches. The transition to the ecosystem approach (ICES, 2004) and MSY-based management will be gradual (COM, 2006).
Biological State and Trend
To access all FIRMS State and Trend summaries available for this Area, please look at: Status and Trend Summaries (extracted from reports)
The fisheries of the Northeast Atlantic expanded rapidly in the late nineteenth and early twentieth centuries. During this time, fishing became increasingly industrialized and applied more advanced technology. This expansion was only interrupted by the First and Second World Wars, which provided periods of little fishing activity, enabling stocks to rebuild. Since the 1950s, fisheries in the Northeast Atlantic region have undergone a significant reduction in numbers of vessels and employment. Despite this, a corresponding increase in fishing power of vessels has meant that fishing mortality has continued to increase. More recently, fishing mortality has levelled off or decreased (Sparholt and Cook, 2009). Most of the traditional fishery resources of the Northeast Atlantic are fully exploited or overexploited, and new fisheries have been developed for some non-traditional stocks. There have been notable improvements in the status of some larger stocks, such as Northeast Arctic cod, Northeast Arctic haddock, mackerel, and the larger herring stocks. Other stocks, such as North Sea plaice and cod, are still in recovery although demonstrable progress has been made in their rebuilding. Overall, real progress is being made in the sustainable management of the fisheries in this region despite many challenges in international cooperation, fishing overcapacity and environmental change.
The resource status described here is based upon the 2009 and 2010 advice (ICES, 2009, 2010a). The advice and working group reports are published on the ICES Web site (www.ices.dk).
Marine resources, Northeast Arctic fisheries (ICES Subareas I and II)
The main demersal and pelagic fisheries all show a similar pattern of depletion and recovery. Northeast Arctic cod and haddock are generally caught together in trawl fisheries under a joint agreement between Norway and the Russian Federation. Both stocks were depleted in much of the period from the 1950s to the 1980s. Since then, they have recovered through reduced fishing mortality and are currently considered to be harvested sustainably. Recent high biomass of both species is the result of the management controls that have limited fishing mortality very effectively. Saithe has recovered to a level on a par with the estimated spawning stock size in the 1960s. Stock condition for capelin is considered good with catches remaining at or below sustainable limits. This is important as capelin is an important prey for many predators in the region, including cod and haddock.
In contrast, Greenland halibut, Norwegian coastal cod and redfishes appear depleted. A rebuilding plan has been proposed by Norwegian authorities for their coastal cod, which is being evaluated by ICES. Greenland halibut (Reinhardtius hippoglossoides) has no recovery plan, and the 2010–12 TAC was set above that recommended for recovery. The scientific recommendation for redfishes (Sebastes marinus and S. mentella) is to keep catches as low as possible. This is not surprising given their current status, low productivity and the high fishing pressure in the region. There is evidence that northern shrimp catches in the Barents Sea have been below their MSY. Similarly, there is no targeted fishery for polar cod (Boreogadus saida), and catches are low compared with the likely resource size of 1.2 million tonnes (Anon., 2009). However, polar cod, like capelin and sandeel, is an important prey for many arctic species, and safe levels of exploitation may be low under an ecosystem approach to fisheries.
Marine resources, the Baltic (ICES Divisions IIIb-d)
The Baltic ecosystem is heavily influenced by environmental conditions that result from the semi-enclosed nature of the sea. Freshwater inflows to the Baltic tend to lower salinity and oxygen levels. These can often raise temperature and nutrients, and can affect cod recruitment in particular. However, intermittent inflows of oceanic water from the North Sea with higher salinity and oxygen levels refresh the environmental state. This makes fishery management in the Baltic particularly difficult as sustainable exploitation levels will vary in response to the environmental conditions. A major period of ecological stress in the Baltic appears to have occurred between 1987 and 1993 (Diekmann and Möllmann, 2010). In this period, low salinity, low dissolved oxygen, high temperatures and high nutrient levels occurred. At the same time, there was high cod fishing pressure, which may have pushed the biotic part of the ecosystem into a new state with reduced cod productivity. The abundance of cod as the main predator of sprat and herring has an important effect on the whole Baltic ecosystem. Western and eastern Baltic cod (Subareas 22–24 and 25–32) appear currently fully exploited in 2009. Both stocks, but particularly eastern Baltic cod, have been through periods of prolonged depletion. Eastern Baltic cod has only recently (2008–09) been rebuilt, mainly by management achieving a significant reduction in fishing mortality. In addition, the Baltic cod fishery has had considerable problems with monitoring and control. Under-reporting of catches was a particular concern in 1993–96, and 2000–07. This problem appears to have reduced more recently. There are several herring stocks in the Baltic that are fully exploited or whose status is unknown owing to a lack of data. The largest stock, central Baltic herring, is overexploited. Sprat is fully exploited and the stock has appeared stable in the last decade despite a trend in fishing mortality to above the precautionary level. However, the recovery in the main predator, cod, may require a reassessment of management objectives for these stocks.
Marine resources, the North Sea (ICES Subarea IV), Skagerrak (Divisions IIIa) and Eastern Channel (Division VIId)
The North Sea cod stock assessment now includes cod caught in Skagerrak, the Eastern Channel and the North Sea. Based on the estimated status in 2009, ICES classifies the stock as having “reduced reproductive capacity and as being at risk of being harvested unsustainably”. The stock has increased in size since the lowest observed biomass in 2006, but rebuilding is not complete. Controlling fishing mortality has been difficult mainly owing to discarding practices and the mixed species composition of the demersal fishery. A major limitation on catches for many small-scale fisheries in this region is due to cod bycatch limits. However, there is a stronger 2005 cod year class, which, together with controls on fishing effort, will support the current rebuilding plan.
Haddock and saithe, in contrast to cod, are at full reproductive capacity and harvested sustainably, despite recent recruitments being poor. Whiting status in the region is unclear. Recruitment has been very low since 2002, with an indication of a modest improvement recently. However, ICES is currently recommending reduced whiting catches to reverse the long-term decline in population size. With reduced importance of cod, smaller fisheries have increased as a proportion of the value of fisheries landings. Of these, the nephrops (Norway lobster, Nephrops norvegicus) are a resource that has increased in importance relatively recently. There are nine management units for nephrops in the North Sea and Skagerrak/Kattegat region with catches averaging between 1 000 and 10 000 tonnes. All of these units are fully exploited.
Plaice (Pleuronectes platessa) and sole (Solea solea) are the major species in the mixed flatfish fishery. Although still under a rebuilding plan in 2009, North Sea sole and plaice are classified as having full reproductive capacity and as being harvested sustainably. The status of smaller stocks of Eastern Channel sole and plaice is less certain. Both stocks are at greater risk of overfishing. Other flatfish species have not been assessed, but the reduction in directed effort on plaice and sole is likely to have had a positive effect on them as well. The main herring stock, autumn-spawning North Sea herring, consists of a number of spawning components. The landings from these components cannot be separated and are therefore treated as a single stock. Recruitment of these stocks has been very poor since 2002. This poor recruitment has been taken into account in developing the EU– Norway agreement that sets exploitation levels on these species. There are some other small spring-spawning herring stocks associated with gravel beds and river estuaries that are managed locally.
The shorter-lived species such as the three sandeel stocks are considered at risk of reduced reproductive capacity. A reduction in their TAC was thus advised (ICES, 2011). The Norway pout (Trisopterus esmarkii) stock is considered at full reproductive capacity. Less is known about the state of sprat, but survey trends indicate the stock size has increased from the 1980s and has varied around an average level since 1998 with no trend. The population sizes of all these species are generally more influenced more by the environment than by longer-lived species. Temperature and salinity affects processes such as natural mortality and recruitment. This causes significant changes in population size even in the absence of fishing. In addition, they are important prey species for a number of other fish stocks (cod, saithe, haddock and mackerel), marine mammals and seabirds. Consideration of these issues makes management of the relevant fisheries difficult, and well-defined reference points are as yet unavailable.
Marine resources, Iceland (ICES Divisions Va), the Faeroe Islands (Vb), the Irminger Sea and Greenland (Subareas XII and XIV)
Cod is the most important resource in this region in terms of volume. Icelandic cod is the largest fishery. Although the current biomass remains low compared with levels observed in the 1950s, the stock is increasing in size and is above the limit reference point. A management plan is being implemented that should keep fishing mortality to levels more consistent with the MSY. The state of the slightly smaller Iceland and East Greenland cod stock is uncertain. The ICES recommendation was that no fishery should take place in 2011 to improve the likelihood of establishing offshore spawning stocks. The smaller Faroese cod stocks are also in a more parlous state than Icelandic cod; and ICES has recommended that the Faroe bank cod fishery be closed to allow stock recovery. Faroe plateau cod is in a better state, although its biomass is still below the target level.
Cod is often caught with haddock, but the haddock stock in the same area is probably in a better state, with its biomass as high as that observed in 1980s. However, haddock lacks a management plan, which is currently under development. Faroe haddock is also considered to be at risk, and ICES recommends catches should be as low as possible to allow rebuilding. The two stocks of saithe, in Faroe Islands and Iceland, are both considered at risk, and ICES recommends a reduction in fishing mortality on these stocks as well.
Greenland halibut stock in this region has remained close to its limit reference point. Despite recommendations to the contrary, fishing mortality on this stock has risen. The recommendation of ICES has been to set the TAC below 5 000 tonnes, which is substantially lower than the 2009 landings of just under 30 000 tonnes. There are five management units for redfish (Sebastes sp.) identified in the region. These are slow-growing species that are likely to be vulnerable to overexploitation. Three of the stocks are considered fully exploited, whereas the Iceland and eastern Greenland shallow and deep water pelagic stocks of beaked redfish (S. mentella) are considered overexploited.
The status of Iceland–East Greenland–Jan Mayen capelin is unclear owing to the lack of reference points. The spawning stock left in spring 2009 was estimated to be below the management target, suggesting that the stock is at risk. Icelandic summerspawning herring face a different problem. The stock increased from 2003 to well above the precautionary level owing to a reduction in fishing mortality. However, the stock has fallen dramatically since 2008, coinciding with an outbreak of Ichthyophonus infection, which continued in 2009. As it progresses, the disease will require the stock assessment to rely on the annual survey to obtain estimates of stock status.
Marine resources, the West of Scotland and Rockall (ICES Divisions VIa-b) the Irish and Celtic Seas (VIIa-c and VII e-k), and the Bay of Biscay (VIIIa-b)
The ICES Divisions VI–VIII (excluding the Eastern Channel), covering areas to the west and south of the British Isles, contain upwards of 42 stocks monitored by ICES. The fisheries in this region have been under stress and present significant challenges for management. Many of these stocks are overexploited and others lack data to provide any scientific advice. Most stocks are relatively small with landings of less than 10 000 tonnes. Some stocks, for example haddock in Division VIa, are biologically part of the North Sea.
Western horse mackerel (Trachurus trachurus) is probably the largest fishery in terms of volume in this region. The fishery is considered fully exploited, although the exact status is unknown. The cod stocks form most of the other major landings. West of Scotland and Irish Sea cod are considered to have reduced reproductive capacity. The status of Celtic Sea and Rockall cod is unknown. However, precautionary advice for Celtic Seas suggests a reduction in fishing. Catches of the small Rockall stock appear to have declined without management intervention.
Many of the demersal fisheries are part of a mixed trawl fishery and are affected by discarding and misreporting. West of Scotland haddock and whiting are overexploited, whereas Rockall haddock appears fully exploited. There are inadequate data to assess Celtic Sea and Irish Sea haddock stocks. Irish Sea whiting is overexploited. Northern shelf anglerfish (Lophius spp.) and megrim (Lepidorhombus spp.) and West of Britain whiting are considered fully exploited.
There are separate plaice and sole stocks in the Western Channel, Irish Sea, West of Ireland, Southwest of Ireland and the Celtic Sea, all of which with the exception of Celtic Sea sole and Irish Sea plaice are considered at risk or harvested unsustainably. Irish Sea, West of Ireland and Scotland, and North of Scotland herring probably form a complex of stocks, which are at significant risk of overexploitation. The Celtic Sea/South of Ireland stock, however, has recently recovered and the stock is at full reproductive capacity. The non-finfish fisheries in the region mainly target nephrops. There are 10 management units in the region with landings of between 500 and 7 000 tonnes. Of these, six are considered overexploited or at risk of reduced reproductive cacapacity. As with other small-scale fisheries, assessments are severely limited by data.
The Bay of Biscay sardine and sole fisheries are not likely to be overexploited, but assessments are severely data-limited. In contrast, the larger anchovy fishery is thought to be at risk. There is almost a 50 percent chance that the stock is below its limit reference point, where the risk to the reproductive capacity is considered unacceptable. This region also includes the larger of the two hake stocks (Merluccius merluccius) in the Northeast Atlantic. The northern hake stock, which also extends into the North Sea, is at full reproductive capacity and is being harvested sustainably.
Marine resources, Iberian Region (ICES Division VIIIc and Subareas IX and X)
The main demersal species in the Iberian Region are hake (Merluccius merluccius),anglerfish (Lophius spp.) and megrim (Lepidorhombus spp.). In contrast to the northern hake stock, the southern hake is at reduced reproductive capacity and at increased risk of overfishing. Spanish and Portuguese megrim (L. boscii and L. whiffiagonis) are fully exploited. Anglerfish status is uncertain, but one of the two species is likely to be overfished. Scientific advice recommends reduction in catches to build the stocks to their MSY. There are also two small nephrops stocks, one of which, the North Galicia and Cantabrian Sea management unit, is considered to be overexploited.
The Spanish and Portuguese sardine (Sardina pilchardus) fishery, which is the largest by volume, the anchovy (Engraulis encrasicolus) fishery and the southern horse mackerel fishery are considered fully exploited and stable. While the sardine biomass has recently declined, this is due to poor recruitment, probably caused by chance or environmental effects.
North Atlantic and Baltic salmon stocks
There are more than 1 500 rivers with salmon (Salmo salar) stocks in the Northeast Atlantic Commission (NEAC) Area of the North Atlantic Salmon Conservation Organization (NASCO). Overall, data from monitored rivers suggest that there has been no trend in smolt production.
Salmon is divided broadly into three stock complexes. The smaller Northern European (Scandinavia and the Russian Federation) 1 sea-winter (1SW) and multi-seawinter (MSW) stock complex is considered to be fully exploited, but at full reproductive capacity. The larger Southern European (Ireland, the United Kingdom of Great Britain and Northern Ireland, and France) 1SW stock is considered to be at reduced reproductive capacity, and the Southern European MSW stock complex is considered to be at risk of reduced reproductive capacity. The current estimates for the sizes of both stock complexes are among the lowest in the time series. Although estimated exploitation rates have generally been decreasing over time for all stock complexes, there has been little improvement in the status of stocks. This is mainly because of continuing poor survival in the marine environment, probably because of climate effects.
Baltic salmon is assessed separately. The natural smolt production of salmon populations in the Baltic has continued to increase and is now about 70 percent of the overall potential wild production. However, in common with other salmon populations, survival of post-smolt fish has remained low, and has suppressed recovery of wild salmon stocks.
Widely distributed, deepwater and migratory stocks
Blue whiting are caught from the Barents Sea to the Straits of Gibraltar. Based on the 2009 estimates of biomass and fishing mortality, ICES classifies the stock as having full reproductive capacity and being harvested sustainably. Recently (in 2008), a new management plan has been implemented by Norway, EU, Faroe Islands and Iceland.
Mackerel is assessed as a single stock for the Northeast Atlantic, although it is made up of distinct spawning components, of which the Western is by far the largest. The SSB has increased from a low of 1.8 million tonnes in 2002 to about 2.5 million tonnes in 2008, a level similar to that seen in the 1990s. At present, the stock as a whole is at full reproductive capacity. However, the North Sea component is still depleted and, hence, catches in the North Sea are prohibited at appropriate times to encourage its recovery.
Despite the recent increased SSB, the fishery has a number of problems. Catches have generally exceeded the levels recommended by ICES. Misreporting has been a serious problem in this fishery, especially in international waters, although the problem has been very much reduced in recent years. There is an agreed management plan, but this has not been followed since 2007 owing to disagreements among the fishing nations. Problems are partly due to the summer mackerel distribution extending farther north in recent decades, so that the stock is being commercially fished in areas where it was previously not fished, particularly in the Icelandic EEZ.
Deepwater species such as the Argentine (Argentina sphyraena), greater silver smelt (Glossanodon leioglossus), roundnose grenadier (Coryphaenoides rupestris) and Atlantic orange roughy (Hoplostethus atlanticus), along with more than 20 other species of bony fish and more than 10 species of sharks are now caught in deepwater fisheries. The productivity of these stocks is often low even where the population sizes are initially large. This makes them particularly vulnerable to overfishing. The advice of ICES is that effort in these fisheries be kept as low as possible until the response of these species to fishing is better understood. Therefore, appropriate data need to be collected from these fisheries if they are to be continued. Indeed, ICES goes so far as to recommend that some stocks, for example, orange roughy, should not be fished at all. For others such as tusk (Brosme brosme), ling (Molva molva) and red seabream (Pagellus bogaraveo), the fisheries may have long-term potential, depending on the area fished.
Source of information
Marine and Inland Fisheries Service, Fisheries and Aquaculture Resources Use and Conservation Division. FAO Fisheries and Aquaculture Department “Review of the state of world marine fishery resources”
. FAO FISHERIES AND AQUACULTURE TECHNICAL PAPER.
No. 569. Rome, FAO. 2011. http://www.fao.org/docrep/015/i2389e/i2389e.pdf
The bibliographic references are available through the hyperlink displayed in "Source of Information".ACKNOWLEDGEMENTS
Robin Cooks and Jean-Jacques Maguire reviewed an earlier version of the text and theirconstructive comments have greatly improved the manuscript.