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Deep-sea Species

The deep-water fish of the North Atlantic live in a cold and dark world. They are adapted to a life with very little food and at a very slow pace, as the small amount of energy available must be conserved as much as possible, with little used on swimming, searching for food, growth or reproduction. As a result, the fish grow extremely slowly and reproduce at a very slow rate — some species such as the orange roughy do not even reproduce every year. Many species become mature only at the age of 1530 years and can live to over one hundred years old.

Because they grow and reproduce so slowly, deepsea stocks cannot be fished and managed in the same way as the faster reproducing stocks in the North Sea. If a group of fish or stock in the deep sea is fished out, it is gone for good, at least on a human time scale. As a result, a fishery on such stocks sometimes appears for one or two seasons and then disappears for the next 20 or even 50 years. The only exceptions appear to be blue ling, alphonsino, tusk or redfish, which have faster reproduction and growth rates and so can sustain somewhat higher exploitation rates than other deep-sea species.

ICES 2003

There are some 340 deep-living species of fish recorded in the North Atlantic. Those targeted commercially or regularly taken as by-catch in deep-sea fisheries west of Ireland include:

Teleosts (bony fish)

Alfonsinos/Golden eye perch (Beryx spp.)
Two widespread species (Beryx splendens and B. decadactylus) which are generally caught at depths of 200-550m.

B. splendens occurs in the Eastern Atlantic off southwestern Europe, Madeira and the Canary Islands. Inhabits the outer shelf (180 m) and slope to at least 1,300m depth; often found over seamounts and underwater ridges. B. decadactylus occurs in the Eastern Atlantic from Greenland and Norway to Western Sahara and South Africa. Found at around 500m depth on mud or sandy-mud bottom. Occurs on the continental slope. Both species are caught in EU fisheries on the continental slope and the Mid-Atlantic Ridge, but the relative proportion of the two species in catches is unknown (ICES 2005d).

Due to their spatial distribution associated with seamounts, their life history and their aggregation behaviour, alfonsinos are easily overexploited by trawl fishing; they can only sustain low rates of exploitation. Fisheries on such species should not be allowed to expand above current levels unless it can be shown that such expansion is sustainable. To prevent wiping out entire subpopulations that have not yet been mapped and assessed the exploitation of new seamounts should not be allowed.

ICES 2006 advice on Alfonsinos/Golden eye perch (pdf 34k). Emphasis in bold is ours.

There is currently no TAC regulation for Alfonsinos. Irish vessels took 4 tonnes in 2003 and reported a zero catch in 2005. ICES states: "Underreporting of catches from international waters is suspected" (ICES 2006).

Anglerfish/Monkfish (Lophius spp.)
Found in shallow shelf waters and waters on the upper continental slope between the depths of 200-600m. There has been a tendency for shelf fisheries for anglerfish to extend into deeper waters. Lophius spp. are targetted in the upper slope gillnet fishery west of Ireland (see Gillnet Fishery).

Black scabbardfish (Aphanopus carbo)

Black scabbardfish (Aphanopus carbo)
This valuable fish is caught all along the eastern North Atlantic from Iceland to Madeira. It is a fast moving predator found at depths of 200-1,600m. Spawning is currently only known to take place off Madeira between November and December, although it may also occur elsewhere. There is very little objective information currently available on the stock structure of this species (ICES 2005d).

Targeted by French and Irish trawlers to the west of the British Isles in sub-areas VI andVII, particularly in the Rockall Trough. Taken in a mixed species trawl fishery along with roundnose grenadiers, blue ling, cochon, siki sharks and other deepwater sharks.

Given the perceived decrease in stock abundance in the northern areas, ICES recommends a reduction in exploitation to the level before the expansion of the fishery started (1990-1996) in Subareas V, VI, VII, and XII, corresponding to landings of no more than 3500 t.

…The fishery should not be allowed to expand unless it can be shown that it is sustainable.

ICES 2006 advice on Black scabbardfish (pdf 54k)

Ireland's catch of black scabbardfish rose from 1 tonne in 1999 to 1,050 tonnes in 2002 before falling to 79 tonnes in 2005 (under an Irish quota of 87 tonnes).

Blue ling (Molva dypterygia)
This deepwater ling is found at depths of 350-500m in the North-East Atlantic from Northern Norway and Iceland down as far as the south-west coast of Ireland. An important species for Irish vessels, being taken as by-catch on the continental slopes in sub-area VI and in deepwater longlining operations in sub-areas VI and VII. Blue ling are taken in directed fisheries on spawning aggregations by French vessels in subarea VI, but also in mixed species slope fisheries by French, Scottish and Irish trawlers, but also by Norwegian, Irish and Spanish longliners.

Blue ling is more vulnerable to over-exploitation than ling due to a slower growth rate and higher age at first maturity. It is particularily susceptible to rapid local depletion due to its highly aggregating behaviour during spawning.

…Trends in abundance from all areas indicate declines of varying gravity. In Iceland the decline appears to have halted, west of the British Isles it is stable but at a very depleted level, while it appears seriously depleted in Subdivisions I and II. In all areas the species is at a low level of abundance relative to when the fisheries commenced.

Blue ling in Subdivisions Vb, VI, and VII

…There should be no directed fisheries and measures should be implemented to reduce/minimise catches in mixed fisheries to the lowest possible level. Closed areas to protect spawning aggregations should be maintained and expanded where appropriate.

…Experience in Divisions Va and Vb indicates that once stocks are fished down they do not recover even when fishing pressure has been low. The introduction of closed areas to protect spawning aggregations should be accelerated.

…New exploratory assessments have not altered the perception of a declining stock. The advice remains for closed areas and reduction in exploitation.

ICES 2006 advice on Blue ling (pdf 60k). Emphasis in bold is ours.

The 2002 catch by Irish vessels in sub-areas VI and VII was 335 tonnes. Under EU quota restrictions this fell yo 18 tonnes in 2004 and 12 tonnes in 2005 (ICES 2006).

Bluemouth (Helicolenus dactylopterus)
Common on the lower continental shelf of Western Europe and extends as far as South Africa. It lives on mud and sandy mud at depths of 200-800m.

Cardinalfish/Bullseye (Epigonus telescopus)
A deep-sea pelagic fish found in mid-water, not on the seabed. It lives at depths of 180-900m. Commonly caught in deepwater trawls off Ireland's west coast.

Deepwater cod/Mora (Mora moro)
This fish belongs to the family of the Morids, which are closely related to the cod family. It is a semi-pelagic fish found at depths of 600-1,000m and is mainly caught as bycatch on longlines and occasionally in trawls, mainly in sub-area VII.

Deepwater redfish (Sebastes mentella)
Found at depths up to 1,000m and is caught in large numbers by deep-water trawlers in the colder regions of the North Atlantic. Targeted by Irish trawlers mainly in the Faroe-Shetland Channel. There are indications that there may be three separate components of S. mentella viz. deep-sea, oceanic and pelagic races. (See Redfish Fishery)

Greater silver smelt/Argentine (Argentina silus)
Argentine lives on the edge of the continental shelf and is primarily fished in the depth range 100-700m. Commonly caught in deepwater trawls. Targeted mainly by Irish pelagic vessels.

Argentine is vulnerable to over-exploitation due to its low productivity. It is particularly susceptible to rapid local depletion due to its highly aggregating behaviour.

…Greater silver smelt can be a very significant discard of the trawl fisheries of the continental slope of Subareas VI and VII, particularly at depths of 300-700m. The existing knowledge base is insufficient to determine if the current exploitation is sustainable.

ICES 2006 advice on Greater silver smelt/Argentine (pdf 39k).

Irish vessel landings declined from 7,593 tonnes in 2002 to 19 tonnes in 2005 from a quota of 383 tonnes (ICES 2006).

Greater forkbeard (Phycis blennoides)
An offshore hake-like fish, which may be caught in coastal waters. Generally found on sandy or muddy bottoms at depths of 100-350m. Caught mainly on longline as bycatch off south-west Ireland in sub-area VII, and by demersal trawlers working in shelf waters such as the Porcupine prawn grounds. ICES (2006) states: "There is no information available that allows for evaluation of the stock trends. The state of the stock is unknown…The fishery should not be allowed to expand unless it can be shown that it is sustainable."

Greenland halibut (Reinhardtius hippoglossoides)
A demersal flatfish that can be found in depths of 100-1,200m with the largest concentrations occurring between 250-800m. It has widespread distribution in the North-East Atlantic. Targeted by Irish trawlers in sub-areas IV and VI, particularly the Faroe-Shetland Channel grounds.

Hake (Merluccius merluccius)
A bycatch species more commonly associated with fisheries above the continental shelves.

Ling (Molva molva)
Not generally regarded as a "true" deep-water fish species although it is found in waters on the upper continental slope between depths of about 200-600m. Ling are mainly found in waters less than 200m deep on the outer continental shelf. An important species for Irish vessels, being taken mainly as bycatch. Several Irish longliners target ling and tusk jointly along the shelf edge west of Mayo. In 2005 Irish vessels landed 888 tonnes from a quota of 1,102 tonnes (ICES 2006).

Megrim (Lepidorhombus spp.)
Found in shallow shelf waters and waters on the upper continental slope between the depths of 200m-600m.

Orange roughy (Hoplostethus atlanticus)
Little is known about their distribution in the North Atlantic and, until a French vessel caught 20 tonnes in one tow in 1990, they were thought not to exist in commercial quantities in the North Atlantic, though they are widely exploited in New Zealand and Australian waters. They occur at depths generally greater than 1,000m. Targeted by Irish trawlers on seamounts and along slopes of sub-areas VI and VII — generally as by-catch in mixed species trawl fisheries. In subarea VII there is a directed fishery by Irish and French trawlers. (See Orange Roughy Fishery)

Rabbitfish (Harriotta spp.)
Of increasing commercial importance, with markets mainly existing in France. Irish vessels have landed rabbitfish in 2000 and 2001.

Red seabream (Pagellus bogaraveo)
Based on historical catches, the stock in VI, VII, and VIII appears to be depleted.

Red seabream are hermaphroditic and are particularly susceptible to overexploitation, thus measures to ensure balanced exploitation between younger fish (males) and older fish (females) are critical. Fisheries on red seabream should always be accompanied by programmes to collect data on both target and bycatch fish. The fishery should not be allowed to expand unless it can be shown that it is sustainable.

…A TAC of 350 t was introduced for red sea bream in 2002 for areas VI, VII, and VIII. In 2005 the TAC was reduced to 298 t. Landings have been below 300 t since 1991, averaging about 140 t over the last decade. From 1960 until the 1980s, landings were of the order of 10,000 t per year.

…In Subareas VI, VII, and VIII red seabream appears mostly as bycatch in longline and trawl fisheries.

ICES 2006 advice on red seabream (pdf 54k). Emphasis in bold is ours.

Irish vessels have not reportedly landed red seabream since 2001 (11 tonnes), although the 2004 quota was 10 tonnes and 2005 quota 9 tonnes.

Redfish/Golden redfish (Sebastes marinus)
S. marinus might be segregated into a "giant" form and the normal-sized form. Targeted by Irish trawlers in the Faroe-Shetland Channel since 1994. (See Redfish Fishery)

Roughhead grenadier (Macrorus berglax)
Lives in colder Atlantic waters and are most abundant at depths of 400-1,500m. Landed in small quantities by Irish trawlers targeting Greenland halibut and redfish in sub-areas IV and VI.

Roundnose grenadier (Coryphaenoides rupestris)
Roundnose grenadier has a longevity of 80-100 years and a slow growth rate. Mainly distributed from about 750-2,000m depth over slope areas and deep banks of both sides of the North Atlantic basin, as well as on the Reykjanes and Mid-Atlantic Ridges and on isolated oceanic features.

The main fisheries are located to the west of the British Isles (ICES areas Vb, VI, and VII) and further offshore along the western slope of the Hatton Bank and on the Reykjanes and northern Mid-Atlantic Ridge (sub-area XII). In the mixed bottom trawl fishery to the west of the British Isles, roundnose grenadier and black scabbardfish are caught together (ICES 2005d).

Targeted by Irish trawlers in sub-areas VI and VII. Catches are rapidly increasing in international waters of the Hatton Bank area and the Mid-Atlantic Ridge.

For the fishery in Divisions Vb, VI, VII, and XIIb, the fishing pressure should be reduced considerably to low levels and should only be allowed to expand again very slowly if and when reliable indicators show that increased harvests are sustainable. ICES recommends a 50% reduction of effort compared to the level before the expansion of the fishery started (1990-1996). This is interpreted as a reduction in catches of 50% over that period. This means that the catch level in 2007 should be at most 6,000 t.

…Roundnose grenadier is taken as one of the target species in a mixed-species fishery, along with other deepwater species (black scabbard and deepwater sharks in Division Vb, Subareas VI and VII) or as a bycatch in fisheries for other species (Pandalus borealis in the deeper parts of Division III). Any measures taken to manage the stocks of grenadier should take account of the advice given for all the species taken in the same deepwater mixed fishery.

ICES 2006 advice on Roundnose grenadier (pdf 93k). Emphasis in bold is ours.

In 2002 Irish vessels took 617 tonnes of roundnose grenadier in sub-areas VI and VII. With a 346 tonne quota in 2004, Ireland landed 328 tonnes; in 2005, 72 tonnes of roundnose grenadier was landed from a reduced quota of 294 tonnes (ICES 2006).

Tusk (Brosme brosme)
This fish is caught along the continental shelf and upper slopes off Norway, Rockall, the Faroes and Greenland. Not generally regarded as a "true" deepwater fish species although it is found in waters on the upper continental slope between depths of about 200-600m. Tusk are mainly found in waters less than 200m deep on the outer continental shelf. An important species for Irish vessels, being taken mainly as bycatch. Several Irish longliners target tusk and ling jointly along the shelf edge west of Mayo.

ICES (2006) states: "Tusk is more vulnerable to overexploitation than ling due to a slower growth rate and higher age at first maturity." In 2004 ICES advised a 30% decrease in effort compared to 1998 across divisions IIIa, IVa, Vb, VI, VII, VIII, IX, XII, and XIV. ICES 2006 advice is for a further 30% reduction in landings. (See ICES 2006 advice for tusk in all areas pdf 121k).

Irish vessels landed 47 tonnes of tusk in 2003, 25 tonnes in 2004, and 19 tonnes in 2005 (ICES 2006).

Wreckfish (Polyprion americanus)
Limited landings data exist. However, this species is of increasing interest to the Irish industry.

Note concerning:

Roughhead grenadier (Macrourus berglax)
Smoothhead (Alepocephalus spp.)
Rabbit fish (Chimaera monstrosa and Hydrolagus spp.)
Common mora (Mora moro) and Moridae
Wreckfish (Polyprion americanus)
Bluemouth (Helicolenus dactylopterus)
Silver scabbard fish (Lepidopus caudatus)
Deepwater cardinal fish (Epigonus telescopus)

Vulnerability to exploitation of these species is largely unknown. In some cases, landings data do not reflect true catches due to high levels of discarding.

…There are no assessments of these stocks. The knowledge of the biology of the species is insufficient and it is unclear how vulnerable they are to exploitation.

…Many of these species are caught as bycatch in fisheries targeting other species or as minor components of mixed fisheries. Landings of many of the traditional target species of these fisheries have been reduced in recent years as a result of restrictive quotas. It is possible that this could result in increased targeting of some of these species. Knowledge of the biology of these species is not sufficient to determine their vulnerability to exploitation.

The reported landings on roughhead grenadier and smoothhead have increased substantially in 2005. This could be an indication of a targeted fishery on these species.

Rapid increases in the reported catch of non-aggregating species and/or species of low commercial value (e.g. roughhead grenadier, smoothhead, rabbitfish, and in the past deepwater cardinal fish) could also be an indication of species misreporting. Even if the species are not misreported such rapid expansions of deepwater fisheries is not precautionary and should not be permitted.

…None of these species are currently managed by quotas. It is likely that restrictive quotas on the main deepwater stocks will lead to increasing levels targeting on these species.

ICES 2006 advice on Miscellaneous deepwater fish species (pdf 33k). Emphasis in bold is ours.

Elasmobranchs (cartilaginous fish) or deepwater sharks

There are several species of deep-sea shark taken in large quantities by trawl net, longline and gillnet. Two species — the Portuguese dogfish/Siki shark (Centroscymnus coelolepis) and the Leafscale gulper shark/Cochon (Centrophorus squamosus) — are commercially important, but others such as the longnose velvet dogfish (Centroscymnus crepidater), greater lanternshark (Etmopterus princeps) and the black dogfish (Centroscyllium fabricii) are becoming commercially important. Portuguese dogfish are known to live to 70-years old.

Deepwater sharks are found exclusively in waters deeper than 400m. Leafscale gulper shark is most abundant from 700-900m and Portuguese dogfish in waters of 1,100-1,300 m. Both are important predators and scavengers in the deep-sea habitat. A greater diversity of sharks exists in the deepwater areas compared to the continental shelf. The leafscale gulper shark and Portuguese dogfish were among the most abundant of the deepwater sharks (ICES 2005c)

Deepwater sharks

The newest development in elasmobranch fishing in the ICES area is for deepwater sharks. These sharks are not highly valuable. They are caught in large numbers by fleets that diversified into deepwater fishing in the 1990s as an alternative to traditional fisheries. The main fleets catching deepwater sharks are French and UK trawlers, UK and German gill netters, and Portuguese artisanal longliners. Other countries that have become involved are Spain, Ireland, and Norway. The diversity and widespread nature of deepwater sharks means that fishers in deepwater areas cannot avoid catching them.

What effect have these fisheries had on shark populations?

The effects of fishing on deepwater sharks are a particular concern because of their slow reproductive rates. The rapid development of fisheries for deepwater sharks has also made it difficult for scientists to collect data and perform stock assessments.

The main species taken in these fisheries are the leafscale gulper shark (Centrophorus squamosus) and the Portuguese dogfish (Centrophorus coelolepis). The first assessment, in 2000 by the ICES SGDEEP in 2000, was based on catch per unit effort in kg per hour fished from French deepwater trawlers. The results suggested that in 1998, the combined stocks of Portuguese dogfish and leafscale gulper shark were below 50% of their initial biomass.

Unfortunately, this assessment could not give information on the status of either of these shark species separately, so WGEF has recently tried to address this problem. All available CPUE data from France, UK, Ireland, and Norway were pulled together by WGEF and a stark trend was confirmed: there has been an extreme decline, particularly in Portuguese dogfish, a species that was once an abundant shark in deepwater catches.

The low reproductive output of the Portuguese dogfish, coupled with the fact that females including pregnant females dominate the catches, explains this decline.

Not having species-specific catch data disguised an extreme decline of a vulnerable species. Landings of these species have peaked at about 11,000 t in 2003. Although it is difficult to advise on a sustainable catch with so little information, the current fishing effort is clearly too high.

ICES 2005a

Deepwater sharks are caught in a mixed fishery for deep-sea species and as a targeted fishery using longlines and gillnets.

ICES (2005c) states: "Portuguese dogfish (Centroscymnus coelolepis) and leafscale gulper shark (Centrophorus squamosus) are depleted…The status of other deepwater sharks is unknown…Given their very poor state, ICES recommends a zero catch of deepwater sharks"

Irish vessels catch Portuguese dogfish primarily north-west of the Porcupine Bank mainly using trawls, but also by longlines. The value of Irish landings of deepwater sharks in 2000 was €135,000. Whilst efforts are being made to collect separate landings data for each of these species, at present data are largely being reported at an aggregated level for all deep-sea sharks combined.

Assessing stock status

Finding out more about deep-sea fish stocks

Firstly, the stock structure must be investigated. Which stock is found when and where? Do the different stock units mix; is there gene flow between them? What are their rates of reproduction and growth? Only when these basic biological questions have been answered can management units and plans be endorsed and implemented and, based on this, careful fishing could be sustained. The reality, however, is different.

ICES 2003

Typically, little if anything is known about the behaviour and ecology of deepwater fish species, such as orange roughy, and their populations. All the indications are that most, if not all, stocks can sustain only very low exploitation rates. Yet the deep-sea fisheries are expanding very rapidly and exploitation rates are largely unknown. International experience shows that deep-sea stocks can be depleted very quickly. ICES has said that many deep-sea stocks are in decline and can only sustain very limited fishing pressure. "In light of these concerns, ICES has suggested that there should be an immediate reduction of fishing pressure on fully exploited or overexploited deep-sea stocks" (ICES 2005b).

Deep-water fish species tend to be long-lived, slow to grow and reproduce [1] — in the absence of commercial exploitation, population structures include many old fish [2]; fish reach maturity relatively late in life; they produce small numbers of young that tend to have a high survival rate; they are top predators in their environment, which are stable; and have low rates of natural mortality. Hence they do not have the resilience to recover rapidly from high or even moderate fishing rates. Stock numbers do not increase in the depleted areas in the short or medium term, and fisheries often develop and expand before sufficient information is available on which to base management advice (Marine Institute 2001).

The OSPAR Commission (2000) reports that ageing techniques have been validated for only three of the 340 deep-living species of bony fishes (teleosts) recorded in the North Atlantic, and for only one of the 40 deep-sea species of sharks, rays and skates (elasmobranchs).

Furthermore, many deep-water species have fragile skins and suffer considerable damage in a trawl [3], so that technical conservation measures such as increased trawl net mesh sizes or sorting grids are unlikely to be effective for the protection of these species.

ICES has developed an index in which deep-sea species are ranked in order of their vulnerability to exploitation. The species ranking is given below, the lowest number denoting greatest vulnerability (Marine Institute 2001).

Leafscale gulper shark/Cochon 1.5
Portuguese dogfish/Siki shark 1.5
Orange roughy 1.6
Roundnose grenadier 2.4
Redfish 2.6
Greenland halibut 3.2
Greater silver smelt/Argentine 3.3
Tusk 3.8
Black scabbardfish 4.0
Blue ling 4.0
Ling 4.0
Red seabream 4.3
Alfonsinos (2 species) 4.7 & 5.0
Forkbeard ?

"Although we still have a lot to learn about these species we know that they are particularly vulnerable to overfishing because of their slow ability to reproduce. ICES has warned that several deep-sea stocks are now heavily exploited and in some cases severely depleted. This raises the question as to whether deep-sea fisheries, at their present levels, are sustainable" (ICES 2005b).

The ICES Working Group on the Biology and Assessment of Deep-Sea Fisheries Resources (WGDEEP) has the task of providing assessments of the state of deep-sea stocks in the North-East Atlantic and Baltic Sea. Assessments are generally based on estimates of the size of deep-sea stocks and the level of fishing effort that they can support. However, as the Marine Institute points out, assessments have been hampered by the lack of adequate data (Marine Institute 2001).

Bergstad, Gordon & Large (ICES 2005b) state that analysis of several of the most important deep-sea fisheries using catch per unit effort (CPUE) statistics highlights "a clear declining trend". CPUE is the fish catch taken for a given amount of fishing effort, such as tonnes per fishing day or tonnes per 1,000 longline hooks. According to ICES:

  • Since the 1970s, the CPUE for ling and tusk has fallen by 70% in ICES Subareas north and west of the British Isles.

  • There is evidence of a drop in blue ling stocks. French CPUE data show a decline to a low level during the period 1985-1998.

  • The most valuable but also most vulnerable deep-sea fish considered by WGDEEP is the orange roughy. In deep-water areas north-west of the UK (ICES Area VI), the CPUE for this species declined quite quickly after the fishery commenced in 1991, and by 1994 it was 25% of initial catch rates. In recent years CPUE has increased slightly and has stabilised. The apparent stabilisation may simply reflect the discovery and subsequent fishing of previously unexploited aggregations of fish.

  • Roundnose grenadier is fished in many ICES Subareas. Assessments have only been made for areas near the Faroes and west of the British Isles (ICES subareas Vb, VI, and VII) combined, and these suggest a strong decline in the stock size to a level below the precautionary level set by the ICES Advisory Committee on Fishery Management (ACFM).

A particular feature of deep-sea fisheries is the mixed catch. In deep-water habitats there are invariably a number of species present in a location. Thus there is considerable overlap between one target species and another, and between target and non-target species (bycatch).

Most deep-water trawl fisheries are opportunistic, targeting a species for a certain period then continuing to take it as bycatch. The OSPAR Commission (2000) states that species richness of deep-sea fish assemblages increases with depth to depths of 1,000m: "So as one species is fished out, the temptation is to target another species, thus maintaining the fishing pressure on the original target species.

For example, to the west of Ireland and France the fishery for hake (Merluccius merluccius) and/or red sea bream (Pagellus bogaraveo) has shifted to the exploitation of some of the deep-living sharks (Deania calceus, Somniosus rostratus, Centrophorus granulosus, Centroscymnus coelolepis). Only the livers of these sharks have significant economic value, so the liver is removed (20-30% of weight) and the rest discarded. Because the oil (70-80% of the liver's weight) is extracted, converting the landings to meaningful fishery statistics is a major problem."

The OSPAR Commission (2000) adds that many of the data on landings of deep-sea species "are of questionable value, one of the reasons being the uncertainties of many of the species' identifications." Moreover, with few monitoring programmes and only sporadic participation in the fisheries by many fleets, "reported catches are highly suspect for many target and minor species. Nor do the data on landings reflect the overall impacts on the non-target stocks or the extent of damage inflicted on some deep-sea habitats. Fishing effort in the deeper waters tends to be unpredictable, since it waxes and wanes according to the fluctuations experienced by fishermen as their access to other stocks is limited by regulation or overfishing."

In October 2001, the ICES ACFM reported [4] that many of the deep-sea fish stocks are too heavily exploited and are considered to be in a state that is actually or potentially outside safe biological limits [5]. Depending on the stock in question, ACFM recommended action "implying the restriction of fishing opportunities" and for stocks for which little biological information is available, ACFM recommended that "the expansion of the fisheries should be restricted until comprehensive data-collection systems have been put in place".



1. For example, the orange roughy can live to well over 100 years and in the Atlantic takes 25-35 years to reach maturity.

2. 40% of a greater silver smelt/argentine stock fished experimentally off Ireland was over 20 years old (McCormick 1994).

3. Also, many deep-water fish when hauled to the surface show acute signs of depressurising, causing - according to Hamilton-Paterson (2002): "Their eyes bulge and their swim bladders protrude grotesquely from their mouths".

4. The October 2001 ACFM report was endorsed by the Scientific, Technical and Economic Committee for Fisheries (STECF) of the European Commission.

5. In fact, ICES has been advising the adoption of a precautionary approach for deep-sea fisheries since 1995.


ICES 2006 advice on deep-sea fish stocks.

ICES. 2006. Alfonsinos/Golden eye perch (Beryx spp.). Report of the Working Group on the Biology and Assessment of Deep-Sea Fisheries Resources, 2 11 May 2006, Vigo Spain (ICES CM 2006/ACFM:28). (pdf 34k)

ICES. 2005a. Sharks in trouble? Article on ICES website.

ICES. 2005b. Is time running out for deep-sea fish? Article on ICES website.

ICES. 2005c. Deepwater sharks in the northeast Atlantic (ICES Sub-areas V-XIV, mainly Portuguese dogfish and leafscale gulper shark). ICES ACFM Report October 2005. (pdf)

ICES. 2005d. Report of the ICES Advisory Committee on Fishery Management, Advisory Committee on the Marine Environment and Advisory Committee on Ecosystems, 2005. ICES Advice. Volumes 1-11. 1,403 pp. (pdf)

ICES. 2003. Environmental status of the European seas: quality status. German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety. 75 pp. (pdf 4.7Mb)

Marine Institute. 2001. Deepwater Fisheries Overview. Marine Fisheries Services Division Stock Book 2001. (pdf)

OSPAR. 2000. OSPAR Commission Quality Status Report 2000.


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