Elasmobranchs - Celtic Sea and West of Scotland|
Fact Sheet Title Fact Sheet |
| | Elasmobranchs - Celtic Sea and West of Scotland |
Demersal elasmobranchs in the Celtic Sea and West of Scotland (ICES Areas VI, VIIa-c, e-k) |
| Data Ownership | This document provided, maintained and owned by International Council for the Exploration of the Sea (ICES) , is part of ICES Advice data collection. |
| ident Block | ident Block | | Species List: | Species Ref: en - Rays, stingrays, mantas nei, fr - Raies, pastenagues, mantes nca, es - Rayas, pastinacas, mantas nep, ru - Скатообразные (скаты, хвостоколы, манты) |
Species Ref: en - Dogfish sharks, etc. nei, fr - Squaliformes nca, es - Squaliformes nep |
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| ident Block Elasmobranchs - Celtic Sea and West of Scotland Map tips - Click on to turn layers on and off
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fao Div |
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27.7.a | Irish Sea (Division 27.7.a) |
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27.7.b | West of Ireland (Division 27.7.b) |
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27.7.c | Porcupine Bank (Division 27.7.c) |
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27.7.e | Western English Channel (Division 27.7.e) |
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27.7.f | Bristol Channel (Division 27.7.f) |
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27.7.g | Celtic Sea North (Division 27.7.g) |
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27.7.h | Celtic Sea South (Division 27.7.h) |
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27.7.j | Southwest of Ireland - East (Division 27.7.j) |
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27.7.k | Southwest of Ireland - West (Division 27.7.k) |
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fao Sub Area |
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27.6 | Rockall, Northwest Coast of Scotland and North Ireland (Subarea 27.6) |
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| Aq Res | Biological Stock: No Value: Sub-Regional Management unit: Yes Reference year: 2008
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Considered a management unit: An aquatic resource or fishery is declared as [Fishery] Management Unit if it is effectively the focus for the application of selected management methods and measures, within the broader framework of a management system. According to the FAO Glossary for Responsible Fishing, "a Fishery Management Unit (FMU) is a fishery or a portion of a fishery identified in a Fishery Management Plan (FMP) relevant to the FMP's management objectives." FMU's may be organised around fisheries biological, geographic, economic, technical, social or ecological dimensions , and the makeup and attribute of a fishery management unit depends mainly on the FMP's management objectives. |
Jurisdictional distribution: Jurisdictional qualifier (e.g. "shared", "shared - highly migratory") of the aquatic resource related with its spatial distribution. |
Environmental group: Classification of the aquatic resource according to the environmental group (e.g. pelagic invertebrate, or demersal fish) to which the species belong. |
Reference Year: The Reference Year is the last year considered in the stock assessment and/or fishery status. |
| | | | Aq Res State Trend In the absence of defined reference points, the status of the stocks of demersal skates and rays and demersal sharks cannot be evaluated. The following provides a qualitative summary of the general status of the major species based on survey and landings data. Landings of skates and rays in the Celtic Seas have generally declined (Figure 5.4.39.1). There have been regional changes in species composition and indices of relative abundance. Species | Scientific name | Area1 | State of stock | Common skate | Dipturus batis | VI | Depleted | | | VII | | Thornback ray | Raja clavata | VIa | Stable/increasing | | | VIIa,f,g | | Spotted ray | Raja montagui | VIa | Stable/increasing | | | VIIa,f,g | | Cuckoo ray | Leucoraja naevus | VIa | Stable/increasing | | | VII | Uncertain | Blonde ray | Raja brachyura | VIa, VIIa and VIIf | Uncertain | Undulate ray | Raja undulata | VIIj (Tralee Bay) and VIIde | Uncertain (but with cause for concern) | Smalleyed ray | Raja microocellata | VIIf | Stable/increasing | Sandy ray | Leucoraja circularis | VI | Uncertain | | | VIIb,c,h–k | Stable/increasing | Shagreen ray | Leucoraja fullonica | VII | Uncertain | White skate | Rostroraja alba | VII | Severely depleted | Lesser spotted dogfish | Scyliorhinus canicula | VIa and VII | Stable/increasing | Greater spotted dogfish | Scyliorhinus stellaris | VII | Locally stable and increasing in VIIa | Smooth hounds | Mustelus mustelus and Mustelus asterias | VII | Stable/Increasing | Angel shark | Squatina squatina | VII | Severely depleted | 1 There is insufficient information to assess the status of stocks in the Rockall area (Division VIb). | Skates and raysCommon skate Depleted. It was formerly widely distributed in the Irish Sea (VIIa), but is now rarely found in this division. Now mostly found off Northwest Scotland (VIa), west of Ireland (VIIb,c), and in the deeper waters of the Celtic Sea (VIIg–j), with occasional individuals in shallower areas (VIIe–f). Thornback ray Stable/increasing. Catches in the main areas of abundance (VIa, VIIa,f,g) have been stable/increasing in recent years (Figures 5.4.39.2 and 5.4.39.3). Spotted ray Stable/increasing. Catches in the main areas of abundance (VIa, VIIa,f,g) have been stable/increasing in recent years (Figures 5.4.39.4 and 5.4.39.5). Cuckoo ray Uncertain and more robust studies on stock identity are required. Data from surveys give contrasting signals (Figures 5.4.39.6, 5.4.39.7, and 5.4.39.8), showing stable/increasing catches in VIa, but stable or declining catches within Subarea VII. French lpue in the Celtic Sea is also declining (Figure 5.4.39.9). Blonde ray Uncertain. This species has a patchy distribution in the Celtic Seas ecoregion, so interpretation of survey trends is problematic. Undulate ray Uncertain. Given that this large-bodied species has a patchy distribution in the inshore waters of the Celtic Seas ecoregion, it is susceptible to localized over-exploitation. Smalleyed ray Stable/increasing. Catches in the main area of the stock distribution (VIIf) have been stable/increasing over the survey time-series (Figure 5.4.39.10). Sandy ray Uncertain. This offshore species is not well sampled in most groundfish surveys. Catches on the Porcupine Bank have been stable/increasing in recent years (Figure 5.4.39.11). Shagreen ray Uncertain. This offshore species is not well sampled in most groundfish surveys. White skate Severely depleted and possibly extirpated from most parts of this ecoregion. No authenticated records in recent groundfish surveys. Demersal sharksLesser spotted dogfish – Stable/increasing in all areas (Figures 5.4.39.12, 5.4.39.13, and 5.4.39.14). Greater spotted dogfish – Stable/increasing in localized areas (e.g. off Northwest Wales) (Figure 5.4.39.15), but not well sampled by existing surveys, as it prefers rocky, inshore grounds, which are not sampled effectively in most surveys. Smoothhounds Abundance seems to have been increasing in recent years both in survey catches (Figure 5.4.39.16) and in commercial/recreational fisheries, but the stock status is very uncertain. Identification by species is considered unreliable in the surveys. Angel shark Severely depleted and possibly extirpated from parts of its former range where it was once common, including Start Bay (VIIe) and Cardigan Bay (VIIa). Habitat Bio Depth Zone: Shelf (50 m - 200 m). Vertical Dist: Demersal/Benthic. Geo Dist Geo Dist: Shared between nations Water Area Overview Spatial Scale: Sub-Regional Water Area Overview | Water Area Overview Elasmobranchs - Celtic Sea and West of Scotland
fao Div | 27.7.a: Irish Sea (Division 27.7.a) | 27.7.b: West of Ireland (Division 27.7.b) | 27.7.c: Porcupine Bank (Division 27.7.c) | 27.7.e: Western English Channel (Division 27.7.e) | 27.7.f: Bristol Channel (Division 27.7.f) | 27.7.g: Celtic Sea North (Division 27.7.g) | 27.7.h: Celtic Sea South (Division 27.7.h) | 27.7.j: Southwest of Ireland - East (Division 27.7.j) | 27.7.k: Southwest of Ireland - West (Division 27.7.k) | fao Sub Area | 27.6: Rockall, Northwest Coast of Scotland and North Ireland (Subarea 27.6) |
| | | | Water Area Overview |
Water Area OverviewElasmobranchs - Celtic Sea and West of Scotland fao Major | 27: Atlantic, Northeast | Large Marine Ecosystem Areas (LME) | 22: North Sea | 24: Celtic-Biscay Shelf | 60: Faroe Plateau |
Aq Res Struct Biological Stock: No Bio Assess Assess Models Methodology Scientific basisData and methodsSurvey data are the basis for the assessments of skates, rays, and demersal sharks in the Celtic Seas (see ICES, 2007, 2008). Uncertainties in assessment and forecastSurvey data are the most reliable species-specific data available for demersal skates. However, many of the fishery-independent surveys in this ecoregion are not based on extensive time-series. These surveys are designed primarily for other types of fish and so the gears and sampling grids are not ideal for skate stocks, especially those species with patchy distributions. Comparison with previous assessment and adviceICES has never provided advice on these elasmobranchs in this area. Sci Advice Single-stock exploitation boundariesNo fisheries – Species where indicators show extirpationWhite skate – has a localized and patchy distribution, and is extirpated from most parts of the Celtic Seas ecoregion. It should receive the highest possible protection. Any incidental bycatch should not be landed, but returned, to the sea, as they are likely to have a high survival rate. Angel shark – has a localized and patchy distribution, and is extirpated from parts of its former range. It should receive the highest possible protection. Any incidental bycatch should not be landed, but returned, to the sea, as they are likely to have a high survival rate. No target fisheries – Species where indicators show depletion (or may be susceptible to local depletion)Common skate – has declined in many inshore areas of England and Wales, although is still present in the inshore areas of Scotland and Ireland. Target fisheries for this species should not be permitted and measures should be taken to minimize bycatch. Undulate ray – has a patchy distribution, with some of these areas showing signs of depletion. As a precautionary measure, target fisheries for this species should not be permitted unless exploitation rates are shown to be sustainable. Status quo catch – Species where indicators show recent stability or increaseThornback ray, spotted ray in VIa and VIIa,f,g. and cuckoo ray in VIa. Smalleyed ray in VIIf – has a restricted distribution and is locally abundant in the Bristol Channel, this stock should be monitored to ensure that it does not decline. Lesser spotted dogfish – the current exploitation rates appear to be sustainable. As there are no apparent detrimental impacts on the stock from current commercial fisheries, no management actions are required for this species at this time. Greater spotted dogfish –has a restricted distribution and is locally abundant in parts of the Celtic Seas ecoregion, and should be monitored appropriately. Smoothhounds –have a relatively higher productivity than similar elasmobranchs and can probably sustain fisheries. Management measures should prevent overexploitation. Fisheries should only expand when accompanying measures lead to improved data collection and biological studies to ensure its sustainable harvest. No advice – Species where indicators are unknownCuckoo ray in VII – Further studies to better understand stock structure are required, although this species is one of the more abundant skates in the Celtic Seas ecoregion. Blonde ray – is widely distributed in the Celtic Seas ecoregion, but it has a tendency to form local aggregations and so may be prone to localized depletions. Sandy ray – most abundant on the outer continental shelf and upper continental slope, it is not well sampled in most existing groundfish surveys. Shagreen ray – most abundant on the outer continental shelf and upper continental slope, it is not well sampled in most existing groundfish surveys. Skates and rays. Year | ICES Advice | Single-stock exploitation boundaries | Predicted catch corresponding to advice | Predicted catch corresponding to single-stock exploitation boundaries | Agreed TAC (1) | ACOM landings | Disc. slip. | ICES Catch | 1992 | No advice | | | | No TAC | 16.6 | | | 1993 | No advice | | | | No TAC | 14.5 | | | 1994 | No advice | | | | No TAC | 13.9 | | | 1995 | No advice | | | | No TAC | 15.3 | | | 1996 | No advice | | | | No TAC | 19.0 | | | 1997 | No advice | | | | No TAC | 20.5 | | | 1998 | No advice | | | | No TAC | 20.0 | | | 1999 | No advice | | | | No TAC | 19.9 | | | 2000 | No advice | | | | No TAC | 19.9 | | | 2001 | No advice | | | | No TAC | 17.8 | | | 2002 | No advice | | | | No TAC | 18.8 | | | 2003 | No advice | | | | No TAC | 17.6 | | | 2004 | No advice | | | | No TAC | 13.2 | | | 2005 | No advice | | | | No TAC | 13.0 | | | 2006 | No advice | | | | No TAC | 10.0 | | | 2007 | No advice | | | | No TAC | 7.9 (2) | | | 2008 | No advice | | | | No TAC | | | | 2009 | Various (3) | NA | | NA | | | | | Weights in ‘000 t. (1) EU only. (2) Incomplete data. Landings are expected to be ~9000 tonnes. (3) If landings of major species recorded by species. With zero catch of common skate, white skate and angel shark, and no targeted fishery for undulate ray. | Management Management unit: Yes Objectives Management objectives have not been adopted. An European sharks action plan was published by the European Commission in December 2007 and went out for consultation in 2008. Advice Management considerations demersal elasmobranchs are normally landed as a bycatch in the demersal fisheries for teleosts, with localized targeted fisheries. They are usually landed and/or reported in mixed categories such as “skates and rays” and “sharks”. Landings of skates and rays should be declared at species level for all species. For assessment purposes species-specific landings data are essential. In most countries skates and rays are landed together, most often sorted in particular size categories, rather than by species. They are usually gutted, and sometimes only wings are landed. Only some countries report (part of) the landings by species, i.e. France, Belgium, and Spain (Basque country). There is currently no TAC for skates and rays in the Celtic Seas. The introduction of TACs can only regulate the landings, and any TAC on a bycatch species may induce more discards. Mesh-size regulations are probably not restrictive as there are few directed fisheries for these species. Certain elasmobranch species such as lesser spotted dogfish are primarily a bycatch species and are normally discarded. Discard survivorship of skates and rays is not known. Survivorship of coastal, demersal catsharks ( Scyliorhinus spp.) is considered high. Elasmobranchs are typically slow growing, have a high age-at-maturity and a low reproductive capacity. Measures to afford protection to the larger species are required. Historically, angel shark and white skate have been common locally in some inshore areas of the ecoregion. Neither species has been recorded during recent groundfish surveys. Landings data for angel shark have declined to near-zero. The extirpation of these large-bodied, inshore elasmobranchs that have patchy distributions is a cause of concern, because there may be a low rate of population growth and low level of immigration from adjacent areas. Both species are likely to be equally threatened in more southerly European seas. This represents a potential loss in the fish diversity in the ICES area. Sources ICES. 2008. Report of the ICES Advisory Committee, 2008. ICES Advice, 2008. |
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