338 ICES WGEF REPORT 2009 21 Other issues 21.1 Evaluation of recent species-specific landings data for skates This Section provides an overview on ToR (b), to “critically review species‐specific landings data for demersal elasmobranchs from national landings statistics, market sampling programmes and discard/observer programmes, in order to compile spe‐ cies‐specific data by stock area”. Background Within the EU, skates landings have traditionally been reported at the family level (mixed skates and rays) or at even a more generic level. However some nations have reported varying proportions of skates to species level, especially for the main spe‐ cies. Some nations also report landings of other batoids, such as stingrays and electric rays. This situation has caused a lot of concerns to WGEF and in 2007 WGEF stated that the data collected for skates (Rajidae), and possibly other elasmobranchs, from market sampling and discard surveys were compromised by inaccurate species identifica‐ tion. As a consequence WGEF recommended that the ICES Planning Group on Commercial Catch, Discards, and Biological Sampling (PGCCDBS) provided the nec‐ essary supporting information to ensure that data collection (including species identi‐ fication) and raising procedures (by gear, season, ICES Division and nation) for skate and ray sampling were standardized across laboratories. In 2008 PGCCDBS analysed five examples (France, Portugal, Spain – AZTI, Spain – IEO and UK – Scotland) where estimates of landings were calculated at species level from the quantity landed of “mixed skate”. PGCCDBS considered that methods of estimating the landings of individual species from identified groups of “mixed spe‐ cies” were well established and could be used on a routine basis. It also concluded that each country was in a position to estimate landings of individual species from grouped “mixed species” landings. From 2008 onwards EC regulations stated that landings of Leucoraja naevus, Raja clavata, Raja brachyura, Raja montagui, Amblyraja radiata and Dipturus batis in ICES Di‐ vision IIa and Subarea IV should be reported separately (Council Regulation (EC) No 40/2008 (16/01/2008). At this meeting 2008 species‐specific landing data for skates reported in the North Sea were analysed (see also Section 15). Here we provide a brief overview of the data presented by Member States with reference to the major concerns on species identifi‐ cations which might reflect deficiencies that need to be corrected in future, particu‐ larly as these issues may well apply to other ecoregions, for which species‐specific data will be collected from 2009. UK (England and Wales) In 2008 altogether 2486 t of ‘batoids’ were reported from UK‐registered fishing ves‐ sels, of which 1055 t (42.5%) were recorded to species level and 1431 t recorded at a generic level, although there was considerable regional variation in the proportion of batoids that were reported to species level (Table 21.1). In Subarea IV (North Sea) the proportion of identified species was just under 50%. The species composition of batoids being taken by UK‐registered vessels by ICES region is demonstrated in Table 21.2. In Subarea IV, misidentification problems do not appear to be a major issue, although the proportions of R. brachyura and R. monta‐ ICES WGEF REPORT 2009 339 gui need to be viewed with some caution. UK (Scotland) A smaller proportion of Scottish landings were reported to species level, with small quantities of Raja brachyura and Dipturus batis reported (see Table 15.6). The Netherlands Up to 2008, the Netherlands reported skate landings at family level. From 2000 to 2007 the species composition of these landings was estimated from a market sam‐ pling programme conducted by researchers from IMARES. The results demonstrated that the species composition (based on market sampling) did not differ greatly be‐ tween years (Table 21.3). In 2008, species‐specific landings data were made available by the Dutch government. The fishers and market workers were presumably respon‐ sible for species identification. In 2008 only a small proportion (~12%) of rays and skates were not discriminated to species level. The estimated landings of Raja brachyura (ca. 3%) appear to have de‐ creased dramatically compared with previous years (2000–2007), when R. brachyura accounted for 14–31% of skates (Table 21.3). This difference may reflect misidentifica‐ tion between R. brachyura and R. montagui. In addition, it is possible that mixed land‐ ings of these sister taxa may be included within landings for R. montagui and also in the unspecified skate landings. France French landings have been reported at species level annually. The proportion of French landings assigned to Subarea IV has decreased between 1983 and 1997 and it has been more or less stable in the more recent years. The species composition of landings in Subarea IV is presented in Table 21.4. Within the French landings data for which species were identified, the relative pro‐ portions of species varied between years (Figure 21.1). For example, the proportion of Leucoraja naevus has declined, whereas the proportion of Raja clavata has increased. This may reflect either differences in relative abundance of the species or spatial‐ temporal changes in the fishing grounds. Germany No landings discriminated by species in 2008 were provided. Denmark Danish landings in 2008 were not reported by species. Belgium In 2008 Belgium provided landing data mostly discriminated to species (Table 21.5), nearly 67% were discriminated by species. Compared with the previous years there were no major changes in the amount of skates landed. Nearly 68% of Belgian skate landings were from Subarea IV. In this subarea the landings with comprised primar‐ ily of R. clavata (59%), followed by R. brachyura (28%) and R. montagui (12%). Identification issues Table 21.6 summarizes the potential inconsistencies found. What is apparent is that there is confusion between Raja brachyura and R. montagui. 340 ICES WGEF REPORT 2009 Raja brachyura is a large‐bodied species with a patchy distribution, and is locally abundant in parts of the southern North Sea (IVc). The smaller R.montagui is normally more abundant in the slightly deeper waters of IVb, c. UK (England and Wales) re‐ ported a greater proportion of R. brachyura (6.4%) than R. montagui in IVc, and vice versa in IVb. Belgian data indicated a much greater proportion of R. brachyura (27.8%) than R.montagui. Dutch data indicated a much greater proportion of R.montagui than R. brachyura (3.2%). In the Bay of Biscay, both France, and Basque Country (Spain) have reported data for spotted ray (between 0.5% and 9.5% of total catches in the last 10 years), but no species‐specific data for R. brachyura. In the Division IXa Portugal reports landings of both species, however the specific composition in the landings of Basque Country (Spain) and Portugal is based in the extrapolation of proportions of species obtained as result of special port sampling carried out some years ago. To resolve this problem, either improved training in species identification of these species, or these two species are allowed to be landed as a combined unit and it is ensured that there is sufficient market sampling (by gear, season and location) to split the landings, is required. Recommendations Taking into account the inconsistencies and deficiencies mentioned above and the fact that EC require that landings of skates and rays be better discriminated by spe‐ cies in other ICES subareas from 2009 (Table 21.7) WGEF recommends that: • Due to changes that might occur in the specific composition of landings the sampling methodology be continuously appraised and updated; • More detailed landings data discriminated by species (by gear, ICES rec‐ tangle and season) be available for analysis at WGEF; • National laboratories ensure that appropriate identification material and training be available at port offices and for the fishing industry. WGEF reiterates that improved species‐specific data are required so that better as‐ sessments of the state of skate resources can be made and so that ICES can provide appropriate management advice. In particular it is strongly recommended that dedicated studies for the development and implementation of sampling schemes towards the improved evaluation of fish‐ ing fleets and métiers catching rays and skates be undertaken on an appropriate tem‐ poral and spatial scale. 21.2 Photo-identification guide to elasmobranchs in the ICES area This Section provides an overview on ToR (f), to “finalize the manuscript of a photo‐ ID key for elasmobranchs in the ICES area”. Several countries have provided guides for the identification of elasmobranchs, pre‐ sented in slightly different formats. These guides are used mainly to improve the identification for fish samplers and fishers on vessels and in sampling ports and mar‐ kets. Some examples of the design of guides can be seen in Figures 21.2–6. WGEF urge that national laboratories finalize national guides in the coming year and make electronic copies of photographs (with appropriate © details) available to other laboratories. ICES WGEF REPORT 2009 341 21.3 Biological sampling of deep-water elasmobranchs during NEACS surveys WGEF were given the following ToR: “to review the biological parameters that should be collected on the NEACS survey by stock in addition to those specified by PGNEACS”. Many deep‐water sharks are data poor stocks and as such the collection of data from NEACS surveys would be of great use in the assessment and management of these species/stocks. There are several issues that need to be addressed, and WGEF have the following comments for PGNEACS: 21.3.1 Species identification Several of the deep‐water sharks and skates taken in the surveys can be easily mis‐ identified, and the taxonomic knowledge of some families is poor. For example the genera Centrophorus and Apristurus are known to be problematic taxa.