Browsing Irish Fisheries Bulletin by Author "Stokes, D."
Irish fisheries-science research partnership trawl survey of the Porcupine Bank Nephrops Grounds July 2010Stokes, D.; Lordan, C. (Marine Institute, 2011)The Nephrops fishery on the Porcupine Bank takes place on a large area, approximately 7000km2, of complex muddy habitat between depths of 300 to 470m. Irish effort has been increasing and Ireland is now responsible for the majority of the landings. The scientific advice has indicated that the stock has declined and fishing mortality should be reduced to the lowest possible level. This Irish Fisheries Science Research Partnership (IFSRP) survey was developed in 2010 to address the pressing need for data from the closed area established by the EC between 1st May to 31st July 2010. 46 hauls were carried out and the results indicate high CPUE for the survey relative to recent observations for the fleet. Strong patterns in size and sex ratio were observed spatially. The male biased sex ratio and size-at-maturity are similar to historical observation. The size distributions of the catches are very different to the Spanish survey in the area which took place two months later. The utility of the survey for monitoring the stock is discussed.
Status of non-assessed fish species in Irish watersPalma-Pedraza, S.; Sarrazin, V.; Clarke, M.; Stokes, D. (Marine Institute, 2020)This report gives the latest assessment results for abundance of several fish species not otherwise assessed by international bodies or national agencies within Ireland. The assess-ment was performed to support Ireland’s obligations under the EU’s Marine Strategy Frame-work Directive (MSFD) to assess the state of commercial and non-commercial fish stocks. The commercially important stocks included in this assessment are recorded as being caught in Irish MSFD waters, from ICES FISHSTAT database, and for which sufficient trawl survey data are available to assess them. The non-commercial fish species included in this assess-ment are those present in the Irish MSFD area, which are either listed as being of conserva-tion concern under the EU’s data collection programme for fisheries, those on the OSPAR list of threatened species, elasmobranch species prohibited from being caught in commercial fisheries under the EU CFP legislation and/or those listed as endangered with extinction on the EU fish red list. The evaluation of the status of commercial and non-commercial species in the subareas VI and VII of FAO fishing area 27 was carried out using data from research vessels surveys. Data since 1998 were used and results show that only 4 of 10 commercial stocks were above the Good Environmental Status (GES) threshold value. The results of this work were then used to populate an overall assessment of GES for MSFD Descriptors D1 and D3 by Ireland in 2019.
A survey by hydraulic dredge of interstitial bivalves with commercial potential in Cill Chiaráin and Beirtreach buí Bays and along their connecting shoreline, Co GalwayFahy, E.; Carroll, J.; Browne, R.; Ní Rathaille, A.; Casburn, P.; Breathnach, S.; Norman, M.; Stokes, D. (Marine Institute, 2002)The shellfish co-operative, Comharchuman Sliogéisc Chonamara Teó (CSC) manages oyster and scallop in Beirtreach buí and Cill Chiaráin Bays, both of which are designated aquaculture areas. Cill Chiaráin is also a candidate Special Area of Conservation (cSAC). Various traditional fishing activities are carried on in the bays and CSC has rights to exploit clam species there. The work described here is a survey of interstitial clam species by hydraulic dredge between November 2001 and January 2002. Investigations were restricted from some of the upper bay areas where surface bivalve management was in progress. Much of the remaining areas within the Bays proved unsuitable for hydraulic dredging by virtue of the nature of the substratum. The exposed parts of the lower bays and the intervening coastline where the substratum was coarse sand (maërl or shell sand) were suitable for hydraulic dredging but bedrock and loose boulders often proved obstacles to towing. There was evidence of two assemblages of bivalves in the bays: one typified by Venus verrucosa, Venerupis senegalensis and Tapes rhomboides, all large and potentially valuable, occurred within maërl mixed with fine mud, the other whose most valuable components included Ensis arcuatus and Spisula solida, occurred in disintegrating maërl and in shell sand. The bivalve fauna in the two bays appeared to be typified by relatively high diversity and low biomass – which is accentuated by recent natural mortalities of Ensis arcuatus, a dominant species - and this is likely to prove a challenge to marketing; the Irish market typically exploits small numbers of clam species simultaneously. The terms of the licence under which CSC operates may provide opportunities to exploit clams within their designated area by means other than hydraulic dredging and these should be investigated. In view of the scientific values of the area and its status as a cSAC any plan to exploit its interstitial bivalves should be discussed with the relevant state agency.