Marine Institute Open Access Repository
Welcome to the Marine Institute Open Access Repository
The Marine Institute Open Access Repository facilitates full text access to the publications of the Marine Institute in accordance with copyright permissions. The aim of the Repository is to collect, preserve and provide open access to the publications of the Marine Institute, including the research publications supported by National and European funded marine research programmes.
Communities in the Marine Institute Open Access Repository
Select a community to browse its collections.
Cruise report: Irish Anglerfish & Megrim Survey 2023The 2023 Irish Anglerfish and Megrim Survey (IAMS) took place from 11th February to 7th March in ICES (International Council Exploration of the Sea) Divisions 7.b-c and 7.j-k, and 14th to 23rd April in ICES Division 6.a on-board the Research Vessel Celtic Explorer. The main objective of the survey was to obtain biomass and abundance indices for anglerfish (Lophius piscatorius and Lophius budegassa) and megrim (Lepidorhombus whiffiagonis and Lepidorhombus boscii) in ICES Division 6.a (south of 58°N) and Subarea 7 (west of 8°W). Secondary objectives were to collect data on the distribution, relative abundance and biology of other commercially exploited species. For the fifth year, additional sampling took place in deep water (up to 1,500m) in order to monitor the recovery of exploited deep-water species following the decline of the deep-water fisheries in Irish waters since early 2000s (Kelly and Gerritsen, 2022). This work was funded under Marine Biodiversity Schemes of the European Maritime and Fisheries Fund (EMFF) from 2019 to 2021 and European Maritime, Fisheries and Aquaculture Fund (EMFAF) since 2022. The IAMS survey is coordinated with the Scottish Anglerfish and Megrim Survey (SIAMISS) as part of ICES International Bottom Trawl Survey Working Group (IBTSWG) and uses the same gear and fishing practices.
Atlantic Herring in 6aS/7b, Industry Acoustic Survey Cruise Report, November-December 2022An acoustic survey of Atlantic herring Clupea harengus was conducted in ICES areas 6aS/7b in November/December 2022 and January 2023. The 2022 survey was conducted using five vessels; MFVs Crystal Dawn WD201, Ros Ard SO745, Girl Kate SO427, Johnny G S653 (d) and Conquest SO852. The 6aS/7b survey design in 2022 focused on 6 core areas with prior knowledge of herring distribution from previous surveys and the monitoring fishery were targeted for surveying. The change in survey design since 2020 was largely based on the results from ICES WKHASS (ICES 2020) and from lessons learned in the previous surveys in this area from 2016-2019. This design resulted in a much reduced survey area compared to previous years, but with better coverage of most of the important inshore bays where the monitoring fishery takes place. The survey design objective remained the same; to capture the distribution of winter spawning herring in the 6aS/7b area, but this design was not expected to achieve overall stock containment. The timing of surveys in the core areas was flexible from the outset by design. The greater flexibility allows for a targeted spatial and temporal approach which avoided the inevitable poor weather that can happen in this area during this time of the year and which led to reduced survey effort in some previous years. Using smaller vessels allowed surveys to be conducted in shallow inshore areas where herring are known to aggregate during this time of the year. This survey is the seventh consecutive annual acoustic survey for pre-spawning herring in this area at this time of the year. A pole-mounted system with a combi 38 kHz (split) 200 kHz (single) transducer was used successfully for the survey on small vessels (<18m) in 2022. Herring were again distributed inshore in shallow areas, and the improved survey design and use of small vessels for the survey resulted in a good measure of uncertainty (CV =0.25). The stock was not overall contained in 2022, particularly in the Donegal Bay area (Malin Beg, etc.) and more effort is required to target surveys earlier and later than December and January when herring tend to show up in these areas in difficult to predict patterns. Very strong herring marks were evident in Lough Foyle and Lough Swilly in the channel in marks that extended for many miles in some cases. This was in areas where smaller boats in the fishery were concentrating effort. Herring had left the Swilly and Foyle by mid-February. There was also a series of strong herring marks in Bruckless Bay, Fintra Bay and Inver Bay in discreet areas, particularly in December. The monitoring fishery was being conducted on smaller boats in the same areas and close to the same time as the survey and biological samples from some of these vessels were used. There was a fairly tight distribution of length classes in all hauls, with most hauls dominated by larger (> 22 cm) mature fish. The 2- and 3-wr age class of herring accounted for 72% of the overall numbers in 2022. The total stock biomass (TSB) estimate of 54,046 tonnes is considered to be a minimum estimate of herring in the 6aS/7b survey area at the time of the survey. The 2022 estimate is the highest estimate in the time series. The flexible survey design and focusing on discreet areas was generally successful and is providing a good template for future survey designs.
International Blue Whiting Spawning Stock Survey (IBWSS) Spring 2023Coordination of the survey was initiated at the meeting of the Working Group on International Pelagic Surveys (WGIPS) in January 2023 and continued by correspondence until the start of the survey. During the survey, effort was refined and adjusted by the survey coordinator (Norway) using real time observations.
National Survey Of Sea Lice (Lepeophtheirus salmonis Krøyer and Caligus elongatus Nordmann) on Fish Farms in Ireland – 2022Farmed stocks of Atlantic salmon in Ireland are inspected on 14 occasions throughout the year to monitor sea lice levels as part of a national programme. Sea lice are a naturally occurring parasite found on marine fish, including salmonids. They are small ecto-parasitic copepod crustaceans and there are approximately 559 species. The objectives of the National Sea Lice Monitoring Programme are: *To provide an objective measurement of infestation levels on farms. * To investigate the nature of infestations. * To provide management information to drive the implementation of control and management strategies. * To facilitate further development and refinement of this strategy. The sea lice control and management strategy has five principal components: * Separation of generations. * Annual fallowing of sites. * Early harvest of two-sea-winter fish. * Targeted treatment regimes, including synchronous treatments. * Agreed husbandry practices.