• Activity patterns of some inshore fishing vessels in 2006-2007

      Fahy, E.; Fee, D.; O'Connor, S.; Smith, T. (Marine Institute, 2007)
      Observations of daily “absence-from-port” patterns and indications of gears used were carried out on 147 vessels ranging from 5 to 13 m overall length, between April 2006 and March 2007 at three ports in west, southwest and southern Ireland. The vessels numbered approximately 6% of the total national fleet and they were larger than the average length of boats observing a daily working “absence-from-port” pattern. Fishing gears belonged to one of five categories: shellfish dredges, nets, hook and line, pots and otter trawl. More than half of the vessels observed did not carry any indication of fishing gear; 46 % had evidence of using one gear and 3% showed signs of using two. Activity (absence) patterns were low, ranging between 14 and 42 % of week-days on which observations were made. The annual pattern of gear usage described by BIM in 1999 was not apparent in any of the three ports. Instead, the local availability of fishing opportunities was influential in deciding which methods predominated. In only one port was there a marked seasonal activity pattern. Visible signs of vessel registration were similar to the situation in 2002.
    • Aspects of the exploitation of hake Merluccius merluccius belonging to the northern stock by fleets based in Ireland

      Fahy, E.; Gleeson, P. (Department of the Marine, 1993)
      The development of the hake fishery in the ICES Divisions adjoining Ireland displays strong similarities to the fishery for megrim; Ireland's landings of hake rose from 100t per year in 1979 to 2,000t ten years later. Most hake comes from Divisions Vllg-k. The Communities Logbook of the Irish-Spanish joint venture fleet provides a short time series. CPUE by both demersal trawl and long line declined sharply between 1985 and 1991. The second quarter is the most productive of hake landings but otherwise there is no clear seasonal pattern. Hake were sampled on a half yearly basis and the fish were aged on the otoliths with a success rate of 70%. Ages in the first half were adjusted to a birth date of 1 January. Mean lengths at age were higher than those calculated by statistical methods (Normsep.). Length frequencies indicated two age groups in the discards. Methods of capturing hake have altered over the past five years, gill nets have increased their share of the Irish catch and, in 1991, were a close second to demersal trawl. Age of recruitment to the landings is 2-4 years. Discard hake was calculated at 25-163% by weight of landings per quarter in 1991, higher values coming from small-meshed nets targeting Nephrops. Survivorship curves based on aged length frequencies of hake taken by whitefish boats provided F values of between 0.40 and 0.76. These results are high and together with sharply declining CPUE would seem to suggest the part of the stock in Divisions Vllb-c and Vllg-k is more heavily fished than the stock in other parts of Sub-area VII.
    • The Beltra Fishery, Co. Mayo and its sea-trout Salmo trutta stocks

      Fahy, E. (Department of Fisheries and Forestry, 1981)
      The sea trout stocks of the Lough Beltra catchment in Co. Mayo are described from a sample of 620 specimens collected in 1973 and 1974. These angler-caught fish displayed a low diversity in age categories and the samples contained few previous spawners. Variation in the success of parr growth in different years, between males and females and between A and B type smolts is compared. The incidence of A type growth is high, resembling that of a neighbouring catchment and the amount of B type growth can be related to length of the estuary. The Beltra angling fishery for sea trout exploits mainly two year smolt post-smolt. Traditionally the angling clientele have originated largely out of state and the decline in catches in recent years is attributed to a smaller volume of tourism in the post-1969 period. Catch per effort does not correlate with the supposed availability of sea trout and angling effort is regarded as the main factor deciding the yield from the fishery.
    • A Benthic Survey of Inner Bantry Bay

      Neiland, S.; McMahon, T. (Marine Institute, 1999)
      In February 1993 sediment samples were collected from a total of 18 stations in Bantry Harbour, Glengarriff Harbour and along the north shore of Whiddy Island. The samples were analysed for grain size, organic carbon content and the abundance of benthic infauna. The benthic infauna were identified to family level. The sediments in Bantry Harbour and Glengarriff Harbour were comprised of fine particles with typically >80% of the dry weight being in the silt/clay (<63 μm) fraction. In contrast, the sediments close to Whiddy Island contained relatively high amounts of coarser material. In Bantry Harbour a total of 53 families with 742 individuals were identified from the ten stations sampled. Of the 53 families identified, 21 were Polychaeta, 6 Bivalvia, 7 Gastropoda, 3 Echinodermata, and 16 Crustacea. A total of 31 families with 491 individuals were identified from the five stations sampled in the Glengarriff Harbour area. Of these 16 were Polychaeta, 4 were Bivalvia, 3 were Gastropoda, 1 was Echinodermata, and 7 were Crustacea. From the three stations sampled in the vicinity of Whiddy Island 47 families with 461 individuals were identified. Of these 23 were Polychaeta, 8 Bivalvia, 4 Gastropoda, 2 Echinodermata, and 10 Crustacea. In Bantry Harbour and Glengarriff Harbour cirratulid polychaetes were dominant and the benthic infaunal composition was indicative of stressed environmental conditions. In contrast, the sediments close to Whiddy Island exhibited a very healthy faunal composition with no one family predominating and high numbers of amphiuroid echinoderms were recorded from these sampling stations.
    • Catch analysis of shrimp Palaemon serratus (Pennant) taken by different mesh sizes

      Fahy, E.; Forrestt, N.; Oakley, L. (Marine Institute, 1998)
      Five mesh sizes were used to sample shrimp Palaemon serratus at depths of less than 30 m in Bantry Bay, southwest Ireland from June 1996 to March 1997. All of the meshes, with the exception of the smallest (2.5 mm) were made up of polyethylene and they were distributed over a gang of 20 Chinesehat-ended creels which were fished on fourteen occasions throughout the period which overlapped with the commercial fishing season. Some 5,000 shrimp were captured and the size distribution of the total catch per month reflected the growth of the species so it is supposed that the population was representatively sampled throughout. Selection was calculated using the alternate hauls method. Shrimps did not enter the pots in any numbers below the length of 50 mm (total length) and mesh selection could not he demonstrated at a mesh size of 5.2 mm. Thereafter, as the mesh sizes were ascended, selectivity became more significant. It was however weak; Lc values ranged between 58-75 mm for females and 71-88 mm total lengths for males for mesh sizes of 7.5 - 13.5 mm. These lengths coincide with the centre of the length frequency distribution of shrimp. As the mesh size increased, the ratio of females to males rose, but the numbers per haul declined abruptly in the 13.5 mm mesh.
    • Chemical contaminants in Irish estuarine and coastal waters, 1978 to 1988

      O'Sullivan, M. P.; Nixon, E. R.; McLaughlin, D.; O'Sullivan, M. L.; O'Sullivan, D. (Department of the Marine, 1991)
      Observations on the concentrations of heavy metals (mercury, cadmium, copper, lead and zinc) and chlorinated hydrocarbons (PCBs and the pesticides, lindane, dieldrin, DDTs and chlordanes) are presented. Sources comprise mussels and oysters from twenty six estuarine and coastal locations and in fin fish landed from all coasts. Data on heavy metals and nutrients in sea water and heavy metals in sediments for nine estuaries are also reported. Data were collected to comply with the Joint Monitoring Programme of the Oslo and Paris Commissions and with the Cooperative Monitoring Programme of the International Council for the Exploration of the Sea. The locations sampled included Boyne estuary, Dublin Bay, Wexford Harbour, Barrow estuary, Waterford Harbour, Cork Harbour, Bandon estuary, Tralee Bay, Shannon estuary, Clarinbridge, Kilkieran Bay, Clew Bay, Killary Harbour and Mulroy Bay. Four cases of elevated concentrations of cadmium, two each of copper, zinc and mercury and one of lead are reported. The general overall temporal trend in metal levels has been of stability or, in the case of more marked contamination, of reduction. The degree of organochlorine contamination was low in all the estuaries and shellfish growing areas monitored. No instances of contamination exceeding tolerance levels in shellfish and fin fish for human consumption were recorded. With very few exceptions, it was found that Irish coastal waters enjoyed exceptionally low levels of contamination.
    • Development of the Irish Eel Fishery: Proceedings of a National Workshop - Dun Laoghaire, 7 July 1998

      Watson, L. (ed); Moriarty, C. (ed); Gargan, P. (ed) (Marine Institute, 1999)
      Increasing awareness of the value of eel fishing led to a decision by the Minister for the Marine to formulate a national eel strategy. As a contribution to the necessary gathering of views and information, the principal authorities concerned convened an Eel Management Workshop on 7th July 1998 at the Royal Marine Hotel in Dun Laoghaire. The Workshop was co-hosted by an Bord Iascaigh Mhara (BIM), the Marine Institute (MI) and the Central Fisheries Board (CFB), and was attended by 100 participants representing all sectors, including the eel fisheries and co-operatives, eel farmers, eel processors and smokers, the regional fisheries hoards and the state development and regulatory agencies from both sides of the border. It was decided to hold a workshop on eel to heighten awareness of this most intriguing and valuable resource in Ireland, and to establish the baseline data for a national strategy for the development of the Irish eel fishery to be announced by the Minister for the Marine and Natural Resources during 1998.
    • The escallop Pecten maximus in Mulroy Bay

      Minchin, D. (Department of Fisheries and Forestry, 1981)
      Following the discovery in 1978 of large numbers of escallops in the North Water of Mulroy Bay, a detailed study of stocks was made in 1979. Spat settled out at shell height 190 to 220 µm from late July to 9 August, greatest density was 1,390 spat per metre of 12 mm diameter blue polypropylene rope. Mean daily growth rates from August to mid October ranged from 196.6 µm failing to 17.5 µm from mid October to December. Greatest densities of adult escallops occurred near rocks at depths from 3 to 15 m. Age frequency determinations showed that settlement had occurred every year since 1967. Serious predation by Asterias rubens took place on escallop held in lantern nets. The most successful containers for growth were North West plastic trays held below 5 m depth.
    • The European eel fishery in 1993 and 1994

      Moriarty, C. (Marine Institute, 1996)
      A group of 17 experts, representing 9 member states of the EU, undertook in March 1995 the Concerted Action AIR A94-1939 entitled Enhancement of the European eel fishery and conservation of the species. This paper presents the results of the first phase of the study which aimed to compile a database of information on the eel in the 9 states. The total annual yield of European eel was estimated to lie between 20,000 t and 30,000 t. Glass eels account for 4% of the total by weight and 33% by value. The value of the catch as paid to the fisherman was estimated at 180 M ECU and with value added as 375 M ECU. Manpower engaged fulltime in eel fishing was relatively low, fewer than 500 individuals. Numbers engaged part-time totalled at least 25,000. Although rarely providing the mainstay of a fishing community, the eel made a sociological contribution out of all proportion to its cash value. Yields greater than 5 kg per hectare were attained in a variety of habitats throughout the region. The highest yields per hectare recorded were 324 kg in one Italian coastal lagoon, 75 kg in another, 52 kg in a French Mediterranean lagoon and 40 kg in a Norwegian river and lake system. The yield from most fisheries was less than 5 kg per ha. This implied that proper management could greatly increase yields throughout the geographical range of the species. Between 2 and 3 billion young eels were captured annually, of which more than 95% were killed for consumption at that young stage, while less than 5% were harvested at later stages or left to contribute to the breeding stock. The implication was that adequate glass eels existed for a greatly enhanced stocking programme. Many eel fisheries had declined in the course of the previous twenty years, the principal factors appearing to be recruitment failure and inadequate management measures. Eel fishing can be undertaken with a low capital investment and provides important opportunities for work in communities where unemployment is high.
    • Evaluation of the Benefits to Sustainable Management of Seasonal Closure of the Greencastle Codling (Gadus morhua) Fishery

      Ó Cuaig, M.; Officer, R. (Marine Institute, 2007)
      The project examined whether the seasonal closure of the traditional cod fishing grounds off Greencastle, Co. Donegal, could be an effective alternative management measure. The project was instigated by the local fishing industry and operated in cooperation between industry, the Marine Institute and Bord Iascaigh Mhara. The main objectives of the project were to demonstrate the change in yield likely to result from seasonal closure, and, to determine the pattern of movement of cod from the Greencastle fishery. Each winter from 2003 to 2005 the fishery was closed by Statutory Instrument. This was achieved with the voluntary commitment of the local industry. During this period over 13,000 cod were tagged and released by Marine Institute and BIM staff working aboard chartered fishing vessels. The closure itself provided a significant conservation benefit. During 2000-2002 50% of the Irish catch weight of cod in Division VIa (> 60% by number) was taken in the winter. The closure will therefore have markedly reduced the fishing mortality on cod that would otherwise have occurred from 2003 to 2005. As the Greencastle codling fishery is a mixed whitefish fishery, any benefits flowing from the closure are likely to have extended to other whitefish stocks. Growth was extremely variable but averaged around 17 cm per annum for cod at liberty for extended periods. During the winter tagging surveys the repeated recapture of recently tagged cod on the grounds indicated the retention of cod on the grounds during winter. Tagged cod at liberty for extended periods were subsequently recaptured on, or near the Cape grounds. This strong fidelity towards the Cape grounds during winter coupled with high growth rates may mean that a short winter fishing season, with a delayed opening, may yield a similar total weight of codling than the traditional fishery but with the catch of a reduced number of cod. Such schemes may reduce current fishing mortality rates. However, the stock status of Division VIa cod is so poor that a complete closure of the fishery is warranted. It is recommended that continuation of the project be considered as a mechanism for maintaining a closure of most of the Irish fishery, whilst simultaneously improving the quality of data available for stock assessment.
    • Gutted to round-weight conversion factors for anglerfish (Lophius poscatorius and Lophius budegassa)

      Lordan, C.; Gerritsen, H.D. (Marine Institute, 2006)
      In response to a request from the Department of Communications Marine and Natural Resources and fishing industry, the conversion factors used to estimate round or live weights from gutted anglerfish were re-examined. A number of data sources was available from survey data, port sampling and observer trips. In some cases, the liver is left in place when the fish are gutted. For these landings a separate conversion factor is necessary. The conversion factors were found to be independent of fish size, however, some significant differences between the data sources were found. Significant differences between the conversion factors of the two species of anglerfish (Lophius piscatorius and L. budegassa) were also found. As commercial landings of anglerfish are not usually speciated, a generic conversion factor was estimated for Lophius spp. by combining the data for both species after weighting by the estimated proportions of the two species in the Irish landings. The resultant conversion factor for fully gutted fish is 1.23 and 1.17 when the liver is left in place; both estimates are lower than the current Irish factor of 1.28.
    • An Inventory of Irish Herring Spawning Grounds

      O’Sullivan, D.; O’Keefe, E.; Berry, A.; Tully, O.; Clarke, M. (Marine Institute, 2013)
      Herring, an important commercial and forage species in Irish waters, are benthic spawners and specifically rely on gravel and/or rock on which to lay their eggs. The present study collates information from both the fishing industry and seabed surveys (INFOMAR) to produce a detailed inventory of individual herring spawning beds, grounds and areas around the coast of the Republic of Ireland.
    • Irish fisheries-science research partnership trawl survey of the Porcupine Bank Nephrops Grounds July 2010

      Stokes, 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.
    • Management of the European Eel

      Moriarty, C. (ed); Dekker, W. (ed) (Marine Institute, 1997)
      Concern expressed by fishermen, fish culturists and scientists alike on the decline in recruitment and fishery yields of the eel led to the establishment of a working group, EC Concerted Action AIR A94-1939, to pursue a project entitled Enhancement of the European eel fishery and conservation of the species. Scientists from ten countries have contributed to the current report and its predecessor, published in 1996. The reports present an account of the eel fishery together with scientific data of significance in control of the stocks and make recommendations for future management.
    • National Survey of Sea lice (L. salmonis Krøyer and C. elongatus Nordmann) on Fish Farms in Ireland – 2006

      O'Donohoe, P.; Kane, F.; Kennedy, S.; Nixon, P.; Power, A.; Naughton, O.; Jackson, D. (Marine Institute, 2007)
      This bulletin reports on the National Sea Lice Monitoring Programme carried out by the Marine Institute in 2006. Results presented in this report are mean ovigerous sea lice levels and mean mobile sea lice levels for Lepeophtheirus salmonis and Caligus elongatus
    • National Survey of Sea lice (L. salmonis Krøyer and C. elongatus Nordmann) on Fish Farms in Ireland – 2007

      O'Donohoe, P.; Kane, F.; Kelly, S.; Nixon, P.; Power, A.; Naughton, O.; Jackson, D. (Marine Institute, 2008)
      This bulletin reports on the National Sea Lice Monitoring Programme carried out by the Marine Institute in 2007. Results presented in this report are mean ovigerous sea lice levels and mean mobile sea lice levels for Lepeophtheirus salmonis and Caligus elongatus
    • National Survey of Sea lice (L. salmonis Krøyer and C. elongatus Nordmann) on Fish Farms in Ireland – 2008

      O'Donohoe, P.; Kane, F.; Kelly, S.; Nixon, P.; Power, A.; Naughton, O.; Tully, D.; Jackson, D. (Marine Institute, 2009)
      This bulletin reports on the National Sea Lice Monitoring Programme carried out by the Marine Institute in 2008. Results presented in this report are mean ovigerous sea lice levels and mean mobile sea lice levels for Lepeophtheirus salmonis and Caligus elongatus
    • National Survey of Sea Lice (Lepeophtheirus salmonis Kroyer and Caligus elongatus Nordmann) on Fish Farms in Ireland - 2009

      O'Donohoe, P.; Kane, F.; Kelly, S.; Nixon, P.; Power, A.; McDermott, T.; Drumm, A.; Jackson, D. (Marine Institute, 2010)
      This bulletin reports on the National Sea Lice Monitoring Programme carried out by the Marine Institute in 2009. Results presented in this report are mean ovigerous sea lice levels and mean mobile sea lice levels for Lepeophtheirus salmonis and Caligus elongatus
    • National Survey of Sea Lice (Lepeophtheirus salmonis Kroyer and Caligus elongatus Nordmann) on Fish Farms in Ireland - 2010

      O'Donohoe, P.; Kane, F.; Kelly, S.; McDermott, T.; Drumm, A.; Jackson, D. (Marine Institute, 2011)
      This bulletin reports on the National Sea Lice Monitoring Programme carried out by the Marine Institute in 2010. Results presented in this report are mean ovigerous sea lice levels and mean mobile sea lice levels for Lepeophtheirus salmonis and Caligus elongatus.
    • National Survey of Sea Lice (Lepeophtheirus salmonis Kroyer and Caligus elongatus Nordmann) on Fish Farms in Ireland - 2011

      O'Donohoe, P.; Kane, F.; Kelly, S.; McDermott, T.; Drumm, A.; Jackson, D. (Marine Institute, 2012)
      This bulletin reports on the National Sea Lice Monitoring Programme carried out by the Marine Institute in 2011. Results presented in this report are mean ovigerous sea lice levels and mean mobile sea lice levels for Lepeophtheirus salmonis and Caligus elongatus.