• Lobster trap census 1972

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      This leaflet continues the information provided by Fishery Leaflets Nos. 11, 23, 26, and 39. There was little change in the types of Lobster fishing gear in use in 1972 compared with previous years.
    • Lobster Trap Census, 1970

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1971)
      This leaflet continues the information given in Fishery Leaflets No. 11 and 23 concerning lobster traps in use around the Irish coasts. As in previous years the lobster catch figures supplied to the Fisheries Division by various collectors have been correlated with the fishing gear used by boats fishing off the 12 maritime counties. There was little change in 1970 in the preference of the fishermen for the different designs of fishing traps used.
    • Lobster trap census, 1973

      Bhatnagar, K M (Department of Agriculture and Fisheries (Fisheries Division), 1974)
      This leaflet continues the information provided by Fishery Leaflets numbered, 11, 23, 26, 39, and 57. Although more lobster traps (51.0%) were used in relation to French crawfish, (49.0%) in 1973 (Table 1), the order of preference of lobster fishing (all types) remained the same as in previous years as follows: (a) French crawfish traps (b) Scottish creels (or variation thereof) (c) Other types of traps.
    • Local Irish Names of Fishes

      Farran, G. (Irish Naturalists' Journal, 1946)
      A localised translation of common Irish fishes names into Irish, compiled by G. P. Farran.
    • Long term trends in population dynamics of NW Ireland herring revealed by data archaeology

      Clarke, M.; Egan, A.; Mariani, S.; Miller, D. (International Council for the Exploration of the Sea (ICES), 2011)
      Herring populations to the northwest of Ireland are considered to constitute a single stock. They consist of a diverse array of autumn, winter and spring spawning components. They have been subject to large catches in the past. Landings peaked at 50 000 t in 1987 and have shown a slow decline since, as 2 dominant year classes, born in the 1980s, declined. No strong year classes have appeared since, and the stock is now outside safe biological limits. The time series of data available for stock assessment only covered the period 1970- present, even though routine sampling began after the end of World War I. In order to examine the stock trajectories over time, all catch at age data for the period 1921-1970 were compiled and analysed. The study revealed large fluctuations in the size of the stock and its productivity over time. Occasional strong cohorts occurred either singly, or in close together within 5 years of each other, and were observed at roughly 20-40 year intervals. Interspersed with this were long intervals of poor recruitment. Further historical analyses of 18th and 19th century records confirm this general periodicity. Overall results were examined in the context of time series of sea surface temperature data. The study can provide a basis for development of a long term management plan for the stock, using management strategy evaluation (MSE). The implications of this work, for the rational management of this stock for the future, are discussed.
    • A longitudinal study of amoebic gill disease on a marine Atlantic salmon farm utilising a real-time PCR assay for the detection of Neoparamoeba perurans

      Downes, J.K.; Henshilwood, K.; Collins, E.M.; Ryan, A.; O'Connor, I.; Rodger, H.D.; MacCarthy, E.; Ruane, N.M. (Inter Research, 2015)
      Amoebic gill disease (AGD) is a proliferative gill disease of marine cultured Atlantic salmon Salmo salar, with the free-living protozoan Neoparamoeba perurans being the primary aetiological agent. The increased incidence of AGD in recent years presents a significant challenge to the Atlantic salmon farming industry in Europe. In this study, a real-time TaqMan® PCR assay was developed and validated to detect Neoparamoeba perurans on Atlantic salmon gills and further used to monitor disease progression on a marine Atlantic salmon farm in Ireland in conjunction with gross gill pathology and histopathology. The assay proved specific for N. perurans, with no cross-reactivity with the related species N. pemaquidensis, N. branchiphila or N. aestuarina, and was capable of detecting 2.68 copies of N. perurans DNA μl−1. Although the parasite was detected throughout the 18 mo period of this study, mortality peaks associated with clinical AGD were only recorded during the first 12 mo of the marine phase of the production cycle. The initial AGD outbreak resulted in peak mortality in Week 17, which was preceded by PCR detections from Week 13 onwards. Freshwater treatments were an effective method for controlling the disease, resulting in a reduction in the weekly mortality levels and also a reduction in the number of PCR-positive fish. In comparison to traditional diagnostic methods, our PCR assay proved to be highly sensitive and a valuable tool to monitor disease progression and, therefore, has the potential to provide information on the timing and effectiveness of treatments.
    • A Low-Complexity Mosaicing Algorithm for Stock Assessment of Seabed-Burrowing Species

      Corrigan, D.; Sooknanan, K.; Doyle, J.; Lordan, C.; Kokaram, A. (IEEE Xplore, 2018)
      This paper proposes an algorithm for mosaicing videos generated during stock assessment of seabed-burrowing species. In these surveys, video transects of the seabed are captured and the population is estimated by counting the number of burrows in the video. The mosaicing algorithm is designed to process a large amount of video data and summarize the relevant features for the survey in a single image. Hence, the algorithm is designed to be computationally inexpensive while maintaining a high degree of robustness. We adopt a registration algorithm that employs a simple translational motion model and generates a mapping to the mosaic coordinate system using a concatenation of frame-by-frame homographies. A temporal smoothness prior is used in a maximum a posteriori homography estimation algorithm to reduce noise in the motion parameters in images with small amounts of texture detail. A multiband blending scheme renders the mosaic and is optimized for the application requirements. Tests on a large data set show that the algorithm is robust enough to allow the use of mosaics as a medium for burrow counting. This will increase the verifiability of the stock assessments as well as generate a ground truth data set for the learning of an automated burrow counting algorithm.
    • Mackerel Egg Survey, July 8th - 28th 2010

      O'Hea, B (Marine Institute, 2010)
      Every three years the International Council for the Exploration of the Sea (ICES) coordinates a series of mackerel and horse mackerel egg surveys covering the eastern Atlantic from Gibraltar to the north coast of Scotland between January and July. The aim of this survey programme is to assess the northeastern Atlantic mackerel and horse mackerel stock. The Marine Institute participates in this programme and covers stations in the Celtic Sea and West of Ireland. Plankton samples were collected at 102 stations, and the eggs they contained were preserved in 4% buffered formaldehyde. Preliminary analysis shows that egg numbers were concentrated close to the shelf edge, around the 200m contour line. Ten fishing hauls were made to collect mackerel and horse mackerel samples for fecundity analysis. Samples were collected to ensure maximum temporal and geographical spread.
    • Mackerel Egg survey, June 26th – July 16th, 2007

      O'Hea, B (Marine Institute, 2007)
      Every three years the International Council for the Exploration of the Sea (ICES) coordinates a series of mackerel and horse mackerel egg surveys covering the eastern Atlantic from Gibraltar to the north coast of Scotland between January and July. The aim of this survey programme is to assess the northeastern Atlantic mackerel and horse mackerel stock. The Marine Institute participates in this programme and covers stations in the Celtic Sea and West of Ireland. Plankton samples were collected at 88 stations, and the eggs they contained were preserved in 4% buffered formaldehyde. Preliminary analysis shows that egg numbers were concentrated close to the shelf edge, around the 200m contour line. Seven fishing hauls were made to collect mackerel and horse mackerel samples for fecundity analysis. Samples were collected to ensure maximum temporal and geographical spread.
    • Mackerel Egg Survey, March 5th – 29th, 2010

      O'Hea, B (Marine Institute, 2010)
      Every three years the International Council for the Exploration of the Sea (ICES) coordinates a series of mackerel and horse mackerel egg surveys covering the eastern Atlantic from Gibraltar to the north coast of Scotland between January and July. The aim of this survey programme is to assess the northeastern Atlantic mackerel and horse mackerel stock. The Marine Institute participates in this programme and covers stations in the Celtic Sea. Plankton samples were collected at 105 stations, and the eggs they contained were preserved in 4% buffered formaldehyde. Preliminary analysis shows that egg numbers were concentrated close to the shelf edge, around the 200m contour line. Four fishing hauls were made to collect mackerel and horse mackerel samples for fecundity analysis. Samples were collected to ensure maximum temporal and geographical spread.
    • Mackerel Egg survey, March 6th – 26th, 2007

      O'Hea, B (Marine Institute, 2007)
      Every three years the International Council for the Exploration of the Sea (ICES) coordinates a series of mackerel and horse mackerel egg surveys covering the eastern Atlantic from Gibraltar to the north coast of Scotland between January and July. The aim of this survey programme is to assess the northeastern Atlantic mackerel and horse mackerel stock. The Marine Institute participates in this programme and covers stations in the Celtic Sea. Plankton samples were collected at 112 stations, and the eggs they contained were preserved in 4% buffered formaldehyde. Preliminary analysis shows that egg numbers were concentrated close to the shelf edge, around the 200m contour line. Eleven fishing hauls were made to collect mackerel and horse mackerel samples for fecundity analysis. Samples were collected to ensure maximum temporal and geographical spread. CTD’s were also carried out for the Oceanography section of the Marine Institute.
    • The Maharees spider crab Maja squinado fishery in 2000

      Fahy, E. (Marine Institute, 2001)
      A pot fishery directed on spider crab (Maja squinado) grew out of a mixed tangle net and pot fishery for large crustaceans in the early 1980s. Approximately twenty half decked vessels of 10m in length have been involved for the duration of the fishery but the numbers of pots per vessel has increased; currently 10,000 pots are set for spider crab in Tralee and Brandon Bays during the summer months. Cpue rose initially during the early years of the fishery, then it stabilised and declined although in the late 1990s it again recovered somewhat. Sampling in 2000 suggests that the size composition of the catch has altered since the early years of the fishery, its main consequence being the removal of the older age groups so that the landings now consist almost entirely of a single year class. Aspects of the biology of the Maja squinado are compared with what is already known of the species and a number of recommendations are made for the future management of the fishery. These include a further increase in the size limit, a ban on tangle nets and a cap on fishing effort.
    • Making more money from Periwinkles

      Crowley, M (Department of Agriculture and Fisheries (Fisheries Division), 1975)
      Each year about £250,000 worth of periwinkles are picked on our shores. This makes them far and away the most valuable molluscs in our fishing industry. What is more, the value might be doubled if the catch were to be handled carefully. The fact is that, although they appear very tough, the periwinkle are in some ways delicate animals and rough treatment kills many of them. An important fact in the periwinkle industry is that the resource is a natural one which costs little to exploit. No equipment is required to harvest them because they are simply picked by hand when the tide is out.
    • Making the European Fisheries Ecosystem Plan Operational (MEFEPO) North Western Waters Atlas

      Connolly, P L; Kelly, E; Dransfeld, L; Slattery, N; Paramor, O A L; Frid, C L J (Marine Institute, 2009)
      MEFEPO (Making the European Fisheries Ecosystem Plan Operational) is a group of ecologists, economists, management experts and fisheries scientists who are trying to make ecosystem based fisheries management a reality in Europe. This Atlas is intended for policy makers, managers and interested stakeholders. Its purpose is to provide an ecosystem overview of the North Western Waters area (NWW) Regional Advisory Council (RAC) area. The Atlas includes general summary information on the physical and chemical features, habitat types, biological features, birds, mammals, fishing activity and other human activities of the NWW region. Background material on four NWW case study fisheries is presented (North East Atlantic Mackerel, Northern Hake, Dublin Bay Prawn and Scallops). This NWW Atlas was produced by the Marine Institute, Ireland as part of the EU funded MEFEPO project.
    • Management and control of proliferative kidney disease (PKD) in a freshwater Atlantic salmon (Salmo salar L.) farm in Ireland: a case history

      Quigley, D.T.G.; McArdle, J.F. (Fish Veterinary Society, 1998)
      During July 1992, an acute clinical outbreak of proliferative kidney disease (PKD) was experienced in two strains (‘Irish’ and ‘Norwegian’) of juvenile (age 0+) Atlantic salmon (Salmo salar L.) held at two adjacent freshwater sites on the River Lee in southern Ireland. Various management strategies (including reduced stocking densities, handling, feeding rates and increased oxygenation), and treatment regimes (involving malachite green and fumagillin DCH) were used to control the disease. A total of 1·3 million juveniles died during the PKD outbreak, representing 61·6% and 54·6% of the Norwegian stock at the two farms respectively. The Irish stock appeared to be more resistant to the disease and only 15·6% died. The weekly prevalence of PKD fluctuated throughout the summer but seemed to disappear by mid-August. Although PKD was detected again during 1993, no clinical outbreak occurred. In conjunction with the management strategies adopted in 1992, seven consecutive weekly prophylactic bath treatments with malachite green (1·6 ppm for 40 minutes) administered prior to mid-July appeared to control the disease. During August 1993, a ten day course of fumagillin (6 mg/kg bodyweight per day) reduced the prevalence of the PKD parasite in a trial batch of juveniles from 24% to zero. The results of this study demonstrated the effectiveness of various management strategies and treatment regimes in controlling PKD.
    • Management of health risks associated with oysters harvested from a norovirus contaminated area, Ireland, February–March 2010

      Doré, B.; Keaveney, S.; Flannery, J.; Rajko-Nenow, P. (European Centre for Disease Prevention and Control, 2010)
      Oysters from a harvesting area responsible for outbreaks of gastroenteritis were relaid at a clean seawater site and subsequently depurated in tanks of purified seawater at elevated temperatures. This combined treatment reduced norovirus levels to those detected prior to the outbreak. On the basis of norovirus monitoring the sale of treated oysters was permitted although the harvest area remained closed for direct sale of oysters. No reports of illness have been associated with the consumption of treated oysters.
    • 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.
    • Management recommendations for the sustainable exploitation of mussel seed in the Irish Sea

      Maguire, J A; Knights, T; Burnell, G; Crowe, T; O'Beirn, F.X.; McGrath, D; Ferns, M; McDonough, N; McQuaid, N; O'Connor, B; et al. (Marine Institute, 2007)
      As it currently stands, the management of the bottom mussel aquaculture in Ireland is a complex process that is governed by three overriding factors; these are; 1) Government policy and regulation, 2) industry and economics and 3) Science and biology. These three factors are influenced by a range of different issues that influence the implementation of resource management either individually or in combination and include, inter alia, aquaculture licensing, carrying capacity, company structure and operating practices, animal health legislation, vessel registration and licensing and North/South agreements, prevailing weather conditions and uncertainty of seed supply. The mussel seed fishery in the Irish Sea, as the primary source of seed, is integral to the continued viability of the bottom mussel sector in Ireland. This report is the outcome of a project initiated over concerns raised regarding the sustainability of the fishery. A goal of this project is to develop and implement a science based management system for the sustainable exploitation of seed mussels in the Irish Sea. A specific goal of the project was to identify environmental drivers governing the distribution and abundance of the seed mussel resources in the Irish Sea. A number of outputs were expected from this project: 1. A literature search and review of existing biological, fisheries, survey and hydrographic data. 2. Studies to estimate adult reproductive cycles and spatfall patterns. 3. Hydrographic models of targeted areas of high mussel population. These models allow for behavioural characteristics of the larval swimming phases. 4. Draft a management strategy to detail the optimum manner in which to effect the sustainable exploitation of the resource, including the hatchery option. This report addresses the final workpackage above, wherein a series of recommendations encompassing both management and research aspects, based upon the scientific outputs of the project, are presented.
    • Managing a complex population structure: exploring the importance of information from fisheries-independent sources

      Hintzen, N.T.; Roel, B.; Benden, D.; Clarke, M.; Egan, A.; Nash, R.D.M.; Rohlf, N.; Hatfield, E.M.C. (Oxford University Press, 2014)
      Natural resource managers aim to manage fish stocks at sustainable levels. Often, management of these stocks is based on the results of analytical stock assessments. Accurate catch data, which can be attributed to a specific population unit and reflects the population structure, are needed for these approaches. Often though, the quality of the catch data is compromised when dealing with a complex population structure where fish of different population units mix in a fishery. The herring population units west of the British Isles are prone to mixing. Here, the inability to perfectly allocate the fish caught to the population unit they originate from, due to classification problems, poses problems for management. These mixing proportions are often unknown; therefore, we use simulation modelling combined with management strategy evaluation to evaluate the role fisheries-independent surveys can play in an assessment to provide unbiased results, irrespective of population unit mixing and classification success. We show that failure to account for mixing is one of the major drivers of biased estimates of population abundance, affecting biomass reference points and MSY targets. When mixing of population units occurs, the role a survey can play to provide unbiased assessment results is limited. Either different assessment models should be employed or stock status should be considered from the survey data alone. In addition, correctly classifying the origin of fish is especially important for those population units that are markedly smaller in size than other units in the population complex. Without high classification success rates, smaller population units are extremely vulnerable to overexploitation.
    • Mapping and Assessment of the Seaweed Resources (Ascophyllum nodosum, Laminaria spp.) off the West Coast of Ireland

      Hession, C; Guiry, M D; McGarvey, S; Joyce, D (Marine Institute, 1998)
      The seaweed biomass survey was designed to gather important information on those seaweed resources that are extensively harvested at present (mainly Ascophyllum nodosum) and those that offer a significant potential for future development (Laminariaceae). The first major objective of the project was to measure the intertidal biomass of Ascophyllum nodosum at selected sites along the Irish west coast. A total of 258 survey sites of varying size were selected by the survey team. They were considered to encapsulate all of the important regions where Ascophyllum nodosum harvesting was currently practiced and/or could take place in the future. Sites were selected using existing harvesting records, detailed map and chart studies and on-site visits. The total coastal area surveyed has the potential to yield 74,845 tonnes (t) of Ascophyllum nodosum sustainably per annum. The total amount harvested in 1996 was 35,850 t or some 48% of the total annual potential. The location and classification of the major Laminarian (kelp) beds off the Irish west coast was the second major objective of the project. Laminarians form the most extensive community inhabiting sublittoral rocky coasts of the North Atlantic. There are five species of the Laminariaceae and Alarinaceae families common to Irish waters, namely; Laminaria digitata, Laminaria hyperborea, Laminaria saccharina, Alaria esculenta and Sacchoriza polyschides. A process of public and private consultation, in conjunction with a number of field studies, was used to determine the distribution and relative abundance of these species on the west coast of Ireland. An estimate of the area of coastline (from Malin Head, Donegal, to Galley Head, Cork), covered by laminarians indicated that they were abundant at 22% of sites, common at 23%, scarce at 11% and absent from the remaining 44% of sites surveyed. All of the information gathered from the seaweed survey was been entered into a custom designed Geographical Information System (GIS). The system is made up of two information 'layers'. The first layer comprises a digitised outline of the Irish west coast from Donegal to Cork at a scale of 1:10,000 (6 inch to one mile). The second information 'layer' derived from data collected during the survey, comprising such details as amounts of seaweed present, harvesting details, accessibility and harvesting potential.