• The Parasitology of Irish Mussels

      Crowley, M (Department of Agriculture and Fisheries (Fisheries Division), 1972)
      Investigations of the distribution of three parasites of mussels, an internal copepod parasite of the gut (Mytilicola intestinalis), an external decapod parasite in the gill region (Pinnotheres pissum) and an analid shell parasite (Polydora ciliata) were carried out from October 1971 to April 1972. Samples from 26 locations around the Irish coast were investigated. One hundred mussels from each sample were weighed, measured in 5 mm groups, boiled and the following were estimated as percentages of the whole mussel:- a. Shell; b. Meat; and c. Loss.
    • Parasitology of Irish Mussels

      Crowley, M (Department of Agriculture and Fisheries (Fisheries Division), 1975)
      Investigations of the distribution of three parasites of mussels, an internal copepod parasite of the gut (Mytiliocola intestinalis), an external decapod parasite in the gill region (Pinnotheres pissum) and an annelid shell parasite (Pylodora ciliata) were carried out from September 1974 to May 1975. Samples from 28 locations around the Irish coast were investigated. One hundred mussels from each sample were weighed, measured in 5 mm groups, boiled and the following parameters were determined as percentages of the whole mussel:- a. Shell: b. Meat; c. "Loss"
    • Performance of the Crumlin sea-trout Fishery, Co. Galway

      Fahy, E (Department of Agriculture and Fisheries (Fisheries Division), 1979)
      The physical features of the Crumlin catchment, a small sea-trout fishery in Co. Galway, are described. Its sea-trout stock is examined and found to be typical of others in the region: the fish are slow growing in the sea, poorly conditioned, mortality in the stock is high and the fish have a low weight at capture. Fishery statistics date from 1896. The main influence on the numbers taken by anglers appears to have been the two wars. Individual catch weights do not show any inverse relationship with catch numbers of the kind that has been reported already in the vicinity. Catch per effort has not altered in keeping with any identifiable long-term trend but is within the range recently reported elsewhere in the region. Regulations designed for the protection of smolts in past years also protect about 20% of post-smolts (finnock) currently captured. Yield from Crumlin has most in common with output from a small neighbouring fishery. It is tentatively suggested that sea-trout production from the Connemara catchments is dependent primarily on the physical features of the systems concerned.
    • Population estimates of juvenile salmonids in the corrib system 1980

      Browne, J; Gallagher, P (Department of Fisheries and Forestry, 1981)
      Population assessments of the juvenile salmonids in the Corrib System are being made as part of the overall management plan for the Galway Fishery. In 1980 the first of a series of reports which will be issued annually gave information on the juvenile stocks and on the state of the spawning and nursery tributaries during 1979. Details of the methods used and some background on each of the tributaries were presented. Chemical and biological data on water quality along with numbers, size, age and survival of both salmon and trout are given in Fishery Leaflet 103. During 1979 eight tributaries were surveyed and in two cases upstream and downstream reaches were examined. In 1980 the effort in terms of personnel and equipment was increased but the high rainfall during the period of work, from mid-July to mid-September, meant that only two further stations were studied, one on the Dalgan river and the other on the Balinbrack river. The methods used and the scope of the work were identical in 1979 and 1980. In these assessments the emphasis is on salmon type tributaries and salmon type habitats within these tributaries so that trout numbers could be expected to be low.
    • Population estimates of juvenile salmonids in the Corrib system 1981

      Browne, J; Gallagher, P (Department of Fisheries and Forestry (Trade and Information Section), 1982)
      This is the third in a series of reports regarding the stocks of juvenile salmonids in the Corrib system. During the 1981 season fourteen tributaries were surveyed and in two cases upstream and downstream reaches were examined. These included three which had not been studied previously: the Failmore, Letterfore and Black. The methods were identical to those used in 1979 and 1980. As in the previous years the rivers were selected because they were known salmon holding tributaries and do not reflect trout numbers in the system. The population numbers are assessed by electrically fishing a selected area. The fish caught are marked by fin clipping and allowed to re-mix with the fish in the stream. The next day fishing is repeated in the same place and the proportion of marked to unmarked fish gives an estimate of the population. While it is not essential that river conditions remain the same on both days it does help the accuracy of the estimate. There is a tendency for fish to move out of their home territories during floods. Population surveys yield the best results when a large proportion of the tagged fish are recovered. Ideal electro fishing conditions are low water, overcast sky and similar river conditions on both days.
    • Populations Estimates of Juvenile Salmon in the Corrib System from 1982 to 1984

      Browne, J; Gallagher, P (Department of Tourism, Fisheries and Forestry, 1987)
      This leaflet gives the details of juvenile salmonid densities for the years 1982 to 1984 in the Corrib system. In general, since these investigations began in 1979, the Corrib tributaries have appeared to be adequately stocked with salmon. The salmon densities in the rivers to the west of Lough Corrib are much higher than in the rivers to the east. However, survival is higher in the latter. A detailed survey of juvenile salmon habitat revealed that there are 392,000 square metres of suitable habitat in the system. Of this 253,000 square metres are on the west side and 139,000 on the east side.
    • Prawn Fishing

      Gibson, F A (Department of Lands, 1956)
      The common prawn (Leander serratus) is widely distributed around the Irish coasts, but obviously varies in abundance from place to place. This prawn should not be mistaken for the Norway Lobster, sometimes called the Dublin Bay Prawn (Nephrops norvegicus) or with the brown shrimp (Crangon vulgaris). Alive, the common prawn is a grey-brown colour and has blue bands on its legs. The Norway lobster is a pink colour, and its body is profusely covered with white tipped spines. The common prawn also has a projection from its head, called a rostrum, which is absent from the shrimp. As the prawn is of economic importance, some notes on simple methods of capture will be of interest to fishermen.
    • Preliminary Catch, Discards and Selectivity Results of Trawl Survey on Deepwater Slops of the Rockall Trough

      Clarke, M W; Connolly, P L; Kelly, C J (Marine Institute, 1999-10)
      A deepwater trawl survey programme has been operated since 1993 by the Fisheries Research Centre (FRC) in the deep waters of the Rockall Trough and Porcupine Bank. The present survey took place over a period of 10 days in October and November 1997 on the eastern and southern slopes of the Rockall Trough from 54°N to 59°N. Fishing was carried out in five separate areas, in four depth strata: 500-700m, 700-900m, 900-1100m and 1100-1300m. The primary objective of the survey was to obtain samples of chondrichthyan and teleost fish for the FRC deepwater research programme, for contaminant analysis offish by the FRC chemistry section and for food technology analysis at the Teagasc National Food Centre. The survey was carried out on a commercial trawler using commercial deepwater demersal otter trawl gear. In total 15 species of chondrichthyan, 41 species of teleost fish and 5 species of cephalopods were taken. Among the most abundant species in the catch were roundnose grenadier, Portuguese dogfish, leafscale gulper shark, and Baird's smoothhead. Over the entire survey discarding was estimated as 50.5% of the total catch. Discard rates expressed as kg discarded per tonne roundnose grenadier landed and as a percentage of the total catch when compared with those of previous years showed no appreciable change. The main species discarded were rabbitfish, birdbeak dogfish, Baird's smoothhead, roundnose grenadier and Lepidion eques. Catch per unit effort rates expressed as kg caught per hour fished compared with rates for previous trawl surveys showed marked declines. Length frequency distributions for the main chondrichthyan species showed absence of smaller individuals from the samples and sexual dimorphism with respect to length. Attachment of fine-mesh cod-end liner suggested that the commercial gear selects all length frequencies present and that mesh size may not be an effective management measure in this fishery. This leaflet documents the survey and presents some preliminary results. The data from this survey are currently under analysis at the FRC and results will be published in the scientific literature.
    • Preliminary Investigation of the Population of Juvenile Salmonids in the Corrib System

      Browne, J; Gallagher, P (Department of Fisheries and Forestry (Trade and Information Section), 1980)
      Population assessments of the juvenile salmonids in the Corrib system are being made as part of the overall management plan for the Galway Fishery. This leaflet is the first of a series of reports which will be issued annually to give up-to-date information on the stocks and on the state of the tributaries used for spawning and nursery grounds. Eight tributaries were surveyed in 1979 and in two cases an upstream and a downstream reach were examined.
    • Preliminary Investigations of the Sprat stocks off the South coast of Ireland

      Molloy, J; Bhatnagar, K (Department of Agriculture and Fisheries (Fisheries Division), 1977)
      The development of a new fishery for sprat off the south coast is reviewed. The fishery during 1976 and 1977 produced over 1,600 tons of sprat, valued at over £92,000. The quality of sprat landed was excellent throughout the fishing period. While it is difficult to estimate the size of the stock in the area, it would appear that landings could be substantially increased. This, together with the quality of the sprat, could make this fishery a valuable alternative to the Celtic Sea herring fishery.
    • Preliminary Results of Salmon Tagging in the Killala Bay Area 1977

      Browne, J (Department of Fisheries (Trade and Information Section), 1978)
      Salmon movements in and around Killala Bay in 1977 were investigated by tagging. A total of 40 tags (20%) were returned. The areas of recovery ranged from the River Shannon to the south coast of England.
    • Preliminary Survey of the Littorina littorea (the Periwinkle) in South-East and South Coasts of Ireland

      Crowley, M (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      Of the three periwinkles Littorina littorea, Littorina saxatilis and Littorina littoralis only L. littorea, is of commercial value. The other two species are used mainly for decorative purposes and not for human consumption. Periwinkles are found on rocky shores and also on muddy intertidal zones which have a good cover of seaweed. They spend most of their existence in the intertidal zone below high water of neap tide and are found associated with the brown sea weeds such as bladderwrack (Ascophalium nodosum) and also the green sea weeds (Enteromorpha spp.). These weeds provide them with both shelter and food. Periwinkles browse on the sedentary animals which live on sea weed and on the weed itself. The investigations were confined to the size and quality of the periwinkles from Wexford, Waterford, Dungarvan, Youghal and Cork Harbours. The numbers per kilogram and the percentage meat yield were determined together with length frequency distribution.
    • Profile of the Caragh, County Kerry: A Salmonid Producing Catchment

      Fahy, E (Department of Tourism, Fisheries and Forestry, 1987)
      From the mid 1960s competition for Atlantic salmon intensified with the expansion of high seas fisheries in the marine sub-Arctic and drift-netting closer to home. Inshore commercial fishermen and freshwater anglers saw progressively more of the salmon stock being landed outside its river of origin which prompted some to seek an alternative game species. Sea trout, which have traditionally been a by-catch of the commercial salmon fishery and which game fishermen valued, were considered and various clubs and individuals (fishery owners and managers) addressed queries to the Department responsible for fisheries on the possibility of developing a sea trout run to supplement a declining salmon population. The majority of queries examined by this writer concerned the introduction of sea trout to parts of river systems outside their normal range. A review of sea trout distribution (Fahy, 1977) described their migratory limit inland and contained adequate information to assess the suitability of the majority of fresh water bodies for the fish. The Caragh (Glencar) catchment was more intriguing. There are now in existence many investigations on the inter-relationships of salmonid species in fresh water and on their interactions with their environment but there are few specific references to the suitability of catchments for particular species. This investigation examines a case in point.
    • Prospects for the development of the Irish eel fishery

      Moriarty, C (Department of Fisheries and Forestry (Trade and Information Section), 1981)
      It is considered that the lakes and rivers of Ireland (Republic) could be managed to achieve a production of 1,500 tonnes of eel a year. The value of this catch would be £3 million for fresh fish. A fishery with this yield could form a basis for a processing industry and enhanced value. Experience indicates that the current catch, of not more than 150 tonnes per year, does not provide a sufficiently regular supply of fresh eels to maintain a processing operation and consequently the eels are sold only to wholesalers. The poor catch results from inadequate stocks rather than from inefficient methods of capture. This leaflet gives a description of the eel fishery and its progress in recent years and explains how the stocks can be increased for the future. The special attraction of the proposal is that it offers a means of making a tenfold increase in the yield of one of the most highly priced species of fish without posing any threat to the ultimate survival of the species. The method to be used is the transfer to good feeding grounds of elvers which would otherwise die within months of arrival on our coasts.
    • Recaptures of Adult Salmon tagged as smolts at Carrigadroghid

      Browne, J; Doyle, J (Department of Fisheries and Forestry (Trade and Information Section), 1979)
      A total of 2936 salmon were tagged at Carrigadroghid Co Cork in January 1973. From this tagging there were 34 recaptures, a return rate of 1.16%. In 1975 the number of salmon smolts tagged was 4860 and 18 were recovered, representing a return rate of 0.37%. Details of the recaptures resulting from these two tagging operations are given.
    • Recaptures of Irish Tagged Salmon off Greenland

      Browne, J (Department of Agriculture and Fisheries (Fisheries Division), 1977)
      Since tagging of smolts began in Ireland there have been sixteen distant water recaptures of adult salmon tagged as smolts or parr in Irish waters. Fifteen of these were recaptured from the Greenland fishery and one salmon was recovered from the Faroe Islands. The recaptures resulted from a number of salmon smolt and salmon parr tagging programmes. Some of these programmes were designed specifically to obtain information on the distant migrations of Irish salmon but other programmes were to study migrations and mortality in the home waters. Information on recaptures has been published elsewhere (Piggins 1970, Went 1973). This leaflet brings together all the available information on recaptures of tagged Irish salmon in distant waters up to December 1975 and gives background information on the tagging programmes.
    • Report on Inshore Surveys Around the Irish Coast

      Crowley, M A (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      The purpose of this leaflet is to discuss the quantity and quality of some species of commercially valuable shellfish found in certain estuaries around the Irish coast. In recent years the shellfish industry has attracted considerable interest in Ireland, partly because of the demand in England and on the Continent of Europe for Irish shellfish and shellfish products and partly because of the interest which the general public has in fish farming.
    • Results of 1997 Longline Survey of the Rockall Trough

      Connolly, P L; Kelly, C J; Clarke, M; Hareide, N (Marine Institute, 1999)
      The present survey took place over a period of 12 days in August 1997 along the eastern slope of Rockall Trough between 53 and 58ºN including the Northern slope of the Porcupine Bank. Fishing was carried out in six separate areas, in depths between 300 and 2,925 meters. The primary objective of the survey was to obtain samples of chondricthyan and teleost fish for the Marine Institute (MI) deepwater research programme, for contaminant analysis of fish by the MI chemistry section and for food technology analysis at the Teagasc National Food Centre. The survey was carried out on the Norwegian commercial long-liner "Skarheim," using commercial deep-water autoline gear. In total over 70,000 hooks were set during the trip and on average 80% of these were baited. In total 20 species of chondricthyan and 18 species of teleost fish were taken. Among the most abundant species in the catch were leafscale gulper shark Centrophorus squamosus (36%), bird beak dogfish Deania calcea (21 %), Portuguese dogfish Centrascyflium coefofepis (13%), tusk, Brosme brosme (11%) and mora, Mora mora (6%). Over the entire survey, discarding was estimated as 30% of the total catch. The main species discarded were bird beak dogfish and greater lantern shark Etmopterus princeps. Catch per 1,000 hooks showed that highest abundances were found at 600 - 1,100 metres throughout the whole fishing area. Three settings were made at depths between 2,000 and 3,000 meters. These shots gave valuable information about depth distribution of different species and also brought up species that have never been recorded in the Rockall Trough before.
    • Results of Magnetic tag Recovery Programme in the Mayo Area in 1985

      Gallagher, P (Department of Tourism, Fisheries and Forestry, 1986)
      This leaflet deals with the results of the magnetic tag recovery programme for the Mayo area in 1985. The commercial salmon catch was sampled for adipose fin clipped and micro tagged fish at a number of locations in Mayo. All fish with adipose fin clips were screened with a magnetic tag detector for tags, and the tags were read to establish the origin of the fish. Fish are tagged at various locations throughout the country with magnetic wire tags. These tagged fish are released at different times of the year, and in various river systems to establish the best time of year to release fish and the best locations. The majority of all the tagged fish are hatchery reared, only in the Corrib river are wild fish tagged.
    • Results of Magnetic Tag Recovery Programme in the Mayo Area in 1986

      Gallagher, P; Browne, J (Department of the Marine, 1987)
      Young salmon are tagged at various locations throughout the country with coded wire tags. They are released at different times of the year, and in various river systems to establish the best time of year and the best locations for release. The majority of the tagged fish are hatchery reared, the only exception being in the Corrib and Blackwater rivers where wild smolts are tagged. All micro-tagged fish are adipose fin clipped. Some hatcheries also use an adipose fin clip to mark their reared fish. Twenty nine thousand net caught salmon were examined at a number of locations in Mayo. All fish with adipose fin clips were screened with a magnetic tag detector. A total of 736 tags were recovered from which it was estimated that rearing stations contributed over 1,300 fish to the north Mayo catch.