• American Hard-Shelled Clam Experiments in Irish Waters

      Gibson, F A; Duggan, C B (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      In each of the years 1969, 1970 and 1971, the Fisheries Division of the Department of Agriculture and Fisheries, introduced experimental batches of second generation, disease free American hard-shelled clams from the hatchery operated by the Ministry of Agriculture, Fisheries and Food at Conmay North Wales to selected areas of the Irish coast. An analysis of the 1969 plantings of seed hard-shelled clam has already been made by Gibson and Duggnn in Fishery Leaflet No. 24 published in 1970. The results of further observations carried out from 1970 to 1972, are now incorporated with the 1969 data and together form the material for this Leaflet.
    • Appraisal of the whelk (Buccinum undatum) fishery on a part of the Codling Bank following aggregate extraction for beach restoration at Bray, Co Wicklow

      Fahy, E; O'Toole, M; Stokes, D; Gallagher, M (Marine Institute, 2002)
      The Codling Bank is an important contributor to the south west Irish Sea whelk fishery; a large proportion of the whelk population there are juveniles. Traditionally, whelks have been harvested ungraded from this area. Fishing trials were undertaken on the Codling Bank in May 2001 to ascertain the consequences for the whelk fishery of aggregate removal by suction dredging during the previous winter months. The results suggested some localised diminution in CPUE in the vicinity of dredging operations four months after the event. However, it is not feasible to conclusively attribute the reduction to dredging operations.
    • The Assessment of the Western Mackerel Stock

      Molloy, J (Marine Institute, 1996)
      The mackerel fishery is one of the most important components of the Irish fishing industry. The annual Irish quota is based on the scientific assessments of the size of the spawning stock. These assessments are based on the mackerel egg surveys which are carried out every three years and on the age composition of the total catches. The assessments have indicated that the stock in recent years has declined substantially and is now below 2 million tonnes. Predictions on the development of the stock indicate that it will decline even further unless catches are substantially reduced. The management target for the stock is that it should be rebuilt to a level above 2 million tonnes as quickly as possible. The decline in the stock has resulted in severe reductions in the Irish annual quota and this in turn has had a serious effect on both the catching and processing sectors of the industry.
    • The Avonmore Brown Trout Fishery at Rathdrum, Co. Wicklow

      Fahy, E; Reynolds, J (Department of the Marine, 1987)
      A massive ore body in the Vale of Avoca has been mined since 1752. Environmental consequences have included a sulphide rich effluent entering the river from the workings and creating a pollution block which effectively disrupts migrations of migratory salmonids. The angling fishery upstream of the block, in the vicinity of Rathdrum, exploits small resident brown trout. Prospects for the further development of this fishery are considered and the present arrangements are reckoned to be most suitable for the foreseeable future.
    • Bibliography of Irish Salmon

      Twomey, E (Department of Agriculture and Fisheries (Fisheries Division), 1976)
      Documents papers and articles, published up to 1975, that focus on Irish Salmon.
    • Capture of sea-trout by illegal means in the Western Fisheries Region: Some Observations for Discussion

      Fahy, E (Department of Fisheries and Forestry, 1986)
      Circumstances concerning the possible illegal exploitation of sea trout in two western fishery districts in which the fish are an important component of the salmonid catch are reviewed. Legal methods of capture in the districts are described. The illegal fishery consists largely of nets fixed close inshore. The meshings available are described in terms of colour, size, thread width and materials. The meshes belong to one of two size groups. The larger of these is suitable for salmon and only trout of more than four sea winters are likely to be caught in them; these fish are relatively rare on the western seaboard. The group of smaller meshes would be effective in the capture of sea trout and fish of one sea winter would be particularly susceptible. Unfortunately the mesh marks inflicted by such nets would be similar to those made by a draft net, used legally. The greater part of the illegal salmonid fishery is apparently directed at salmon.
    • Catch and Discards for a Deep-Water Trawl Survey in 1996

      Kelly, C J; Clarke, M; Connolly, P L (Marine Institute, 1997)
      The Fisheries Research Centre has conducted a deep-water survey programme since 1993 and as part of this programme a deep-water trawl survey was carried out in September 1996. The survey fished areas along the continental slope west of Ireland from 52° N to 58° N at depths of 500-1,200m The primary objective was to secure samples of potentially commercial deep-water shark and teleost species in order to examine aspects of their age, growth, reproduction and diet. The survey was conducted on a chartered commercial fishing vessel using a deep-water otter trawl fitted with a small mesh cod-end liner. A total of 26 hauls were made during 87 hours of fishing and yielded a total catch of 29,345 kg. The ground covered ranged from mud to gravel and bare rock and there was no significant gear damage during the survey. Thirteen species of chondrichtian and 33 species of teleost fish were recorded. Length, weight sex and maturity data were taken from some of these species. The most abundant species in the catch were Baird's smoothhead, roundnose grenadier, leafscale gulper shark, black scabbard and orange roughy. Trawl discards expressed as kg discarded per tonne of roundnose grenadier landed were calculated for a broad range of the most abundant species in the catch. During the survey in the Rockall Trough an estimated 16t of deep-water species were discarded and results are compared to estimates for 1995. The main species discarded were smoothhead, squaliform sharks and Lepidion eques. Results indicate up to 16,783t of deep-water species may have been discarded from the deep-water fishery in this area in 1996. This report documents the survey and presents some preliminary results. The data gathered during these surveys are currently under analysis at the PRC and the results will be published in the scientific literature.
    • Catch and Effort and Size Distribution in the Irish Lobster and Lobster/Crawfish Fisheries

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1972)
      In recent years, increasing attention has been paid to the interpretation of the effects of fishing effort upon the stock abundance of commercially valuable decapod crustacea. Simpson (1970) has emphasised the value of and urgent need for, precise information concerning the effects of fishing effort on lobster and crawfish stocks. By their very nature, lobsters and crawfish do not lend themselves particularly well to conformity with established methods of catch and effort analyses as applied to fish stocks. Therefore, whilst this almost traditional approach is adopted for lobster and crawfish studies, it may well be that considerable adjustments in the methodology are required if firmer estimations are to be achieved concerning the effects of fishing effort upon these animals. A most important gap in our knowledge is that of the mechanism of recruitment. Without reliable estimates of annual recruitment it is difficult to interpret its effects on abundance of good or poor year classes. Fully reliable methods of ageing lobsters have not been perfected.
    • Catch and Effort in the Irish Lobster Fishery During 1971

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      Once again it must be reported that only a small number of fishermen participated in the log book scheme operated by the Fisheries Division of the Department of Agriculture and Fisheries. Valuable as the data given by these fishermen are, and important as they are to the future of management in the Irish lobster fishery, it must be said that the participation of a very much more extensive section of fishermen would greatly enhance the value of the catch effort data. A further appeal is made to the readers of this Leaflet, that they should join this scheme and thereby contribute information important to the future of this fishery, which in 1971 brought in £338,000 to the fishermen.
    • Catch Effort and Size Distribution in the Irish Lobster Fishing Industry in 1969 and 1970

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1972)
      This leaflet continues the study of catch and effort in the Irish lobster fishery, commenced in 1968, which was the subject matter of Fishery Leaflet No. 14 (Gibson 1968), As before, the results set out in this Leaflet have been obtained mainly from information supplied by Irish lobster fishermen who kept log books of their catch and effort in 1969. The response by fishermen to the requests by the Department to keep and fill in log books was still not as satisfactory as was expected, with the result that once again less than twenty log books were returned which contained information of sufficient standard to be useful in calculating the relationship between fishing and effort. The recording of this data is essential for the proper management of the lobster fishery in Irish waters and it is unfortunate that more fishermen are not co-operating in the log book scheme which is designed to help them. Those fishermen who have taken part in the scheme have already freely acknowledged that the log books (which remain their own property) have proved invaluable to them in their fishing operations, Furthermore the reproduction of all the data supplied by fishermen in one Leaflet enables those interested to see the rate of catch made by each type of boat or fishing gear. This information enables fishermen to compare their fishing results with those of others and so perhaps helps them to choose alternative and more satisfactory means for the capture of lobsters. However, if this service is to be of most advantage to all fishermen, the numbers of fishermen filling in log books must be increased considerably. It is hoped that the annual publication of these records will encourage other fishermen to join the scheme thereby furthering everyone's knowledge of this important species in Irish waters.
    • Catch Effort and Size Distributions of the Catch in the Irish Lobster Fishery (1968)

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1969)
      The object of this leaflet is to discuss methods of comparing the success (catch per unit effort) of various types of traps for the capture of lobsters and the relationship of the information thus obtained to the lobster stocks themselves.
    • Catch Per Unit Effort by the Joint Venture (Irish-Spanish) Fleet from 1985 to 1992

      Fahy, E; Gleeson, P (Department of the Marine, 1993)
      The formation in 1979 of the joint venture (Irish-Spanish) fishing fleet, Eiranova, introduced to the industry in Ireland a range of target species and fishing grounds on which the Irish demersal fishery has subsequently expanded. From the second quarter of 1985 the European Communities' Logbook has provided a format on which landings and details of fishing effort have been recorded. This leaflet reviews the catches of various species per effort expended by joint venture demersal trawl and long-lining vessels for the eight years documented by the Logsheets. The high value components of the trawl fishery are the prime fish (hake, monkfish and megrim) which are exported fresh to Spain. Hake is the principal target of long-liners. The fishery is concentrated in ICES statistical Divisions VIIb and VIIj. Since 1985, the CPUE of all species has declined by 39% and the trend in prime fish landings runs in parallel with this, mainly because of the reduction in hake landings. CPUE indices for all other species which are consistently recorded are given. Some comparisons are made among CPUE indices in Divisions VIlb, j and adjoining areas. However, these indices depend much on the exploited size range of a target species and the area in which fishing effort is concentrated and the bulk of the data are presented without further comment. A brief glossary of Spanish terminology is appended.
    • The Clogherhead herring fishery 1971-73

      Molloy, J (Department of Agriculture and Fisheries (Fisheries Division), 1974)
      Landings of herrings have occasionally been made at Clogherhead during the last twenty years. The amounts however have varied considerably, the variations being caused both by changes in the availability of herrings and by the effort of the local fishing fleet. Throughout the last few years the scarcity of herrings throughout Europe has resulted in a very good demand and considerable attention is now being paid to the herring stocks in the northern part of the Irish Sea. The annual catches in tons since 1951 in the ICES statistical area VIIa (Irish sea) are shown. These figures have been altered to include landings made in the Isle of Man and to exclude landings made at Dunmore East in the year 1960-1966. Also shown are the landings made along the eastern Irish coast and the landings made at Clogherhead. After considerable fluctuations in the nineteen sixties, the total catch has risen dramatically since 1969. This increase is particularly evident in the catches made from the Isle of Man fishery. In 1969 also the Irish catch increased considerably because of the establishment of a fish meal factory at Mornington. Incidentally almost all the herrings taken from area VIIa are taken from that portion which is north of a line drawn from Dublin to Liverpool.
    • The Closure of Herring Spawning Grounds in the Celtic Sea and Div. VIIj

      Molloy, J (Department of the Marine, 1989)
      The development of the demand for roe from the Celtic Sea has resulted in an intensification of the fishery for herring while the shoals are on the spawning beds. Stocks at this time are at their most vulnerable and uncontrolled fishing could lead to a repetition of the disaster of the 1970s. At the same time, no effort must be spared in maximising the profit from such a lucrative fishery. The problems arise from the fact that the type of herring required by the Japanese market is very specific and large quantities of unsuitable fish may be caught and discarded. Furthermore, because fishing takes place in the breeding area, there is an obvious risk of seriously disrupting all spawning. This paper presents some of the aspects that must be considered so that on the one hand maximum catches may be obtained and on the other the long-term survival of the fishery may be guaranteed. In particular, the reasons for the closure of selected spawning areas are explained.
    • Contaminants in marine biota 1990 monitoring programme

      Nixon, E R; McLaughlin, D; Boelens, R G; O'Sullivan, G (Department of the Marine, 1991)
      In 1990, samples of fish from commercial catches landed in Ireland, and fish and shellfish collected at Irish coastal sites, were analysed in accordance with the requirements of the Joint Monitoring Programme (JMP) of the Oslo and Paris Commissions (OSPARCOM). The methodologies employed were consistent with JMP Purpose A: Significance to human health, and JMP Purpose C: Existing geographical distributions. The levels of heavy metals and chlorinated hydrocarbon compounds were generally low: well below the internationally accepted levels for protection of human health, and below the levels known to be of significance to marine life. Higher than Irish average levels were found in areas such as Dublin Bay, Cork Harbour, Mornington on the river Boyne, and the Barrow and Rogerstown Estuaries. These are all adjacent to densely populated and industrialised catchments and coasts. There were no cases of serious contamination.
    • The Contribution of Hatchery-Reared Smolts to the Irish Drift Net Fishery

      Twomey, E (Department of Fisheries and Forestry, 1982)
      This Leaflet gives the results of the examination of 104,851 salmon caught by the drift nets between 1978 and 1981. The majority of salmon taken in the Irish commercial fishery are caught by drift nets. The drift net fishery takes place in coastal waters from May onwards and exploits, in the main, one sea-winter fish. In order to quantify the contribution of hatchery reared smolts to the fishery, the commercial catch was sampled at various landing sites between 1978 and 1981. The results obtained showed that the reared fish were randomly distributed in the drift net catch around the coast from Malin Head to Ardmore Bay. The highest contribution (12.9%) was found in the fish captured along the Galway and South Mayo coasts. The next highest contribution was in West Cork where 6.3% of the fish sampled were recorded as reared. The analysis of each day's sample throughout the season indicated that the reared fish arrived concurrently with the wild salmon. A calculation of the value of the salmon which were derived from hatchery-reared smolts was made, based on the percentage of reared fish observed in the catch samples. The conclusion was drawn that, although the contribution of reared smolts to the total catch is small, the principle of artificial rearing of smolts is justified in view of the contribution to the national catch and the spawning stock.
    • Crawfish Investigations 1966-68

      Molloy, J P (Department of Agriculture and Fisheries (Fisheries Division), 1970)
      The fishery for crawfish (Palinurus elephas) in Irish waters has previously been described by Gibson and O'Riordan (1965) and by Gibson (1967). Molloy (1968) has given some details of the scientific work done on this species in recent years. One of the most important aspects of this fishery is that both lobsters and crawfish are exploited simultaneously by boats which use the same type of traps and baits for the two species. Neither the location nor extent of the fishery has shown any marked change since it first became an important aspect of the Irish fishing industry but the annual landings still show considerable variations. These fluctuations in the yearly catch would seem to depend more on the duration of the season and its length, rather than on changes in stock abundance (Gibson 1967). The annual landings (to the nearest thousand fish) since 1951 are shown. The landings in 1968 were surprisingly low for a season which was marked by exceptionally fine weather.
    • Deepwater longline survey of the slopes of Porcupine Bank and Porcupine Seabight

      Clarke, M; Hareide, N; Hoey, S (Marine Institute, 2001)
      This survey took place over a period of 12 days in November and December 1999 on the western slope of the Porcupine Bank and the western and eastern slopes of the Porcupine Seabight. Fishing was carried out in five separate areas, in depths between 400 and 2,000 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 Teagase National Food Centre. The survey was carried out on a commercial long-liner, using commercial deep-water autoline gear. In total 18 species of chondricthyan, 24 species of teleost fish and 1 species of cephalopod were taken. Among the most abundant species in the catch were bird beak dogfish, leafscale gulper shark, Portuguese dogfish and mora. Over the entire survey, discarding was estimated as 42% of the total catch. The main species discarded were birdbeak dogfish, black mouth dogfish and greater lantern shark. Catch per 1,000 hooks (CPU E) was highest abundances were found in the western and northwestern slope of the Porcupine Bank. The catch rates in the slopes of the Porcupine Seabight were considerable lower. CPUE compared with rates from previous years in the northwestern slope, showed a reduction for the commercial species Portuguese dogfish and leafscale gulper shark.
    • Deepwater longline survey on the continental slopes of Porcupine Bank, Rockall Bank and Hatton Bank

      Clarke, M; Moore, S J (Marine Institute, 2002)
      A deepwater survey programme has been operated since 1993 by the Marine Institute (MI), in the deep waters of the Rockall Trough and Porcupine Bank. The first leg of the present survey took place over a period of 12 days in August 2000 on the Western slope of the Porcupine Bank and the western slopes of Rockall Bank and Hatton Bank. The second leg took place on the slopes and shelves of the Porcupine Bank. Fishing was carried out in depths between 150 and 1,800 meters. The primary objective of the survey was to obtain biological samples of chondricthyan and teleost fish, for contaminant analysis of fish by the MI chemistry section and for food technology analysis at the Teagase National Food Centre. The survey was carried out on the commercial long-liner "An Capall Bán," using commercial deepwater autoline gear. In total 26 species of chondricthyan and 24 species of teleost fish were taken. Among the most abundant species in the catch were birdbeak dogfish (22%), leafscale gulpershark (14%), Portuguese dogfish (8%), tusk (17%) and mora (8%). Over the entire survey, discarding was estimated at 43% of the total catch. The main species discarded were bird beak dogfish and greater lantern shark. Catch per unit effort showed that highest abundances were found in the northwestern slope of the Porcupine Bank at 600 - 700 metres and in the western slopes of Rockall Bank and Hatton Bank at 1,000 to 1,200 metres depths.
    • Deepwater Trawl and Longline Surveys in 1995

      Connolly, P L; Kelly, C J (Marine Institute, 1997)
      Two surveys were carried out in 1995 as part of the continuing deep water fish research programme at the Fisheries Research Centre. The trawl survey fished areas on the eastern slopes of the Rockall Trough and on two seamounts of the mid-Atlantic ridge approximately 300 miles north of the Azores. The deep water longline trip was the first such survey carried out by the Fisheries Research Centre and concentrated on previously fished grounds in the Rockall Trough and on new areas along the slope of the Porcupine Bank. Both surveys were carried out in conjunction with an Bord Iascaigh Mhara (BIM) and the objective was to locate commercial quantities of deep water fish and to obtain samples for biological analyses. The trawl survey was conducted on a chartered fishing vessel using a commercial otter trawl, fitted with a small mesh cod-end liner. Twenty-six trawling operations were carried out in the depth range 750m-1,400m, of which 21 produced fish catches. Longlines were set between 542m and 1,521m and only one line was lost. Thirteen chondricthian and 38 species of teleost fish were recorded from the catches. The most abundant species in the catches were Portuguese shark, roundnose grenadier, black scabbard, Baird's smoothhead, blue ling and orange roughy. Length, weight, sex, maturity and catch data together with samples of otoliths and gonads were collected. Discards were monitored from both fishing methods. In comparison with the trawl, longline catches produced larger specimens of fewer species which were more dominated by sharks. Overall catch rates for the longlines were similar to Norwegian data for the Rockall area. Trawl catch rates showed a decrease since the last Irish survey in this area in 1993.