• Salmon and Trout: Natural and Artificial Propagation as Factors in the Maintenance of Stocks

      Anon. (Department of Agriculture, 1939)
      The object of fishery regulations whether statutory or departmental is, in the ultimate, conservation. That is to say, it is sought by the imposition of certain restrictions to ensure such a run of fish for breeding purposes as will increase or at least maintain the stocks. Many citizens profess dissatisfaction with the existing stocks of fish in our rivers and lakes and persistently urge that they should be enhanced by all practical means. Generally the method which suggests itself to such persons is the setting up of a hatchery, to be operated either by stripping fish captured locally or by procuring supplies of ova (eggs) from outside sources. There seems to be a rather widespread belief that such a procedure even on a modest scale is bound to produce immediately beneficial results for the waters concerned. In other words, the operation of a hatchery is expected to offset completely the evils of over-fishing, as well as the damage resulting from illegal activities (whether within or outside the fishing season) and the reduction in stocks caused by predatory birds, fish and mammals added to the pollution of waters by the entrance of deleterious matter. Such a belief is, however, fallacious as it cannot be accepted in any degree without serious reservation.
    • Salmon movements in Galway Bay in 1978 and 1979

      McCarthy, D T (Department of Agriculture and Fisheries (Fisheries Division), 1980)
      In 1978 tagging investigations commenced into the origin of salmon caught in drift nets in Galway Bay. This fishery began in 1969 with a catch of 355 fish and, by 1975 had increased dramatically to 33,607. However the catch declined to less than half the maximum and in 1979 was down to 15,171. There are 76 drift net licences in the Bay which incorporates two fishery districts, Galway and Connemara. The vessels used vary from 5 metre currachs to 20 metre trawlers. The majority of the boats are half deckers of between 9 and 11 metres. The fishery starts in mid-May but the bulk of the catch is taken in June and July. The main component of the catch is grilse with an average weight of 3 kg. During the period fishing is carried on over 24 hours daily except for the weekly close season time. The fishery extends from west of a straight line from Spiddal Harbour to Blackhead, Co Clare in the east , and from Slyne Head to Hag's Head, Co. Clare in the west and also incorporates the Aran Islands. Drift nets are shot at right angles to the coastline in roughly a north-south direction, all vessels staying quite close to land, the furthest distance out being 2km. The maximum length of net permitted in the area is 730 metres or 800 yards. The majority of boats fished nets of this length; however some of the smaller craft used nets as short as 300 metres. All nets are 30 meshes deep. Throughout the programme fish were tagged using Lea's hydrostatic tags described by Went (1951). As in previous tagging programmes, recovery baths were used to ensure that only the fittest fish were released after tagging.
    • Salmon Tagging in the West of Ireland 1986 to 1988

      McDermott, T (Department of the Marine, 1990-07)
      The analysis of more than twenty-six thousand micro-tag recoveries has led to important discoveries for the management of Irish salmon stocks. This Leaflet gives details of the tagging over half a million young salmon and of the results of recovering 4,000 tags from 1986 to 1988. The most important conclusions are: Careful control of place and time of release of hatchery-reared smolts has a dramatic effect on their survival. In the Corrib system, transportation of smolts from Cong to Galway resulted in a substantial improvement in yield, with a tenfold increase on one occasion. This means that up to ten times as many salmon can be produced at no increase in the cost of rearing them. The returning adult salmon produced from smolts which were released at Galway tended to stay for a long time below the Galway weir and therefore made a major contribution to the rod fishery. Marine survival fluctuated yearly for hatchery and wild smolts released. For hatchery smolts those released later survived best. In contrast wild smolts which migrated in May had a lower survival than those which left in April. Marked differences in homing accuracy, timing and speed of migration were noted between wild and hatchery smolts within the Corrib system. Drift net fisheries depend mainly on the salmon which originate from rivers nearby. There is a distinct division between the catches north and south of Galway Bay: those to the south come mostly from the rivers Shannon and Corrib, those to the north from Connemara rivers. The drift net fishery continues to rely heavily on a self sustaining population of wild salmon despite improved hatchery performance and increasing catch of cage farm escapees. Hatchery smolts transferred to different rivers learned to recognise the new river within a remarkably short time. Two weeks were sufficient to achieve a degree of homing success approaching that of fish returning to their own rivers. This discovery is of major significance in the development of salmon ranching.
    • Salmonid Stocks of the Cloonee Catchment in Co. Kerry

      Fahy, E (Department of Agriculture and Fisheries (Fisheries Division), 1978)
      An assessment of the status of the salmonids in the Cloonee system in Co Kerry is the objective of this work. The rivers and lakes make up a small coastal catchment, typical in many respects of those along the Western seaboard. The composition of its fish stocks is described; the strength of the salmonid species is evaluated and the factors which possibly affect their survival are listed. These estimates derive from observations made at a particular time but other details of the Cloonee system, its water chemistry, invertebrate community and nursery' areas of more lasting interest are also presented.
    • Sampling surveys for deep-water demersal fish in 1993

      Connolly, P L; Kelly, C J (Department of the Marine, 1994-09)
      Potential for new developments in deep water fishing have been identified by two sampling surveys carried out in April and September 1993, in the deep waters off the west coast of Ireland and Scotland. The primary objective of the two surveys was to secure samples of a variety of potentially commercial deep water fish species in order to examine aspects of their age, growth, reproduction and diet. These data will be essential in formulating management plans for the expanding deep water fisheries in the area. The surveys were conducted on a chartered fishing vessel using a commercial otter trawl, fitted with a small mesh cod-end liner. Fishing activity concentrated on the depth range 400m-1200m and a total of 81 trawling operations were carried out, of which 75 produced fish catches with limited gear damage. Fifteen species of cartilaginous and 50 species of teleost fish were recorded from the catches. These include the roundnose grenadier Coryphaenoides rupestris, black scabbard Aphanopus carbo, greater forkbeard Phycis blennoides, blue-mouth rockfish Helicolenus dactylopterus and Baird's smooth-head Alepocephalus bairdii. Length, weight, sex, maturity and catch data together with samples of otoliths, gonads and stomachs were secured. In general terms, the fishing ground off the north west of Ireland and west of Scotland caused little problems with gear damage and yielded good catches of deep water species. The two surveys have shown the areas have potential for commercial deep water fishing but the development of this fishery in the area will be contingent on the establishment of suitable markets. This initial report documents the surveys and presents some preliminary results. The data gathered from these surveys are currently under analysis at the FRC and the results will be published in the scientific literature.
    • Science and Fisheries Management

      Went, A E J (Department of Agriculture and Fisheries (Fisheries Division), 1977)
      The W.J.N. Menzies Memorial Lecture delivered at the Annual Course of the Institute of Fisheries Management at the University of East Anglia, Norwich, on 16 September, 1975.
    • Sea trout of the River Argideen

      Went, A E J (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      A small collection of material consisting of scales and relevant information collected in 1964/5 from sea trout of the Argideen Rive in County Cork was examined and the results compared with those obtained in the years 1954/5.
    • The sea trout year 1980

      Fahy, E (Department of Fisheries and Forestry (Trade and Information Section), 1981)
      The fol1owing pages comprise the first of a brief and, hopefully, annual account of research in progress on sea trout, a summary of results recently available and a short account of stocks of this fish during the preceding fishing season with a tentative prognosis for the coming year. The purpose of the report is to inform user groups, anglers and netsmen, about the work and to promote an interchange of information with interested parties; a primary objective is the identification of priority research objectives and hence the promotion of better management of fisheries in which sea trout are an important or the only quarry.
    • The Sea trout Year 1981

      Fahy, E (Department of Fisheries and Forestry (Trade and Information Section), 1982)
      1981 was not a great year for sea trout landings. Rods which account for a large proportion of the total catch took fish of lower mean weight than in 1980 and various estimates suggest that fewer sea trout were caught in 1981. Numbers of "specimen" sea trout however were high and they are expected to remain so in 1982 after which it is thought they will decline. The draft net catch was also down on 1980; estimates of the drift net catch are inconclusive. In 1981 climatic factors favourable to trout production continued to improve from 1919 but indicators of growth still fell Short of those prevailing in the mid 1970s. The migration of juvenile trout to sea was good but the run seemed to consist largely of slow growing individuals whose development was arrested in 1979. A recovery of sorts would appear to be underway in the stocks and this is the explanation for the low mean weight of individuals caught in 1981. However the extended occupation of nursery areas by parr between 1919 and 1981 may well have inhibited the development of prospective migrants in 1982 and 1983.
    • The Sea Trout Year 1983

      Fahy, E (Department of Fisheries and Forestry (Trade and Information Section), 1984)
      Climatic conditions favourable to sea trout production did not improve in 1983 and juvenile output from freshwater was poor. Several years of a reduced smolt exodus have resulted in the stocks being depleted of older fish and a large proportion of the 1983 landings consisted of post-smolt (finnock). The mean smolt age has been tending upwards so that the prospect for "specimen" sea trout in the future is not good. In spite of the depleted recruitment of the past few years the yield from sea trout fisheries has remained fairly constant: the estimated total catch between 1980 and 1982 varied from 49.4 to 59.3 tonnes. A steady catch total against a background of fluctuating recruitment is due to two factors: first, the catch being a small proportion of the stocks and second, the fact that sea run trout make a divided return to fresh water.
    • The Sea Trout Year 1984

      Fahy, E (Department of Fisheries and Forestry, 1985)
      Climatic conditions favourable to sea trout production continued their decline in 1984 and the indicators are now at their lowest since records commenced in 1948. The exodus of juvenile trout was poor and the age composition of landings in the Waterville fishery suggests finnock were not well represented in the summer catches. The reduced descent of juveniles to the sea and an upward tendency in the mean smolt age of newly recruited fish combine to reduce the prospects for specimen sea trout in the short term. In 1984 seven of these fish were reported, corroborating the reported cyclical trends in their production. All indicators of the rod catch suggest that a reduction in landings took place in 1984, from 1983. The average weight of individual sea trout taken was higher than in the previous year, due to a relatively poor finnock run. The ratio of sea trout to salmon fishing days was far higher than in the previous three years. Whether it represents a genuine switch in interest to the smaller species should be investigated in future years. A scrutiny of licence returns indicates, for the second year, that late season licences yield a high proportion of the total sea trout catch. Licence returns from commercial engines are difficult to interpret. Both drift and draft, however, suggest reduced landings from 1983, of both salmon and trout.
    • The Sea Trout Year 1985

      Fahy, E (Department of Tourism, Fisheries and Forestry, 1986-07)
      The wet year of 1985 yielded good catches to the rod and to commercial engines. Salmon were taken in reasonable numbers in the drift nets although only small numbers of sea trout were captured by this method. The wet angling season is thought to have provided productive fishing conditions contributing largely to a 22% increase over the previous year's landings of sea trout.
    • The Sea Trout Year, 1982

      Fahy, E (Department of Fisheries and Forestry (Trade and Information Section), 1983)
      The large juvenile trout exodus from fresh water to the sea which occurred in 1981 was not repeated in 1982. Climatic indicators suggest alternately good and poor years in the output of juvenile fish with a reduced recruitment to the fishery in the immediate future. The mean smolt age is likely to rise and the consequences of this will most likely be a reasonable post-smolt (or finnock) run and a diminution in the contribution of larger sea trout to the catch. Added to the poor run of exploitable fish in 1982, the angling season was curtailed by very dry weather which reduced effective fishing effort. In spite of this, yield per rod licence was almost identical to that in the previous year. However figures for the fishery districts suggest that fewer sea trout were captured. Draft net catches were up on those of 1981 by 68%. This had been anticipated in Fisheries Leaflet number 116 which suggested that trout from the larger juvenile exodus of 1981 would become exploited as one sea winter fish by this method: the recorded increase in the catch was almost certainly promoted by dry summer weather which confined sea trout to the estuaries. Both draft and drift net sea trout catches constituted a higher proportion of the salmon net catch in. 1982 than in 1981. The latter showed a marked reduction on the previous year but this evaluation of the data does not include returns from the Western and particularly the Northern fisheries regions where the salmon catch was said to be high.
    • The Sea-Trout Year 1986

      Fahy, E (Department of the Marine, 1987-06)
      Available indicators describe 1986 as a poor year for sea trout catches, the reason for this being depleted stocks. A brief growing season contributed to a poor recruitment; runs out of Burrishoole were low and the Waterville catch contained few post-smolt (finnock). While, on the commercial licence returns submitted to the Department, the salmon catch held up to the levels reported in 1985, draft net caught sea trout were fewer. Reports from Fishery Boards suggest catches were about a quarter lower in 1986 than in the previous year. Their report s are corroborated by the rod licence return s which indicate there was a slight rise in the aver age weight of sea trout caught, consistent with a reduced finnock run, and that there was a reduced yield per rod day .
    • Seasonal and Annual Catches of Lobsters, Crawfish, and Crabs 1961-1970

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1972)
      During the ten year period from 1961 to 1970 certain changes took place in the lobster, crawfish and crab fisheries of Ireland which are worth recording and provide valuable information about the seasonal pattern of fishing for those species.
    • Shellfish Survey of Castlemaine Harbour (Cromane)

      Crowley, M (Department of Agriculture and Fisheries (Fisheries Division), 1973)
      Castlemaine Harbour has the oldest mussel fishery in Ireland and the only mussel purification tank to date (capacity 360 tons per month built in 1941) is operated in that area. The monthly landings and their values since 1966 are given in. Recently Castlemaine Harbour has shown a sustained annual growth in mussel landings. In September 1972 a survey was carried out in Castlemains Harbour and the inner part of Dingle Bay to estimate the total quantity of available commercial shellfish. There are bout 6,840 acres in Castlemaine Harbour inside a straight line drawn from Inch Point to the old Coastguard Station at Cromane. About 2,000 of these are sub-littoral and the rest consist of about 1,800 acres of sand (which is less suitable for shellfish farming). A further 2,240 acres of mud and sandy mud at Banc Fluic are suitable for shellfish cultivation. There are a further 880 acres suitable for cockle cultivation outside these boundaries in Glenbeigh Straid known locally as the Cockle Strand.
    • Shellfish Survey of Estuaries and Bays of West Cork

      Crowley, M (Department of Agriculture and Fisheries (Fisheries Division), 1972)
      A survey was carried out in the summer of 1971 in the estuaries and bays of West Cork, by biologists from the Department of Agriculture and Fisheries. The purposes of the survey were to: (1) determine the potential of this area for possible shellfish farming; (2) discover any existing beds of edible mussels or other commercial shellfish species; and (3) describe the type of mussel found in each area.
    • Some comments on the management of the Irish mackerel fishery

      Molloy, J (Department of Fisheries and Forestry (Trade and Information Section), 1981)
      The total Irish catch of mackerel has increased dramatically in recent years and has risen from about 1000 tonnes in 1970/71 to approximately 50 000 tonnes in 1980/81. The total international catch taken by all countries in the ICES division VI, VII and VIII has also increased dramatically in the same period and has risen from 104,000 tonnes in 1970 to 604,000 tonnes in 1980. In 1980 mackerel contributed 40% of the total weight of the Irish wetfish catch and about 18% of the total value (based on the official statistics). Fishermen and processors have, in recent years, invested heavily in new vessels and in processing facilities, on the assumption of a continuation or even possible expansion of the recent high levels of mackerel catches. At the same time it is realized that pelagic fisheries such as herring and mackerel are liable to produce extremely erratic yields when intensively fished and there is always the danger of a sudden collapse of the fishery as has happened in many of our herring stocks. It is therefore important that those engaged in the mackerel fishery should be aware of the latest information relating to the assessment of the mackerel stock and also of the objectives as to how the stock should be managed.
    • Some notes on crab fishing

      Gibson, F A (Department of Agriculture and Fisheries (Fisheries Division), 1957)
      Specific fishing on a commercial scale for the edible crab is practised only to a limited extent in this country and, although fairly substantial quantities of edible crabs are landed annually, these are largely the by-product of creel fishing for lobsters and crawfish. These notes give a short account of certain crab fishing methods and record the results of some experimental fishing undertaken by the Fisheries Division.
    • Some Problems and Methods in Dublin Bay Prawn (Nephrops norvegicus) Research

      Hillis, J P (Department of Agriculture and Fisheries (Fisheries Division), 1972)
      Much is in the process of being learned about the Dublin Bay Prawn or Norway Lobster Nephrops norvegicus (referred to simply as the prawn hereafter) but compared with many other commercially fished species much still remains a mystery. This paper describes methods of examination of its biology and ecology designed to yield information on habits, movements and especially growth and death-rates, these being the two most important factors in the prosperity of the fishery.