• 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 Mortalities at Inver Bay and McSwyne’s Bay Finfish farms, County Donegal, Ireland, during 2003

      Cronin, M.; Cusack, C.; Geoghegan, F.; Jackson, D.; McGovern, E.; McMahon, T.; O'Beirn, F.X.; Ó Cinneide, M.; Silke, J. (Marine Institute, 2004)
      This report details the investigations into a major mortality of farmed salmon at Inver Bay and McSwyne’s Bay, Co. Donegal in July 2003. Previous reports were provided on 29th July 2003 and on 11th August 2003. The information is based upon analysis and research by MI scientists, a review of environmental data, survey reports by external consultants, inputs from veterinary practitioners who visited the site, reports from DCMNR staff in Killybegs, and site visits made by DCMNR / MI inspectors. Following a review meeting of the principal investigators on the 9th October, 2003, MI proceeded to carry out further scientific investigations. DCMNR also commissioned Kirk McClure Morton Consulting Engineers (KMM) to carry out a parallel investigation of the mortalities at Inver Bay and McSwynes Bay salmon farms. MI provided support as required to the KMM study, the report for which was furnished to DCMNR and MI on 11 February 2004. (KMM, 2004) MI wishes to acknowledge the high level of co-operation and assistance that it received from the owners and staff of Creevin Fish Farm Ltd, Eany Fish Products Ltd and Ocean Farms Ltd. It also wishes to acknowledge the assistance of veterinary practitioners, DCMNR staff and others in the course of this investigation.
    • 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 carrying capacity of streams in the Connemara region, a resource appraisal

      Fahy, E.; Nixon, J. J.; Murphy, M.; Dempster, S. (Department of Fisheries and Forestry, 1984)
      Standing crops of salmonids in the Connemara region are described from 80 site fishings made between March 1982 and May of the following year. Trout were more widely distributed than salmon, being able to exploit isolated water bodies as resident populations. High salmonid densities were associated with salmon which during the dry summer months were caught in large numbers on riffles. The smallest streams in the region supported only trout presumably because there was insufficient depth of water to permit the entry of salmon. Trout biomass and density within the region were distributed within the lower range reported from a number of countries in which brown trout are endemic and naturalised. Low saimonid densities at 16% of sites were in some cases associated with the rooting of angiosperms, and possibly oligotrophic conditions resulting from geological structure. Length at age of salmon and trout was similar to measurements recorded in Britain. The streams were important only for the first year of the trout life cycle. Because trout move downstream as they grow, occupying lakes during the later parr phase, and the entire streambed area in Connemara is one fortieth of the lake area, space is unlikely to be a critical constraint on the later parr phase. The condition of the stream substratum may be a factor in the production of sea trout; where loose gravels do not occur in shallow nursery streams, the catchments tend towards producing "brown" or "resident" rather than sea trout.
    • 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.
    • Save the sea 3D poster

      Marine Institute (Marine Institute, 2013)
      The aim of the lesson plan is for students to develop drawings, paint and colour, as well as use fabric, fibre (including shells, seaweeds, flotsam and jetsam from the seashore) to create a 3D - poster showing how people can protect the marine environment and save the sea. This lesson plan should be delivered after the students have learned about the environment and the sea.
    • Scale Growth Analysis of Atlantic salmon (Salmo salar Linnaeus) Unlocking Environmental Histories

      Thomas, K. (Galway-Mayo Institute of Technology, 2018)
      Atlantic salmon (Salmo salar L.) populations have declined rapidly in recent years across all geographical ranges with populations becoming extinct within certain areas. Direct observation of the salmon’s life is difficult and costly; therefore, scales remain the most widely used material to indirectly assess and monitor the recent changes in growth. Growth marks (circuli) in scales of Atlantic salmon are used to estimate age and to reconstruct growth histories. This thesis investigated mechanisms of circuli formation and the causes of variation in scale growth measurements. Comparison of scales from multiple body locations (Chapter 2) showed that growth, size and shape measurements varied significantly between body locations. Scale measurements taken from the sampling location recommended by ICES were sufficiently correlated with measurements from two adjacent locations in the posterior body region to facilitate conversion; calibration equations are presented for this purpose. Scale measurements from the anterior body region were highly variable and their use is not recommended. Scale size measurements from the recommended sampling location and from the two adjacent locations in the posterior body region were sufficiently correlated with fish fork length. Differences in scale size could potentially be used to determine the body location from which a scale was most likely sampled if this information has not been recorded (e.g. in archived scale collections); regression equations are presented for this purpose. Analysis of scales from experimentally reared Atlantic salmon post-smolts (Chapters 3 and 4), showed that scale growth and circuli number was proportional to fish growth under a range of different water temperatures and feeding conditions, justifying the use of these measurements as a proxy for growth. The rate of circuli deposition varied between temperature and feeding treatments and circuli number was proportional to cumulative degree day. Narrow inter-circuli spacings were observed during periods of slow growth at low temperatures and during periods of fast growth at high temperatures; therefore, circuli spacing should not be used to infer growth rates. In Chapter 5, scales from Atlantic salmon collected from three Irish rivers (Burrishoole, Moy and the Shannon) between 1954 and 2008 were analysed to determine if marine growth has changed during that period and to establish if trends are consistent across populations. Scale growth measurements and their temporal trends varied between populations. Post-smolt scale growth and circuli number were negatively correlated with SST (Burrishoole and Moy), NAO (Burrishoole) and AMO Burrishoole and Shannon). The results indicate that trends observed in one national index river may not be representative of change across all populations. The new knowledge generated in this thesis supports more accurate interpretation of scale growth measurements, furthers our understanding of this important species and ultimately benefits the future management of this species.
    • Science - Creature Features and Chemosynthesis

      Marine Institute; Tulca (Marine Institute, 2018)
      The Creature Features and Chemosynthesis Presentation is a simple PowerPoint presentation about life in the hydrothermal vent ecosystem. The presentation introduces students to some of the unique creatures that live there and how the vents provide energy for them to survive through the process of chemosynthesis.
    • 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.
    • Science: 1st Class and 2nd Class: Beach Towels - What Material Works Best (Irish and English Version)

      Marine Institute (Marine Institute, 2014)
      The aim of the lesson plan is for the children to identify and investigate materials that absorb water.
    • Science: 1st Class and 2nd Class_ Exploring Materials which will protect Scuba Steve from Electric Fish (Irish and English Version)

      Marine Institute (Marine Institute, 2014)
      The aim of the lesson plan is for children to identify materials that allow electricity to pass through them. Experiments and demonstrations are to be conducted by the teacher. Students will become aware of the dangers of electricity as well as learn about animals in the ocean that conduct electricity.
    • Science: 3rd and 4th Class - Design and Make a Compass (Irish and English Version)

      Marine Institute (Marine Institute., 2014)
      The aim of the lesson plan is for the children to explore relationships between magnets and compasses.
    • Science: 3rd and 4th class - Flood Defences

      Marine Institute (Marine Institute, 2015)
      Children will explore and experiment with the properties and characteristics of a variety of materials in making a structure based on the theme of creating a flood defence. The children will use their scientific, engineering and mathematical skills.
    • Science: 5th and 6th class- Introduction to degradation and how long it takes for materials to break down

      Marine Institute (Marine Institute, 2015)
      The children will learn about the degradation of items typically found on the seashore. This activity can be done in class before visiting the seashore and carrying out a beach clean. Also see geography lesson plan on how to organise a beach clean: http://hdl.handle.net/10793/1108
    • Science: 5th and 6th class- Plant and Animal Life on the Seashore - Creating a Seashore, Species and Seaweed Guide

      Marine Institute (Marine Institute, 2015)
      The children will create a Seashore Species and Seaweed Guide. The lesson plan includes a series of activities for in the classroom and / or on the seashore including completing drawings and illustrations from observation. The children will also write about the seashore, sand, animals and plants demonstrating their understanding of the habitats and the zones where the animals and seaweeds are typically found.
    • Science: 5th and 6th class- Seashore Exploration and Guided Tour

      Marine Institute (Marine Institute, 2015)
      Conduct a fieldtrip to the seashore exploring the plants and animal life. Working scientifically the children will learn about the variety and characteristics of living things and processes of life typically found on the seashore.
    • Science: 5th and 6th class- Squid Dissection and Project lesson plan and worksheet

      Marine Institute (Marine Institute, 2015)
      The children will be provided with an introduction to the life process of a squid. The will also learn about the external and internal parts of a squid. The children will also explore some of the ways squid have adapted to environmental conditions as well as discuss simple food chains. As an extension the children may complete a project on the different types of squid found in the ocean.
    • Science: 5th and 6th class-Biodegradation quiz and beach activities using the biodegradation information sheet

      Marine Institute (Marine Institute, 2015)
      The children will learn about the biodegradation of items typically found on the seashore. This activity can be done in class or on the seashore. See also the geography lesson plan on how to organise a seashore safari and beach clea at http://hdl.handle.net/10793/1108