• 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.
    • Experiments with the American Hard-Shelled Clam (Mercenaria mercenaria) 1969

      Gibson, F A; Duggan, C B (Department of Agriculture and Fisheries (Fisheries Division), 1970)
      The American hard-shelled clam (Mercenaria mercenaria) is a valuable bivalve molluscan shellfish in the U.S.A, and Canada. This bivalve is somewhat like the cockle (familiar to most Irish people) or the palourde (Venerupis decussata) which is gathered on some parts of the Irish coast and exported to France. Unlike the cockle which lives in sand, or the palourde which is found mainly in coarse sand and shingle, the hard-shelled clam lives in sandy mud. Some years ago this clam established itself in Southampton Water, on the south coast of England. It is thought that this particular stock originated from live clams thrown overboard from an American liner. Due to the warming effect of the outflow from a large power station near Southampton, coupled with naturally occurring high sea-water temperatures in this area, the clams were able to breed and multiply. Normally the seawater temperatures around the coasts of Gt. Britain and Ireland are too low to permit the clams to multiply by natural breeding.