ENVIRONMENTAL-CHANGE IN LOUGH-GARADICE SINCE THE 17TH-CENTURY BASED ON CLADOCERAN REMAINS IN THE SEDIMENTS

A palaeoecological study of cladoceran remains in the sediments of Lou gh Garadice has been made, covering the past three centuries. From con siderations of the absolute rates of accumulation of microfossils, thr ee notable changes in the recent history of the lough can be dated to (i) the early eighteenth century (significant increase in Bosmina core goni), (ii) the mid-nineteenth century (halt in the B. coregoni increa se and temporary absence of Alona guttata), and (iii) the twentieth ce ntury (decline in B. coregoni, significant appearance of B. longirostr is and increase in Daphnia spp). These changes are interpreted in term s of cladoceran ecology against historical evidence of changes in huma n and animal populations, the construction of the Ballinamore canal, s anitary history and soils of the catchment.