THE MANAGEMENT OF GLASS EELS IN THE SHANNON ESTUARY, IRELAND
Abstract
Fisheries Conservation Hydro Group of the Electricity Supply Board have been trapping elvers on the Shannon since 1959, for subsequent planting in lakes throughout the Shannon catchment as part of the E.S.B. conservation programme and to sustain the yellow and silver eel fisheries in some of these areas.
With the numbers of elvers caught declining in recent years, an assessment of the current stocks of glass eels entering the Shannon Estuary was deemed necessary to improve and maintain the supply of elvers to stock the Shannon lakes. This study, which began in October 1992, is to examine abundance and distribution of glass eels in the estuary and evaluate the possibility of developing a fishery for glass eels for the continued stocking of the Shannon lakes. Experimental methods for developing a more efficient fishery using a trawling net, hand nets and a Portuguese botirão were explored.
Catch data shows the main movement of glass eels to occur at the begining of April.
Details on morphometrics and stage of pigmentation revealed that the length of glass eels of similar pigment stage decreases while weight increases from February through till April. There is also very little variation in the length and weight of the different pigment stages examined on the same date after the VB stage and before the VIB stage.
