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Aspects of the culture‐based fishery of the shortfinned eel, Anguilla australis , in western Victoria, Australia
Author(s) -
Skehan Bradley W.,
Silva Sena S. De
Publication year - 1998
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.1998.tb00609.x
Subject(s) - stocking , fishery , shore , estuary , hectare , biology , fish <actinopterygii> , fish farming , aquaculture , ecology , agriculture
Summary The Victorian eel fishery is based primarily on the shortfinned eel, Anguilla australis , and is essentially a culture‐based fishery. The fishery is highly regulated and adopts two basic strategies: stocking of glass eel and elvers caught in estuarine waters during their inland migration, and stocking of undersized, juvenile fish which are in poor condition when caught from various inland waters. The latter group is popularly known as ‘restock’ fish. In the present study commercial catch, effort and stocking data for 17 culture lakes in western Victoria (37°26'‐38°15'S, 142°13'‐144°06'E) were consulted with the view to improving the selection and management of culture lakes and their eel fishery. The database was used to explore the development of various yield‐predictive models, incorporating different mor‐phometric data of the lakes and fishery data, and combinations thereof. Models depicting curvilinear relationships between the annual mean fish yield per hectare of several lakes and their catchment area: shoreline development (D J ratio (where D L = s/2 √∏A and A = lake surface area in km 2 and s = shoreline length in km), and mean water surface area were the most valid statistically. While fish yield was most strongly correlated with surface area, other factors such as lake fertility may have had an important contribution. The effectiveness of the stocking program was investigated using time‐lapse analysis which was also used to estimate when elvers and larger ‘restock’ fish appear in the commercial catches. Whereas ‘restock’ eels entered at 1–5 years after stocking, elvers entered after 8–13 years. The mean yield per hectare was linearly related to the stocking rate of ‘restock’ eels. The preliminary results of elver stockings caution that a re‐evaluation of this program may be necessary.