The eradication and management of European carp from two large freshwater lakes in Tasmania — ASN Events

The eradication and management of European carp from two large freshwater lakes in Tasmania (#170)

Jonah Yick 1
  1. Inland Fisheries Service, New Norfolk, TAS, Australia

European carp (Cyprinus carpio) were first discovered in Lakes Crescent and Sorell in January 1995, where they had previously been deemed absent from Tasmania. As a result, the Carp Management Program was established to contain, control, and ultimately eradicate carp from the lakes. Through the development of various techniques over 12 years (1995-2007), a complete eradication of carp from Lake Crescent was achieved using an integrated approach. By using these strategies in Lake Sorell, the carp population was estimated to have been reduced to less than 50 fish by 2009. However, a spawning event which occurred in spring that year resulted in the introduction of approximately 50 000 carp. The techniques used to target these fish varied with life stage. Juvenile carp were initially targeted using rotenone poison, as they were concentrated in marsh environments. As they developed further, intensive netting, electro-fishing, barriers, and traps were used to target these fish as they became more mobile. Biotelemetry techniques were also used to gather knowledge of seasonable habitat preference. In early 2012, a mark/recapture population estimate was initiated using both the Peterson and Schnabel methods of calculation. The most current population estimate calculated in May 2014 suggested that there are now less than 10 000 fish remaining, with 82% of the original population removed. There will be increased emphasis on targeting the remaining carp this coming spring/summer, to take advantage of a strong sex bias towards maturing males. The prevention of spawning will also be a high priority.

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