ASFB Home > 2003 > Biological Invasions: Consequences for Parasites, Pathogens, Emerging Diseases, and Fisheries in the Marine Environment.

Assisted dispersal of freshwater fish species in southeastern Australia: what are the mechanisms and what can we do about it?

Mark Lintermans ^1,2

¹ Environment ACT, PO Box 144, Lyneham ACT 2602, Australia.
2 Cooperative Research Centre for Freshwater Ecology, University of Canberra, ACT 2601, Australia
Email: mark.lintermans@act.gov.au

Human assisted dispersal or movement of freshwater fishes has occurred in Australia since the earliest days of European settlement. In the 19^th Century the majority of cases of assisted movement of fish involved the introduction and spread of alien sportfish by acclimatisation societies. In the first half of the 20^th Century there were no new freshwater fish species introduced into Australia, but deliberate movement of both native and alien species for recreational purposes within the country continued. At this time large-scale engineering projects such as the Snowy Mountains Hydroelectric Scheme commenced, along with the construction of dams and irrigation schemes. By the latter half of the 20^th Century, dam construction was at its peak due to increasing demand for irrigation water, an aquaculture industry had become established, and a large industry based around exotic aquarium fish had developed, all of which had the potential to move fish outside of their normal or established distributional range. At the same time it was becoming increasingly apparent that riverine and floodplain ecosystems were in decline, with a consequent drop in the resilience of fish communities, and resistance to invasion.

This presentation outlines the variety of human-mediated mechanisms that have lead to the spread of and invasion by freshwater fish species in southeastern Australia in the latter half of the 20^th Century. Recent management approaches to the problem are reviewed, and future management actions are suggested.

Room 1 Tuesday 4.05 pm