Stock enhancement strategies can be a cost-effective means of restoring or maintaining fisheries, and have proven essential in catchments with barriers to migration (Knights and White 1998). Regulation of natural river systems has obstructed eel migration in many catchments, and with the implementation of appropriate management tools such as fish passes / ladders and translocation through trapping / netting programs, restoration of stocks can be achieved. Such strategies have not only proven successful in increasing commercial fishery yields, but also contribute to enhanced spawning stocks and increased silver eel escapements.

Hydro electric operations (dams and power generating turbines) reduce the chance of successful emigration of silver eel, especially for larger female eel (Dekker 1999), and, depending on flow and turbine type and number, may represent a major source of mortality to pre-spawning adults (Ritter et al 1997).The design of downstream passage ways and the use of non-generating periods to reduce mortality have been trialled and implemented in New Zealand, the USA and Europe, but have yet to be adopted or investigated in Australia.

The sustainability of the eel resource in Tasmania and of existing (and potentially new) commercial eel fisheries in hydro-impounded catchments will ultimately depend on the implementation of appropriate and effective mitigation strategies (passage and/or translocations) specific to both upstream and downstream migrations.

This proposed program addresses the issue of sustainability by assessing both cause and effect of impacts and various mitigation options. It is envisaged that the results and recommendations arising from this proposed study will underpin the development of an integrated management strategy for managing eel fisheries in hydro-impacted catchments with direct benefits to managers and industry alike. Results from this study could be readily transferred to other States, with coordination and dissemination through the existing Australian and New Zealand Eel Reference Group (ANZERG).

REFERENCES

Dekker, W. 1999. Effects of Transfers and Restocking of Eel. Report of the EIFAC Working Group on Eels - Denmark, September 1999. Pp13-17.

Knights, B. and E. White, 1998. An appraisal of stocking strategies for the European eel, Anguilla anguilla - In Cowx, I.G. (ed): Stocking and Introduction of Fish. Fishing News Books. Pp 121-140.

Ritter, J.A., Stanfield, M. and Peterson, R.H. 1997. The American Eel in Eastern Canada - Stock Status and Management Strategies. Proceedings of Eel Workshop January 13-14 1997, Quebec City, QC. Can. Tech. Report 2196. 174p.

Fyke nets are used exclusively in the Victorian Eel Fishery and, although potentially large quantities of bycatch are encountered in the fishery, the ecological risk of using fyke nets is low as bycatch is generally released from fyke nets unharmed.

An ecological risk assessment has been undertaken on the impact of eel fishing on bycatch, including fish and protected fauna, and the risk has been determined to be low. For some sectors of the community however, the bycatch of protected species such as native waterbirds, tortoises and platypuses is considered to be unacceptable. There is therefore a need to implement cost-effective strategies to reduce bycatch.

The BAP recognises that the development of efficient Bycatch Reduction Devices (BRDs) is expected to aid in the reduction of capture and/or mortality of endangered, threatened or protected species.

This project addresses the recommendations of the BAP to develop new methods of reducing bycatch in sensitive waterbodies, such as wildlife reserves and dams where commercial eel fishing is permitted. This is consistent with the overarching objective of the Victorian Eel Fishery Management Plan to establish a management framework for the ecologically sustainable development of the fishery.

Social and economic risks to the industry of the project not being funded include the development of community perceptions that the commercial eel fishery is not managing bycatch adequately. This may ultimately lead to reactive management impositions upon the fishery, rather than proactive bycatch management and responsible fishing practices by industry which this project will propagate.