Eel capture and transport prototype

Two native species of eel are relatively common throughout northern Australian waterways, except where barriers to their migration exist. The longfinned eel, Anguilla reinhardti, and the Pacific shortfinned eel, Anguilla obscura, commence their life cycle in the deep waters of the Coral Sea before migrating as small eels (elvers) into freshwaters where they continue their life cycle before returning to the ocean to breed.

These fish have the ability to move over damp land to bypass obstructions such as waterfalls, weirs and most dams, which to all other fish species may be impassable barriers. However, there are four major dams in the Burdekin Dry Tropics NRM (BDTNRM) region that may be impassable barriers even to eels. One of these dams is the Ross Dam in the Ross River catchment.

BDTNRM in collaboration with Townsville Water and SunWater have engaged Alluvium to develop an eel capture and transport device to assist the elvers in their migration beyond the Ross Dam. Initially a prototype device has been created to determine effectiveness of the design from a capture and operational perspective. Given the protype status, recycled materials were used to manufacture the trap including an old wheelie bin which led to the naming of the trap “Eels on Wheels”.

The trap initially consisted of a gutter style channel extending up the embankment close to the dam through which an artificial water flow was introduced, being the main attractant for elvers. At the top of the gutter was the wheelie bin in which elvers were to be trapped and then transported manually over the dam. In the subsequent version much of the long gutter has been replaced with a netting material that is hung over the vertical wall of the dam abutment (a known corridor for elver movement) to assist the elvers to climb. The device is now installed and awaiting the first flush of the wet season to trigger their migration.