Protecting Lamprey During a Roading Upgrade

A nationally significant population of threatened lamprey was discovered in Canal Reserve Drain, an inconspicuous roadside drain, right beside a planned bridge and intersection upgrade.

Instream worked with contractors, engineers, NIWA, the Department of Conservation and both the regional and district council to develop methods to ensure critical lamprey habitat was protected during the construction project.

Larval lamprey are black, but prior to migrating to sea they change form and turn a distinctive blue-grey colour, like the one pictured.

We met regularly with contractors during the construction process, to provide ecological guidance, and we caught and relocated larval lamprey outside of the construction footprint.

The project was a great success, with the intersection upgrade completed ahead of schedule and subsequent monitoring revealing that all our efforts to protect the lamprey population had worked well.

 Instream team members using electric fishing to ‘draw out’ larval lamprey

This project highlighted the importance of good project communication and the value of getting good advice early, to avoid unexpected delays and cost escalation on major infrastructure projects.