New passage to Rakaia and ocean investigated

A variety of fish species may soon be able to move more freely between the Rakaia River lagoon and Jollies Brook near Southbridge, which would be a massive boost for biodiversity and fish numbers in the creek and surrounding wetland areas.

The project idea was initiated by local landowners Tim Ridgen and Lindsay Gilbert who have both carried out extensive native wetland and riparian restoration work on their properties and are both members of Ellesmere Sustainable Agriculture Inc (ESAI).

ESAI and Project Tinaku staff have been working closely with Lindsay to plant natives along the Jollies Brook that runs through his arable farm.

Lindsay shared his idea to open up the passage between the Rakaia River, the ocean and Jollies Brook to enhance natural ecosystems in that part of Ellesmere with Project Tinaku lead David Hewson, who agreed it was a wonderful concept.

ESAI has now received funding from Environment Canterbury to carry out a feasibility study to investigate the viability of the idea and what challenges need to be considered in the planning process.

Last week, Project Tinaku staff met with local landowners and ecologists from Pattle Delamore Partners who are conducting the feasibility study on location at the Rakaia Lagoon and Jollies Brook to discuss the history of the area, water movement and to talk about the next steps involved.

“As it currently stands, natural fish passage is prevented between Jollies Brook and the ocean via the Rakaia River lagoon as there is no permanent access,” says Hewson.

He explains that if the project is deemed viable by the feasibility study and goes ahead, the work will aim to reinstate natural drainage pathways by remediating and removing existing barriers that currently prevent native fish passage.

“This in turn will improve habitat and enhance the biodiversity of the Jollies Brook stream and wetlands surrounding. Creating new areas of wetland and allowing fish passage has the ability to enrich the mahinga kai and cultural values of the site as well as increasing recreational values,” says Hewson.

Landowner Tim Ridgen thinks the project has good merit and couldn’t see any reason why it wouldn’t work.

“We want to be involved and get on board with this. We’ve already started native planting and fencing the wetland areas off and this would just further increase the biodiversity of the whole area,” says Tim.

A survey on Jollies Brook earlier this year found small numbers of Upland Bully fish and Longfin eels in the creek and creating a passage to the ocean is hoped to boost the fish population significantly.

“Opening the passage would increase the total area of wetland habitat which in turn will create larger habitat for other native species including, plants, insects and birds,” says Hewson, who adds that a large wetland area with improved biodiversity would also create an educational destination, both for local schools and for university students.

“The idea to open up a passage to the ocean ticks all the boxes for Project Tinaku.  Increasing biodiversity through planting, improving water quality and enriching native fish and eel populations, as well as creating educational opportunities for students, and benefitting local farmers,” says Hewson.