Offshore islands a haven for birds

Monday, 23 September 2024

The offshore islands and reef built for the Petone to Ngauranga shared path and seawall is starting to pay dividends.

As well as a large offshore reef and penguin habitat, two offshore islands were constructed. The islands were required to provide a safe haven for birds to land and roost clear of construction activity.

Four concrete tidal pools were installed at each offshore habitat and are designed to mimic the rocky shore.

These are placed in and around the rocks that form the offshore habitats to support marine ecosystems for species such as crabs, molluscs, sea urchins, plankton and other invertebrates.

One of the offshore islands created as part of the Petone to Ngauranga shared path and seawall.

Waka Kotahi regional manager systems design Kesh Keshabiona said he was pleased to see the offshore habitat doing what it was designed for.

“The project team’s ecologists have been keeping a close eye on the offshore habitats, which were completed in November last year and they are already showing promising signs of various birds and marine species using them as habitat.”

As well as shags and herons, kororā are using the islands.

Resource consent required the New Zealand Transport Agency Waka Kotahi to complete a range of projects to offset the environmental impact.

Track repairs on the storm damaged rail line between Petone and Ngauranga in 2013. The repairs cost more than $5m and the closure of the rail corridor resulted in severe traffic congestion.

The project is also on target to achieve its aim of protecting the rail corridor and state highway.

“Parts of this system have been damaged by severe weather in the past, like in 2013 when the rail line was washed out causing days of travel disruption,” he said.

A 2013 report by the Ministry of Transport on the economic impact of the storm and the temporary closure of rail line found it cost the region between $12m and $43m.

Last month, The Post reported the original shared pathway and seawall project budget of $312m had increased by $36.8m but was still on track to be completed in 2026.