NIWA looks at fish nursery hotspots

14 Mar 2013
Aerial photography shows a subtidal bed in Kaipara Harbour, New Zealand

Aerial photography shows a subtidal bed in Kaipara Harbour, New Zealand

In order to provide detailed information on New Zealand’s largest harbour and its fishery hotspots, the National Institute of Water and Atmospheric Research (NIWA) is carrying out studies on subtidal seagrass meadows in the southern Kaipara Harbour.

From February to March this year, NIWA is using aerial photography to look at shallow water habitats and how they are distributed, to produce detailed habitat maps.

Most recently, the organisation has used the maps to record critical areas for fish nurseries, in particular juvenile snapper, and monitor their health over time through cost effective remote sensing.

Dr Mark Morrison, marine ecologist, NIWA Auckland, said: “The Kaipara is the major harbour for west coast juvenile snapper habitats, so it is a really key place, and we know it’s under stress from sedimentation and other land based impacts that degrade key habitats.”

Scientists will collect fish using small, fine mesh beach seines, deployed from an oyster barge. They will sample 80 to 100 sites spread across 300 sq km in the harbour.

He added: “Sampling across different habitat types and environmental conditions will allow us to quantify which fish are associated with each habitat. The research will then help us identify which factors are most critical, so that the most important habitats can be identified, mapped, and protected.”

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