Science Centres: Aquatic Biodiversity and Biosecurity

NIWA scientist Brian Sorrell surveys a fen in the upper Freshwater Valley, Stewart Island. [Photo: Alastair Suren, NIWA]

Around 90% of New Zealand’s wetlands have been drained or otherwise destroyed in the last 150 years. To protect the remaining 10%, we need to understand what makes our wetlands tick and, conversely, what damages them.

Little is known about life in our wetlands – which include swamps, bogs, and marshes – and how the small aquatic organisms drive these systems. Algae underpin wetland food webs and are important indicators of environmental stress. Invertebrates are the next link up the food chain; important sustenance for birds and fish.

NIWA scientists are documenting algal and invertebrate diversity in New Zealand wetlands for the Department of Conservation (DoC). This research will help DoC prioritise wetlands and wetland habitats for conservation.

Our initial study of four near-pristine wetlands on the West Coast has shown that each has its own unique assemblage of algae and invertebrates. Within a wetland, different habitats support different algae. This means that, to protect wetland biodiversity, you need to protect examples of each wetland type and habitat.

Further work is investigating variation among wetlands on a wider scale, and the impacts of human activities on these endangered natural systems.