Coastal and Freshwater news

11 August 2020

Cawthron Institute supports report calling for consistent & robust monitoring of estuaries

Cawthron Institute welcomes the Parliamentary Commissioner for the Environment’s ‘Managing Our Estuaries’ report that calls for estuaries to be better protected through policy and consistently and robustly monitored across New Zealand.

Cawthron’s Group Manager for Coastal Sciences Dr Chris Cornelisen said the report shows estuaries have ‘fallen through the cracks’ of New Zealand’s environmental monitoring and management frameworks.

“Estuaries are valuable but vulnerable ecosystems and matter a great deal to New Zealand in economic, environmental and cultural terms,” Dr Cornelisen said.

“Estuaries are a dynamic mixing zone between rivers and the ocean and include some of the most productive habitats in the world. They are the ‘nurseries of the sea’ and of upstream habitats because they act as breeding grounds for kaimoana, fish, plants, birds and insects. They also play a key role in both ocean and freshwater health.”

Dr Cornelisen agrees with the PCE’s argument that consistent and robust monitoring of estuaries across New Zealand is required to ensure we can effectively manage freshwater and coastal ecosystem health.

“We need more data and better data about estuary health across New Zealand. We also need those data to be collected in the same way, and analysed using the same measures, so that we can say, ‘this is what good looks like’, and this is what ‘not so good’ looks like, and compare results regionally and nationally. This has to happen if we want to support the people and organisations responsible for managing estuaries to keep them healthy,” Dr Cornelisen said.

Cawthron also supports the PCE’s call for estuaries to be incorporated into the National Policy Statement for Freshwater Management because this would ensure there were clear guidelines and standards for protecting the health of estuaries.

In addition to the PCE’s recommendations, Cawthron is an advocate for the utilisation of molecular technologies like eDNA analysis which offer great benefits to estuary managers in assessing ecosystem health.

“Our team of estuarine scientists, and specifically one of our marine ecologists Dana Clark, have been doing excellent work developing estuary-specific eDNA assessment methodologies that complement macrofaunal sampling methods,” Dr Cornelisen said.

“Macrofaunal sampling methods capture what kind of life and how of much of it there is in the estuary bed, and molecular technologies add a much more robust picture of all aquatic life in the area, from bacteria through to shellfish.

“So far we’ve been focused on monitoring the benthic environment - in fact Cawthron scientists recently worked with NIWA and the University of Waikato to produce a tool called the National Benthic Health Models, which can be used to assess the health of any estuary in New Zealand.

“However, Cawthron is keen to see New Zealand adopt a ‘mountains to sea’ approach, paying more attention to the relationships between the health of streams and rivers, and catchment land use, and the health of our estuaries and coastal habitats,” Dr Cornelisen said.

“Without this information, there has been a serious gap in our ability to manage freshwater and coastal water quality and understand these relationships, but we hope to see that change and think that if the PCE’s recommendations were adopted it would be a significant step towards achieving that and obtaining the economic, environmental and cultural benefits that occur when estuarine ecosystems are healthy and thriving.”

Cawthron Marine Ecologist Dana Clark talks about Cawthron’s expertise in molecular technologies in estuarine monitoring and our support of the recommendations made in the New Zealand PCE Managing our Estuaries Report.