From today, people can access information about the health of estuaries locally and across the country using a new topic
on the LAWA website that makes results from regional and unitary council monitoring programmes freely available.
The new LAWA Estuary Health topic presents environmental data from New Zealand’s largest estuary monitoring dataset,
covering nearly 400 monitoring sites across 80 estuaries.
LAWA Estuary Health Science Lead Dr Tarn Drylie said the places where rivers and streams meet the sea are complex, yet
there are things councils monitor to understand the pressures that estuaries are under.
“New Zealand’s estuaries are culturally and ecologically significant. We know that many of them are under pressure and
the LAWA Estuary Health topic provides results from regional and unitary council monitoring of contaminants, mud
content, and estuary macrofauna.
“Estuary health is impacted when concentrations of contaminants like metals and hydrocarbons get too high. From the
monitoring data on LAWA, we see estuaries that are most affected by high loads of contaminants tend to be downstream of
built-up areas.
“Another important factor for estuary health is the amount of mud content from the surrounding land that is in the
surface layers of the sandflats. Higher mud content is found in places with the most modification to land use,” said Dr
Drylie.
LAWA also presents the results of regular estuary macrofauna check-ups. Estuary macrofauna include hundreds of
intertidal species such as worms, snails, crustaceans, and shellfish like pipi and cockles.
“We monitor the makeup of macrofaunal communities because some critters only live in pristine environments while others
thrive in degraded conditions,” said Dr Drylie, “Regular monitoring of estuary macrofauna gives us a good indication of
the overall health of an estuary and any changes in conditions over time.”
The estuaries along the coastline of New Zealand come in various shapes, sizes, and state of health.
Dr Chris Daughney, Chief Science Advisor for Te Uru Kahika – Regional and Unitary Councils Aotearoa said estuaries are
dynamic and provide a window into the health of the wider catchment.
“Regional and unitary councils monitor estuaries to understand their ecological condition and how this is changing over
time, especially in relation to human activities that may degrade them.
“Some regions have been formally monitoring estuaries for three decades, while others have only recently established
programmes in acknowledgement of the importance of estuary health for our collective wellbeing.
“The health of an estuary can be impacted by sediment, nutrients, and pollution from land use upstream, marine pressures
such as over-harvesting, dredging, and invasive species, shoreline activity and development, and climate change.
“The results from regular monitoring of these highly connected environments help us to understand whether catchment
activities and pressures are being managed effectively and direct future management and restoration efforts,” said Dr
Daughney.
Estuaries provide several ecosystem services and support water quality through natural filtration and binding pollutants
within sediment. They are home to diverse plants and animals, some of which are only found here in Aotearoa.
Department of Conservation Marine Technical Advisor Helen Kettles encouraged people to explore the LAWA website and get
acquainted with their local estuaries.
“Estuaries are truly special places that provide outsized benefits for us and the planet. If we can look after
estuaries, they can look after us.
“The new LAWA Estuary Health topic can help us all to better understand our local estuaries and act for them.
“Improving estuary health will take time, so we must continue and extend the good work happening across the motu from
riparian planting to reducing the use of pollutants at home and work. I want to recognise everyone that’s involved in
estuary restoration and protection,” said Ms Kettles.
LAWA Chair Dr Tim Davie said the LAWA website presents quality data and information collected regionally in a way that
is nationally consistent.
“We are delighted to launch the LAWA Estuary Health topic today. This is the eighth topic on the LAWA website, and it
helps to connect our water reporting from ki uta ki tai (mountains to sea).
“We all want the same thing; healthy environments for generations to come. To do this we need accessible, reliable, and
quality data to help inform restoration efforts and track improvement over time.
“Through the LAWA project, we’re putting environmental data in the hands of researchers, iwi, government, industry, and
communities so they can make informed decisions,” said Dr Davie.Link: lawa.org.nz/explore-data/estuaries
Upcoming webinars: To celebrate the launch of the new LAWA Estuary Health topic, the LAWA project are hosting two ‘Estuary Health in New
Zealand Webinars’. The webinars will feature quickfire presentations, followed by an audience Q
Wednesday 27 July 10am – 10:45am: Register now »