Our coast

How healthy is our marine environment?

How healthy is the marine environment?

As with any major city, the health of Auckland's marine environment varies across the region, with some pristine areas at the edges of the region and less healthy areas close to urban areas.
Coastal water quality varies throughout the region and tends to decline as the level of exposure declines. Contaminant levels tend to be higher in the more sheltered areas close to urban areas.
Levels of pesticides such as Chlordane, DDT, Dieldrin and Lindane have decreased in oysters since such pesticides were deregistered.
Some persistent contaminants such as PAH's and PCBs have not shown the same consistent decrease. This is likely to be due to historical stores of these persistent chemicals on and in land and contaminated marine sediments.
Marine sediment concentrations of the key stormwater contaminants (copper, lead and zinc) are greatest in sheltered waterways adjoining older urban and industrial parts of Auckland, Waitakere and Manukau cities.
Contaminant concentrations in waterways near newer urban catchments tend to be below guideline values and in most cases the contaminant concentrations are stable or increasing only slowly.
Monitoring suggests that sediment contamination is having an effect on the animals living in estuaries subject to stormwater contamination.

Monitoring marine environment health

To keep track of the health of Auckland's marine environment the ARC monitors:

coastal water quality
contaminants in shellfish and sediment
the abundance and diversity of animals that live in the sediment (ecology).

The physical environment and populations of animals, all fluctuate through time so long-term monitoring programmes are essential to allow natural fluctuations to be distinguished from changes due to human activity.

In April 2008 the ARC hosted the Manukau Harbour Techncial Symposium to celebrate the long term monitoring and research information on the Manukau Harbour collected over the last 20 years.

Coastcare

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What affects our coastal and marine environment?

There are many environmental issues associated with a growing population, like Auckland's, in a coastal area.
Stormwater transfers contaminants deposited on land to the sea.
The toxicity of stormwater contaminants can affect shellfish and other animals living on, or in, the sediment.
In the Auckland region, the build up of zinc, copper, lead and PAH are causing the most concern.
Vehicles are a major source of all four pollutants, but other factors like roof runoff and industrial discharges also contribute.
Sediment runoff from land development, agricultural practices and stormwater also affects the marine environment.
Sediment can smother and kill marine organisms or make areas unsuitable for some marine organisms to live there.
Too much sediment in the water column can reduce water clarity and light penetration which can reduce the productivity of marine ecosystems.

The ARC - Looking after the coastal and marine environment

The ARC is developing strategies and policies specifically to deal with the issues associated with growth in the Auckland region.
The ARC consistently monitors the state of Auckland's coastal and marine environment and through more specific land development monitoring programmes we monitor the effectiveness our policies and decisions.
To try and minimise impacts on the marine environment we conduct compliance monitoring on consents and carry out pollution control and response activities.
Protecting the coastal and marine environment requires everyone to be involved. ARC supports community initiatives to help the marine environment through the Environmental Initiatives Fund and the Coastal Enhancement Fund.

More info:

reports from all of ARC's marine state of the environment monitoring programmes are available on our publications webpage
if you have a specific enquiry about Auckland's coastal and marine environment please contact ARC on 09 366 2000
Hauraki Gulf Forum State of the environment report.