News Video | Policy | GPs | Hospitals | Medical | Mental Health | Welfare | Search


Slow Recovery At Moa Point

Monitoring of the marine environment at Moa Point, on Wellington's south coast, has shown that recovery after the closure of the 100-year-old sewerage outfall in June 1998 took longer than initially thought.

A study by Foundation for Research, Science and Technology post-doctorate fellow Karyne Rogers has shown that the gut and tissue of shellfish was affected by sewage for some considerable time afterward the closure.

A new treatment plant was commissioned at Moa Point last year. Dr Rogers, an isotope geochemist, has been monitoring the site to investigate the extent of sewage pollution of flora and fauna, both before and after the outfall was closed.

The project has profited by the use of a newly installed mass spectrometer at Dr Rogers' host organisation, the Institute of Geological and Nuclear Sciences, in Lower Hutt. This machine measures the extent of sewage in biota (flora and fauna) from the sewage-contaminated environment, and compares it with data from nearby non-polluted sites. The mass spectrometer analyses stable carbon and nitrogen isotope signatures of the flora and fauna.

"Monitoring of Moa Point after the outfall closure showed that while the water cleared, the sewage isotopic signature was still present in the gut and tissue of the shellfish, suggesting that recovery would take longer than initially anticipated," Dr Rogers says.

However, she says the diversity of seaweed is returning to normal levels.

Before closure of the outfall, the biological diversity was fairly low at Moa Point, with the main biota present as limpets, blue mussels and ulva seaweed. Ulva is a green seaweed typically found in areas with high nitrogen input. Immediately after closure, the ulva levels declined rapidly as the large limpet population chewed through the available ulva supply, which was not renewed as quickly because of the lack of nutrients from the sewage.

"Today, biological diversity of seaweed is returning, and the balance in the food chain has stabilised," Dr Rogers says. "The isotopic signatures of the limpets and mussels has returned to similar levels of the control sites."

However, she says the extent of other pollutants associated with sewage sites, such as heavy metals, has not been investigated, and therefore Moa Point might not be fully recovered.

© Scoop Media

Culture Headlines | Health Headlines | Education Headlines


Tom Scott's Avantdale Bowling Club: The 10th Annual Taite Music Prize Announced

The Taite Music Prize 2019 ceremony also saw the presentation of the Auckland Live Best Independent Debut, Independent Spirit Award, and Independent Music NZ Classic Record award. More>>


Elisabeth Calder: Gifted Editor And Publisher To Receive Honorary Doctorate

The English editor and publisher who discovered some of the greatest writers of our times, including Salman Rushdie, Julian Barnes and Anita Brookner, will be awarded an honorary Doctor of Letters (honoris causa) by the University of Canterbury (UC) at the University’s Arts and Science graduation ceremony on 18 April. More>>

Howard Davis: Charlie Parker With Strings - Live!

Hear these swinging rhythms with lush strings and a twist of bebop when Dick Oatts performs Charlie Parker with Strings accompanied by the New Zealand String Quartet and Jazz Ensemble, Musical Director Rodger Fox. More>>

Disaster Response: Canterbury Quakes - 'Widespread Adverse Effects' On Mental Health

The researchers noted that while support services such as free counselling exist, New Zealand's public health services are already under strain and even small increases in demand may result in a considerable extra burden for health workers. More>>



  • Wellington
  • Christchurch
  • Auckland