Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 


Stormwater continues to affect harbour sediment

Survey reveals stormwater continues to affect harbour sediment quality


The results of a 2011 Wellington Harbour sediment survey show Wellington’s stormwater continues to be an ongoing source of heavy metal contamination for the harbour.

The survey which was carried out by Greater Wellington Regional Council and part funded by Wellington City Council, was the second of its kind. It investigated sediment quality and the health of the sediment-dwelling animals, at 16 subtidal sites in the Wellington Harbour.

Results show that concentrations of copper, lead, zinc and mercury exceeded nationally recognised guidelines at several sites with the highest concentrations found at sites closer to the city. Sources of these contaminants include vehicle brake and tyre wear, galvanised roofs, road dust and soil that has in the past been contaminated with leaded petrol and lead based paints.

Hydrocarbon concentrations (such as from vehicle exhausts and tyre wear) also exceeded guidelines at inner harbour and Evans bay sites but it is thought that much of this contamination is historic from industries such as the gasworks at Miramar. Despite being banned in the late 1980s, the pesticide DDT is also apparent throughout the harbour with higher concentrations closer to the city.

Examination of creatures living on the harbour floor identified 124 species, among them tiny crustaceans, worms, urchins, bivalves and brittle stars. These invertebrate communities have shown little change in the last five years and remain reasonably diverse. However, invasive species and those with a high degree of pollution tolerance appear to dominate at sites with higher amounts of mud and contaminants.

Regional Council coastal scientist, Dr Megan Oliver says that while there were some statistically significant changes in contamination levels between this survey and the 2006 study, it is still too early to determine if the changes are environmentally meaningful. “The accumulation of contaminants is a relatively slow process and at least another three surveys will be needed before we can say if the situation is improving or worsening.” Dr Oliver says. “Overall there are contamination hotspots but the animal communities living there appear reasonably healthy and diverse and are similar to harbour communities found elsewhere in New Zealand”.

The contaminated sediment poses little risk to people but could, if the accumulation of contaminant continues, have an adverse effect on marine life as sediment-dwelling organisms provide vital habitat and food for numerous fish and other species.

To confirm assumptions about contamination source, tests were also carried out on sediment collected from roadside stormwater catchpits. These also contained substantial amounts of copper, lead and zinc indicating that urban stormwater run-off is an ongoing source of heavy metal contamination for the harbour.

Wellington Regional Council’s Environmental Management spokesperson, Councillor Chris Laidlaw says the study reinforced the need for us to increase our awareness of how our actions on land impact on the quality of water.

“Wellington Harbour is one of our most important coastal environments. We have built our communities around it and because of this everything we do has an impact on it. The study is a timely reminder that we need to reduce the amount of contaminants we allow to flow into the stormwater system and ultimately the harbour. It is up to us to protect the marine ecosystem and we do that by caring for our waterways both, natural and manmade,” the councillor says.

Councillor Laidlaw points out that a catchment committee is soon to be established in the Hutt/ Wellington area and this committee will focus on land and water management ultimately influencing the rules and policies in the Regional Plan.

Ends

© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Patience: Drive Safe

Be patient before passing is the AA's message for drivers this Labour weekend.

"People taking crazy risks to get past other vehicles is one of the most dangerous things on the road,” says AA spokesperson Dylan Thomsen.

“The weather is looking good for the long weekend so the roads will be busy. Unfortunately, that also increases the chances of people getting frustrated and trying a risky passing manoeuvre. When they get past, there will probably be more traffic up ahead anyway so it won’t get people there faster.” More>>

 
 

Parliament Today:

Employment Relations Bill: Govt Strains To Get Tea Break Law Through

The Government has been left with egg on its face - failing to get its much-vaunted, but hugely unpopular, meal break law passed in the first week of its new term, Labour spokesperson on Labour Issues Andrew Little says. More>>

ALSO:

Guns: Police Association Call To Arm Police Full Time

"The new minister gave his view, that Police do not need to be armed, while standing on the forecourt of parliament. The dark irony was that the interview followed immediately after breaking news of a gunman running amok in the Canadian parliament in Ottawa..." More>>

ALSO:

Gordon Campbell: On The Tokenism Of New Zealand's Role Against Islamic State

Our contribution against IS will be to send SAS forces to train the Iraqis? That’s like offering trainers to General Custer just as the 7th cavalry reached the Little Big Horn. More>>

ALSO:

Scoop Business: Shell And Todd Caught Drilling Without Approval

Multi-national oil company Shell’s New Zealand arm and local energy giant Todd Energy have breached the new law governing New Zealand’s Exclusive Economic Zone, the Environmental Protection Authority says in an Oct. 10 document released by the Green Party. More>>

ALSO:

Gordon Campbell: On Pharmac, Gough Whitlam And Sleater-Kinney

We’re not at the outset of these negotiations. The outset was six years ago, and negotiators were hoping to have some sort of ‘framework’ deal finished in time for the APEC meeting in a few weeks’ time. These ‘extreme’ positions are what we’ve reached near the intended end of the negotiations… More>>

ALSO:

PM Of Many Hats: Questions, No Answers On Whale Oil

Dr RUSSEL NORMAN (Co-Leader – Green) to the Prime Minister: How many times since November 2008 has he spoken with blogger Cameron Slater on the phone and how many times, if any, has he texted him?
Rt Hon JOHN KEY (Prime Minister): None in my capacity as Prime Minister. More>>

ALSO:

Aussie Investigation Dropped: Call On Minister McCully To Pursue The Case Of Balibo Five

West Papua Action is deeply concerned at the lack of any clear outcome from the Australian Federal Police inquiry into the 1975 deaths of the ‘Balibo Five’ including NZ journalist Gary Cunningham. More>>

ALSO:

'Feed The Kids' Bill: Metiria Turei To Lead Fight On Feeding Hungry Children

Green Party Co-leader Metiria Turei is urging all political parties to support the Feed the Kids Bill which she inherited today from Mana leader Hone Harawira. More>>

ALSO:

Parliament Today: State Opening Of Parliament

The House sat at 10.30am on Tuesday before MPs were summoned to hear the Speech from the Throne in the Legislative Council Chamber. More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news