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

 


Important Porirua Harbour habitats at risk

Important Porirua Harbour habitats at risk


The results of a recent survey show sediment entering the harbour continues to be a problem in Porirua Harbour.

The latest five-yearly survey of Porirua Harbour intertidal habitats has shown that the area of estuary covered in freshly deposited mud has increased substantially, particularly near the Kakaho and Horokiri streams.

Soft mud reduces the water clarity, the amount of oxygen in the sediment, and the growth of vital seagrass. This results in a loss of habitat, reduces recreational and aesthetic values and the estuary’s ability to function effectively.

The density of seaweed growth near the mouths of the Porirua, Pauatahanui and Horokiri streams is evidence that nutrient inputs (nitrogen and phosphorus) remain high. Seaweed mats can smother sediment and seagrass. When the seaweed dies it starves the sediment of oxygen and causes black smelly mud.

Although there are large, healthy areas of saltmarsh in the eastern Pauatahanui Arm, saltmarsh is absent in the Onepoto Arm of the harbour. Saltmarsh areas are highly productive, provide valuable habitat for fish and birds, and offer flood and erosion protection.

“Though this is only the second habitat mapping survey in Porirua Harbour, the findings confirm that important habitats such as seagrass and saltmarsh remain vulnerable to the effects of human activities on land” says Greater Wellington Regional Council’s Coastal Scientist, Dr Megan Oliver.

“Sediment and nutrient inputs from the surrounding land and waterways are reducing sediment quality, biodiversity and healthy functioning of the estuary”.

The Regional Council commissioned the second broad scale habitat mapping survey of the intertidal area to assess the changes in key estuary habitats (eg, saltmarsh and seagrass) and substrate (e.g. areas of mud and sand).

The information has been gathered as part of the Regional Council’s State of the Environment Monitoring requirements under the Resource Management Act.
Information from the report will feed into the Porirua Harbour and Catchment Strategy and Action Plan’s sediment reduction and estuary restoration work and help focus policy and management decisions related to land-based activities.

The Strategy and Action Plan is a council and community project that has been prepared and adopted by four key stakeholders – Te Runanga o Toa Rangatira, Porirua City Council, Wellington City Council and Greater Wellington Regional Council - along with 10 other agencies. A new joint committee of the four organisations is now being set up to work more closely and to oversee the implementation of the strategy.

Ngati Toa Rangatira kaumatuaTaku Parai says it’s good that the regional council is closely scrutinising the condition of the harbour to ensure everyone is aware of these issues and helps to turn them around.

“Loss of significant habitat in the harbour is a problem that has affected Ngāti Toa for many generations. Having access to the information provided by these surveys is empowering for iwi and the whole community to work together for positive change,” says Mr Parai.

The issues arising from the survey are being addressed as part of the harbour strategy.

Porirua Mayor Nick Leggett and Regional Councillor Barbara Donaldson point out that a lot of work is happening including sewer and stormwater upgrades, community education, the development of an estuary restoration and catchment revegetation framework, research and a review of the region’s regulations
Work on a catchment erosion control plan will be completed in February followed by its implementation. This, along with improved earthworks control, will have an impact on reducing sediment entering the harbour. It’s also a reminder to the community that re-vegetation of the catchment is one of the most significant things we all can push to reduce sedimentation.

Over summer, the regional council will be carrying out routine annual measurements of sedimentation in the harbour. There are also plans to undertake habitat mapping of the subtidal areas of the harbour.

The report can be downloaded from the document library on GWRC’s website – search for “Porirua Harbour broad scale survey” or visit http://www.pcc.govt.nz/Publications/Porirua-Harbour-and-Catchment-Management-Programme

ENDS

© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell:
On War Crimes And The Afghan Insurgency

Truly, with friends like former defence Minster Wayne Mapp, the SAS does not need enemies. At the very least, the Hit and Run book has raised the possibility that the New Zealand SAS committed war crimes in the attack they led in Afghnistan upon the villages of Naik and Khak Khuday Dad...

Mapp’s attempted defence of the SAS on RNZ this morning unintentionally indicated that collective punishment was baked into the planning exercise for the raid, and also into how the raid proceeded on the ground. More>>

 
 

Little Heading For Court: Apology Over Donation/Hotel Contract Claims Not Accepted

Today I want to publicly apologise unreservedly to Mr Hagaman for any hurt, embarrassment or adverse reflection on his reputation which may have resulted from my various media statements. I have offered that apology to the Hagamans. More>>

ALSO:

Biscuit Tin Of Democracy: World Heritage Site Protection, Ombudsman and Equal Pay Bills Drawn

On Thursday, 23 March 2017 three places are available on the Order Paper for the first reading of a Member’s bill. The ballot was held, and resulted in the following bills being drawn... More>>

ALSO:

Emissions Plan: NZ Needs More Science, More Trees, Fewer Beasts

A combination of technology breakthroughs, much more plantation forestry, and a big switch away from pastoral, particularly dairy farming, are identified as the key elements of any approach New Zealand takes to reducing its carbon emissions to a net zero level, according to a new report sponsored by the New Zealand chapter of GLOBE, a multi-party, global parliamentary grouping. More>>

ALSO:

"Backed To Win Seats": Labour Māori Seat MPs Won't Stand On List

The Labour Party is backing a request from its Māori seat MPs to stand as electorate MPs only, says Labour Leader Andrew Little. More>>

OutsKey: John Key's Valedictory Speech

I rise to address this House for the very last time. It has been a huge privilege to have served the people of Helensville as their member of Parliament, and, of course, the people of New Zealand as their Prime Minister. More>>

ALSO:

Productivity Commission: New Models Of Tertiary Education Are Coming

The report is a broad-ranging inquiry into how well New Zealand’s tertiary education system is set up to respond to emerging trends in technology and the internationalisation of education, and changes in the structure of the population, and the skills needed in the economy and society... More>>

ALSO:

PM's Press Conference: Water Everywhere

Monday's Post-Cabinet press conference focused on water, with the Prime Minister fielding questions about the possibility pricing water taken for export. Mr English said the government was directing their water allocation technical advisory group to include export water in considerations. More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news