Ocean acidification – what impacts?
NIWA scientists are among those highlighting the consequences in increased ocean acidity – an outcome of the ever-rising levels of atmospheric carbon.
As ocean acidity increases, a number of physical and chemical changes are occurring which will almost certainly impact on ocean life.
Argo deployment reaches new milestones
Kaharoa’s Argo deployment voyages to date.
John Hunt prepares to deploy an Argo float. (Photo: Mike Naidanovici, NIWA)
NIWA’s 28 m research vessel Kaharoa may merit a place in the Guinness Book of Records, having recently returned from a voyage to deploy a further 42 Argo floats. The floats bring the total deployed by Kaharoa to 439 over four years.
Bringing the harbour back to life
A team sets up a trial on the sandflats at Whangarei Harbour. (Photos: Vonda Cummings, NIWA)
Declining numbers of shellfish is recognised as a problem in many estuaries and coastal areas around New Zealand, and local communities who traditionally gather kai moana are becoming concerned for the future of their customary food source.
In Whangarei Harbour, the Kaitiaki Roopu (caretaker group) has been working with NIWA over the last few years in an innovative project to restore shellfish beds.
In the wake of the ferries
The sort of wake which can be a concern in Tory Channel. (Photo: Warren Thompson, NIWA)
NIWA-designed ‘Dobie’ data logger.
NIWA has recently completed work to measure the wake waves of the vessels of one Cook Strait ferry operator.
The safety and environmental impacts of wake waves of large commercial vessels are a concern in a number of places around the NZ coast, none more so than Tory Channel, the route of the Cook Strait ferries.
Bathymetric survey helps Cook Strait shipping
Bathymetric survey showing the rock pile, which was 1.8 m high and at a seafloor depth of around 14.6 m.
When a barge carrying rocks from Picton to Wellington turned turtle at the entrance to Wellington Harbour at 3.00 a.m.
Rivers: the land-coast connection
Gravel extraction, Waimakariri River, Canterbury. (Photo: above, Graham Fenwick, NIWA)
(Photo: above, Alistair McKerchar, NIWA)
NIWA scientists are developing models to predict the impact of changes in river sediment loads on coastal erosion. Rivers are a key connection between the land and the sea, carrying sand, gravel, and cobbles down river, and depositing them at the coast. This material is then redistributed and groundup by waves and currents.
What risk to human health?
Sequence of calculations to model health risks at a beach, either from swimming or from consumption of raw shellfish.
One of the direct consequences of land-based activities on the coast is the discharge of treated sewage into the sea. Pathogens (bacteria, protozoa, and viruses) in sewage can pose a risk to human health, through people swimming in polluted areas or eating contaminated shellfish.
Special Issue – Effects of land-based activities on the coastal environment
New Zealand’s coastline is increasingly affected by land-based activities, particularly intensified agriculture and nitrate runoff, sewage disposal, coastal subdivision and sediment runoff, and heavy metal and contaminate runoff from urban centres into estuaries. Such issues are the focus of increasing and better environmental management practice.
