Coasts

Latest news

New findings from the record-breaking Tongan volcanic eruption are “surprising and unexpected”, say scientists from New Zealand’s National Institute for Water and Atmospheric Research (NIWA).
NIWA is contributing to an international effort to help developing countries reduce the impact of biofouling on aquatic-based industries and environments.
NIWA and The Nippon Foundation are undertaking a mission to discover the undersea impacts of the recent Tongan volcanic eruption.
A robot sea craft is the latest tool NIWA scientists are using to help them count fish.

Our work

Aotearoa New Zealand’s coastal lowlands are our flat low-lying land (or plains) adjacent to coasts and estuaries. Our coastal lowlands are valued for many reasons, including unique ecological wetlands, cultural sites of significance, valued recreational areas, highly-productive agriculture and are popular places to live.

We need information on the food web structures of our marine ecosystems in order to manage the effects on the ecosystem of fishing, aquaculture and mining, as well as understanding the potential impacts of climate variability and change on our oceans. 

NIWA is looking for people who have had a long association with the Hauraki Gulf or Marlborough Sounds to help them with a research project on juvenile fish habitats.

NIWA is developing guidelines and advice to help coastal communities adapt to climate change.

Latest videos

Dive into the alien world of plankton in the Ross Sea

Plankton are the base of the oceans food web and are vital to our survival. But as our world changes will they be able to continue to play this essential role? Join us as we follow a group of NIWA scientists investigating various aspects of this question in the ocean around Antarctica.

Shifting Sands - Tsunami hazard off Kaikoura, NZ

Dr Joshu Mountjoy discusses NIWA's work in assessing the tsunami hazard just south of Kaikoura. 

Find out more about this research. 

Antarctic Coastal Marine Life in a Changing Climate

NIWA marine ecologist Dr Vonda Cummings discusses the likely effects of climate change on marine invertebrates living on the seafloor of the Ross Sea coast.

Next Stop Antarctica

Our Far South is an expedition that aims to raise New Zealanders' awareness of the area south of Stewart Island. Gareth Morgan, Te Radar, scientists and 50 everyday Kiwis are onboard to learn and then share their experience. This is the first video produced by them, showing some of the highlights of the trip so far.

Verifying the wave model
The results from the model hindcast have been compared with data from wave buoys deployed at various times in the past at several sites around New Zealand (shown below).

Foveaux Strait Buoy
This was located in 100 m water depth. Model results were corrected for the effects of limited fetch to the coast before comparison with the data (shown below, click to enlarge).

Mangawhai Buoy
This was located in 30 m water depth, in a site sheltered by surrounding land, and affected by refraction of waves over the seabed topography the variable depth.

Tsunami is a Japanese word meaning great wave in harbour
NIWA coordinates a network of remote video cameras, called Cam-Era, which regularly monitors coastal and river behaviour in real-time.

Sumatra tsunami recorded at 1-minute sampling intervals at 9 sites:
a) Date/time in NZ Standard Time (UTC+12), with earthquake (EQ) time shown.
b) Elapsed time in hours since the earthquake occurred.

Sumatra tsunami recorded at 5-minute sampling intervals at 19 sites:
a) Date/time in NZ Standard Time (UTC+12), with earthquake (EQ) time shown.
b) Elapsed time in hours since the earthquake occurred.

Tsunami run-up height reached up to 12 m in Khao Lak (Thailand) as shown by damage to tiles on roof.

Solar semidiurnal tide (S2) as an animation.

Waves from Satellites
Waves are available from a number of satellite sensors, including radar altimeters and synthetic aperture radar (SAR).

A radar altimeter aims a narrow beam directly downwards. From the spread in the return signal, the wave height can be measured.

Solar Semidiurnal Tide (S2)
Twice-daily M2 tidal currents animation around the North Island of New Zealand based on a TIDE2D model.
Tidal and surface currents - besides tidal height, the NIWA tide model of New Zealand's EEZ also produces tidal currents. For the first time, a detailed overall picture has emerged of the strength (speed) and direction of tidal flows on the continental shelf and around various islands, headlands and straits.
Animation of the lunar semidiurnal tide (M2) in New Zealand.
Diurnal Tide (K1)

Hazard planning, awareness and building resilient communities

Sea level on the move?
Effect of global warming
Educational CD-ROM “New Zealand’s Sandy Coasts”
Coastal & Storm Hazards Workshop

Sea level on the move?

Long-term sea level varies at timescales of years, decades and centuries. Before the long-term trend in sea-level rise can be obtained from any sea-level record, we must understand the fluctuations that occur over years and decades. The longest sea-level record in New Zealand is from the Port of Auckland (click to see accompanying figure).

Foveaux Strait M2 Tidal Component

This animation shows the chief tidal current in Foveaux Strait. Tidal currents on the west coast of Stewart Island are small, but around the northern and southern coasts of the island and in Bluff Harbour and Oreti Estuary there are strong tidal currents. Overall currents (not shown here) in Foveaux Strait however, are strongly wind-driven with the prevailing wind being from the west. The Southland current, which carries water from the subtropical convergence west of New Zealand, flows through Foveaux Strait.

Tide forecasts, Sea-level network, Tidal model of New Zealand’s EEZ and Red-alert days for coastal flooding
NZ has a range of different types of coasts, and so very different coastal erosion and sediment systems.

Cook Strait M2 Tidal Component

Currents in the Cook Strait are made up of many different components, chiefly the tidal and storm driven currents.

The tidal current shown here is the main component of currents around Banks Peninsula.

The study team is interdisciplinary and includes sedimentologists, physicists, oceanographers, and modellers working on a range of research projects within the programme.
Publications from the physical hazards team.

New Zealand's icy visitors - past and present

New Zealand's icy visitors - past and present

Scour marks of the seabed were probably made by an iceberg measuring between 2 and 5 km long.

November saw some unusual visitors to New Zealand waters, with several icebergs reaching the South Island’s east coast. NIWA oceanographer Dr Mike Williams estimated that the bergs probably came from the Ronne Ice Shelf on the other side of Antarctica.

Estuary health check

Estuary health check
Scientists from NIWA and Canterbury University are developing a diagnostic toolkit to assess the health of the Avon-Heathcote Estuary before and after a new wastewater outfall is installed.
Treated wastewater has been discharged into the estuary for about 40 years. The high levels of nutrients it contains may be responsible for problem blooms of sea lettuce in summer.

Customary Coastal Management Workshop

Customary Coastal Management Workshop

Karengo harvest at Mahia. (Photo: Sheryl Miller, NIWA)

21–22 June, Te Papa, Wellington.
NIWA’s National Centres for Coasts & Oceans and Fisheries & Aquaculture will host a workshop to highlight how increased scientific knowledge can advance customary management of the coastal environment.
Increasingly, iwi and managers of taiapure and mātaitai (traditional fishing grounds) have regulatory responsibilities for customary management of the coastal environment and kaimoana resources.

A flexible way to model sediment dispersal

A flexible way to model sediment dispersal

Water depth in the Middle Waitemata Harbour, represented on a flexible grid.

NIWA has recently upgraded its modelling software for simulating the dispersal of sediments and contaminants in coastal waters.
The new software represents water depth on a ‘flexible grid’. This allows the user to zoom in on water flow and sediment transport in areas that are complicated or of particular interest, such as valuable habitats or near stormwater discharges.

GeoEel sees beneath the seafloor

GeoEel sees beneath the seafloor

Profile of sedimentary basins in the Gulf of California. Scripps Institute of Technology

Ever wished you had Superman’s X-ray vision? Our new digital seismic streamer is the next best thing.
The ‘GeoEel’ streamer is an array of 768 hydrophones towed behind a ship. The hydrophones pick up sound signals reflected off sedimentary layers and geological structures up to 3 km beneath the seabed.

Sophisticated sonar for marine habitat mapping

Sophisticated sonar for marine habitat mapping

Map of seafloor habitat types on Wellington’s south coast.

NIWA vessels’ multibeam sonar capabilities offer a rapid, accurate means of mapping marine habitats, with myriad applications.
NIWA recently applied this technology to map 46 square kilometres of seafloor habitats in and around the proposed Taputeranga Marine Reserve on Wellington’s south coast, in conjunction with Victoria University and the Department of Conservation.
Combining the shallow water capabilities of survey launch Pelorus and RV Kaharoa enabled the team

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All staff working on this subject

Principal Scientist - Ecosystem Modelling
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Hazard and Risk Analyst
Principal Scientist - Marine Ecology
Regional Manager - Nelson
Principal Scientist - Natural Hazards and Hydrodynamics
Strategy Manager - Coasts & Estuaries
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Principal Scientist - Marine Ecology
Senior Regional Manager - Wellington
Strategy Manager - Oceans
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Marine Invertebrate Systematist
Coastal and Estuarine Physical Processes Scientist
Principal Scientist - Marine Ecology
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Physical Oceanographer
Principal Scientist - Coastal and Estuarine Physical Processes
Fisheries Scientist
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Coastal Technician
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Marine Ecology Technician
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