World Marine Data

The location and extent of Marine reserves (type 1 marine protected areas) in the territorial sea.

The pH of New Zealand subantarctic waters is calculated from pCO2 (dissolved carbon dioxide) and alkalinity measurements using refitted Mehrbach constants (see Mehrbach et al, 1973; Dickson & Millero, 1987), and in-situ temperature taken from the Munida time-series transect off the Otago coast. Measurements of pCO2 are taken every two months.
The Munida transect, in the subantarctic waters off Otago, is the Southern Hemisphere’s longest-running record of pH measurements (NIWA, 2015).
More information on this dataset and how it relates to our Environmental reporting indicators and topics can be found in the attached data quality pdf.

New Zealand’s four million km2 marine environment is diverse, with a range of coastal habitats and offshore seabed environments. There are also many marine species unique to New Zealand. Marine protected areas (MPAs) conserve or manage some of these unique habitats and species, while a range of other tools also provide marine protection. We report on the area covered by these tools as an indirect measure to understand the state of the marine environment.
Type 2 MPAs have lower levels of protection than marine reserves. For example, they may allow fishing but restrict seabed trawling.

New Zealand has a diverse range of marine mammal species. Marine mammals are indicator species for the state of our marine environment. They are apex species (near the top of the food chain) and can thrive only if their ecosystems are healthy. A decreasing population can indicate that the ecosystem is degrading.
This dataset relates to the "Conservation status of marine mammals" measure on the Environmental Indicators, Te taiao Aotearoa website.

New Zealand waters have at least 117 species of chondrichthyans (sharks, rays, and other cartilaginous fish species). They are particularly vulnerable to overfishing because they are long-lived, mature slowly, and have a low reproductive rate. Chondrichthyans are important for healthy ocean ecosystems, and reporting their commercial catch and bycatch helps us understand the sustainability of our fisheries.

The Hector’s and Māui dolphins are subspecies of the small dolphin Cephalorhynchus hectori. These coastal dolphins are endemic to New Zealand (not found anywhere else). Māui dolphins are found on the west coast of the North Island, most often between Maunganui Bluff, north of Dargaville, and New Plymouth. Hector’s dolphins are mostly found around the South Island. Both subspecies are threatened with extinction. The Hector’s dolphin is classified as nationally endangered, while the Māui dolphin is nationally critical. Dolphins can become entangled in fishing gear used by both commercial and recreational fishers, with set nets posing a particularly high risk. Reporting the bycatch of protected species helps us understand the pressures our protected marine species face from fishing.
We report on two aspects of Hector’s and Māui dolphin deaths based on data extracted from the Department of Conservation (DOC) Incident Database for 1921–2015: the number of dolphin deaths by cause of death, including a comparison of deaths over 1996–2015; and the number of dolphin deaths from entanglement by type of fishing gear.

The 15 class Benthic-Optimised Marine Environment Classification (BOMEC). The BOMEC divides the benthic environment into ecosystem types. These are grouped into three inshore groups, three continental shelf groups, and nine deeper-water groups. Each group represents areas with similar environmental variables, such as depth, temperature, salinity, and suspended sediment. The classification system considers the distributions of eight benthic taxonomic groups: asteroids, bryozoans, benthic foraminiferans, octocorals, polychaetes, matrix-forming scleratinian corals, sponges, and benthic fish.

These data estimate the occurence of extreme wave events in coastal and oceanic waters for 2012, particularly for wave events where significant wave height exceeds a threshold of 6 metres and for a period of at least 12 hours. Significant wave height is defined as four times the square root of the variance of sea surface elevation due to wave motion.

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Extreme wave indexes estimate the occurrence of extreme wave events in coastal and oceanic waters. Extreme wave indexes estimate the number of times a significant wave height exceeds one of three threshold values for at least 12 hours in 24 marine regions. The three wave-height thresholds are four metres, six metres, and eight metres.
This indicator estimates the exceedances of wave-height thresholds for each year from 2008 to 2015 in oceanic regions around New Zealand.
Significant wave height is a measure of the ‘typical’ wave height in a place over a time period. It is four times the standard deviation of the water surface if, for example, you were to measure water moving up and down a jetty piling for an hour. The largest individual wave will typically have a height around twice the significant wave height.
We use three wave-height thresholds because of the regional variation in extreme wave events. In general, the north experiences less exposure to consistently strong winds, and the waves generated by them, than the south. Four-metre tall waves are considered extreme in the northern-most parts of New Zealand but are more common in the south. For the southern-most parts of New Zealand, eight-metre waves better represent extreme wave events.
This dataset relates to the number of extreme wave events exceeding the four metre threshold in oceanic regions.

New Zealand’s four million km2 marine environment is diverse, with a range of coastal habitats and offshore seabed environments. There are also many marine species unique to New Zealand. Marine protected areas conserve or manage some of these unique habitats and species, while a range of other tools also provide marine protection. We report on the area covered by these tools as an indirect measure to understand the state of the marine environment.
Seamount (underwater mountain area) closures are one of the marine protection tools used. They are designated areas in the exclusive economic zone, which extends to the 200 nautical mile limit. Seamount closures protect underwater mountain areas through the prohibition of all trawling activity. There are some areas where seamount closures overlap with benthic protection areas. In these cases the seamount closure restrictions apply.