Marine Data

Coastal and estuarine ecosystems are affected by changes in the levels of nutrients, oxygen, and light. An overload of nutrients can be toxic or lead to algal blooms. These blooms can kill marine life by depleting oxygen levels. Suspended sediment can smother habitats or reduce light levels, affecting photosynthesis. We report on five measures of water quality: turbidity (murkiness), dissolved oxygen, and the dissolved nutrients nitrate- and nitrite-nitrogen, ammoniacal nitrogen, and total phosphorus.
This dataset relates to the "Coastal and estuarine water quality" measure on the Environmental Indicators, Te taiao Aotearoa website.

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).
Trends were assessed using linear regression at the 95% confidence level.
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.

Coastal sea-surface temperature is influenced by solar heating and cooling, latitude, and local geography. It is hard for some marine species to survive when the sea temperature changes. This can affect marine ecosystems and processes. It can also affect fish-farming industries based in our coastal areas.
This dataset relates to the "Coastal sea-surface temperature" measure on the Environmental Indicators, Te taiao Aotearoa website.

New Zealand waters have at least 113 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.
This dataset relates to the "Commercial catch: sharks and rays" 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.

New Zealand’s fisheries and aquaculture sector is an important primary industry. It provides New Zealanders with food, economic returns, and employment. Reporting on the value of this industry helps us to understand the marine economy.
This dataset relates to the "Value of fisheries and aquaculture" measure on the Environmental Indicators, Te taiao Aotearoa website.

Along with sea lions, fur seals, and dolphins, seabirds are the protected species most directly affected by fisheries in New Zealand waters (exclusive economic zone and territorial sea). Estimating seabird deaths from bycatch in commercial fishing is one way of assessing the pressure some seabird species face from current fishing practices. About one-third of our 92 resident seabird species and subspecies are considered to be threatened with extinction.
The fishing-related mortality category is derived from a semi-quantitative risk assessment conducted by Richard and Abraham (2015). We are using the threat rating assigned by Richard and Abraham (2015) for Our Marine Environment 2016. The Environment Aotearoa 2015 report used the Ministry for Primary Industries (MPI) risk rating. This results in a change to risk rating for one threatened species, which has a medium rating in the report but a high rating from MPI. This species is the Stewart Island shag, Leucocarbo chalconotus.

Along with sea lions, fur seals, and dolphins, seabirds are the protected species most directly affected by fisheries in New Zealand waters. Reporting on the risk of threatened and at-risk seabirds dying as a result of fishing activities each year is one way of assessing the pressure some seabird species face from current fishing practices.
This dataset relates to the "Bycatch of protected species: seabirds" measure on the Environmental Indicators, Te taiao Aotearoa website.

Our fish stocks are affected by commercial, customary, and recreational fishing, and environmental pressures (eg ocean temperature, acidity, and productivity). The Ministry for Primary Industries uses three performance measures to assess influences on fish stocks: a soft limit (below which a rebuilding plan is required), a hard limit (below which closing a fishery should be considered), and an overfishing threshold (where the rate of extraction is higher than the rate of replenishment).
This dataset relates to the "State of fish stocks" measure on the Environmental Indicators, Te taiao Aotearoa website.

Phytoplankton are primary producers and form the basis of the oceans’ food chains. They contain the pigment chlorophyll-a (chl-a), which they use to create their own food through photosynthesis. We study concentrations of chl-a in phytoplankton to assess primary productivity in our oceans. Changes in productivity are likely to affect food chains and ultimately affect marine biodiversity, including the species we rely on for economic, cultural, or recreational purposes.
This dataset relates to the "Primary productivity" measure on the Environmental Indicators, Te taiao Aotearoa website.