Marine Data - Page 5

New Zealand has 92 seabird and 14 shorebird species and subspecies (taxa). We have the highest number of endemic seabirds (found only in a particular area) in the world. Nearly 25 percent of the world’s seabird species breed in the New Zealand region, and almost 10 percent only breed here. Seabirds and shorebirds tend to be at or near the top of the food chain, and thrive only if the marine ecosystem is healthy. Decreasing bird populations can signal that the ecosystem is degrading.
This dataset relates to the "Conservation status of seabirds and shorebirds" measure on the Environmental Indicators, Te taiao Aotearoa website.

The ocean storm index estimates the number of days in a year when wind speeds exceed gale and storm force on the Beaufort Scale. In a gale, sea conditions are rough and waves can be over six metres high. In a storm, waves can be over 10 metres high. To put this into context, on land a near gale would make walking difficult, and a storm would cause some damage to roofs, chimneys, and trees. Climate change could lead to changes in the frequency and intensity of storms. More frequent and intense storms will likely be a stressor for habitats and species.
The ocean storm index estimates the number of days that wind speeds exceed gale and storm force on the Beaufort Scale. The Beaufort Scale is a widely used international classification that rates sea conditions from 0 (calm) to 12 (hurricane). We report on estimated wind speeds broken down to:
- gales – measure 8 on the scale, have rough sea conditions with wind speeds of approximately 62–74 km per hour and wave heights of 5.5 metres
- storms – measure 10 on the scale, have wind speeds of approximately 89–102 km per hour and wave heights of 9–11.5 metres (McDonald & Parsons, 2016).
This data relates to the average number of days wind speed exceeded gale force (Beaufort Scale 8) from 1979–2015.

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.

New Zealand’s four million km2 marine environment is diverse, with a range of coastal habitats and offshore seabed environments. We also have many marine species found only in 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 marine reserves as an indirect measure to understand the state of the marine environment.

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 ocean storm index estimates the number of days in a year when wind speeds exceed gale and storm force on the Beaufort Scale. In a gale, sea conditions are rough and waves can be over six metres high. In a storm, waves can be over 10 metres high. To put this into context, on land a near gale would make walking difficult, and a storm would cause some damage to roofs, chimneys, and trees. Climate change could lead to changes in the frequency and intensity of storms. More frequent and intense storms will likely be a stressor for habitats and species.
The ocean storm index estimates the number of days that wind speeds exceed gale and storm force on the Beaufort Scale. The Beaufort Scale is a widely used international classification that rates sea conditions from 0 (calm) to 12 (hurricane). We report on estimated wind speeds broken down to:
- gales – measure 8 on the scale, have rough sea conditions with wind speeds of approximately 62–74 km per hour and wave heights of 5.5 metres
- storms – measure 10 on the scale, have wind speeds of approximately 89–102 km per hour and wave heights of 9–11.5 metres (McDonald & Parsons, 2016).
This dataset relates to the number of days when wind speed exceeded gale force (Beaufort Scale 8) in 2015.

Seabed trawling and dredging (where fishing gear is towed near or along the ocean floor) can physically damage seabed (benthic) habitats and species. These fishing methods can also stir up sediment from the seabed, creating sediment plumes that can smother sensitive species. Recovery times for affected habitats and species depend on their sensitivity and the area affected by trawling or dredging. Bottom trawling is carried out on or near the seabed in both shallow and deep waters. Dredging is carried out on the seabed in shallow waters and targets marine creatures such as scallops. This measure focuses on deepwater areas (waters deeper than 200m).

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.

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.

The unintended catch of marine species other than the target species puts pressure on the populations of marine species by removing individuals or potentially modifying ecosystems.
This dataset relates to the "Bycatch of fish and invertebrates" measure on the Environmental Indicators, Te taiao Aotearoa website.