Marine Data - Page 12

Ocean acidification is the long-term decrease in the pH of our coastal waters and oceans. This indicator measures the change in pH in subantarctic surface waters at a station east of Otago from 1998 to 2017, and also the pH at selected coastal sites via the New Zealand Ocean Acidification Observing Network (NZOA-ON) from 2015 to 2017.

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.

These data estimate the occurence of extreme wave events in coastal and oceanic waters for 2011, 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.

This index was generated using NIWA’s operational wave forecasting model NZWAVE-12.

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 events can damage marine ecosystems and affect coastal infrastructure, ocean-based industries, and other human activities.

Changing wave characteristics can have impacts on natural systems, as most coastal and near-shore biological communities can be damaged or destroyed by extreme wave action (Ummenhofer & Mehl, 2017). In another example, extreme waves can disrupt ferries such as those crossing the Cook Strait. Sailings are often cancelled when significant wave heights exceed six metres.

It is important to report on extreme waves to gain greater insight into their frequency, particularly as sea level and storm surges are projected to increase and can compound wave effects.

In this dataset, an extreme wave event is defined as a continuous 12-hour period during which the significant wave height equals or exceeds one of three height thresholds: four, six, or eight metres.

Four-metre-tall waves are considered extreme in the northern-most parts but are more common in the south. For the southern-most parts of New Zealand, eight-metre waves better represent extreme wave events.

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.

These data estimate the occurence of extreme wave events in coastal and oceanic waters for 2008, particularly for wave events where significant wave height exceeds a threshold of 8 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.

This index was generated using NIWA’s operational wave forecasting model NZWAVE-12.

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.

This indicator measures the amount of phytoplankton in ocean water around New Zealand using satellite data. Phytoplankton are microscopic algae and primary producers, meaning they enable those higher up the food web to survive. Phytoplankton growth is affected by the availability of nutrients and light, which in turn are affected by the structure of the upper water column. Large-scale changes to climate and oceanographic conditions can change the water column structure and thus lead to changes in phytoplankton growth and primary productivity. Phytoplankton growth supports marine organisms throughout the marine environment, including fish, mammals, and seabirds (Pinkerton et al, 2019). We monitor the changes in phytoplankton by measuring chl-a concentration to provide an understanding of how marine ecosystems are changing. This affects the services we rely on for economic, cultural, and recreational purposes, such as fisheries (Nixon & Buckley, 2002).

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.

These data estimate the occurence of extreme wave events in coastal and oceanic waters for 2011, particularly for wave events where significant wave height exceeds a threshold of 4 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.

This index was generated using NIWA’s operational wave forecasting model NZWAVE-12.

This index was generated using NIWA’s operational wave forecasting model NZWAVE-12.

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.

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 4 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.

This index was generated using NIWA’s operational wave forecasting model NZWAVE-12.

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.

These data estimate the occurence of extreme wave events in coastal and oceanic waters for 2011, particularly for wave events where significant wave height exceeds a threshold of 8 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.

This index was generated using NIWA’s operational wave forecasting model NZWAVE-12.

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.