Tagged: Environment Aotearoa 2015

Ocean acidification, measured by the reduction in sea water pH, is mainly caused by oceans absorbing and storing carbon dioxide from the atmosphere. Ocean acidification affects marine species in various ways. The growth and survival rates of some shell-building species are affected because they struggle to build their shells. The behaviour and physiology of some fish is also affected. This could influence marine ecosystems and commercial, customary, and recreational fishing or harvesting.
This dataset relates to the "Ocean acidification" measure on the Environmental Indicators, Te taiao Aotearoa website.

Lightning is the discharge of electricity from thunderstorms. Ground strikes can cause significant damage to property and infrastructure, and injure or kill people and livestock. Lightning is often associated with other severe weather events, such as strong wind gusts. Thunderstorms may increase in frequency and intensity with climate change.
This dataset relates to the "Lightning" measure on the Environmental Indicators, Te taiao Aotearoa website.

Sea-level rise is a consequence of climate change. Increases in global temperature cause ocean waters to expand, and glaciers and ice sheets to melt into oceans. Sea-level rise affects estuaries, coastal wetlands, and intertidal and sub-tidal habitats and species. The increased likelihood of coastal erosion from sea-level rise presents a risk for seaside communities and their infrastructure, and for the marine environment itself, from increased suspended sediments.
This dataset relates to the "Coastal sea-level rise" measure on the Environmental Indicators, Te taiao Aotearoa website.

Seabed trawling and dredging, when fishing nets or dredges are towed near and along the seabed, can physically damage seabed (benthic) habitats and species. It can also stir up sediment from the seabed, shading (in shallow waters) or smothering marine species. This measure focuses on coastal areas (waters shallower than 250m). Focusing on coastal benthic habitats is important as these face multiple threats (for example from land-based activities) in addition to fishing.

Seabed trawling and dredging, when fishing nets or dredges are towed near and along the seabed, can physically damage seabed (benthic) habitats and species. It can also stir up sediment from the seabed, shading (in shallow waters) or smothering marine species. This measure focuses on coastal areas (waters shallower than 250m). Focusing on coastal benthic habitats is important as these face multiple threats (for example, from land-based activities) in addition to fishing

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).

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 Hector’s and Māui’s dolphins are subspecies of the small dolphin Cephalorhynchus hectori. They are endemic to New Zealand (not found anywhere else). The Hector’s dolphin is classified as nationally endangered, while the Māui’s dolphin is nationally critical. Reporting incidental dolphin deaths from fishing helps us understand the pressures our protected marine species face from fishing.
This dataset relates to the "Bycatch of protected species: Hector’s and Māui’s dolphin" measure on the Environmental Indicators, Te taiao Aotearoa website.

The South Island Hector’s and Māui dolphins are among the world’s smallest marine dolphins. Both are subspecies of the Hector’s dolphin Cephalorhynchus hectori. These coastal dolphins are endemic to New Zealand, which means that they are not found anywhere else. The Māui dolphin is found in the inshore waters of the west coast of the North Island, most often from Maunganui Bluff, north of Dargaville, to New Plymouth. The South Island Hector’s dolphin (hereafter referred to as ‘Hector’s dolphin’) is mostly found in the inshore waters around the South Island. Both subspecies are threatened with extinction: Hector’s dolphins have a population estimated at 15,000 and are classified as nationally vulnerable, while Māui dolphins have a population estimated at 63 individuals over one year old and are classified as nationally critical (Baker et al, 2019; MacKenzie & Clement, 2016; Baker et al, 2016).

Dolphins can become entangled in fishing gear used by both commercial and recreational fishers, with set nets posing a particularly high risk. The accidental capture of marine life in fishing gear is typically referred to as bycatch. Reporting the causes of death of protected species and specifically identifying the number of animals killed as a result of fishing activities helps us understand the pressures our protected marine species face from fishing.

DOC’s Hector’s and Māui dolphin incident database 1921-2018 provides data on reported deaths of Hector’s and Māui dolphins.

This indicator measures the number of reported Hector’s and Māui dolphin deaths from entanglement, categorised by type of fishing gear where possible, since 1998. The number of entanglements is compared to the total number of reported deaths.

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.

Marine mammals, seabirds, and shorebirds are indicator species for the state of our marine environment. A decreasing population can indicate that the ecosystem is degrading. New Zealand has a diverse range of marine species, many of which are endemic to (only breed in) New Zealand. They are apex species (near the top of the food chain) and can thrive only if their ecosystems are healthy.
This measure reports on the number of indigenous marine species that have had a genuine change in conservation status between two monitoring periods (2008–11 and 2012–14). A change in a species’ conservation status reflects a change in its risk of extinction.