World Marine Data - Page 3

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, 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.

The marine economy shows the contribution marine-based economic activities make to the New Zealand economy as measured by gross domestic product (GDP). Measuring the marine economy shows how New Zealand’s marine environment is used to generate economic activity and how this changes over time. However, these activities can also be a source of pressure on New Zealand’s marine environment.

New Zealand has a diverse coastline, which spans 15,000 km. Reporting on our coastal seabed (benthic) habitats provides important contextual information on the state of the marine domain.
This dataset relates to the "Coastal habitats" measure on the Environmental Indicators, Te taiao Aotearoa website.

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.

Measured oceanic chlorophyll-a (chl-a) concentrations as an indicator of marine primary productivity. Phytoplankton are primary producers of biomass (mass of living organisms) and form the main basis of marine food chains. They use the chl-a pigment to capture the sun’s energy through the process of photosynthesis. Phytoplankton growth is affected by the availability of nutrients and light, which in turn are affected by the structure of the surface water column. The surface water column structure is affected by oceanographic and climate processes; large-scale changes to climate and oceanographic conditions can lead to changes in phytoplankton growth and chl-a concentrations.

Marine non-indigenous (exotic) species arrive in New Zealand waters on the hulls of international vessels (biofouling) or in discharged ballast waters. Some have little impact or cannot survive in New Zealand waters; others have a negative impact on our native habitats and species and become pests. They can compete with, and prey on, indigenous species, modify natural habitats, affect marine industries or can alter ecosystem processes. The potential impact of non-indigenous species on our native habitats and species means they could threaten our cultural and natural heritage, as well as economic activities such as commercial and recreational fishing, shellfish harvesting, and aquaculture.
The maximum latitudinal extent is the range between the northern-most and southern-most records of these species.

The marine trophic index (MTI) measures the changing abundance and diversity of demersal fish species (living and feeding on or near the seabed) in fishery catches. The Chatham Rise has more than 180 species of fish. It is one of the most productive areas of our exclusive economic zone (EEZ) and an important fishing ground. We calculate the Chatham Rise MTI to assess the change in marine ecosystems resulting from fishing and climate variability.
This dataset relates to the "Marine trophic index: Chatham Rise" measure on the Environmental Indicators, Te taiao Aotearoa website.

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.

Marine exotic species arrive in New Zealand waters on the hulls of international vessels (biofouling) or in discharged ballast waters. Some have little impact or cannot survive in New Zealand waters. Others are pests that can out-compete indigenous species and alter ecosystems. Marine pests could threaten our cultural and natural heritage, as well as economic activities such as commercial and recreational fishing, shellfish harvesting, and aquaculture.
This dataset relates to the "Marine pests" measure on the Environmental Indicators, Te taiao Aotearoa website.