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7 EEZ Classification - B

7.4 Biological characteristics of the EEZ classes

The biological character of classes defined by the 20-class level and for which data was available is shown for chlorophyll concentration (Appendix 2, Figure A2.1), fish assemblages (Appendix 2, Table A2.2), and benthic invertebrates (Appendix 2, Table A2.3). Description of the biological character of the environmental classes was hampered by the limited range of sampling of some geographic locations and/or environmental combinations and could therefore only be produced for some classes. Information about average chlorophyll concentrations was available for 16 classes and fish assemblage data was available for 14 classes, but information about invertebrates was only available for nine classes. In the following descriptions classes are ordered according to the dendrogram (Appendix 1, Figure A1.1) rather than in strict numerical order, so that closely related classes are grouped together in proximity to each other.

7.4.1 Oceanic subtropical environments

A map of the EEZ showing the occurrence of Class 1 as part of the 20 class level EEZ Marine Environment Classification.

Class 1 - is extensive in the far north, occurring in deep (mean = 3001 m) subtropical waters with high solar radiation and warm winter sea surface temperatures. Average chlorophyll a concentrations are very low, but there are insufficient trawl or benthic invertebrate records to provide descriptions of these components.

A map of the EEZ showing the occurrence of Class 22 as part of the 20 class level EEZ Marine Environment Classification.

Class 22 - is extensive in moderately deep waters (mean = 1879 m) over a latitudinal range from about 33-38°S. It is typified by cooler winter SST than the previous class. Chlorophyll a reaches only low average concentrations. Characteristic fish species (i.e. occurring at 50% or more of 20 sites) include orange roughy, Baxter's lantern dogfish, Johnson's cod, and hoki.

A map of the EEZ showing the occurrence of Class 9 as part of the 20 class level EEZ Marine Environment Classification.

Class 9 - occurs in offshore waters of considerable depth (mean = 5345 m) both in the northeast and northwest of the study area. Average chlorophyll a concentrations are very low, but no benthic invertebrate or trawl samples have been collected in waters of these depths.

7.4.2 Oceanic, shelf and subtropical front environments

A map of the EEZ showing the occurrence of Class 47 as part of the 20 class level EEZ Marine Environment Classification.

Class 47 - occurs extensively in deep waters (mean = 2998 m) over a latitudinal range from around 37-47°S. Average chlorophyll a concentrations are moderately low. Characteristic fish species (24 sites) include smooth oreo, Baxter's lantern dogfish, the rattail Macrourus carinatus, Johnson's cod and orange roughy.

A map of the EEZ showing the occurrence of Class 55 as part of the 20 class level EEZ Marine Environment Classification.

Class 55 - is of restricted extent occurring at moderately shallow depths (mean = 224 m) around northern New Zealand and has high annual solar radiation and moderately high wintertime SST. Average chlorophyll a concentrations are moderate. Characteristic fish species (26 sites) include sea perch, red gurnard, snapper and ling, while arrow squid are also caught frequently in trawls. The most commonly represented benthic invertebrate families (i.e. occurring at 50% or more of 27 sites) are Dentallidae, Nuculanidae, Pectinidae, Carditidae, Laganidae and Cardiidae.

A map of the EEZ showing the occurrence of Class 63 as part of the 20 class level EEZ Marine Environment Classification.

Class 63 - is extensive on the continental shelf including much of the Challenger Plateau and the Chatham Rise. Waters are of moderate depth (mean = 754 m) and have moderate annual radiation and wintertime SST. Average chlorophyll a concentrations are also moderate. Characteristic fish species (29 sites) include orange roughy, Johnson's cod, Baxter's lantern dogfish, hoki, smooth oreo and javelin fish. The most commonly represented benthic invertebrate families (14 sites) are Carditidae, Pectinidae, Dentaliidae, Veneridae, Cardiidae, Serpulidae and Limidae.

A map of the EEZ showing the occurrence of Class 178 as part of the 20 class level EEZ Marine Environment Classification.

Class 178 - is extensive to the south of New Zealand occurring in moderately deep water (mean = 750) as far south as latitude 55°S. It experiences low annual solar radiation and cool wintertime SST. Chlorophyll a reaches only low to moderate average concentrations. Characteristic fish species (26 sites) include ling, javelin fish, hoki and pale ghost shark. The most commonly represented benthic invertebrate families (eight sites) are Terebratellidae, Serpulidae, Pectinidae, Temnopleuridae, Veneridae, Carditidae, Glycymerididae, Spatangidae and Limidae.

7.4.3 Oceanic sub-Antarctic environments

A map of the EEZ showing the occurrence of Class 127 as part of the 20 class level EEZ Marine Environment Classification.

Class 127 - is the most extensive class, occurring in deep waters of the southwest Pacific and Tasman basins (mean = 4799 m) from about latitude 42°S south. Both annual solar radiation and wintertime SST are low, and there is minimal seasonal variation in SST. Chlorophyll a reaches only moderate concentrations.

A map of the EEZ showing the occurrence of Class 204 as part of the 20 class level EEZ Marine Environment Classification.

Class 204 - occurs in moderately deep waters (mean = 2044 m) on the continental slope south of about latitude 46°S. Conditions are otherwise similar to that in the previous class (Class 127), and chlorophyll a reaches only low average concentrations. Some of the most commonly occurring fish species are orange roughy, smooth oreo, Baxter's lantern dogfish, the rattail Macrourus carinatus, hoki, Johnson's cod and javelin fish.

A map of the EEZ showing the occurrence of Class 273 as part of the 20 class level EEZ Marine Environment Classification.

Class 273 - occurs in the far south of the study area encompassing deep water sites (mean = 2550 m) along the MacQuarie Ridge where the ocean floor slopes very steeply. Mean annual solar radiation and wintertime SST have the lowest values of any class and chlorophyll a reaches only low average concentrations.

7.4.4 Northern coastal environments

A map of the EEZ showing the occurrence of Class 12 as part of the 20 class level EEZ Marine Environment Classification.

Class 12 - occupies a small area of shallow waters (mean depth = 94 m) on the shelf that surrounds Norfolk Island. It experiences high mean annual solar radiation, warm wintertime SST and moderately high orbital velocities.

7.4.5 Central coastal environments

A map of the EEZ showing the occurrence of Class 58 as part of the 20 class level EEZ Marine Environment Classification.

Class 58 - is of relatively restricted extent occurring in moderately shallow waters (mean = 117 m) around the northern tip of the North Island and in Cook Strait. Strong tidal currents are the dominant feature of this class. Some of the most commonly occurring fish species are red gurnard, snapper, leather jacket, spiny dogfish, barracouta, hoki and eagle ray, while arrow squid are also frequently caught in trawls. The most commonly represented benthic invertebrate families are Veneridae, Carditidae and Pectinidae.

A map of the EEZ showing the occurrence of Class 60 as part of the 20 class level EEZ Marine Environment Classification.

Class 60 - is much more extensive than the previous class, occupying moderately shallow waters (mean = 112 m) on the continental shelf from the Three Kings Islands south to about Banks Peninsula. It experiences moderate annual solar radiation and wintertime SST and has moderately high average chlorophyll a concentrations. Some of the most commonly occurring fish species are barracouta, red gurnard, john dory, spiny dogfish, snapper and sea perch, while arrow squid are also frequently caught in trawls. The most commonly represented benthic invertebrate families are Dentaliidae, Cardiidae, Carditidae, Nuculanidae, Amphiuridae, Pectinidae and Veneridae.

A map of the EEZ showing the occurrence of Class 64 as part of the 20 class level EEZ Marine Environment Classification.

Class 64 -occupies a similar geographic range to the previous class but occurs in shallower waters (mean = 38 m). Seabed slopes are low but orbital velocities are moderately high and the annual amplitude of SST is high. Chlorophyll a reaches its highest average concentrations in this class. Some of the most commonly occurring fish species are red gurnard, snapper, john dory, trevally, leather jacket, barracouta and spiny dogfish. Arrow squid are also frequently caught in trawls. The most commonly represented benthic invertebrate families are Veneridae, Mactridae and Tellinidae.

A map of the EEZ showing the occurrence of Class 124 as part of the 20 class level EEZ Marine Environment Classification.

Class 124 - although of limited extent, occurs around the entire New Zealand coastline occupying shallow waters (mean = 8 m) with very high orbital velocities. Some of the most commonly occurring fish species are leather jacket, snapper, red gurnard, eagle ray, trevally and john dory. The most commonly represented benthic invertebrate families are Veneridae, Mactridae, Carditidae and Terebratellidae.

A map of the EEZ showing the occurrence of Class 130 as part of the 20 class level EEZ Marine Environment Classification.

 

Class 130 - occurs only in the Marlborough Sounds, occupying sites with a distinctive set of environmental conditions typified by very shallow water (mean = 10 m), minimal slope, moderate orbital velocities and tidal currents, and high gradients of SST.

A map of the EEZ showing the occurrence of Class 169 as part of the 20 class level EEZ Marine Environment Classification.

 

Class 169 - is moderately extensive east of the South Island, occupying shallow waters (mean = 66 m) with low to moderate orbital velocities, moderately low annual solar radiation and wintertime SST, and moderate tidal currents. It supports high average concentrations of chlorophyll a. Some of the most commonly occurring fish species are barracouta, spiny dogfish, hapuku, red gurnard, ling and sea perch, while arrow squid are also taken frequently in trawls. The most commonly represented benthic invertebrate families are Veneridae, Terebratellidae, Mactridae, Pectinidae, Cardiidae, Amphiuridae, Nuculidae, Balanidae and Carditidae.

A map of the EEZ showing the occurrence of Class 190 as part of the 20 class level EEZ Marine Environment Classification.

Class 190 - is of limited extent, occurring in waters of moderate depth (mean = 321 m) along the Southland Coast. It experiences moderately low mean radiation and wintertime SST, and high gradients of SST. It supports high average concentrations of chlorophyll a. Some of the most commonly occurring fish species are spiny dogfish, barracouta, ling, hapuku, hoki and sea perch. Arrow squid are also frequently taken in trawls.

A map of the EEZ showing the occurrence of Class 170 as part of the 20 class level EEZ Marine Environment Classification.

 

Class 170 - is extensive in moderately shallow waters (mean = 129 m) on the continental shelf surrounding the Chatham Islands, and from Foveaux Strait south, including around the Bounty Islands, Auckland Islands and Campbell Island. Annual solar radiation and wintertime SST are both moderately low, as is the annual amplitude of SST. Tidal currents are moderate and average concentrations of chlorophyll a reach moderate levels. Some of the most commonly occurring fish species are barracouta, spiny dogfish, hapuku and ling, while arrow squid are taken with very high frequency in trawls. The most commonly represented benthic invertebrate families are Terebratellidae, Serpulidae, Veneridae, Pectinidae, Temnopleuridae, Carditidae Cardiidae, Glycymerididae, Spatangidae and Limidae.