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1.
The Subtropical Convergence east of New Zealand   总被引:1,自引:1,他引:0  
Hydrographic data from the region of the Subtropical Convergence east of New Zealand between 177°E and 179°E show that in spring the convergence occurs near the Chatham Rise. North of the Chatham Rise the structure is fairly regular with isolines of temperature and salinity sloping upwards towards the south. To the south of the Chatham Rise the structure is more complex with an apparent intrusion of Subtropical Water into the Sub‐antarctic Water below depths of about 150 m.  相似文献   

2.
Trolling surveys showed that albacore tuna are about equally abundant in subtropical and Subtropical Convergence Zone surface waters off the south‐east coast of New Zealand. Few albacore were located in Subantarctic Surface Water, indicating that the Subtropical Convergence Zone is the southern limit for albacore in this area.  相似文献   

3.
Configuration of major sound channels in the ocean around New Zealand is derived from the temperature and salinity data available from the region between latitudes 28°S and 56°S and between 158°E and 174°W. The “SOFAR channel” is established throughout the area northwards of the Antarctic Convergence, with its axis in a depth of about 1,300 m. Little variation in the depth of this axis was found except in the southern part of the subantarctie zone, where the weak vertical temperature stratification cannot maintain a velocity minimum; the axis of the SOFAR channel tends to decrease in depth as it loses its identity. In the northern part of the subantarctie region, a second channel was found at a depth of about 100 m. The depth of the axis of this “subantarctie channel” increases to about 500 m under the surface outcrop of the Subtropical Convergence. It loses its identity at about 400 m in the stronger vertical temperature stratification of the subtropical region. To the south of the Antarctic Convergence, an “antarctic channel” was found with its axis at a depth of some 400 m in a temperature inversion between Antarctic Winter Water and the underlying Pacific Deep Water.

Sound velocity on the surfaces defined by the channel axes is mapped. A ridge of maximum SOFAR velocity is defined extending east and west of the northern part of New Zealand. This feature does not seem to appear in the north Pacific and has been tentatively associated with the dynamics of east‐flowing subtropical currents in this region.  相似文献   

4.
Records are presented of sightings of 6 cetacean species (15 common dolphins, Delphinus delphis Linnaeus, over 5000 dusky dolphins, Lagenorhynchus obscurus (Gray), approximately 74 bottlenose dolphins, Tursiops truncatus (Montagu), 8 sperm whales, Physeter catodon Linnaeus, 6 southern humpback whales, Megaptera novaeangliae lalandi (Fischer), and 36 southern pilot whales. Globi‐cephala melaena edwardii (Smith)) from m.v. Lloret Lopez II between 8 January and 2 April 1970. A large school of dusky dolphins was observed south of Solander Island. Monthly water temperatures in the summer of 1970 were high and in January ranged from 15.4°c (9.2 km west of Fiordland) and 21.6°c (55 km west of Cape Farewell), in February from 16.2°c (Fiordland) and 20.4°c (Cape Farewell), and in March from 16.0°c (Fiordland) and 20.5°c (Cape Farewell).  相似文献   

5.
Distribution of shipworms (Bivalvia: Teredinidae) in the New Zealand region   总被引:1,自引:1,他引:0  
Bankia neztalia was found in temperate waters around New Zealand, mainly south of New Plymouth and Tauranga. Bankia australis was found in warm‐temperate waters north of Nelson; it requires water temperatures above 19–20°c for successful breeding and is euryhaline. Lyrodus pedicellatus also occurred in warm‐temperate waters north of Nelson and had a lower water temperature limit for survival of about 10 °c. Lyrodus medilobatus occurred in warm‐temperate waters on the north‐east coast of the North Island north of Tauranga. Nototeredo edax is uncommon and occurred over the same range as B. australis.

The presence of shipworms in wood collected from depths of greater than 50 m around New Zealand is reported. Teredora princesae is recorded from driftwood around New Zealand.  相似文献   

6.
Four drift bottles, cast adrift south of the Subtropical Convergence at 48°S, 156°E in November 1980, landed within 123 days of release at a short stretch of coast north of Banks Peninsula. A high degree of coherence in the responsible drift pattern is indicated. The contemporary surface circulation inferred from satellite‐derived sea‐surface temperature distributions indicates that the bottles were entrained in a meridionally‐converging flow after drifting across the southern Tasman Sea without crossing the Convergence. They were prevented from further eastward drifting because of a marked southward flexing of the Convergence east of the Southland Current during February 1981. Because of local weather and tide effects, the bottles finally beached in Pegasus Bay.  相似文献   

7.
Low cloud boundaries coincident with oceanic convergences   总被引:1,自引:1,他引:0  
Low stratus cloud was present over the cool water on the southern and western sides of the Subtropical Convergence east of New Zealand during two airborne infrared radiation thermometer surveys made on 2 April and 17–18 November 1969. The alignment of the northern boundary of such cloud with the Subtropical Convergence, and of cloud boundaries elsewhere with other areas having large horizontal temperature gradients, demonstrates that often such cloud boundaries can be useful indicators of surface temperature discontinuities.  相似文献   

8.
The distribution and movements of sperm whales, Physeter catodon Linn., in the western South Pacific (latitudes 30–70° S, longitudes 150E‐150°W) are examined. An undetermined number of catches by nineteenth century American whaleships, 9,720 catches by pelagic fleets in 1961–70, and 427 sightings in 1967 are analysed and correlated with oceanographic data from Australian and New Zealand surveys.

The proportion of females decreases southwards, abruptly at about latitude 44° S in the Tasman Sea, and at about 46–47° S east of New Zealand. Virtually no females occur south of 50° S. The male population density also decreases southwards: the density between 50–70° S appears to be less than 25% of that between 30–50° S. Sperm whales also appear to be less abundant in the eastern part of the region away from the New Zealand plateau, but more data are required.

The pattern of distribution and its seasonal changes probably correlate with vertical temperature gradients of about 5°c in the upper 100 m of water, i.e., optimal conditions for squid schooling. Catch per unit effort in autumn is lower than in spring. A northward population shift in autumn is inferred, based on reduction of available food species and probable temperature tolerances of calves, most of which are born in February and March, towards the end of the southern summer. Some males overwinter in areas where suitable gradients persist, e.g., around the Chatham Islands.

Possibly the summer surface temperature maxima south of the South Island are low enough to inhibit the passage of breeding schools with calves from one side of the New Zealand archipelago to the other. Sperm whales do not pass through Cook Strait normally. Thus, unless considerable mixing of stocks occurs north of New Zealand in winter, there may be two “unit stocks”, one oscillating seasonally between the central Tasman Sea and the Fiji‐Tonga region, and another (probably smaller) between the east coast of the South Island and the region just north of the Chatham Islands.  相似文献   

9.
Two species of spiny lobsters (marine crayfish) inhabit New Zealand waters: Jasus edwardsii (Hutton, 1875), and J verreauxi (H. Milne Edwards, 1851). J edwardsii, the more common species, is present along most rocky coastlines in New Zealand, but is more abundant in the south‐west of the South Island and at the Chatham Islands. The species apparently reaches its northern limit of distribution at the Three Kings Islands (34°S) and its southern limit at the Auckland Islands (51°S).

J. verreauxi, the less common species, is almost solely restricted in New Zealand waters to the north‐east coast of the North Island. It is uncommon in the west and the south of the North Island, and is rare in the South Island. J. verreauxi apparently reaches its northern limit of distribution at the Kermadec Islands (31°S), and its southern limit near Bluff (47°S) in the South Island.  相似文献   

10.
Seasonal and tidal variations in the hydrology of Wellington harbour   总被引:1,自引:1,他引:0  
Observations were made on several hydrological features of Wellington Harbour, New Zealand (41° 16’ S, 174° 51’ E) during 1970 to 1972. These suggest that the harbour is topographically partially isolated from oceanic influences, and that waters within the harbour undergo efficient mixing.

Monthly mean sea‐surface temperatures ranged seasonally between 10.5°c and 18.5°c, and some stratification was observed during summer and winter. Salinities usually ranged from 33.5‰ to 34.5‰, and water transparency by Secchi disc from 3 m to 6 m. Dissolved oxygen content ranged from 96% to 127% saturation, usually exceeding 100% saturation in surface waters.

Under normal discharge conditions during winter, the Hutt River was observed to markedly affect surface temperatures and salinities as far south as Somes Island to a depth of about 5 m.  相似文献   

11.
Data from 36 whale shark (Rhincodon typus Smith, 1828) sightings off north‐east North Island, New Zealand are summarised. Sightings were concentrated over the outer shelf and shelf break in areas influenced by the East Auckland Current at sea surface temperatures (SST) of 21–24°C. Sightings occurred from late spring to early autumn (November‐April) but were most frequent in midsummer (February) when upwelling along the north‐east shelf is weakest. The data indicate whale sharks occur off north‐east New Zealand most summers, including those when SST is colder than usual. A cluster of sightings and three observations of whale sharks feeding on schools of anchovy (Engraulis australis) near Whale Island, Bay of Plenty, suggest whale sharks may aggregate seasonally in this area. Estimated total lengths (TL) of 26 whale sharks ranged from 3.5 to 15 m, with 73% between 6 and 9 m TL.  相似文献   

12.
The proximate composition was determined of the white muscle of albacore tuna, Thunnus alalunga, caught by surface trolling along the Subtropical Convergence Zone east of the South Island of New Zealand ("Area 1"), and to the north and west of the North Island ("Area 2"). Fish from Area 1 were 70 ± 10 cm (mean ± s.d.) in fork length, and higher in oil content (4.6 ± 2.9%), than Area 2 fish which measured 55 ± 10 cm and contained 2.8 ±1.7% oil. The ash content of the white muscle of all fish sampled was 1.2 ± 0.1%, and the soluble carbohydrate content 0.36 ± 0.04%. Crude protein contents were calculated at c. 25%. Statistical relationships between moisture and oil contents of both white and red muscle were determined; they can be used to predict oil content from a known moisture content. Oil content was positively correlated with fork length, and negatively correlated with the sea surface temperature at time of capture. Oil levels in the fillet were highest in the muscle layer immediately below the skin and decreased logarithmically with depth. In fish with low white‐muscle oil content (below 5%), the corresponding red‐muscle oil content was higher; above 6% white muscle oil content the corresponding red‐muscle oil content was lower. The proximate composition of whole fish, the head, frame, skin, and viscera is presented.  相似文献   

13.
Temperature and salinity observations at 17 stations off the east coast of New Zealand are presented. Geostrophic current stations just north of the Subtropical Convergence suggest the presence of an anticyclonic eddy similar to but east of that found by Garner in the period February‐March 1963 (Garner 1967). Ridgway (in press) has suggested that eddies formed at East Cape proceed down the east coast of the North Island of New Zealand giving rise to the East Cape Current. It is proposed here that these eddies move east after leaving the coast in the vinicity of the southern limit of the Hikurangi Trench.  相似文献   

14.
Hydrological observations, mainly sea surface temperature measurements, are presented for the triangular region bounded by New Zealand, New Caledonia, and Western Samoa. The existence of the Tropical Convergence and the general seasonal variation of the surface parameters are discussed. A secondary convergence lying between the Subtropical Convergence and the Tropical Convergence is proposed and its relationship to the general surface circulation of the Tasman, Sea is examined.  相似文献   

15.
Two juvenile slender tuna Allothunnus fallai Serventy, 278 mm and 282 mm fork length, were identified from a catch by a purse seiner 23 km off the Moko Hinau Islands, New Zealand, on 23 January 1974. As the slender tuna were observed to school in association with skipjack tuna Katsuwonus pelamis L., it is probable that adults also school, and could be available as a yet unexploited resource to New Zealand fishermen, especially to the south‐east of New Zealand.  相似文献   

16.
Sightings of 85 icebergs south‐east of New Zealand in February and March 1967 are reported, with associated sea surface temperatures.  相似文献   

17.
This account of studies on the algae and bacteria of North Island thermal areas records temperature, pH and species found in these microbial habitats, with special attention to organisms living at the highest temperatures. Thermal features were studied at Rotorua (Whakarewarewa and Ohinemutu), Waiotapu (Tourist Reserve and Lady Knox Geyser), Orakei Korako, Taupo Spa, Waikite Springs, Wairakei thermal valley, Wairakei geothermal field, Tikitere, Ketetahi, Lake Rotokawa (Taupo region), Waimangu, De Brett Thermal Hotel (Taupo).

The upper temperature limit for blue‐green algae in New Zealand is 60–65°c, and the species living at the thermal limit is generally Mastigocladus laminosus, although in some cases Phormidium sp. or Synechococcus sp. was found. The Synechococcus sp. characteristic of high temperatures (73–74°c) present in North America was not found in New Zealand. In virtually all boiling pools (99–101°c) with pH values in the neutral and alkaline range bacteria were found, but in acidic boiling pools, bacteria were absent. The presence in New Zealand of the eucaryotic algae Cyanidium caldarium and Zygogonium sp. is reported for the first time. Further records for the hot spring brine fly Ephydrella thermarum and other ephydrids are given. The observations are compared with previous data on thermal habitats in Yellowstone Park, in Iceland, and in other parts of the world.  相似文献   

18.
Halosaurus pectoralis McCulloch is recorded from off Gisborne, New Zealand, and from south‐east of Lord Howe Island, thus adding a second species of the order Heteromi to the New Zealand fauna.  相似文献   

19.
The winter distributions of mesopelagic fishes, crustaceans, and cephalopods across the Subtropical Convergence east of New Zealand are shown to reflect the hydrological changes associated with convergence of Subtropical and Subantarctic Surface Waters. Samples collected in the upper 400 m in each of these water masses and in mixed water over the Chatham Rise contained members of faunal associations apparently characteristic for each area. The area of strongest hydrological change was characterised, at least for fishes and crustaceans, by a considerable decrease in species richness. Use of cluster analysis confirmed the clear correpondence between geographic species associations and water masses.  相似文献   

20.
Cetacean-oriented tourism has experienced rapid growth in the last two decades, accompanied by increasing concerns about the effects of tourism on target species. Here, we used shore-based observations of dusky dolphin (Lagenorhynchus obscurus) groups near Kaikoura, New Zealand, and generalised additive models to quantify changes in group speed, reorientation and linearity relative to natural and anthropogenic factors. Summer months were characterised by slower speeds and more changes in direction than winter months. Group speeds were higher at the beginning and end of the day, with slower speeds at midday. Speeds were slower when vessels were present, and dolphin groups changed direction more often when aircraft circled overhead. Effects were positively correlated with number of vessels present within 300 m. Short-term changes have potential to lead to long-term impacts, and further acoustic and energetic studies are proposed to elucidate whether these effects are likely to reduce individual fitness.  相似文献   

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