ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515595

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Some characteristics of the subsurface temperature structure in the north Tasman Sea as measured by expendable bathythermograph probes are discussed, Vertical sections of temperature generally show a subsurface thermal front which appears to meander north‐eastward from an area shallower than 1000 m and centred on 33°S, 162° 30 E on the Lord Howe Rise to an area on the Norfolk Ridge near 32° S, 167° 30 E where the depth is less than 500 m; the warmer water lies north‐west of the front. This front, which is given the name “Tasman Front”, probably results from the flow of the East Australian Current as a zonal jet across the north Tasman Sea from the east coast of Australia to the north of New Zealand.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515596

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Numerical calculations carried out for tidal flow on a small region of the New Zealand coast near Mana Island (41° 5 S, 174° 47 E) solved a finite difference form of the tidal equations, and assumed that the velocity boundary conditions could be approximated by a modified Kelvin wave formula. The results were exponentially smoothed in time at each step in the calculation to remove spurious modes.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515597

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The seasonal cycles of abundance of the phytoplankton and zooplankton in Lake Ototoa, Northland, at 36° 31 S, 174° 14 E, are described. Concentrations of chlorophyllawere low (range 0.04–4.61 mg.m‐3; mean 0.97 mg.m‐3), and highest values were in winter. Phytoplankton densities were also low; an oligo‐trophic diatom‐desmid assemblage associated withBotryococcus, Dinobryon,andSvhaerocysliswas found.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515598

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The chemistry and mineralogy of the sediments of Lakes Rotoroa and Rotoiti, South Island, New Zealand (41° 51 S, 172° 38 E and 41° 50 S, 172° 50 E respectively) , were studied. In general, the cation exchange properties, element concentrations, and mineral compositions of the sediments show little variation between samples from each lake. However, some nutrient concentrations, notably exchangeable calcium, magnesium, and potassium, and total nitrogen and sulphur, are higher in sediments from weed beds than in sediments underlying deeper water; iron and manganese concentrations tend to show the opposite trend. Concentrations of exchangeable calcium and total nitrogen, sulphur, manganese, and iron generally decrease down the sediment profiles from the sediment/water interface. Differences between lakes, notably higher concentrations of illite and of the elements potassium, aluminium, titanium, and zirconium, and lower concentrations of calcium in the sediments of Lake Rotoiti than in those from Lake Rotoroa, are probably due mainly to the different geological settings rather than to differences in the diagenetic processes operating within the lakes. Mineralogical analyses indicate that the lake sediments are derived mainly from the valleys of the major inflow rivers rather than from the slopes at the sides of each lake.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515599

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The viable heterotrophic bacteria of Lake Grasmere in inland Canterbury (43° 05 S, 171° 45 E) were studied. Numbers of bacteria in water above a spring were positively correlated with rainfall in the 7 days before sampling, but bacteria in open water and from over the macrophyteElodea canadensiswere not. There was some increase in the bacterial population in the water overE. canadensisin the autumn to winter months. Numbers of bacteria in the open water ranged from 55 to 1020 cells per millilitre, and were outnumbered by algae by a factor of between 4 and 34. The bacterial population tended to increase after blooms of zooplankton, but there was little or no response to changes in phytoplankton populations. Benthic bacteria rarely increased in numbers after the deposition of organic matter.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515600

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A comparative study of the heterotrophic potentials of ten New Zealand lakes was carried out. Two sampling periods were chosen, one during late August and early September 1972 (late winter, minimal thermal stratification) and another during February 1973 (mid summer, strong thermal stratification in all but two lakes). A wide range of heterotrophic potentials occurred which enabled the lakes to be placed in the following basic groups according to descending trophic levels:

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515601

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The construction and operation of a simple mechanical grab, suitable for sampling dense beds of aquatic macrophytes, is described. The technique has several advantages over the diver‐quadrat method. Both methods have been used in vegetation surveys of the Rotorua lakes where plant densities attain the maximum recorded for freshwater lakes. The results indicate marked variations in weed density over short distances, and thus both methods require a large number of samples for an accurate determination of biomass.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515602

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Stomach contents of 68 black petrels,Procellaria parkinsoni,12 Westland black petrels,P. westlandica,and 3 white‐chinned petrels,P. aequinoctialis,were compared. The main prey were Cephalopoda and fish, and these indicated predominantly nocturnal feeding with selection for bioluminescent forms. There is marked latitudinal variation in the Cephalopoda available to these petrels.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515603

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Differences between males and females in the morphology of the fifth legs were found in stage IV copepodites ofBoeckella hamataand in stage V cope‐podites ofB. hamata, B. propinqua, B. dilatata, B. triarticulata,andCalamoecia lucasi.There were also sexual differences in overall body size. InB. hamata, B. triarticulata,andB. dilatata,the differences were sufficiently obvious for stage V copepodites to be sexed at low magnifications. The diagnostic features of all stages are described.

ISSN:0028-8330    

DOI:10.1080/00288330.1976.9515604

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor