摘要:

Growth rates ofHeterosigma carterae(Hulburt) comb, nov., isolated from the 1989 bloom in Big Glory Bay, New Zealand, were studied in continuous batch cultures, with 48 combinations of light and nitrogen (N) sources: NO3–, NH4+, and urea. Light had more influence on cultures grown with NO3–than cultures grown with the other N sources. At 160 μmol photons m–2s–1, the growth rate ofH. carteraewas highest with NO3–, intermediate with NH+4, and lowest with urea. At lower irradiances, growth rates of NO3–‐grownH. carteraewere lower than those of either form of “recycled” N. For NH4+‐ and urea‐grown cultures, nutrient concentration contributed to a greater variation of growth than did light.H. carteraeexhibited signs of toxicity at high concentrations of NH4+and urea, particularly at low light levels. The implication of the variations in growth rate under different combinations of light and N sources is that maximum growth ofH. carteraein the field is probably attained in the well‐illuminated, upper water column with NO3–as the major N source. When either NH4+or urea is the major N source, a lower maximum growth rate is probably attained over a greater range of illumination deeper in the water column.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516664

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Six species of spionid polychaete worms were identified from the shells of Pacific oysters,Crassostrea gigas(Thunberg), grown in Admiralty Bay, Marlborough Sounds, New Zealand:Polydora websteri, P. hoplura, Boccardia(Paraboccardia)knoxi, B. (P.)acus, B. atokouica, andB. chilensis. Previously unrecorded as a shellfish pest, the dominant speciesB. knoxiinduced the formation of shell blisters in subtidal oyster cultivations. Shell blisters contained little or no accumulated sediment but released hydrogen sulphide when punctured. The highest incidence of shell blisters was 57% and the lowest yield of oysters suitable for the half‐shell trade was 78%. The use of phenol as a vermifuge proved a more efficient method for extractingB. knoxifrom oysters than dissecting worms from shell blisters.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516665

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Wave measurements were made for 3 years from a buoy moored in 34 m water depth off the Katikati inlet in the western Bay of Plenty, New Zealand. The significant wave heights were less than 1 m for 70% of the time, with a mean of 0.8 m, and a maximum of 4.3 m. The peak in the spectral density occurred each year at 0.09–0.10 Hz (10–11 s period). Wave steepness suggests that many of the measured waves originated close to the buoy. The year‐to‐year uniformity in averaged spectral density masks considerable short‐term variability although there is some evidence of higher wave energy in winter. Most wave energy arrived from the north‐east to east sector. Calculations of the longshore wave energy flux factor suggest that the direction of littoral drift fluctuates frequently, but during the 3 years studied there was a small nett drift in a north‐west direction. Significantly less wave energy was measured at Katikati than in previous studies at Great Barrier Island and Hicks Bay. Our Katikati wave data may not be typical of the long‐term climate, because they were obtained in El Nino conditions when fewer storms occur.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516666

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effectiveness of two stimuli on the spawning success of wild caughtHaliotis iris(New Zealand abalone, paua) were compared. Hydrogen peroxide with a sodium hydroxide buffer induced spawning in 43% of the males and 15% of the females tested one week after capture. Ultraviolet irradiation of the sea water was less effective with only 4% of males and no females spawning.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516667

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Four new species of the genusDiaphusare described. Three of these are in the subgeneric group with a suborbital luminous organ and are members of theD. fulgensspecies group with a raised AOa1photophore.D. impostorsp. nov. from the Indo‐West Pacific is most similar toD. aliciae, differing in lower gill raker count and smaller size.D. wisnerisp. nov. from north of Hawaii and south Pacific lacks a luminous scale at the PLO and has a lower gill raker count than similar species.D. korasp. nov. from north‐east of New Zealand has a large luminous scale at the PLO, and a longer Vn and lower gill raker counts than similar species.D. kapalaesp. nov. from the south‐western Pacific is most similar toD. splendidusandD. antonbruuni, from which it differs by the presence of an Ant, higher gill raker counts, and position of the VLO photophore.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516668

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Gephyrocapsa oceanicaandEmiliania huxleyiwere major components of extensive blooms in New Zealand's coastal waters from September to February, 1992/93. Unusually cold sea surface temperatures at that time were related to the El‐Nino phase of the Southern Oscillation and consequent climatic patterns.G. oceanicaco‐dominated withFibrocapsa japonica(Raphido‐phyceae) along the north‐east coast (spring‐early summer) in a bloom which immediately preceded a toxic dinoflagellate event.E. huxleyibloomed in the colder waters of Big Glory Bay, Stewart Island, where a significant water column temperature gradient and depleted nitrate and phosphate concentrations were recorded. An isolate ofE. huxleyifrom Big Glory Bay grew optimally at a salinity of 29 × 10−3, pH of 7.5–8.9, and temperature of 15–25°C. An isolate ofG. oceanicafrom Leigh grew optimally at salinity 17–29 × 10−3, pH 8.4–8.9, and 20–25°C.G. oceanicagrew with ammonium chloride, urea, or potassium nitrate as nitrogen source;E. huxleyigrew optimally with ammonium chloride. Maximum growth rates were 1.9 doublings d−1forE. huxleyiand 1.4 doublings d−1forG. oceanica.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516669

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

FITC‐conjugated lectins proved to be effective probes for differentiating between morphologically similar dinoflagellate species isolated from New Zealand coastal waters. In particular the binding (fluorescence) of peanut (PNA) lectin differentiatedG. mikimotoifromGymnodiniumsp. (Waimangu) andG. pulchellumand the non‐binding ofHelix pomatia(HPA) and wheat germ (WGA) lectins discriminated betweenG. mikimotoiand the otherGymnodiniumspecies tested.G. breve(Florida) was differentiated from the New Zealand isolates by binding with soy bean (SBA) lectin.Ulex europeus(UEA) distinguished the toxic speciesAlexandrium minutumfrom the morphologically similar, but non‐toxic,Cachonina hallii. Two strains ofProrocentrum lima(Spain and Rangaunu) were not differentiated by the lectins, butP. limawas differentiated fromP. compressum.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516670

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Cells ofProrocentrum lima, isolated from sediments collected from Rangaunu Harbour,P. lima(a Spanish isolate), andP. compressum, isolated from wrack collected at Ninety Mile Beach, Northland, New Zealand, were cultured and analysed for okadaic acid by high‐performance liquid chromatography (HPLC), using the derivatisation method with ADAM (anthryldia‐zomethane).P. lima(from Northland) was found to be equally toxic as cultures of the known toxic strainP. lima(Spanish isolate), and both strains were toxic toArtemia salina. P. compressumwas not toxic toA. salinaand did not produce okadaic acid.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516671

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We report the first observation of the fungal parasite of unicellular algae,Pseudosphaerita euglenae, in New Zealand. The parasite infection was observed in the Mangere oxidation pond algaeEuglena acusandEuglena polymorphaand increased potential for pond odour problems, posing a threat to pond operations.E. acuswas particularly susceptible to parasitism and was identified as the putative primary host; this is the first record ofP. euglenaeinfectingE. acus. Epidemic levels ofP. euglenaewere seasonal, lasting for 4–5 weeks from early November until late December of 1992 and 1993. Physico‐chemical parameters showing a significant relationship toE. acusinfection levels were temperature, cell numbers ofE. polymorphaandChlorella. Parameters associated withE. polymorphainfection were temperature, cell numbers ofE. polymorphaandChlorella, dissolved oxygen (a.m.), and negative redox potential. The calculated critical temperature forP. euglenaeinfection ofEuglenawas 17°C.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516672

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Invertebrates were collected from the benthos, drift, and stomachs of juvenile rainbow trout (Oncorhynchus mykiss) in different flow environments and at different times of day in the lower Tongariro River in December 1992, to investigate spatial and diel patterns in prey abundance and diet. The benthic and drift communities were dominated numerically by Diptera (both 71%), Oligochaeta (22–23%), and Trichoptera (5% and 2% in the benthos and drift, respectively). Terrestrial invertebrates comprised 3% of the drift. The most common prey in the stomachs of juvenile rainbow trout (44–130 mm fork length) were Diptera (74%), Trichoptera (19%), Ephemeroptera (6%), and some terrestrial organisms. Relative abundances of different invertebrate taxa in the benthos, drift, and stomachs of juvenile rainbow trout were all significantly intercorrelated. Juvenile trout fed selectively on Trichoptera (particularly emerging adults), the ephemeropteranDeleatidiumspp., and some Diptera (mostlyMaoridiamesaandAphrophila neozelandica), and avoided Oligochaeta. The stomach fullness index was similar during three periods between dawn and dusk, indicating that feeding activity was continuous. The proportion of Diptera in the diet of small fish was higher than in larger fish and the reverse was observed for the proportion of Trichoptera. Densities of most benthic invertebrate taxa favoured by juvenile trout were highest in medium or fast flowing habitats, suggesting that maintenance of such conditions is important for food production.

ISSN:0028-8330    

DOI:10.1080/00288330.1995.9516673

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor