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1.
One hundred and four taxa of planktonic cyanobacteria (blue‐green algae) have been recorded from New Zealand lakes: 32 belong to the Chroococcales, 72 to the Nostocales. None of the taxa is endemic to New Zealand; most (if not all) are cosmopolitan. On average, more taxa have been reported from North Island (7.8 ± 6.7, N = 69) than South Island lakes (3.3 ± 3.9, N = 59). This difference is attributable, in part, to the large proportion of glacial lakes in the South Island, which are commonly poor in plant nutrients and possess sparse phytoplankton populations. Many of the taxa show a strong preference for eutrophic conditions. Notable exceptions are Anabaena affinis and Gomphosphaeria lacustris, which occur in a large proportion of mesotrophic (48%) and oligotrophic lakes (43%), respectively. Taxa which are often abundant and frequently responsible for conspicuous water‐blooms are Microcystis aeruginosa, Anabaena circinalis, A. flos‐aquae and A. spiroides. The limited population data available indicate a high level of interannual variability in the timing, magnitude, and duration of cyanobacterial blooms in New Zealand lakes.  相似文献   

2.
The problem of New Zealand‐Antarctic faunal relationships is discussed on the basis of echinoderm distribution. The limitations of the data upon which past zoogeographical speculations have been based are pointed out.

Macquarie Island (occupying an intermediate geographical position between the New Zealand Plateau and the Antarctic) shows definite relationships with New Zealand, and the submarine Macquarie Ridge may have provided a connecting migration route. However, only four species of echinoderms are shared between the Ross Sea‐Balleny Islands area (the New Zealand sector of the Antarctic Region) and the New Zealand Pliateau‐Macquarie Island area (the New Zealand Region). Although the as yet unsampled part of the Macquarie‐Balleny Ridge may reveal other faunal similarities, the present systematic sampling has made possible a sounder understanding of the zoogeographical affinities of the two regions.  相似文献   

3.
Abstract

Given sufficient light and heat, the growth of aquatic macrophytes and algae associated with eutrophication is generally controlled by the concentration, form and ratio between nitrogen (N) and phosphorus (P). Data from 1100 freshwater sites monitored for the last 10 years by New Zealand's regional councils and unitary authorities were assessed for streams and rivers with mean nitrate/ nitrite‐N (NNN), dissolved reactive P (DRP), total N (TN) and total P (TP) concentrations in excess of New Zealand guidelines, and to generate a data set of N:P ratios to predict potential periphyton response according to the concentration of the limiting nutrient. The frequency of sites exceeding the guidelines varied from 0 to 100% depending on the parameter and region, but South Island regions were generally more compliant. The dissolved inorganic N (DIN) to dissolved reactive P (DRP) ratio was used to group data into three nutrient limitation classes: <7:1 (N‐limited), between 7:1 and 15:1 (co‐limited), and>15:l (P‐limited), by mass. P‐limitation was the most frequent scenario in New Zealand streams (overall, 76% of sites were P‐limited, 12% N‐limited, and 12% co‐limited). The mean concentration of the limiting nutrient for each site was combined with empirical relationships to predict periphyton densities (the average of N‐and P‐limited growth was used for sites with co‐limitation). This assessment predicted that 22 sites were likely to exceed the periphyton guideline for protecting benthic biodiversity (50 mg chlorophyll a m?2), but this assessment is likely to be highly changeable in response to climatic conditions and present and future land use. As an example, we modelled N and P losses from an average sheep and a dairy farm in Southland (South Island, New Zealand) in 1958, 1988, 2008 and 2028. We predicted that with time, as farm systems have and continue to intensify, N losses increase at a greater rate than P losses. Since the pathway for N to reach fresh waters may be more tortuous and take longer than P to reach a stream or river, focusing mitigation on P losses may have a quicker effect on potential algal growth. In addition, with time, it is expected that P‐limitation in New Zealand's rivers and streams will be more widespread as N‐losses are unabated. Hence, although strategies to decrease N losses should be practised, mitigating P losses is also central to preventing eutrophication.  相似文献   

4.
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5.
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6.
Lepidocybium flavobrunneum (Smith, 1849) is widespread in warmer oceanic waters and has recently been recorded in the catches of tuna longline vessels in the New Zealand region. Twenty‐five specimens were caught at 31°46′‐32°03′S, 170°49′‐171°11′ E on 23–27 June 1979, thus extending the known range of the species to northern New Zealand.  相似文献   

7.
I report on a group of orca (Orcinus orca (Linnaeus, 1758)) near the Bay of Islands, New Zealand, which were a lighter coloration than orca usually seen in these waters. Differences in pigmentation included a light grey caudal peduncle area and a dorsal cape, which has previously only been described for Antarctic orca. The size and shape of the eye patches were not consistent with orca photo‐identified in New Zealand. I suggest that this group of orca, although observed in New Zealand waters, were of Antarctic origin.  相似文献   

8.
Three new species of calanoid copepod in the family Aetideidae are described, two in Aetideopsis Sars, 1903 and the third in Bradyidius Giesbrecht, 1897. One Aetideopsis species is from off South West Africa (south‐east Atlantic), the remaining species are from the east coast of New Zealand (south‐west Pacific). The genus Pseudaetideus Wolfenden, 1904 is merged with Aetideopsis.  相似文献   

9.
The sandwich hybridisation assay (SHA) is a DNA probe‐based method for rapid identification and enumeration of toxic micro‐algae which uses species specific oligonucleotide probes targeted at ribosomal RNA. It is suited to fragile micro‐algal cells which commonly collapse during the fixation stage of sample collection, compromising identification by traditional microscopy. The assay has been available for research for several years, but was validated and accepted for international accreditation for commercial laboratory use in New Zealand in May 2004 (International Accreditation New Zealand: ISO 17025). During the validation of the raphidophyte assay, some discrepancies were noted between SHA cell concentration estimates and traditional light microscope cell counts. Higher SHA estimates were recorded when blooms had collapsed but rRNA was still present in sea water. Conversely, higher traditional cell counts occurred when sample delivery was delayed more than 48 h, presumably owing to degradation of rRNA in the live cultures used for the SHA. SHA cell concentration estimates of the toxic diatom bloom‐former Pseudo‐nitzschia australis were also compared with whole cell format DNA probe counts and traditional microscope counts; SHA counts were comparable for the three methods tested.  相似文献   

10.
Absorbance at 360 nm and dissolved organic carbon (DOC) concentration were measured on 47 filtered water samples collected from streams and rivers of the west coast of South Island, New Zealand. The regression equation (DOC (g m‐3) = 59.6 Abs1 cm + 1.9) calculated from the data, reliably predicted DOC concentration within the range 1.6–43.2 gm‐3. This relationship is similar to that found fsr some Venezuelan and south‐eastern United Stales waters indicating that it may have widespread utility for estimating DOC concentrations in soft waters where DOC is dominated by humic substances  相似文献   

11.
Wave data derived from radar altimeters carried on four satellite missions are combined into a wave climatology for New Zealand waters. These data provide extensive observations of wave conditions around New Zealand, where the paucity of measurements has previously hindered definition of the wave climate. The data span the period 1985 to the present with the exception of a 2‐year gap in 1989–91. The spatial distribution of the long‐term mean of significant wave heights (SWH) indicates a strong latitudinal variation in the south‐west Pacific, with values of over 4 m at latitudes of 50–60°S and under 2.5 m towards the tropics. The shadowing of New Zealand is quite marked; a result of the dominant contribution of south‐westerly wave events. The annual range of the mean SWH also varies over the region; within 0.6 m in the north and 1.3 m in the south. A principal component analysis of the monthly anomalies in mean SWH identifies spatial patterns of variation. Some components vary with the local wind more than others suggesting that some anomalies are associated with wind sea and some with swell. Some patterns also appear to vary with the Southern Oscillation Index and can be related to the wind anomalies associated with El Nino events. Frequency distributions of SWH are also determined, and it is noted that in the north of the region the spatial pattern of the high waves differs considerably from the means.  相似文献   

12.
Toxic cyanobacteria have been linked to dog deaths in the Waikanae River (1998) and Mataura River (1999 and 2000), New Zealand. These were Oscillatoria‐like species which formed benthic mats. This is the first time in New Zealand that animal deaths have been linked to toxins from benthic cyanobacteria.  相似文献   

13.
Phase distribution of tidal constituents around New Zealand   总被引：2，自引：2，他引：0  
The phase distributions of the M2, S2, K1, and O1 tidal constituents around New Zealand are plotted from existing harmonic analyses of tidal heights. Both semidiurnal constituents exhibit a complete 360° range of phase around New Zealand, with complex areas of rapid phase change through or near the strait separating the two main islands. The K1 amphidrome and that for O1, which previously were thought to be centred on New Zealand, are shown to be located cast of New Zealand. The distributions plotted highlight areas where tidal observations are lacking.  相似文献   

14.
Water quality of a lowland stream in a New Zealand dairy farming catchment   总被引：3，自引：2，他引：1  
A small stream in a predominantly dairying catchment in the Waikato region of New Zealand was monitored for 2 years at three sites. Total nitrogen (TN) concentrations were up to 7.09 g m‐3 in winter, with the bulk comprising nitrate nitrogen (NO‐ 3‐N). During summer NO‐ 3‐N was near zero and TN mostly comprised organic nitrogen. Maximum concentrations of total phosphorus (TP) and dissolved reactive phosphorus (DRP) were 1.64 and 0.555 g m‐3, respectively, and peaks coincided with spring and autumn applications of phosphorus fertiliser. Ammoniacal nitrogen concentrations exceeded 1 g m‐3 on several occasions and mean concentrations at the three sites were 0.165–0.272 g m‐3. Faecal coliform and enterococci bacteria concentrations were 64–26000 and 7–23000 cfu per 100 ml, respectively. Specific yields of TN and NO‐ 3‐N (35.3 and 30.7 kg ha yr‐1, respectively) were much greater than any previously reported for New Zealand pasture catchments, whereas TP and DRP yields (1.16 and 0.54 kg ha yr‐1, respectively) were more in accord with other studies. Greater use of land treatment of liquid wastes will reduce stream inputs of faecal organisms, NH4‐N and P.  相似文献   

15.
Abstract

The ultraviolet (UV) sensitivity of five species of freshwater zooplankton (three Cladocera, two Copepoda) were investigated. The animals were exposed to varying levels of UV‐radiation in a sunshine‐simulator and the UV doses for 10 and 50% mortality (LD10, LD50) were estimated using a dose‐response model. To place these doses in context they were compared with modelled clear‐sky surface UV irradiances in New Zealand. The cladocerans Daphnia carinata and Ceriodaphnia dubia were sensitive to levels of UVB irradiance of LD10 = 18–25 kJ m?2 and LD50 = 35–37 kJ m?2. These sensitivities are consistent with published values for other cladocera. In contrast a third cladoceran, Bosmina meridionalis, exhibited no higher mortality over the full range of the cumulative UVB‐doses used (3–40 kJ m?2) than controls receiving no UV exposure. The copepod Boeckella delicata showed the highest UV‐sensitivity of all organisms tested (LD10 = 7 kJ m?2, LD50 = 33 kJ m?2) whereas for Boeckella triarticulata, which was more heavily pigmented than B. delicata, no UV‐induced mortality was observed. Under natural conditions UV irradiances of up to 100 kJ m?2 day?1 can fall on the surface of New Zealand lakes. Although this is attenuated in natural waters, these data suggest that UVB irradiance may be a significant ecological variable to some zooplankton species.  相似文献   

16.
Despite being endangered internationally and protected nationally, little consideration has been given to the occurrence of green turtles (Chelonia mydas) in New Zealand. New Zealand lies on the southern boundary of the distributional range of green turtles in the southwestern Pacific, with individuals found within these waters historically considered to be occasional visitors or stragglers incidentally carried by ocean currents. However, the present work shows that green turtles are present year round in New Zealand’s northern waters (c. 34°–38° S). A review of sighting, stranding and incidental capture data collected between 1895 and 2013 illustrate New Zealand’s green turtle population comprises post-pelagic immature juveniles to large subadults. The female:male sex ratio of 1.7:1 is similar to those reported from warm temperate foraging grounds in eastern Australia. A subsample of new recruits indicates green turtles recruit to neritic habitats at approximately 40.8?cm curved carapace length. This study suggests that New Zealand’s neritic habitats constitute a transitional developmental ground for post-pelagic immature green turtles. We observed an exponential increase in the number of documented records over time, though whether this is due to increased numbers of turtles or increased reporting rates, or both, is unclear and warrants further investigation. More broadly, this work provides a baseline understanding of the ecology of green turtles at the edge of their range, providing opportunities to investigate regional niche modelling and connectivity of this highly mobile species, while also monitoring broad-scale effects of climate-induced environmental change.  相似文献   

17.
Plaxiphora boydeni n.sp. from wave‐exposed rocky shores of southern New Zealand is described and illustrated. This is the first published record of the genus from the New Zealand mainland. P. boydeni is readily distinguished from the 2 other New Zealand species of the genus, which occur in the subantarctic region, by the absence of bristle‐tufts on the girdle.  相似文献   

18.
Four new species of the genus Diaphus are described. Three of these are in the subgeneric group with a suborbital luminous organ and are members of the D. fulgens species group with a raised AOa1 photophore. D. impostor sp. nov. from the Indo‐West Pacific is most similar to D. aliciae, differing in lower gill raker count and smaller size. D. wisneri sp. 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. kora sp. 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. kapalae sp. nov. from the south‐western Pacific is most similar to D. splendidus and D. antonbruuni, from which it differs by the presence of an Ant, higher gill raker counts, and position of the VLO photophore.  相似文献   

19.
Cylindrospermopsis raciborskii is a planktonic freshwater cyanobacterium that is becoming increasingly prevalent in water bodies worldwide. During a survey of toxic cyanobacteria in New Zealand, C. raciborskii was identified in a sample collected from Lake Waahi (Waikato). This is the first identification of this species in New Zealand. Liquid chromatography‐mass spectrometry and liquid chromatography‐tandem mass spectrometry were used to confirm the presence of the cyanotoxins cylindrospermopsin (CYN) and deoxy‐cylindrospermopsin (do‐CYN). Detection of CYN and do‐CYN demonstrates that C. raciborskii is a now a species of concern in recreational, stock drinking, and potable water supplies in New Zealand.  相似文献   

20.
Sea‐level data from two sites in northern New Zealand, along with the Southern Oscillation Index (SOI), are analysed for interannual and decadal variability using wavelets. The analysis shows, using statistically significant wavelet power, there is a significant relationship between mean sea level (MSL) and SOI. However, the relationship is highly variable, both in magnitude and in the range of time‐scales over which it occurs. This non‐stationarity necessitates the use of techniques such as wavelets for analysis. An interdecadal response in MSL around northern New Zealand has been isolated, with shifts occurring in 1950 and the late 1970s. This behaviour in MSL appears to coincide with shifts in the Pacific Decadal Oscillation, thought previously to be largely centred in the North Pacific. A strong correlation between SOI and sea surface temperature (SST) is also demonstrated. This relationship appears to be stable in magnitude (a large change in SOI produces a large change in SST) and to occur over the same range of time‐scales. More SST and MSL data are required for other parts of New Zealand to determine whether these findings apply elsewhere.  相似文献   

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