The distribution of fish within eight small streams feeding into the lower Taieri and Waipori Rivers on the east coast of New Zealand's South Island was examined. A total of eight native and two introduced species were recorded. Eels ( Anguilla spp.) and giant kokopu ( Galaxias argenteus Gmelin) were the most widely distributed species being located in all streams surveyed. Common bullies ( Gobiomorphus cotidianus McDowall) an...

Absolute geostrophic currents are estimated for the full depth of the water column off the north‐east coast of New Zealand for February 1998. This is achieved by objectively‐mapping subsurface Acoustic Doppler Current Profiler (ADCP) data using horizontal length scales determined from repeat high‐resolution Expendable Bathythermograph (XBT) data and enforcing horizontal non‐divergence. The resulting 2‐dimensional map of veloci...

A small‐scale experiment was done to test the feasibility of thermally marking hatchery‐reared rainbow trout ( Oncorhynchus mykiss Walbaum) fry that are released into rivers and impoundments in New South Wales (NSW), Australia. Fry of rainbow trout were exposed to two different 48‐h thermal cycles each of a cold and warm water period. One thermal regime consisted of a cold water period during which the temperature was reduced...

The first encounter with a live male blanket octopus, Tremoctopus violaceus Chiaie, 1830, illustrates the most extreme example of sexual size‐dimorphism in a non‐microscopic animal. Females attain sizes of up to 2 m long—almost 2 orders of magnitude larger than the 2.4‐cm‐long male. Weight ratios between the sexes are at least 10 000:1 and are likely to reach 40 000:1. Sexual selection and the unique defensive strategy of carr...

The total lipid content of fry (25–30 mm) and parr (55–110 mm) of rainbow trout ( Oncorhynchus mykiss Richardson 1836) was measured in spring 1996 and 1997 and in autumn 1997 in six trout‐rearing tributaries of Lake Taupo, New Zealand. The fat content of fry was variable between streams and some streams had a higher inter‐annual variation than others. The fat content of parr was also variable among streams but no difference co...

We characterised water chemistry, aquatic habitat, macrophytes, and invertebrate assemblages in eight lowland streams—five in Westland, South Island, and three in the Waikato, North Island, New Zealand. Factors influencing invertebrate community structure over large (between ecoregions) and small (within an ecoregion) spatial scales were investigated. The Westland sites had generally lower nutrient concentrations, conductivity...

Fish exclosures were deployed within shallow, eutrophic Lake Rotoroa, Hamilton, New Zealand to assess the influence of an alien‐dominated fish population on establishment by charophytes. Replicated mesh exclosures were placed at sites differing in wave exposure and received transplanted charophyte oospores and plants, with identical material placed outside. Charophyte establishment from oospores and plant biomass were greater...

Nitrogen (N) and light availability limit phytoplankton growth and hence regulate food supply for mussel farming in Pelorus Sound, New Zealand. In Beatrix Bay, a large 35‐m deep embayment off Pelorus Sound, the supply of N is heavily influenced by physical factors. Bottom intrusions of N‐rich or depleted oceanic water occur in the main channel of Pelorus Sound and N‐depleted, phytoplankton‐enriched Pelorus River water characte...

Species assemblages in the Hauraki Gulf, New Zealand, and the factors affecting them, were determined from abundance data collected from 1381 trawl tows by two research vessels during 1964–97. Correspondence Analysis and Ward's Cluster Analysis were used to identify assemblages, and Canonical Correspondence Analysis (CCA) to explore the relationships between the assemblages and depth, sediment type, latitude, longitude, and ye...

We used mitochondrial (mt) DNA sequences to identify nests, emigrating larvae, and whitebait of three species of diadromous galaxiids, collected from eight locations in Taranaki and Manawatu, New Zealand. DNA was extracted from whole larvae and fin clips, and a 416 base pair (bp) sequence of mtDNA control region was determined. Four Galaxias fasciatus Gray (banded kokopu) and 12 G. postvectis Clarke (shortjaw kokopu) nests wer...

Cricotopus van der Wulp and Paratrichocladius Santos Abreu are among the most common genera of Chironomidae found in fresh waters throughout New Zealand. Imago, pupa, and fourth (final) instar larva of Cricotopus hollyfordensis n. sp. are described, and the male imagines, pupae, and larvae of Cricotopus zealandicus Hutton and Para‐trichocladius pluriserialis Freeman are redescribed from new material. C. hollyfordensis n. sp. c...

The influence of large woody debris (LWD) on channel morphology was assessed in five pine plantation and five native forest streams in the Nelson region of New Zealand. LWD volumes averaged 127 m 3 ha –1 in pine plantation streams and 94 m 3 ha –1 in native forest streams. Most of the LWD in pine and native streams had no influence on channel morphology (78 and 54%, respectively). Those LWD pieces influencing channel morpholog...

The thiarid snail Melanoides tuberculata (Müller, 1774), native to the Middle East and East Africa, is recorded from the wild in New Zealand for the first time from a geothermally influenced stream at Golden Springs, near Taupo. Introduction was most likely the result of one or more releases from tropical aquaria, although the timing of release is uncertain. Specimens were collected at temperatures of 29.0 and 30.4°C, and surv...

Meristic and genetic methods were used to determine the stock relationships of black Allocytus niger (James, Inada & Nakamura, 1988) and smooth oreo Pseudocyttus maculatus (Gilchrist, 1906) in the New Zealand Exclusive Economic Zone (EEZ). Samples were collected from four management areas—OEO 1 (south‐west), OEO 3A (Chatham Rise west), OEO 4 (Chatham Rise east), and OEO 6 (subantarctic) during the 1998 October‐December spawnin...

Population dynamics of crayfish ( Paranephrops planifrons White) in streams draining native forest and pastoral catchments, Waikato, New Zealand, were investigated from September 1996 to July 1998. Crayfish densities were generally greater in native forest streams because of high recruitment over summer, but varied greatly between streams in both land uses. Peak densities in summer were 9 crayfish m ‐2 in native forest and 6 c...

A study was undertaken on the distribution of energy in the reproductive output of Crepidula fecunda Gallardo 1979, a species which provides parental care of deposited eggs during their incubation period. A positive relationship was observed between the shell dimensions and dry tissue weight of the females which was not in turn related to the number of capsules incubated, nor with the size or dry weight of eggs deposited. Posi...

The reproductive cycle of Evechinus chloroticus (Val.) was examined at three (outer, mid, and inner) sites in Doubtful Sound, Fiordland over a 3‐year period. We found that sea urchins from all three populations had an annual gametogenic cycle, the timing of which was temporally and spatially consistent. Inter‐individual variation in the gametogenic cycle was noted within each population, however, initiation of gametogenesis wa...

The rhodophyte Compsopogon coeruleus (Balbis ex C. Agardh) Montagne is newly recorded from Fiji, South Pacific. Plants occur in dense masses in the Wainivesi River in the province of Tailevu. Local villagers collect the plants and use them to cook a “pudding” with tinned fish, very similar to “puddings” prepared by coastal Fijians using marine species such as Gracilaria and Hypnea . This is the first documented account of the...

A total of 6085 adult Trichoptera (excluding Hydroptilidae) representing 12 families, 31 genera, and 56 species were collected by a combination of Malaise net and light trapping from July 1998 to July 1999 at three hill‐country sites of contrasting catchment land use (100% native forest, a pasture site with native forest headwaters, and 100% pasture) in the Waikato, northern New Zealand. Forty‐eight species of Trichoptera were...

The regional and annual variability in the abundance of newly arrived glass eels, Anguilla australis (Richardson) and Anguilla dieffenbachii (Gray), were examined using glass eel densities (n = 100 m –2 ) from electric‐fishing samples collected at 14‐day intervals over 5 years from 13 streams/ rivers throughout New Zealand. Although the density of shortfin eels exceeded that of longfin eels for any one year, the annual trends...

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‐e...

Ammocoetes (larvae) of Geotria australis Gray, were sampled in a large South Island, New Zealand, river during summer to determine their distribution and habitat associations. Ammocoetes were widely distributed along the length of the river, being present at 66 of the 95 sites sampled. They ranged in density from 0 to 180 m –2 , and were associated with habitat type (mainly runs), overhead shade, and substrate features (depth...

We investigated temporal (day‐to‐day and season) and spatial (reach) variability of drift with the aim of guiding sampling protocol for quantifying drift at the whole river or reach scale. Overall, we found aquatic drift density and biomass varied considerably seasonally (CV = 72.9, 88.1) and to a lesser extent spatially (CV = 31.3, 30.7) and from day‐to‐day (CV = 45.2, 39.4). Although spatial and day‐to‐day variation in drift...

Photo‐identification has been established as a helpful tool in cetacean research. However, no study to date has attempted to apply this method to short‐beaked common dolphins (Delphinus delphis L.). We present here the results of two studies that were conducted concurrently in Mercury Bay and the Hauraki Gulf on the north‐east coast of New Zealand's North Island. Methods for distinguishing between individual dolphins are discu...

The distribution of toheroa (Paphies ventricosa Gray) beds, and the abundance and size structure of toheroa at Ripiro Beach, Dargaville, New Zealand, were determined by a two‐phase stratified sample survey. The first phase was undertaken in February and March 1999 and the second phase in June 1999. The first phase located and sized 45 toheroa beds, and stratified the beds according to the observed density of siphon holes. A to...