bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical evolution of Tasman Sea Eddy J
Authors: Cresswell GR
Published: November 2005

The evolution of warm-core eddy J was followed from March 1979 until May 1980. From March to October 1979, eddy J developed a deep surface mixed layer that, after summer capping, became a subsurface 'signature' for subsequent identification. During the first half of the observation period, eddy J was subjected to frequent peripheral injections of northern water, mainly from the East Australian Current but on one occasion from a northern eddy. Between mid-December 1979 and early February 1980, the signature layer of eddy J moved on top of the signature layer of another eddy. This is suggested to be an indication of the coalescence of the two eddies. The prehistory of eddy J was conjectured from the nature of a signature layer that the eddy already had in March 1979.
Origins of water within warm-core eddies of the western Tasman Sea
Authors: Rochford DJ
Published: November 2005

Comparison of the salinity within and around warm-core eddies of the western Tasman Sea has shown (a) that such eddies have their origin solely within waters of the East Australian Current (EAC); (b) that as these eddies drift southward within the EAC, their salinity characteristics differ little from those of the surrounding water; (c) that after separation from the EAC at around 34�S., their salinity characteristics are generally conserved in the face of much lower salinities of the surrounding waters. This latter feature was especially marked in the case of eddy J, which maintained in the upper 250 m an abnormally high salinity signature to as far south as 40� Below 300 m, this eddy J contained remnants of another high-salinity eddy. Possible derivations of these deeper waters are examined.
Satellite infrared observations of the kinematics of a warm-core ring
Authors: Brown OB , Olson DB , Brown JW , Evans RH
Published: November 2005

Detailed satellite observations of anticyclonic ring 81-D interacting with the Gulf Stream were collected as part of the August-September 1981 Warm Core Rings Experiment. Position of the ring centre, magnitude of the semimajor and semiminor axes and orientation are computed for 42 atmospherically corrected satellite images taken over a 2-month period in August, September and October 1981. Ring interaction with the Gulf Stream causes marked changes in shape, size, orientation and location of the ring. A longer history of 81-D is determined by using National Oceanic and Atmospheric Administration Gulf Stream analyses. Results of this analysis when compared with the precision estimates obtained above show good agreement in east-west location but relatively poorer correspondence in north-south position. Mean westward translation speeds are found for several rings to be ~0.05 m s-1. Steady westward translation is punctuated by periods of Gulf Stream interaction when a ring is observed to remain either stationary or propagate eastward with the mean Gulf Stream. Ring asymmetries of two types are noted. The first occurs when the ring is outside of the direct influence of the Gulf Stream. During these periods, the ring exhibits a spatially fixed or slowly counter- rotating mode, which is either D-shaped or elliptical. During interaction with the Gulf Stream, a more elliptical asymmetry, which rotates rapidly with the anticyclonic flow around the ring, is observed.
Ring structure in the poleward boundary current off Western Australia in Summer
Authors: Andrews JC
Published: November 2005

Data from five summer cruises off Western Australia are examined objectively using structure functions to establish principal length scales and amplitudes of mesoscale fields. Previous estimates of length scales using geopotential anomaly and geomagnetic electrokinetograph vectors as inputs to structure- function analyses gave length scales that differed by a factor of two. The present analysis shows that there are two length scales, which dominate in different parts of the flow, and this reconciles the two previous estimates. The shorter scale is λs = 157�25 km and the longer is λL = 309�28 km. Regions of strong large-scale currents have warm- and cold-core rings and mesoscale waves associated with them that assume the Rossby deformation scale. These are the λS structures. The longer, λL structures are found in regions of weak large-scale currents. Geopotential anomaly amplitudes and currents in the rings are, respectively, about 0.7 m2 s-2 (geopotential relief = 1 4 m2 s-1) and 70 cm s-1. Data from one summer cruise with a station density of approximately 12 per degree square are analysed in detail subjectively and the structure-function analysis is shown to be quantitatively meaningful. This cruise was near the shelf and shows the advection of low-salinity tropical water poleward over the slope in a narrow baroclinic current. Seaward cyclonic rings were associated with the current. The baroclinic structure of the current and of the rings is compatible with the winter behaviour of Lagrangian drifters released into the Leeuwin Current.
Biological sound scattering in an ocean eddy
Authors: Hall M , Quill AF
Published: November 2005

Acoustic volume-backscattering measurements and midwater net-trawls were conducted in the vicinity of an eddy in the Tasman Sea in 1979 and 1980. At acoustic frequencies greater than about 8 kHz, there is generally good agreement between the measured acoustic backscattering strengths and the predictions based on the results of the trawls. The main difference is that, although the trawls did not catch any fish heavier than 3 g, the acoustic results indicated that many heavier fish were present within the trawling regions. The acoustic scattering inside the eddy was several decibels higher than the scattering in the frontal region or outside the eddy during two of the three cruises that were conducted. For the remaining cruise, there was no significant difference.
Some zooplankton characteristics of warm-core eddies shed by the East Australian Current, with particular reference to copepods
Authors: Tranter DJ , Tafe DJ , Sandland RL
Published: November 2005

Several eddies in the south-western Tasman Sea were investigated to see whether they differed faunistically from the seas around them. Zooplankton samples (0-200 m) were taken by free-fall net for dry weight measurements and copepod analyses. The counts obtained for 20 species of copepod were used to classify 51 stations into (eight) groups. These were taken to constitute the major zooplankton habitats in the study area. These habitats corresponded in most respects with the known physical structure of the study area. Eddies were faunistically distinct from the seas that surrounded them. Eddy J was similar in 1979-1980 to the waters of the East Australian Current, which were periodically entrained within the eddy circulation. There were significant faunal differences between eddy J and eddy F, an isolated eddy sampled in December 1978.
Phyllosoma larvae and other crustacean macrozooplankton associated with eddy J, a warm-core eddy of south-eastern Australia
Authors: McWilliam PS , Phillips BF
Published: November 2005

Crustacean macrozooplankton were more abundant in the surface waters outside compared with the surface waters inside eddy J and included a greater proportion of meroplankton. Small numbers of phyllosoma larvae of tropical and subtropical lobster species were found in the eddy, the dominant form being larvae of the tropical and subtropical spiny lobster, Panulirus longipes femoristriga. Larvae of the temperate and subtropical slipper lobster, Scyllarus bicuspidatus, dominated catches of phyllosoma larvae in waters outside the eddy and in the frontal region.
Isothermal temperatures and transformations of the warm-core eddies in the western Tasman Sea
Authors: Airey D
Published: November 2005

Warm-core eddies off the eastern coast of Australia are characterized by their isothermal core temperatures. For coastal eddies, core temperatures correlate with the latitude of the eddy at the end of winter. The isothermal temperature is used to identify and track eddies. Eddy positions from 1976 to 1981 have been charted to show patterns in their formation, drift and interactions with other eddies and the East Australian Current. To date, eddies have been named alphabetically in an ad hoc way that has caused confusion because of the unexpected behaviour of some eddies. To overcome this, a systematic way of naming eddies is suggested, which takes into account the eddy's history.
On the climatology of warm-core rings from the East Australian Current
Authors: Mulhearn PJ
Published: November 2005

The observed geographical distribution of warm-core rings is discussed in relation to the coverage of past research cruises. It is found that no rings, detached from the East Australian Current, have been found north of 33�S. and that there is a tendency for them to persist for some time to the south- east of Jervis Bay between 35 and 38�S. and 151 and 154�E. Surface mixed-layer temperatures are similar to monthly mean values over 10 years, being 0.35�C higher on average with a standard deviation of 1.0�C. Surface mixed-layer depths within rings are significantly greater than the average values found at 34�S. from February to September but are close to the average values in November and December.
Seasonal movement and size distribution of three commercially important Australian prawn species (Crustacea : Penaeidae) within an estuarine system
Authors: Coles RG , Greenwood JG
Published: November 2005

Three penaeid prawn species, Penaeus plebejus Hesse, Metapenaeus bennettae Racek & Dall, and M. macleayi (Haswell), were sampled using a beam trawl, at four sites for 16 months in the Noosa River, Queensland, and data collected are used to provide generalized life histories for the three species and to discuss the composition and timing of the commercial bait prawn fishery. P. plebejus individuals were recruited to the river throughout the year, M. bennettae between March and June, and M. macleayi between April and July. P. plebejus juveniles remained only briefly in the river and were most numerous at sites near the river mouth. There was no distinct period of migration of this species from the river. M. bennettae and M. macleayi individuals remained in the river until December and March, respectively, when, in the absence of obvious abiotic stimuli such as rainfall runoff and reduced salinities, there was a marked egress from the river. While in the river, both of these species could be caught through the zone of salt-water penetration up to 35 km from the sea, and both were most numerous in the southern half of Lake Cootharaba in a zone of approximately 19 × 10-3 mean salinity. Similarity between these and other distribution patterns recorded in topographically different rivers suggests salinity is an important determining factor in the distribution of these prawns.
A study of food chains in seagrass communities II. Food of the rock flathead, Platycephalus laevigatus Cuvier, a major predator in a Posidonia australis seagrass bed
Authors: Klumpp DW , Nichols PD
Published: November 2005

Feeding habits of P. laevigatus were investigated between February 1980 and November 1981 as part of a larger study on the structure of food chains supporting commercial fishes in the seagrass beds of Corner Inlet, south-eastern Australia. The main food components were crabs, predominantly Nectocarcinus integrifons, and juvenile fishes. Most dietary items were inhabitants of the seagrass zone. Small (25-33 cm) rock flathead showed a preference for fish, squid and shrimp whereas larger (> 33 cm) individuals consumed mainly N. integrifons together with some fish. Seasonal variations in diet and feeding intensity occurred. A decrease in feeding intensity in winter was accompanied by a shift in diet from N. integrifons to fish and squid. A second decline in feeding intensity corresponded to the apparent spawning period. The rock flathead and its main prey, N. integrifons, both showed a rhythm in locomotory activity correlated with nocturnal or crepuscular high tides whereas small fish prey were mostly active during daylight.
Macrobenthic fauna of Great Lake, Arthurs Lake and Lake Sorell, Tasmania
Authors: Fulton W
Published: November 2005

The benthic fauna of Great Lake, Arthurs Lake and Lake Sorell, Tasmania, contained 88 species, with 48-55 species in each lake. All three lakes had abundant and generally similar chironomid faunas. Arthurs Lake and Great Lake shared common oligochaete species of which only some were numerous in Lake Sorell. The crustacean faunas of each lake differed in composition and abundance, with amphipod species being the most abundant group in Arthurs Lake. Gastropod molluscs were the most abundant group in the fauna of Lake Sorell, and chironomids were most numerous in Great Lake. Species composition and abundance in these three lakes are compared to those of other Australian lakes. Numbers of species in Australian lakes as a whole are critically discussed with respect to numbers in lakes elsewhere.
Use by juvenile barramundi, Lates calcarifer (Bloch), and other fishes of temporary supralittoral habitats in a tropical estuary in Northern Australia
Authors: Russell DJ , Garrett RN
Published: November 2005

Use by fishes of temporary pools created by high seasonal tides, which occur each year from October until April, on the saltpans and littorals adjacent to the Norman River estuary in northern Queensland was investigated. Fish entering the pools were sampled with one-way tidal traps placed in inlet gutters, and fish in the pools were poisoned using rotenone. Recruitment to the pools by fish occurred soon after the initial tidal inundation. Juvenile fish of 37 species, including the commercially important food fish L. calcarifer, used the pools. The first barramundi were found 8 weeks after initial inundation and for the remainder of the study they continually migrated into these habitats. The total length of the smallest L. calcarifer sampled was 9.5 mm. Salinities in pools containing fish ranged from 94 × 10-3 to less than 1 × 10-3 and temperatures reached 36�C.
Oxygen isotope variation on a lagoonal platform reef, Heron island, Great Barrier Reef
Authors: Swart PK , Wilson AF , Jell JS
Published: November 2005

A survey of temperature, salinity and oxygen isotope ratio was conducted on the reefal waters of a lagoonal platform reef, Heron Reef, situated near the southern end of the Great Barrier Reef. The oxygen isotope ratio of the water changed by nearly 2‰ during a 3-week period. Daily variations of 1.4‰ were detected. As the maximum oxygen isotope ratios occurred at low tide, during times of high temperature and high salinity, temperature-induced variation in oxygen isotope ratios of skeletal material was masked. Such a phenomenon can easily explain why previous workers have failed to detect the full range of oxygen isotope ratios in coral skeletons and other calcareous organisms.
Water masses, nutrient levels and sesonal drift on the outer central Queensland shelf (Great Barrier Reef)
Authors: Andrews JC
Published: November 2005

A series of 19 cruises in 19 months in the central zone of the Great Barrier Reef was made in 1980-1 981 to examine the seasonal thermohaline cycles and nutrient distributions. The reefs occupy the outer 60 km of the shelf and the mixing there of Lagoon Water, Coral Sea Surface Water, Shelf-break Water and Subtropical Lower Water is examined using thermohaline data. Current meters and thermistors were moored from mid-1980 to mid-1982 to obtain seasonal drift and subseasonal temperature fluctuations. Subtropical Lower Water upwells through the reef zone to create a year-round thermal contrast between Shelf-break and Lagoon Waters, and vertical density stratification reflects this temperature contrast on the shelf Salinity variations reflect monsoonal rainfall and winter evaporation; rainfall and salinity show an interannual variation. The drifts of bottom water over the outer lagoon and of surface water over the continental slope follow the isobaths poleward. In the reef zone between the lagoon and the shelf break, there is a substantial cross-isobath, onshore flow of bottom water. Surface waters exhibit no significant averaged gradients in phosphate, nitrate, nitrite or oxygen utilization aross the reef zone. Surface chlorophyll concentration is high amongst the reefs. Subsurface chlorophyll levels are similarly high inside the shelf break, and subsurface phosphate, nitrate and oxygen utilization increases markedly, seaward across the reefs, particularly near the shelf break.
Migration patterns of five fish species in the Murray-Darling River system
Authors: Reynolds LF
Published: November 2005

Results of a fish tagging study carried out in the Murray River, South Australia from 1974 to 1978, are presented. Of 14 333 fish tagged, 1276 were recaptured and the records of these recaptures yield evidence on the movements of several species of both commercial and recreational interest. Some golden perch (Macquaria ambigua) migrated extensively upstream, many moving more than 1000 km. The migration followed, and appeared to be triggered by, a rise in water level at the onset of major flooding. The upstream migrations, made only by mature fish, appear to be a reproduction strategy to ensure that the eggs, which are buoyant, are distributed downstream. In contrast, common carp (Cyprinus carpio), which lay adhesive, demersal eggs, did not migrate but made only random, short- distance movements. Although data on other species were fewer due to their smaller populations, it appears that Murray cod (Maccullochella peeli) and catfish (Tandanus tandanus), both of which have demersal eggs, show similar movement patterns to carp whereas silver perch (Bidyanus bidyanus), which lays buoyant eggs, is similar to golden perch. The implications of these results, with regard to the establishment and maintenance of populations of each of the species, are discussed.
Australian freashwater mussel Velesunio ambiguus (Philippi) as a biological monitor for zinc, iron and manganese
Authors: Millington PJ , Walker KF
Published: November 2005

The hyriid mussel V. ambiguus has been proposed as a biological monitor of zinc where there are wide environmental fluctuations. However, in the River Murray there is high variation in zinc content among individuals and between populations; part is systematic, associated with body weight and age, but a larger part remains statistically unexplained. Further, although V. ambiguus readily accumulates zinc, depuration is slow. At zinc concentrations of 20 mg I-1 and above, mussels avoid taking up zinc by significantly curtailing siphoning, movement and valve opening. Zinc levels above 20 mg l-1 are lethal, with most deaths occurring in the post-exposure periods immediately after 96-, 176- and 336-h toxicity tests. The estimated 336-h LC50 is 66 mg I-1, with 95% confidence limits 55 and 77 mg I-1. Exposure of caged mussels in the zinc-contaminated Molonglo River, N.S.W., suggests that V. ambiguus is not a suitable species to monitor variations in zinc loads between sites, and does not accurately reflect environmental fluctuations of zinc, iron or manganese, although it may have potential for materials other than heavy metals.
Food and mouthpart morphology of the nymphs of several Australian Plecoptera
Authors: Sephton DH , Hynes HBN
Published: November 2005

The diets of 19 species of Australian Plecoptera from the families Eustheniidae, Gripopterygidae and Austroperlidae are discussed. The eustheniids Stenoperla australis, Eusthenia venosa and Thaumatoperla alpina are predominantly carnivorous but they also ingest plant material. Their mouthparts are of the carnivorous type. The gripopterygids Illiesoperla australis and Eunotoperla kershawi are omnivorous; their mouthparts show similarities with both the carnivorous and phytophagous types. Trinotoperla irrorata, Trinotoperla nivata, Trinotoperla yeoi, Dinotoperla serricauda, Dinotoperla arenaria, Leptoperla kimminsi, Leptoperla bifida and Riekoperla rugosa are detritivore-herbivores. Neboissoperla alpina and Riekoperla williamsi consume detritus. The mouthparts of these species are of the phytophagous type. The austroperlids Acruroperla atra, Austropentura victoria, Austroheptura neboissi and Austroheptura picta are detritivores, consuming woodchips and detritus. Their mandibles have grinding prosthecae. Their guts contain an unidentified protozoan-like organism, which seems to be associated with the ingestion of woodchips.
Re-examination of the contributions of aerobic and anaerobic energy production during swimming in the Bivalve mollusc Limaria fragilis (Family Limidae)
Authors: Baldwin J , Morris GM
Published: November 2005

The file shell L. fragilis displays a slow sustained style of swimming indicative of basically aerobic mechanisms of ATP production. Although it had been proposed that anaerobic glycolysis and arginine phosphate did not contribute to powering swimming, the discovery of high activity of arginine kinase and significant activities of strombine and alanopine dehydrogenases in the adductor muscle led to a reexamination of the relative contributions of aerobic metabolism, anaerobic glycolysis and arginine phosphate during swimming. It was found that, whereas aerobic metabolism predominates with only a minor contribution from anaerobic glycolysis, arginine phosphate supplied up to 23% of the ATP used during 5 min of sustained swimming.
Attempt to determine some properties of the semidiurnal internal tide on the continental slope, Great Barrier Reef
Authors: Tomczak Jr M , Fang XH
Published: November 2005

An experiment designed to determine wave parameters of the internal semidiurnal tide near 18�S. off the Great Barrier Reef is described. It suffered from inaccuracy in position fixing, so no information on the vertical component of the phase speed was gained. Results for the horizontal component show an internal tide of wavelength 15 nautical miles and phase speed 60 cm s-1 propagating east to south-east, at a small angle to the isobaths. A mean current of 50 cm s-1 flowing towards the south-east along the isobaths deflects the outgoing wave; the apparent (observed) direction of propagation is eastward, the apparent phase speed is increased to 80 cm s-1 and the apparent wavelength to 20 nautical miles.
Wind-generated, high-frequency edge waves
Authors: Worthy AL
Published: November 2005

The effect of longshore wind stress on high-frequency edge waves, over a convex, exponential, semi- infinite sheet, is determined analytically. Comparison is made with physical data measured at Port Kembla Harbour, on the eastern coast of Australia. Good agreement is obtained for the amplitudes of the waves, as well as for their periods.
Structure of a fish community in a temperate tidal mangrove creek in Botany Bay, New South Wales
Authors: Bell JD , Pollard DA , Burchmore JJ , Pease BC , Middleton MJ
Published: November 2005

The fish assemblage in the lower reaches of a temperate tidal mangrove creek entering Botany Bay near Sydney, New South Wales, was sampled using rotenone every second month between December 1977 and October 1980. Almost 17 000 fish (weight ~ 115 kg), belonging to 46 species and 24 families, were collected. Six species dominated the assemblage and another four were relatively common. Fourteen species, including four of the above, were economically important. These fishes made up 38% of individuals and 32% of biomass and were represented only by small juveniles. Nineteen species (41%) were temporary residents; these mainly comprised juveniles of large species that live elsewhere as adults. Fifteen species (33%), most of which only attain a small size (< 100 mm), were assumed to be permanent residents. The remaining 12 species (26%) occurred in only one sample and were, therefore, classified as rare. The diversity (HI) and evenness (J') of the fish community were low and showed little seasonality because a few species dominated the assemblage on an irregular basis. Numbers of species and of individuals varied seasonally and were significantly correlated. Peaks in these parameters lagged behind those in water temperature by 4 months and were largely the result of the relatively restricted recruitment periods of several abundant temporary resident species. The large numbers of juveniles and small species in the mangrove creek habitat were attributed to the availability of suitable shelter and food for such small fishes. Concerted use of the mangrove habitat by several abundant temporary resident species during the same general period each year appeared to be facilitated by the occupation of otherwise vacant feeding niches and some staggering of their peak recruitment periods. Exclusive use of this habitat by small juveniles of several species in Botany Bay confirms that mangrove habitats in temperate Australia, like some of those studied in tropical and subtropical regions, are important nursery areas for fishes inhabiting adjacent estuarine and inshore marine habitats as adults.
Invasion and upstream migration by glass-eels of Anguilla australis australis Richardson and A. reinhardtii Steindachner in Tasmanian Freshwater Streams
Authors: Sloane RD
Published: November 2005

The recruitment of glass-eels into fresh water was investigated by hand-netting and electrofishing at the lowest permanent freshwater riffle on several streams in eastern Tasmania. Measurements of the forward extent of the dorsal fin distinguished the short-finned eel, A. a. australis, from the long-finned eel, A. reinhardtii; this separation was verified by vertebral counts and A. a, australis glass-eels were found to be larger than A. reinhardtii. A. a. australis glass-eels were collected at the first riffle during all seasons of the year except mid-summer. Numbers in the catch declined during mid-winter, probably as a result of an effective seaward movement of the freshwater-estuarine interface during periods of high river flow; A. a. australis glass-eels were still found to be abundant near estuary mouths at such times. A. reinhardtii glass-eels exhibited a more restricted movement into fresh water during late summer and autumn with no collections recorded after mid-winter. For both species, the stage of pigmentation was found to advance as the season progressed, and length, weight and condition factor declined with advancing pigmentation. The otoliths of invading glass-eels of both species appeared similar with a single summer ring, suggesting a larval life of 1-1½ years. The restricted invasion period of A. reinhardtii and the similar size throughout the species range suggests a short and precise larval life. The length of larval life of A. a. australis is probably quite variable, resulting in a more substantial and prolonged influx of glass-eels into Tasmanian waters.
Benthic studies of waterfowl breeding habitat in south-western New South Wales. II. Chironomid populations
Authors: Maher M , Carpenter SM
Published: November 2005

The dynamics of chironomid populations in waterfowl breeding habitat were investigated. Of 12 species recorded, Chironomus 'alternans a', C. tepperi, Kieflerulus intertinctus, Polypedilum nubifer and Procladius villosimanus were common in the mud habitats. C. 'alternans a' was the most commonly recorded species over the whole study, and C. tepperi dominated the faunas afier flooding. Dicrotendipes conjunctus and Dicrotendipes sp. 2 were the major species occurring on stick substrata, and Dicrotendipes sp. 2 and Polypedilum nubifer were dominant on plant substrata. Production of chironomids was high in the first 2 years following an extensive flood but thereafter fell rapidly. Correlative evidence is presented that suggests a relationship between abundance of C. tepperi larvae and breeding by waterfowl.
Aromatic hydrocarbons in waters of Port Phillip Bay and the Yarra River estuary
Authors: Smith JD , Maher WA
Published: November 2005

Determination of aromatic hydrocarbons in coastal waters, using solvent extraction and fluorescence emission analysis, shows wide distribution of fuel oils with only a small contribution from crude oil. Oil concentrations are reported as equivalent amounts of m-terphenyl (T) or pyrene (P). Observed concentrations in Port Phillip Bay are generally 0.2-0.3 pg l-1 (T) and 0.1-0.2 pg l-1 (P), with higher values in Corio Bay and the Yarra River estuary.
Mariculture potential of introduced oysters Saccostrea cucullata tuberculata and Crassostrea echinata, and a histoogical study of reproduction of C. echinata
Authors: Braley RD
Published: November 2005

Brood stock of the large tropical intertidal oysters S. c. tuberculata and C. echinata introduced to Guam in 1978 and 1979, respectively, were kept in 1-m2 cages in Sasa Bay and their growth and reproductive condition monitored. Weight of tagged S. c. tuberculata increased by 25.4% in 255 days; weight of tagged C. echinata at an inner bay site increased by 137.7% in 660 days and at a site near the mouth of the bay by 50.6% in 453 days. Based on a mean wet flesh weight of 6.5% of total weight, optimum growth rates for adult C. echinata at a density of 50 oysters per square metre, and a ratio of oyster-tray area to water area of 2/3, an estimated potential yield of 2445-3260 kg flesh weight ha-' year-l could be produced in Sasa Bay. Fouling by the smaller indigenous oyster S. cucullata was considerable (mean number of S. cucullata per C. echinata shell, 34), but growth was highest in areas where fouling was highest. Therefore, it appeared that competition for food was not a problem. Histological examination revealed one complete (plus partial second) gametogenic cycle during 1980. The major peak in spawning activity was in March and the development of another was evident in late November. Environmental parameters (exogenous factors) that were monitored did not act as cues for spawning.
Phyllosoma and nisto stage of the Morton Bay bug, Thenus orientalis (Lund) (Crustacea : Decapoda : Scyllaridae), from shelf waters of the Great Barrier Reef
Authors: Barnett BM , Hartwick RF , Milward NE
Published: November 2005

Samples of macrozooplankton collected from the shelf area of the Great Banier Reef (between 18�35'S. and 19�10'S. and 146�30'E. and 147�00'E.) contained phyliosomes of several different species of scyllarid lobster, including those of T. orientalis. Four larval stages of T. orientalis are described from the plankton and are related to laboratory-reared specimens of the first stage and of the postlarval nisto. An attempt is made to clarify discrepancies in the existing literature relating to descriptions of larval T. orientalis.
Biology of peron's threadfin bream, Nemipterus peronii (Valenciennes), from the north west shelf of Australia
Authors: Sainsbury KJ , Whitelaw AW
Published: November 2005

Samples of N. peronii collected at depths of less than about 100 m showed a slight positive correlation between fish size and depth, but no correlation between abundance and depth and no die1 change in catch rate. Feeding occurred during the day, with crustaceans (Brachyura, Natantia, Mysidacea and Stomatopoda in particular) occurring in 70% of feeding individuals and fish occurring in 17%. Individuals containing ripe eggs were found throughout the year, although the proportion of ripe fish was highest in November and December. Sexual maturity in 50% of females was attained at a fork length of about 15 cm and at an age of 1 year. Zonation on the otoliths was shown to be annual and estimates of the parameters of the von Bertalanfi growth curve were L∞ = 41.9 cm, K= 0.25, t0 = 0.74 years over the age range 0.5-5 years. The growth parameters for sexually differentiated animals differed significantly, but the age-length trajectory of each was very similar over the observed age range. The instantaneous rate of total annual mortality was 1.85 and did not differ between sexes.
Migration of the Ornate Rock Lobster, Panulirus ornatus (Fabricius), in Papua New Guinea
Authors: Moore R , MacFarlane JW
Published: November 2005

In Papua New Guinean waters, there are two reef fisheries and a trawl fishery for the ornate rock lobster, P. ornatus. A single stock of lobsters is the basis of all three fisheries. The migration pattern of this species was determined by tagging 6077 lobsters, of which 719 (11 .8%) were recaptured. In August-September each year, adult lobsters in northern Torres Strait undertake a mass migration across the Gulf of Papua to spawning grounds at the eastern limit of the Gulf. Lobsters walk across an open sand-mud seabed for 2-3 months at an average speed of 6.1 km day-1. The maximum recorded distance was 511 km. No return migration was detected and probably there is a high mortality of lobsters after spawning. The reason and stimulus for this mass migration are discussed. Larval recruitment is generally to a different area from the adult population in northern Torres Strait, necessitating a subsequent migration of juveniles into the adult habitat. Once these juveniles have moved into the northern reef systems, they remain in the area, usually within a specific reef complex, for 1-2 years before undertaking the mass migration into the Gulf of Papua.
Distribution and abundance of some Hyperiidea (Crustacea : Amphipoda) in Northern Queensland Waters
Authors: Zeidler W
Published: November 2005

Hyperiid amphipods (35 species) were collected at eight regular sampling stations, spaced evenly between Townsville and the Great Barrier Reef, over 1 year (October 1972 to October 1973). The distribution and abundance of the Hyperiidea in northern Queensland, where hyperiids were generally most abundant during October-December and April-July, are discussed and quantitatively analysed and related to temperature and salinity data collected at the same time. The quantitative results indicate that hyperiids can be relatively abundant and may be a more important component of the inshore plankton than was thought previously. Only 13 species were sufficiently abundant to permit a more detailed discussion of their ecology. The two most abundant species, Lestrigonus bengalensis and Hyperioides sibaginis, were found most often in inshore waters and may form permanent local populations. Most of the other species were epipelagic oceanic species preferring warm waters (> 25�C) of relatively high salinity (>35 × 10-3) and were rarely found close inshore. Some species, Simorhynchotus antennarius, Tullbergella cuspidata and species of Phronimidae, only occurred in the plankton for a short period.
Cycles of reproduction and condition in Tasmanian blue mussels, Mytilus edulis planulatus
Authors: Dix TG , Ferguson A
Published: November 2005

Major spawning by M. e. planulatus occurred in the late winter or early spring at Hinders Reef, Margate and Birchs Bay in 1980 and 1981. Spawning occurred also over the summer and early autumn although a major spawning was indicated during this period at only one site in one year. At the two sites where temperatures were recorded, the major spring spawning occurred at about or just above 10�C. Gonads built up reproductive condition during late autumn and winter at all sites in 1980 and 1981. Condition indices were highest at these times and fell when spring spawning occurred.
Identification and description of larvae of Spanish mackerels, genus Scomberomorus (Teleostei : Scombridae), in shelf waters of the Great Barrier Reef
Authors: Jenkins GP , Milward NE , Hartwick RF
Published: November 2005

Larvae of Spanish mackerels, genus Scomberomorus, were extracted from plankton samples collected over 3 years from the coastal and Great Barrier Reef lagoon region off Townsville, Queensland. Of the four Scomberomorus species occurring in the shelf region off Townsville, larvae of S. commerson, S. semifasciatus and S. queenslandicus were identified by using meristic, morphological and morphometric characteristics. Growth stages and pigmentation development in larvae of each species are described in detail. The significance of larval characteristics to the generic distinction and interrelationships of the species is discussed.
Distribution of benthic intvertebrates along a disturbed section of the La Trobe River, Victoria: an analysis based on numerical classification
Authors: Marchant R , Mitchell P , Norris R
Published: November 2005

The benthic invertebrates of the banks and main channel at 10 sites along 100 km of the lower reach of the La Trobe River, which flows entirely through agricultural and industrial areas, were quantitatively sampled every two months between May 1979 and March 1981; 23 chemical variables were measured concurrently. In all, 337 taxa were collected. Normal and inverse classifications of the faunal data with two similarity indices (Czekanowski, Canberra Metric) indicated that the uppermost two sites (upstream of the industrial areas) with a rich fauna were clearly distinct from the more depauperate downstream sites; these latter sites could be divided into two groups (main channel samples) or four groups (bank samples). In both habitats, eight groups of common (>0.5% of total numbers) taxa were evident: in each habitat, there were one or two groups of resistant taxa abundant at all sites (mostly Chironomidae), one or two groups of opportunistic taxa common at disturbed sites only (Caenidae, Corbiculidae, Ecnomidae, Chironomidae), and two groups of sensitive taxa that were most abundant at the two uppermost sites (Leptophlebiidae, Baetidae, Ecnomidae, Elmidae, Helodidae, Chironomidae, Ceratopogonidae, Hydracanna). Oligochaeta were abundant at all sites and as a group were considered resistant. Multiple discriminant analysis of the previously established site groups with 17 of the chemical variables indicated that high values for conductivity distinguished the most downstream site groups, which had the poorest fauna; the effect of this factor on the fauna was apparently indirect. The analysis also indicated that a decrease in suspended solids at site groups on an impounded section and an increase in nutrients at a site immediately downstream of the input of treated sewage were associated with changes in the fauna. The release of heated water (<25�C) from a power station at one of the sites on the impounded section had little effect on the fauna.
Nitrates in eastern Australian coastal waters
Authors: Rochford DJ
Published: November 2005

Mean monthly temperature, salinity and nitrate concentration of eastern Australian coastal waters, at 0 and 50 m depth, for periods of up to 36 years have been determined. Using the seasonal changes in the mean properties it has been shown that the prime source of nitrates in coastal waters of eastern Australia between Evans Head and Eden is the intrusion, at various times in the spring-summer seasons, of subsurface slope waters, which are relatively rich in nitrates. Once present in the bottom layers of these coastal waters, these nitrates form a reservoir from which local processes of mixing in the autumn-winter seasons create a surface nitrate maximum, which persists for several months into the following spring. Off Evans Head and particularly off Laurieton, upwelling later in the spring creates a secondary nitrate maximum but these are of a transient time scale and little residual surface nitrate remains after the upwelling ceases. In summer, thermal capping, aided, particularly in the north, by surface salinity dilution, greatly limits the vertical mixing of nitrates to the surface, resulting in very low surface nitrate concentrations in summer.
Off Eden, the spring introduction of nitrates by slope-water intrusions is impeded by a northward flow of Bass Strait waters which, because of their low nitrate content, act as a nutrient diluent. It is only when this northward flow ceases in early summer that these slope-water intrusions occur off Eden and provide the nitrate reservoir for the
winter turnover. Off Maria I., slope-water intrusions are not an important contribution to the nitrate
economy. The winter maximum in nitrate concentration at the Maria I. site is attributed to an onshore
drift of nitrate-richer offshore waters, containing Sub-Antarctic elements. In spring, snow-melt waters
mix with these winter waters off Maria I. and decrease both the salinity and nitrate content of these
waters. In summer, subtropical waters of low nitrate content occur off Maria I.
Seasonal studies on the zooplankton community of Lake Alexandrina, River Murray, South Australia, and the role of turbidity in determining zooplankton community structure
Authors: Geddes MC
Published: November 2005

Zooplankton was quantitatively collected from Lake Alexandrina from November 1975 until March 1978. Twenty-eight species of zooplankton were identified, although momentary species composition usually comprised two calanoids, one cyclopoid, from three to six cladocerans and from zero to four rotifers. There were no consistent patterns in the vertical or horizontal distribution of the major zooplankters. Some species, including Boeckella triarticulata, Calarnoecia ampulla, Bosrnina meridionalis, Ceriodaphnia quadrangula and possibly Daphnia carinata were perennial, whereas Diaphanosorna unguiculaturn, Moina rnicrura and Daphnia lumholtzi were seasonal. Zooplankton density was relatively high and constant throughout the study. The zooplankton community included both large and small species. In Lake Alexandrina, high turbidity may preclude size-selective fish predation, allowing the persistence of large species, while invertebrate predation may be insufficient to remove small species.
Hybridization between the estuarine fishes yellowfin bream, Acanthopagrus australis (Gunther), and black bream, A. butcheri (Munro) (Pisces : Sparidae)
Authors: Rowland SJ
Published: November 2005

The status of bream, from estuaries near Narooma on the south coast of New South Wales, which display morphological characteristics intermediate to those distinguishing the species A. australis and A. butcheri was investigated. The two species were separated electrophoretically at a malate dehydrogenase locus (Mdh-1) where they are fixed for alternative alleles, and by a significant difference in allele frequency at the lactate dehydrogenase locus Ldh-A. Because four individual bream, which displayed intermediate morphometric characteristics, have inherited both species-specific Mdh-1 alleles and are heterozygous at the Ldh-A locus, their status as hybrids is determined. The presence of three bream with allelic characteristics of A. australis at the Mdh-1 locus but allelic characteristics of A. butcheri at the Ldh-A locus is evidence for the presence of later generation or backcross hybrids. No evidence of introgression was found. The reproduction of A. australis and A. butcheri is temporally and spatially isolated under normal circumstances but in some landlocked, coastal lakes there is a breakdown of these isolating mechanisms. Because A. australis and A. butcheri differ morphometrically and ecologically over their sampled ranges, and only appear to hybridize in the unusual environmental conditions of closed lakes, it is suggested that their specific status be retained. Using electrophoretic data, a high level of genic similarity (I = 0.91) was found to exist between the two species. This, together with the close relationship indicated by the production of fertile F1 hybrids, suggests a recent speciation.
Mercury concentrations in four carcharhinid and three hammerhead sharkes from coastal waters of the Northern Territory
Authors: Lyle JM
Published: November 2005

Analysis of mercury in muscle tissue of four species of carcharhinid shark (genus Carcharhinus) and three species of hammerhead shark (genus Sphyrna) from coastal waters of the Northern Territory has indicated that each of the species studied accumulates relatively high concentrations of mercury. Maximum observed concentrations in all species except C. sorrah (Valenciennes) exceeded 1.5 mg kg-1. Concentrations greater than 4 mg kg-1 were recorded in C. amblyrhynchoides (Whitley), S. lewini (Griffith & Smith) and S. mokarran (Ruppell). Mercury concentration was highly dependent on shark size and increased more or less exponentially with length. Apart from S. lewini and S. mokarran, there were significant differences between length-mercury relationships for males and females of each species. At a given length, males tended to have accumulated higher concentrations of mercury than females. With the exception of C. sorrah, weighted mean concentrations of mercury for each species exceeded the current National Health and Medical Research Council standard for mercury of 0.5 mg kg-1. Implications of possible management based on mercury standards are considered using information available for C. limbatus (Valenciennes) and C. sorrah.
Bryozoan interactions: Observations on stolonal outgrowths
Authors: Osborne S
Published: November 2005

Tropical bryozoan and colonial ascidian species were transplanted in pairs onto small slabs of coral skeleton. Microscopic examination of the slabs was carried out every 6 weeks. Five out of eight species of bryozoan studied produced terminal and/or frontal stolonal outgrowths at interfaces with adjacent bryozoans and colonial ascidians. Secondary growing edges, which had the potential to grow back over intruding colonies, sometimes formed subsequently at the position of frontal stolonal outgrowths. The sequence of events following contact between the two species Celleporaria sp. A and Stylopoma duboisii (Audouin) is described. A possible function of stolonal outgrowths is colony defence, and the importance of long-term studies in revealing the dynamic nature of colony interfaces is noted.
Effect of salinity change on early development in Galeolaria caespitosa (Polychaeta : Serpulidae)
Authors: Tait NN , Atapattu D , Browne R
Published: November 2005

Although G. caespitosa is able to survive seawater dilution down to 60% seawater, oocytes released into 60% seawater are not viable. Despite this, a greater percentage of oocytes released into 60% seawater are induced to undergo prematuration (as indicated by the initiation of meiosis) than occurs in oocytes released into normal seawater. Unspawned oocytes in adult worms maintained in 60% seawater are protected from this osmotic shock despite equilibration of the osmotic concentration of the body fluids with the external medium.
Light climate in the Gippsland Lakes, Victoria
Authors: Hickman NJ , McShane PE , Axelrad DM
Published: November 2005

Variation in the light climate of Lakes Wellington, Victoria and King, Gippsland, Vic. occurred both seasonally and between the three lakes studied. Absorption of photosynthetically active radiation was related primarily to concentration of non-chlorophyllous particulate material (tripton) with dissolved organic material (gilvin) and particulate chlorophyll being of lesser importance in influencing light climate. Lake waters were characterized by selective attenuation of red (650-700 nm wavelength) and blue (400-500 nm wavelength) quanta with depth. .Though most photosynthetically active radiation in Lake Wellington was removed in the first 1 m of depth, phytoplankton biomass was higher than in Lake King which had more available light. Vertical mixing, resulting in periodic exposure of phytoplankton to surface light levels, is suggested as a mechanism whereby the relatively high phytoplankton biomass of Lake Wellington is maintained.
Diets of commercially exploited fish from Bass Strait and adjacent Victorian Waters, south-eastern Australia
Authors: Coleman N , Mobley M
Published: November 2005

Stomach contents were analysed to investigate the diets of 52 commercial species of fish. Fish were collected from Bass Strait and adjacent Victorian waters, south-eastern Australia; samples effectively covered the whole of the Victorian coast. Particular emphasis was placed on estimating the importance of arrow squid, Nototodarus gouldri in the diets of the species investigated. For most of the species investigated, the major food items (expressed as the proportion of stomach contents by number, weight and volume or through the calculation of the Index of Relative Importance) were fish or crustaceans. Cephalopods were found in the diets of 21 species but provided a major proportion of the stomach contents in only six species. Arrow squid did not appear to be a major item in the diets of any of the species investigated. For those species that eat large amounts of cephalopods, it appears to be octopus, rather than squid, that is of most significance in the diet.