bluuebunny/crossref_metadata_2025 huggingface dataset:
Trace metals and the productivity of shelf waters off north west Australia
Authors: Mackey D
Published: November 2005

Oceanographic measurements on the North West Shelf of Australia indicated that nutrient enrichment was derived from a combination of terrestrial run-off and interaction with the sediments. There was no evidence for upwelling. In situ fluorescence measurements suggested that the phytoplankton biomass was low and did not increase in regions of nutrient enrichment. On the continental shelf, the concentrations of copper, nickel and cadmium were typical of unpolluted waters and by using a reverse- phase high performance liquid chromatography absorbent (SEP-PAK), about 20% of the copper was found to be organically bound with smaller amounts of organically bound nickel, zinc and iron and even less organically bound cadmium, chromium and manganese. The copper-complexing capacity of the surface waters (5-10 nM) was comparable to the total concentration of trace metals liable to form organic complexes so that the trace metal speciation may change markedly with small changes in trace metal concentration or complexing capacity. Calculations show that the concentration of free copper ions is too low to have any adverse affects on the biota and it is suggested that the productivity of the water may be affected by the limited bioavailability of essential trace metals.
Studies of the hydrobiology of a tropical lake in north-western Queensland. III. Growth, chemical composition and potential for harvesting of the aquatic vegetation
Authors: Finlayson CM , Farrell TP , Griffiths DJ
Published: November 2005

The biomass of aquatic plant species and the standing crop of submerged species were estimated in Lake Moondarra from 1977 to 1979. In July 1978, the biomass of Salvinia molesta exceeded 53 000 t fresh weight, with a density of 167 t ha-1 (0.81 kg dry wt m-2). Hydrilla verticillata reached a maximum density of almost 3 kg dry wt m-2 and Potamogeton crispus more than double that density. Photosynthetic activity of a range of species was high, and was still detectable at water depths allowing only very low light penetration. Organic nitrogen concentrations were high (0.91-4.37% dry wt), and phosphorus (0.07-0.47% dry wt) appeared to be a limiting factor for growth of the aquatic plants. Heavy metal concentrations varied with species, location and season but, although generally higher than world-wide 'mean' values (48 �g g-1 copper, 11 �g g-1 lead, 14.3 �g g-1 zinc), were significantly less than those of aquatic macrophytes in heavily polluted environments. H. verticillata was more efficient than S. molesta in removal of nitrogen, phosphorus and zinc, whereas for copper and lead the reverse was true. The potential for using this property of the aquatic plants and subsequent harvesting in order to remove nutrients and metals from the lake is also discussed.
137Cs diffusion in the highly organic sediment of Hidden Lake, Fraser Island, Queensland
Authors: Torgersen T , Longmore ME
Published: November 2005

The vertical distribution of 137Cs (originating from nuclear fallout since 1954) in the highly organic sediment of Hidden Lake is found to be inconsistent with 14C and 210Pb data. Mathematical models of bioturbation indicate that this mechanism cannot explain the discrepancy. Diffusive migration of 137Cs is modelled using the experimentally determined value of ≈140 for the distribution coefficient, KD, of 137Cs in Hidden Lake sediment. It is concluded that 137Cs is diffusing in the sediment at an effective rate of c. cm2 s-1 due to the low value of KD The diffusive mechanism is further modified by adsorption or absorption at or near the sediment-water interface.
Biological observations on sharks caught by sport fisherman of New South Wales
Authors: Stevens JD
Published: November 2005

Between 1979 and 1982, 523 sharks representing four families and 13 species were examined from sport fishing catches off New South Wales. Additional catch data were available from records of the Sydney Game Fishing Club extending from 1953 to 1979. The species composition of sharks caught changes through the year, probably as a result of seasonal variations in water temperature. Prionace glauca and Isurus oxyrinchus are most abundant in the catches during the cooler months from May to November. Galeocerdo cuvieri, Carcharhinus brevipinna, C. longimanus, C. falciformis, C. limbatus and Sphyrna lewini are taken principally during the warmer months from December to April. The sex ratio of P. glauca and Sphyrna zygaena changes through the year due to a seasonal influx of gravid females. At least six of the species examined give birth off New South Wales and, apart from C. falciformis, all of these appear to have restricted breeding seasons. P. glauca and S. zygaena feed mainly on cephalopods and to a lesser extent on fish, I. Oxyrinchus principally on fish, and G. cuvieri mostly on fish, birds, unidentified mammals and cephalopods.
Comparative distribution of macrocrustaceans in a north-western Australian mangrove system
Authors: Wells FE
Published: November 2005

Species diversity, density and biomass of macromolluscs and macrocrustaceans were investigated in the Bay of Rest (22� 18'S.,114�08'E.), a small mangrove system in north-western Australia. Mollusc species diversity, density and biomass were generally greatest on the seaward mudflat and lower in Avicennia and Rhizophora tree zones; no molluscs were recorded on the landward backflat. Crustaceans were diverse and abundant on the mudflat but the biomass was low. Diversity, density and biomass were high in Avicennia, lower in Rhizophora and the backflat. Filter-feeding molluscs were important on the mudflat, as were deposit feeders which dominated in Avicennia. Surface raspers were most important in Rhizophora. Deposit feeding and omnivorous crustaceans were dominant in all areas. It is suggested that molluscs and crustaceans in the system, both in the tree zones and on the seaward mudflat, are largely dependent on detrital breakdown of the mangroves for their nutrition. They may play a key role in converting primary production by the trees into animal tissue available to higher trophic levels.
Observations on the chinaman leatherjacket Nelusetta ayraudi (Quoy & Gaimard) in the Great Australian Bight
Authors: Lindholm R
Published: November 2005

Biological information on N. ayraudi was collected during a survey of demersal fish of the Great Australian Bight between 1978 and 1980. Fish size increased with water depth, the adults were sexually dichromatic, and the sex ratio of female to male was approximately 2 : 1. Though it is a carnivore, N. ayraudi has a digestive tract that is usually associated with herbivores.
A new method for estimating tag shedding rates with application to data for Australian salmon, Arripis trutta esper Whitley
Authors: Kirkwood GP , Walker MH
Published: November 2005

A new procedure is described for estimation of tag shedding rates from a double-tagging experiment, when exact times of recapture are known. The method requires identical assumptions to existing procedures using recapture data pooled over time, but it avoids approximations inherent in those procedures. Estimates are obtained independently of the history of fishing and natural mortality throughout the experiment. The procedure was developed principally to handle those situations in which the pooled data methods are unsuitable, due to sensitivity of the estimates to the pooling interval adopted. This commonly occurs when recaptures are few and irregularly spaced over time. Use of the procedure is illustrated with data for adult Australian salmon, A. trutta esper, which were tagged with single and double internal tags of two sizes in March 1978. No difference was found between the recovery rates of the two tag types. Of 125 originally double-tagged fish, 47 were recovered and 41 of these retained both tags on recovery. An annual tag retention of 74 5% was estimated, with 95% confidence limits 52 1-89.6%.
Investigations of the Tasman Sea by satellite altimetry
Authors: Coleman R
Published: November 2005

Altimeter data obtained over a period of 3.6 years (from April 1975 to November 1978) and over the winter period July-September 1978 from the GEOS-3 and SEASAT satellites were used to study the spatial distribution of mesoscale sea-surface variability in the Tasman Sea. Satellite data generally agreed with existing hydrographic measurements. Patterns of higher sea-surface variability were shown to be associated with the East Australian Current and eddy areas. Though the Tasman Front is known to be present at certain times of the year, it is concluded that it is not a permanent feature across the Tasman Sea. Low variability levels in the mid-Tasman Sea are seemingly dictated by the Lord Howe Rise, thus suggesting some sort of topographic influence.
Physicochemical differences between lagoons of King anf Flinders Island, Bass Strait
Authors: Bowling LC , Tyler PA
Published: November 2005

In 24 samples of coastal lagoons from the Bass Strait islands, sodium and chloride were the dominant ions, indicating a marine origin for the waters. The extent of geochemical influence varied locally, as did the optical properties. Gilvin values for some lagoons were amongst the highest known for natural waters. Total phosphate concentrations were variable, with some lagoons being highly eutrophic. With one exception, the Flinders Island samples were considerably more saline than those from King Island. A principal coordinates analysis differentiated samples from the two islands, although in the space defined by the first two coordinate axes there was a continuous variation between lagoons.
Temporal and spatial variability in the community structure of the fauna of four sandy beaches in south-eastern New South Wales.
Authors: Dexter DM
Published: November 2005

Four intertidal sandy beaches with different exposures, La Perouse, Ocean Beach, Dolls Point, and Towra Point, were studied for temporal and spatial changes in faunal composition and community structure. Each of these beaches was sampled from 6 to 12 times between July 1980 and July 1981 using a 500 �m sieve. A stratified random sampling procedure across the intertidal zone isolated 40 660 individuals representing 85 species. Distribution and abundance of species were strongly influenced by tidal level. Densities changed during the year but no seasonal changes in intertidal zonation patterns were found. Changes in density were correlated with the reproductive activities of the abundant species, especially Pseudolana concinna and Exoediceros maculosus at La Perouse, and Spio pacifica at Dolls Point and Towra Point. The number of species increased from high to low tide, and also increased with decreasing exposure to wave action. Crustaceans dominated the fauna in the most exposed site and decreased in abundance with increasing protection. Ocean Beach experienced the least fluctuation in physical factors such as wave action, salinity, and temperature, and its fauna exhibited the highest diversity index (H') and evenness (J'), the most stable density, and the greatest stability in faunal composition through time. The highest densities and the most species were found at Towra Point, which also was the most protected site.
Zooplankton of an Australian high alpine lake, Lake Cootapatamba, Kosciusko Range
Authors: Benzie JAH
Published: November 2005

The zooplankton of Lake Cootapatamba, the highest (2070 m) alpine cirque lake in continental Australia, was sampled monthly during the ice-free periods of 1981 and 1982. Eleven taxa were identified, the zooplankton being dominated by Boeckella montana, B, pseudochelae, Daphnia nivalis, and in one month, Keratella slacki. Partial correlations with physicochemical parameters (pH, conductivity, O2 and temperature) indicated no strong and consistent trends with zooplankton numbers. In addition to possible competitive effects between K. slacki and the crustaceans (marked by strong spatial and temporal segregation), circumstantial evidence is produced for a direct control by food on the major population changes in 1981 and 1982.
Functional response analysis of size-selective predation by the notonectid predator Anisops deanei (Brooks) on Daphnia thomsoni (Sars)
Authors: Reynolds JG , Geddes MC
Published: November 2005

The functional response of A. deanei to uncrested D. thomsoni was calculated by predation experiments in the laboratory. A. deanei produced typical type 11 functional response curves when presented with increasing densities of any given size-class of D. thomsoni Predation rates were highest for small size-classes and decreased for prey sizes above 2 mm In mixed-prey populations A deanet showed a greater preference towards the smaller, preferred prey than was predicted from the angle-prey-type expenments, thus demonstrating an exercise of choice by the predator. Crests developed by the smaller, preferred size-classes of D. thomsoni did not act as effective anti-predator mechanisms against A. deanei which may be able to remam an effective predator on crested populations of D. thomsonl.
Effects of environment and population density on the sea anemone Actinia tenebrosa
Authors: Ayre DJ
Published: November 2005

Within each of four Western Australian colonies of A. tenebrosa, adults developed gonads and brooded asexually produced juveniles during the summer months. The brooded juveniles were released throughout the year but most settlement occurred in autumn and winter. Dispersal of brooded juveniles was highly localized and they typically settled within 2 m of adults. Adults were sedentary and long- lived and recruitment rates were extremely low (about 1% per annum during the study period). Adult size and asexual fecundity differed markedly between colonies over three breeding seasons, but between-colony comparisons revealed no simple relationship between those characteristics. The mean number of juveniles per adult varied up to ninefold between colonies. Sex ratios deviated significantly from a ratio of 1 : 1 in samples from three colonies, and males predominated in two of these. Density-manipulation experiments revealed that intraspecific competition affected adult size, sexual maturity, asexual fecundity and rates of settlement and recruitment.
Morphological and electrophoretic studies of the palaemonidae (Crustacea) of the Perth Region, Western Australia
Authors: Boulton AJ , Knott B
Published: November 2005

A reappraisal of the morphological characters currently used to separate the genera Palaemon, Palaemonetes and Macrobrachium reveals that the present system of classification is inadequate to differentiate the species of these genera occurring in the Swan River Estuary, W.A. Since separation on morphological grounds proved to be unreliable, an electrophoretic survey of 17 enzymes at 24 loci was carried out. The results suggest that Palaemonetes australis may be congeneric with Macrobrachium intermedium. The species of Palaemonetes from the Swan River Estuary are genetically dissimilar to P. vulgaris from Nova Scotia, which appears to be phylogenetically closer to Palaemon afinis. A discussion of the affinities and likely oilgins of these species, with emphasis on the anomalous occurrence of Palaemonetes australis in south-western Australia is presented.
Large-scale influence of the New Zealand seafloor topography on western boundary currents of the South Pacific Ocean.
Authors: Heath RA
Published: November 2005

The extensive New Zealand submarine platform lying approximately 1600 km east of Australia has a strong influence on the South Pacific circulation. Together with the Kermadec Ridge, it is the western boundary of the deep South Pacific Ocean with an associated deep western boundary current. Although New Zealand probably influences where the East Australian Current separates from the east Australian coast, at the latitude of northernmost New Zealand, the sloping seafloor on the New Zealand west coast does allow for a meridional flow there. However, the decrease in current speed with depth does decrease the influence of the bottom topography. The net result is that there is both an intensification of the zonal flow across the Tasman Sea at the latitude of northernmost New Zealand, the speed of which is enhanced by the flow over the extensive ridge system, and a general eastwards flow in the Tasman Sea over the latitudinal range of New Zealand, which feeds meridional flows on the New Zealand west coast. It is suggested that the general west to east flow past New Zealand restricts the westward propagation of second- and higher-order baroclinic Rossby waves with the result that, whereas the East Australian Current has rapid near-surface flow which decreases rapidly with depth in the upper 500 m, the surface flow on the east coast of New Zealand is less rapid and decreases more uniformly with depth. One possible consequence of the current speed change with depth is that the flow and eddies on the New Zealand east coast appear to be influenced by the bathymetry whereas the East Australian Current eddies are more a primary component of the current linked to instability in the current system.
Modelling of 210Pb behaviour in the catchment and sediment of Lake Tali Karng, Victoria, and estimation of recent sedimentation rates.
Authors: Smith JD , Hamilton TF
Published: November 2005

The technique of 210Pb dating of sediments over time scales of up to 120 years is described and illustrated by a study of Lake Tali Karng. Results from the study of a sediment core from the deepest part of the lake shows that the flux of unsupported 210Pb to the sediment is about 145 mBq cm-2 year-1. Over the last 100 years, about 75 cm of sediment has accumulated at an average rate of 150-200 mg cm-2 year-1. Calculations using two models to convert 210Pb activity-depth profiles to age-depth profiles indicate that the sedimentation rate has increased slightly over the last 100 years. It is estimated that about 14% of the 210Pb falling in the catchment reaches the lake sediment, but depending on the assumptions made the possible range is 7-60%.
Reproductive cycle of the fork-tailed catfish Arius graeffei Kner & Steindachner (Pisces : Ariidae) from the Clarence River, New South Wales
Authors: Rimmer MA
Published: November 2005

A. graeffei breeds annually from early November to early December when water temperatures reach
26°C and daylength averages 13.7 h. The bulk of ovarian development is restricted to the 2 months
before spawning; the rate of oocyte development varies substantially between individuals. Diameters
of mature oocytes range from 11.0 to 13.7 mm (mean 12.2 mm). Fecundity ranges from 40 to 122
and is linearly related to fish length and weight. The sex ratio of the population studied was 0.82
with a preponderance of males. The pelvic fins of adult female A. graeffei are longer and more rounded
than those of adult males, and have a hook-like thickening (clasper) on the dorsal surface which
develops seasonally in association with the reproductive cycle. Although marine populations of A.
Graeffei appear to undertake extensive anadromous migrations associated with breeding, no such
movements were observed in the fluviatile population studied.
Growth, Feeding and condition of the fork-tailed catfish Arius graeffei Kner & Steindachner (Pisces : Ariidae) from the Clarence River, New South Wales
Authors: Rimmer MA
Published: November 2005

Both sexes of A. graeffei have similar length-weight relationships and mature at approximately the same size. Relative condition factor decreased in winter when water temperatures dropped to minimum. Feeding activity in females decreased before spawning, and males ceased feeding while brooding eggs and larvae. Gonadal maturation and buccal incubation were associated with decreases in stored visceral fat and hepatosomatic ratio, respectively.
Reproductive biology of three congeneric sea cucumber species, Holothuria atra, H. impatiens and H. edulis, at Heron Reef, Great Barrier Reef
Authors: Harriott VJ
Published: November 2005

Three Holothuria species at Heron Reef showed considerable variation in reproductive seasonality, magnitude of gonad index, egg size and numbers, and frequency of asexual reproduction by transverse binary fission. H. atra from the shallow lagoon spawned biannually (in summer and winter), females produced a large number of small ova, and asexual reproduction was frequent. H. impatiens from the reef flat spawned annually in late spring or summer, with females producing a small number of large ova; signs of asexual reproduction were never observed. H. edulis from the deep lagoon showed no annual reproductive pattern, produced an intermediate size and number of eggs, and reproduced asexually moderately frequently. Preliminary results indicated that reproductive maturation and magnitude of gonad index might vary between sites for H. atra. There was little temporal overlap in spawning by the three species at the sites sampled, and this may be a factor in the maintenance of their genetic isolation.
Functional morphology of the balanomorph barnacles Tesseropora rosea (Krauss) and Tetraclitella purpurascens (Wood) (Tetraclitidae)
Authors: Anderson DT , Anderson JT
Published: November 2005

Tesseropora rosea of eastern Australia inhabits exposed, wave-washed rocks, is an extension feeder in fast currents, and has monometric growth, with orifice enlargement by erosion. It has a deep, mobile operculum. Tergal depressor muscles are large, scutal depressors moderately large. The opercular valves play an active part in respiratory pumping beat. Tergal depressors effect opercular withdrawal. Rostral scutal depressors assist in pumping beat. Lateral scutal depressors assist in opercular opening. Cim IV-VI of T. rosea unfurl rapidly in response to fast water currents and are captorial, either singly or in concert. The antenniform third maxillipeds (cirrus 111) turn back laterally in the extended position but fold over and hold down the captorial cirri in the curled position. Tetraclitella purpurascens of southern Australia inhabits crevices and overhangs on rocky shores, is an extension feeder in moderate currents, and has diametric growth, with orifice enlargement by circumferential growth of radii and parietes. It has a shallow operculum with only slight mobility. Tergal depressors are large, scutal depressors small. Valve action is mainly hinge-like and slow, with little apicobasal movement. The small scutal depressors assist the large tergal depressors in opercular withdrawal and have only a very minor role in pumping beat. Cirri IV-VI of T. purpurascens are held erect for long periods in moderate water currents. Captorial movements are similar to but slower than those of T. rosea. The third maxillipeds have short rami involved in forward food transfer. Setation correlates with function on the cirri of both species. The oral cone of T. rosea is broader and the mouthparts relatively larger than those of T. purpurascens, possibly mediating a more powerful triturating mechanism. A comparison of structure and function shows that T. purpurascens retains many primitive balanomorph features, whereas T. rosea has a more advanced functional configuration. In the evolution of tetraclitids, it seems likely that the tetraclitellines diverged early, before the austrobalanines gave rise to the tetraclitines. The four-plated wall may have evolved independently in tetraclitellines and austrobalanines.
Phytoplankton of the La Trobe River, Victoria
Authors: Chessman BC
Published: November 2005

Phytoplankton was sampled on a monthly basis for 1 year at five stations on the La Trobe River in Gippsland, Victoria. In the upper, mostly forested, reaches of the river, chlorophyll a concentrations and cell densities were uniformly very low, and the dominant algae were detached benthic diatoms and flagellated species. In the plains section of the river, downstream of an impoundment (Lake Narracan), spring and autumn blooms occurred, with a marked reduction in abundance in midsummer and midwinter. The lowland planktonic flora was dominated by centric diatoms, particularly Melosira distans in autumn and Skeletonema potamos in spring.
Leeuwin current and wind distributions on the southern part of the Australian North West Shelf between January 1982 and July 1983
Authors: Holloway PE , Nye HC
Published: November 2005

Observations of the current and wind distributions on the southern part of the Australian North West Shelf between January 1982 and July 1983 are presented. Maps of monthly averages of winds and currents from a variety of locations are presented as well as some time series spanning 19 months of currents and water temperatures from a shelf-slope location and corresponding winds from a coastal station. The main feature of the observations is the strong flow to the south-west parallel to the bathymetry known as the Leeuwin Current. From the observations across the continental shelf, the low-frequency flow is strongest over the shelf break reaching a maximum speed of approximately 0 25 m s-1. The current is strongest between February and June. Reversals of the flow to the north- east are usually weak in strength and of short duration and are associated with strong south-west winds. However, observations of water temperature suggest the north-east currents cause weak upwelling events of cold deep water onto the shelf. The south-east trade winds blow from the south- east between March and August, but are shown to be inefficient in generating longshore currents to the south-west and hence in strengthening the Leeuwin Current.
Chlorophyll-total phosphorus relationships in Lake Burragorang, New South Wales, and some other Southern Hemisphere lakes
Authors: Ferris JM , Tyler PA
Published: November 2005

Linear regression of chlorophyll concentration on total phosphorus concentration for phosphorus- limited Lake Burragorang, N.S.W., yields regression coefficients within the range reported for individual lakes in the Northern Hemisphere. Some variation in slope of published regressions is attributable to the choice of different regression subvariables (e.g. annual mean or annual maximum). The extent of this variation is quantified. Data from Lake Burragorang and other sites indicate that chlorophyll-phosphorus relationships in the Southern Hemisphere are concordant with those in the north if turbid waters are excluded from consideration. This is obviously significant in Australia, with so many turbid waters. The notion of 'growing season', as applied to Northern Hemisphere studies, is inappropriate for the warm temperate conditions of Lake Burragorang, and it was necessary instead to use the annual maximum chlorophyll concentration. Prediction of annual maximum chlorophyll concentration is of particular significance to water-quality management. Despite highly significant regressions, 95% confidence intervals and 95% prediction limits are wide, so that prediction of chlorophyll concentration from single values of total phosphorus, using double-In regressions, gives a wide arithmetic range. Use of annual mean total phosphorus concentration as the predictor variable limits the forecasting ability of the Lake Burragorang regressions but facilitates future coupling with a phosphorus loading model. This would assist in the assessment of projected management plans and the formulation of protective loading criteria.
Seasonal changes in gonad maturity, and abundance of larvae and early juveniles of barramundi, Lates calcarifer (Bloch), in Van Diemen Gulf and the Gulf of Carpentaria
Authors: Davis TLO
Published: November 2005

L. calcarifer undergoes a prolonged breeding season that starts just before the summer monsoon. In Van Diemen Gulf the fish spawned in 1978-1979 from September to February, and in the Gulf of Carpentaria in 1979-1980 from November to March. Spawning was localized, occurring near river mouths on coastal mudflats or upstream in rivers where salinities were relatively high (30). There was no evidence for coastal migrations to specific spawning grounds. Juveniles from 9 mm total length entered, on the high spring tides, supralittoral habitats such as tidal pools, gutters, swamps and low- lying inundated coastal floodplain for use as nursery areas.
Early life history of barramundi, Lates calcarifer (Bloch), in north-eastern Queensland
Authors: Russell DJ , Garrett RN
Published: November 2005

Larval barramundi in the size range 2.8-5.2 mm were collected from plankton in two estuaries in north-eastern Queensland from 31 October 1979 until 13 February 1980. After leaving the plankton, barramundi moved into nearby brackish and freshwater swamps. These areas acted as nursery grounds, offering both protection from predators, and abundant prey in the form of insect larvae, other fish and crustaceans. These habitats exhibit a wide range of salinities (fresh water-44 × 103 mg l-1) and surface water temperatures (23-36�C). Juvenile barramundi commenced migration from these swamps into permanent tidal creeks around April where they remained for up to 9 months before dispersal into the estuary, up rivers or along coastal foreshores. The diet of the barramundi in these tidal creeks was exclusively fish and crustaceans. Juvenile barramundi were resident in tidal creeks that had been subjected to substantial human interference through habitat alteration. Destruction of nursery swamps may pose a serious threat to local barramundi stocks near centres of human population on the eastern Queensland coast.
Diet of the Australian bass, Macquaria novemaculeata (Perciformes : Percichthyidae), in the Sydney Basin
Authors: Harris JH
Published: November 2005

Stomach contents of Australian bass, M. novemaculeata, sampled from the Hawkesbury River and Georges River in the Sydney Basin, New South Wales, between November 1977 and January 1982 were analysed by the occurrence and points methods. Stomach fullness was also recorded. A total of 143 aquatic and terrestrial animal taxa were present in the diet, and these were grouped into 19 food types for analysis. M. novemaculeata is a euryphagic carnivore. Season and habitat type had significant effects on composition of the diet. Insects were the most important food type, followed by fish and large crustaceans. A large proportion of the diet of bass was derived from allochthonous sources, mainly during summer, and especially in lotic habitats. Mean stomach fullness was highest in spring and lowest in winter. Young M. novernaculeata (TL 11-47 mm) from the Hawkesbury River estuary fed on far fewer prey taxa (mainly chironomids and copepods) than did adults. Dietary overlap occurs between M. novemaculeata and many other carnivorous freshwater vertebrates in the Sydney Basin. However, persistent competitive clashes are generally avoided, either by differences in microhabitat preference and feeding behaviour or by larger-scale habitat partitioning.
Direct development in Southern Australian cowries (Gastropoda : Cypraeidae)
Authors: Wilson BR
Published: November 2005

Direct development is described in three species of Zoila, three species of Notocypraea and one species of Austrocypraea from the temperate waters of southern Western Australia. Females lay egg-masses like those of tropical cowries but only one embryo develops in each capsule and it hatches at a crawling snail stage. Fecundity is low. Brooding lasts from 40 to 55 days. The ecological and phylogenetic significance of these observations is discussed and compared with tropical species of Cypraeidae, which have high fecundity, incubation periods of 11-18 days and planktotrophic veligers. As a provisional hypothesis, it is suggested that direct development in the southern Australian cowries evolved very early in the history of the family and that it is a successful reproductive strategy in the southern temperate zone because of the lower temperature, lower diversity, higher rates of planktonic predation and greater seasonality of planktonic food resources at these latitudes than in the tropics where planktotrophy has greater selective advantage.
Iodine and arsenic redox species in oxygen-deficient estuarine waters
Authors: Butler ECV , Smith JD
Published: November 2005

The distribution of the redox species of iodine and arsenic in two isolated pools of seawater underlying river water in deep holes in the estuary of the Yarra River is described. In the river water, the dominant species are iodide and As(V). In the saline water of these holes, there are levels of iodine and arsenic greater than are present in the original seawater. The subhalocline waters contained <0.22 ml 1-1 of dissolved oxygen, and the redox poise was intermediate between oxic and anoxic conditions. Most of the iodate originally in the seawater was reduced to iodide, but As111) and As(V) coexisted. Iodine and arsenic appear to have entered the water from the anoxic sediment.
Effects of carp, Cyprinus carpio L., on communities of aquatic vegetation and turbidity of waterbodies in the lower Goulburn River basin
Authors: Fletcher AR , Morison AK , Hume DJ
Published: November 2005

Densities of carp, ranges of turbidity, and details of communities of aquatic vegetation from 1979 to 1982 are given for several waterbodies in the Goulburn River valley including the Broken River, near Shepparton, Victoria. The turbidity values at all sites were high, typical of Australian inland waterbodies. There was no association between high carp densities and high turbidity, and populations of carp did not appear to increase turbidity. Observed turbidity increases at each site appeared to be related to hydrological changes. Fluctuation of water levels was also an important factor determining the extent of aquatic vegetation communities. However, circumstantial evidence is presented that shallow-rooted and soft-leaved aquatic vegetation such as Potamogeton spp. have been reduced by carp.
Distribution and life history of deep-water squid of commercial interest from Australia
Authors: Dunning M , Brandt SB
Published: November 2005

Squid of continental slope and oceanic waters are not currently fished commercially within the Australian Fishing Zone although one species has been caught occasionally in commercial quantities. At least eight species of the cosmopolitan family Ommastrephidae and a variety of mostly mesopelagic species of the families Enoploteuthidae and Onychoteuthidae are represented in Australian waters. The large ommastrephid species Ommastrephes bartrami (red ocean squid), Todarodes filippovae (Southern Ocean arrow squid) and Sthenofeuthis oualaniensis (yellowback squid) have the greatest potential for commercial use. Data on the life history and distribution of the common species are synthesized to provide a baseline for future scientific studies and management strategies.
Population dynamics and feeding ecology of pipefish (Syngnathidae) associated with eelgrass beds of Western Port, Victoria
Authors: Howard RK , Koehn JD
Published: November 2005

Three species of pipefish, Urocarnpus carinirostris Castelnau, Vanacarnpus phillipi (Lucus) and Mitotichthys semistriatus (Kaup), occurred regularly in collections from eelgrass beds of Western Port. A fourth species, Stigmatopora nigra Kaup, was rare. U. carinirostris and V. philippi dominated catches. Brooding males were present for 6-9 months of the year, juveniles were recruited in summer and early autumn, and both species were annual. The pipefish fauna included two main behavioural types. V. phillipi and M. sernistriatus oriented themselves horizontally and were relatively strong swimmers. U. carinirostris and S. nigra were more sedentary, attaching themselves to benthic vegetation by means of a prehensile tail. The latter two species closely mimicked eelgrass leaves in movements, orientation and colour. All inhabited the eelgrass leaf canopy except V. phillipi, which occupied the sediment-water interface. The pipefish were visually orienting, sit-and-wait predators. Pelagic or epibenthic copepods and small epibenthic amphipods comprised the bulk of diets; only V. phillipi ingested polychaetes and plant detritus.
Larval development of Elminius covertus Foster and Hexaminius popeiana Foster (Cirripedia : Archaeobalanidae : Elminiinae) reared in the laboratory
Authors: Egan EA , Anderson DT
Published: November 2005

The presence of embryos in the mantle cavity of E. covertus and H. popeiana has been monitored over a 2-year period. E. covertus has a clearly defined seasonal pattern with peak breeding during the winter and early spring. H. popeiana shows high levels of breeding activity throughout the year. The larval stages of E. covertus and H. popeiana are described from larvae reared in the laboratory. Morphological differences in each larval stage allow the larvae of the two species to be distinguished without difficulty. Differences between the larval stages of E. covertus and E. modestus are more minor, but are sufficient to distinguish most stages. Similarities in the larval morphology of the genera Elminius and Hexaminius support their inclusion in the subfamily Elminiinae. The larvae of H. popeiana also share features with the larvae of archaeobalanines, especially Conopea galeata.
Early development and buccal incubation in the fork-tailed catfish Arius graeffei Kner & Steindachner (Pisces : Ariidae) from the Clarence River, New South Wales
Authors: Rimmer MA
Published: November 2005

Fertilized oocytes of A. graeflei ranged from 12.3 to 15.2 mm in diameter (mean 13.3 mm). Eggs and larvae were incubated orally by the male; maximum observed brood size was 83. The branchial region of brooding males became distended to accommodate the eggs and larvae, and the oral epithelium thickened to cover the palatine tooth patches. The brooding period lasted from 6 to 8 weeks, with hatching at 4-5 weeks. Larvae began feeding on plankton soon after hatching, and juveniles were up to 59 mm total length when released. The average increase in weight from fertilization to release was 20%.
Structure and ecology of the flagellate Scourfieldia caeca (Korsh.) Belcher & Swale in two meromictic lakes in Tasmania
Authors: Croome RL , Tyler PA
Published: November 2005

The minute green flagellate S. caeca occurs in large numbers in two dystrophic meromictic lakes in Tasmania, constantly occupying a narrow stratum immediately above the chemocline, where physical and chemical conditions change dramatically with depth and where available light is less than 1% of surface radiation and restricted to red wavelengths. In its ultrastructure, S. caeca resembles cultured material described previously but differs in the structure and size of its chloroplast and in the structure of its diagnostic keel of starch.
Distribution and abundance of eggs of the anchovy, Engraulis australis antipodum Gunther, in relation to temperature and salinity in the Gippsland Lakes
Authors: Arnott GH , McKinnon AD
Published: November 2005

Observations on the abundance of anchovy eggs in the Gippsland Lakes were made. From these observations, the duration and extent of spawning were inferred. Ten stations along the main salinity gradient were sampled from November 1978 to March 1980. Egg densities ranged from 1 to 38 170 eggs per 100 m3, densities of over 1000 eggs per 100 m3 being recorded on 16 occasions. Larval densities were much lower, only five records being greater than 100 larvae per 100 m3. Spawning extended from October to March. Peak egg and larval densities occurred in January for the two spawning periods examined. Eggs were found from McLennans Strait to the Entrance, with a few also collected from Bass Strait. Limited spawning did occur in the La Trobe River and in Lake Wellington during the 1967-1968 drought, when salinities were considerably higher than normal. The mean 'bottom' to 'top' density ratio for eggs was 3.8 to 1, probably as a result of vertical differences in salinity. Eggs were collected over a temperature range of 14.8-24.2�C, although the main spawning occurred above 18�C. The observed range in salinity was 2.3-35.5, but egg numbers in water below 15.8 were very low.
Tidally induced jet in Koombana Bay, Western Australia
Authors: Hearn CJ , Hunter JR , Imberger J , Van Senden D
Published: November 2005

A study is made of a coastal tidal jet, based on a field program together with numerical and analytical modelling of the tidal discharge and jet dynamics. A new criterion is demonstrated for bottom attachment of low-aspect-ratio buoyant jets. The slightly buoyant jet is attached to the seabed over the initial 2 km of its trajectory, which lies in shallow coastal waters of less than 10 m depth. The jet is about 200 m in width and so its ratio of depth to half-width (aspect ratio) is much lower than for previously reported bottom-attached jets. The longitudinal retardation of the axial speed of the jet is due to bottom friction and entrainment. The jet widens only slowly with distance along its trajectory because entrainment is limited to its sides and is compensated by bathymetric deepening. The jet attaches to the coastline by turning, without loss of speed, to move parallel to the shore. The coastal attachment width is found to be a simple function of the ratio of the jet discharge velocity to the speed of the prevailing alongshore current.
Mercury concentrations of the axial muscle tissues of some marine fishes of the continental shelf adjacent to Tasmania
Authors: Thomson JD
Published: November 2005

The mercury concentrations of 35 commercial and potentially commercial fish species from Tasmanian waters were determined. Four species had mean total mercury concentrations above 0.5 mg kg-1 wet weight and in all four there were individuals with concentrations above 1.5 mg kg-1 wet weight. Two species of shark, Parascyllium ferrugineum and Cephaloscyllium laticeps (with sample sizes of 4 and 1, respectively), had total mercury concentrations above the limit of a mean of 1.0 mg kg-1 wet weight set by the Tasmanian Public Health regulations. Concentrations in the species were compared with published data. Organic mercury concentrations in different species ranged from 40 to 96% of the total mercury concentrations. In fewer than half the species were total mercury concentration and total length or weight significantly correlated, indicating that neither total length nor weight could be used as a universal management tool to control human mercury intake from fish consumption.
Biomass estimation of Artemia at Lake Grassmere, Marlborough, New Zealand
Authors: Haslett SJ , Wear RG
Published: November 2005

During 1980-1982, a sampling program to estimate Artemia biomass was carried out over an annual cycle in the solar salt ponds of Lake Grassmere, Marlborough, New Zealand. Density of Artemia was highest over 238.5 ha of the 1782 ha in 13 ponds, averaging 0.55 m deep, which form the final stages in salt concentration. Artemia and hydrological samples were taken twice a month on 23 occasions from April 1981 to April 1982 inclusive, and on each occasion, 86 sample stations over four ponds were sampled in triplicate. An unbiased estimate of biomass using the arithmetic mean was developed, together with confidence interval estimates based on the bootstrap method giving 95% confidence bound estimates within 25% of the estimated total Artemia biomass in each sampled pond. Artemia biomass concentrations within 50 m of the pond edges were, on average, 2.5 times those at the pond centre, and the biomass estimation procedure was thus accordingly stratified. Generally, Artemia were contagiously distributed with the edge stratum biomass having a log-normal distribution at each sampling time. Biomass was highest during late spring and summer, and lowest in late autumn through winter. Maximum estimated total biomass over 238.5 ha was 12 000 kg dry weight during January 1982.
Revision of the Australian species of the fish family Leiognathidae
Authors: Jones G
Published: November 2005

The Australian species of Leiognathidae are revised and their distinguishing features more clearly defined. Fifteen Australian species are recognized: Gazza minuta, Leiognathus aureus, L. bindus, L. blochii, L. decorus, L. elongatus, L. equulus, L. fasciatus, L. leuciscus, L. smithursti, L. splendens, Leiognathus sp., Secutor insidiator and S. ruconius. Diagnostic characters for the species are difficult to ascertain as the family tends to be meristically constant. Identification relies principally on a combination of body proportions, distribution of scales, tooth shape and arrangement, and body pigmentation patterns. Species descriptions, figures, abbreviated synonymies and geographic distributions within Australia are presented for all species, and an identification key is given. Incorrect usage in the literature of several species names, including L. elongatus, L. brevirostris and L. lineolatus, is discussed.
Occurrence 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

Presence of larvae of Scomberomorus species in plankton samples collected over a 3-year period from the coastal and Great Barrier Reef lagoon region off Townsville was seasonal, occurring over the spring-summer period. S. semifasciatus and S. queenslandicus larvae occurred from October to February, whereas S. commerson larvae occurred over a more limited period, from November to January. S. semifasciatus larvae were restricted to the coastal bays and the inner margin of the lagoon. S. queenslandicus larvae occurred in the coastal bays but extended over the lagoonal region as well. S. commerson larvae occurred only in the lagoon. This inshore-offshore separation is considered to be related to distribution of spawning adults and longshore currents in the lagoon. Absence of S. commerson larvae from inshore stations suggests that juveniles reach their coastal-estuarine habitat through directed movement at the juvenile stage rather than through passive transport of eggs and larvae.
Parameters of the air-sea interface by high-frequency ground-wave Doppler radar
Authors: Heron ML , Dexter PE , McGann BT
Published: November 2005

A 30-MHz ground-wave ocean surface radar has been deployed inside the Great Barrier Reef where the water is sheltered from ocean swell. The spatial resolution of the radar is 3 km radially and 3.5� in azimuth. In each cell a 102.4-s time series is used to determine radial surface currents, wind directions, root- mean-square wave heights and wind speeds. Coincident observations of sea-wave spectra, surface currents and boundary-layer winds are used to evaluate the radar performance and to modify some of the methods of data analysis to suit these conditions. Surface current values are observed by the radar to an accuracy of �0.05 m s-1, wind directions to �10� , root-mean-square wave heights to 0.15 m and wind speeds to �3 m s-1. In some spectra, the peak in the second-order continuum caused by the non-directional sea- wave spectrum is not resolved from a second-order resonance line. This disallows the derivation of the period of the dominant sea wave on a routine basis.
Limnological studies of waterfowl habitat in south-western New South Wales. II. Aquatic macrophyte productivity
Authors: Briggs SV , Maher MT
Published: November 2005

Aquatic macrophyte productivity and soil organic matter were measured in two impermanent wetlands in south-western New South Wales. Macrophyte biomasses (≤463 g dry wt m-2) were similar to or higher than those in submerged communities elsewhere. Macrophyte productivities in both wetlands were greatest in the year following reflooding. But even in that year, macrophyte productivity in Lake Merrimajeel (the only wetland for which data are available) was considerably less than soil organic reserves before reflooding. It is suggested that these soil organic reserves directly contribute to the relationship between wetland flooding and waterfowl breeding, while macrophytes contribute indirectly by providing detritus for invertebrates. It is recommended that wetlands managed for waterfowl breeding should periodically dry out and reflood.