bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on southern Australian abalone (genus Haliotis). I. Ecology of five sympatric species
Authors: Shepherd SA
Published: November 2005

Five species of abalone occur along the southern Australian coastline; of these three species, Haliotis laevigata Donovan, Haliotis roei Gray, and Haliotis ruber Leach, are of commercial importance; the other two species are Haliotis cyclobates Peron and Haliotis scalaris Leach. The habitat, movement, feeding behaviour, food, and ecological relationships with predators were studied for each species at three study sites. Each species of abalone occupies a distinctive microhabitat. H. cyclobates lives in calm-water places associated with communities of the seagrass Posidonia australis and the razor shell Pinna dolobrata; H. laevigata lives on open rock adjacent to sand in moderate to rough water localities; H. ruber prefers caves in calm- to rough-water localities; H. roei occurs in narrow crevices in the upper sublittoral on rough-water coasts ; H. scalaris is an under-boulder or crevice-living species. All species are sedentary, but may make local movements in search of food. Several species may occur in a given habitat but there is little microhabitat overlap. The seasonal variation in food eaten by each species is described. All species show preference for red algae and reject most species of brown algae, subsisting predominantly on red algae and seagrasses according to the possibilities of the habitat. H. laevigata feeds mainly on algal drift and H. roei is substantially a grazing species. The other species feed on algal drift or graze opportunistically. Water movement is an important environmental factor affecting the feeding of those species which feed on algal drift. H. laevigata and H. ruber feed best in conditions of moderate water movement but poorly if the water is too calm or too rough. Water movement elicits a characteristic feeding response in these species. The predators of abalone include fish, crabs, molluscs, and starfish; their interaction with abalone is discussed. Crevices, caves, and cavities under boulders provide a refuge in space from predators for H. roei, H. ruber, and H. scalaris and juveniles of other species, which appear to be confined to these places, except for nocturnal feeding excursions, by the activity of their predators. The adults of the different species differ from each other in their dependence on water movement, their preference for open or cryptic sites such as crevices or caves for resting, their size and their methods of feeding. These differences between the species, taken together, ensure that there will be very little overlap between them in the sorts of places that they seek to live in or their behaviour in seeking food; in those cases where food-seeking behaviour is similar, interspecific competition would seem to be negligible because food is abundant. Predation would seem to have been more important than interspecific competition as the selective pressure that established and maintains these differences between the species.
Derivation of daily phytoplankton production estimates from short-term experiments in some shallow, eutrophic Australian saline lakes
Authors: Hammer UT , Walker KF , Williams WD
Published: November 2005

Measurements of phytoplankton production typically involve short-term (3-6 hr) experiments; some means of conversion is then applied to the results to yield estimates of daily production. Several means of making such conversions are compared on the basis of carbon-14 experiments performed on three shallow, saline, eutrophic lakes. Day-long (12 hr) exposures tended grossly to underestimate the "true" daily production as measured by the cumulative results of consecutive short-term experiments. On the other hand, conversions based on half-day exposures and on radiation data were about equally effective, although both may involve uncertainties of at least 25 %. Conversion factors derived from short-term v. cumulative results varied seasonally and over even short periods of time, apparently in accord with variable biological and meteorological conditions. The accuracies of extrapolations based on these factors are fairly comparable, but to minimize errors short-term experiments should include the midday period when possible. An alternative would be to construct predictive models applicable to each lake as a separate entity, encompassing a wide range of conditions. For small lakes at least, general formulae and models are not likely to be effective.
Chemistry of some sedgeland waters: Lake Pedder, south-west Tasmania
Authors: Buckney RT , Tyler PA
Published: November 2005

Surface waters of the Lake Pedder area are characterized by low salinity, low pH, high colour, and a relative major-ion composition near that of seawater. Factors determining this composition are predominance of inert rocks, a covering of sedgeland peat isolating waters from rock contact, and a high rainfall brought by prevailing oceanic winds. Frequency and intensity of rainfall appear to determine the pattern of chemical variation. Salinity, bicarbonate, and pH may change rapidly during periods of high rainfall. Humic acids are important chemical constituents of the waters, and probably determine the type of biotic community which inhabits them.
Seasonal changes in the chemical composision of the red alga Hypnea musciformis
Authors: Abdel AF , Abed NM , Edrees M
Published: November 2005

Seasonal changes were observed in the chemical composition of the marine
red alga Hypnea musciformis. Lipids, cholesterol, and lanosterol were found as
constituents of the algal material. No low-molecular weight carbohydrates were
found except small amounts of mannitol. The algal hydrolysate was shown to contain
galactose, glucose, and xylose in all seasons and was characterized by a high content of
glucuronic acid and its lactone in February. Definite seasonal variations were found
in the patterns of free amino acids and of amino acid compositions of proteins.
The biology of a landlocked form of the normally catadromous salmoniform fish Galaxias maculatus (Jenyns). V. Composition of the diet
Authors: Pollard DA
Published: November 2005

The composition of the diet of a landlocked form of the normally catadromous
stream-dwelling fish Galaxias maculatus from Lake Modewarre in south-western
Victoria was studied using a new method of stomach contents analysis based on the
principle of ranking. The overall diet of this landlocked fish was found to consist
mainly of amphipods, chironomid larvae, and copepods (basic food types), with other
groups of crustaceans (cladocerans and ostracods) and insects (trichopteran and
zygopteran larvae) being of lesser importance (secondary food types), and a few other
incidental food types occurring in only small amounts. The diet of this landlocked form
thus consists mainly of crustaceans, in contrast to that of the stream-dwelling form
which comprises mainly insects. There was a change in the pattern of feeding in the
landlocked fish with growth, the smaller fish eating more of the smaller planktonic and
the larger fish more of the larger littoral-benthic food organisms. Amphipods were the
dominant food type during all seasons except autumn, when copepods were dominant.
Cladocerans were also important when they bloomed in summer, and chironomid adults
when they swarmed in autumn. Selection coefficients indicated that those food types
which were dominant in the diet were actively selected and those that were unimportant
were avoided. This landlocked galaxiid was found to share most of the available food
resources with the other four fish species found in the lake, and can be broadly classified
as a euryphagic carnivore.
Salinity range and osmoregulatory ability of corixids (Hemiptera: Heteroptera) in south-east Australian inland waters
Authors: Knowles JN , Williams WD
Published: November 2005

The distribution of corixids in Victoria was investigated with respect to salinity. None was found above 13.4%,. Osmoregulatory studies on the two most saline-tolerant species, Sigara australis and Agragtocorixa hirtifrons, indicated that both can weakly hypo-osmoregulate near upper lethal salinity values.
The sand fauna of Lake Pedder: a unique example of colonization by the Phreatoicidea (Crustacea: Isopoda).
Authors: Bayly IAE
Published: November 2005

The larger invertebrates were quantitatively removed from a quadrat of sand 0.5 m² in area on the shore of Lake Pedder (Tasmania) shortly before it was artificially flooded. The numerically dominant animal was Colubotelson (Phreatoicidea). Phreatoicids have not been recorded from freshwater psammon elsewhere. Five species of nematode are recorded from Australia for the first time. Two of these are presently known only from the southern hemisphere.
Inshore surface sea temperatures at Townsville
Authors: Kenny R
Published: November 2005

Detailed inshore surface sea temperatures have not previously been available for the tropical Queensland coast. Recordings were made in Cleveland Bay (19� 15'S., 146� 50'E.) for four separate 1 year periods. A total of 212 readings is available. The maximum monthly mean temperature is 31.2� C in January and the minimum monthly mean is 21.8� C in July. The relationship between sea and air temperatures is discussed. The present data are compared with other available information.
Preliminary estimates of stocks of the king prawn, Penaeus plebejus, in south-east Queensland
Authors: Lucas C
Published: November 2005

Population estimates of the king prawn, Penaeus plebejus, in Moreton Bay and adjacent offshore areas are made from a study of commercial catches and by tag-recapture experiments. Juvenile prawns which are abundant in Moreton Bay during the summer months rapidly migrate to adjacent offshore areas and form the basis of an offshore fishery. Population parameters for Moreton Bay are F1 = 0.04, E1 = 0.17 and M1 ≤ 0.22 week-1. For the adjacent offshore area the parameters are F2 = 0.02, M2 = 0.05 week-1. These estimates indicate that of the order of 17% of the available stock is caught in Moreton Bay and that of the order of 26% of the available stock is caught in the offshore area off Mooloolaba. From a yield equation the response in catch to variations in fishing intensity is estimated.
The reproductive cycles and geographical distribution of some common eastern Australian prosobranchs (Mollusca: Gastropoda)
Authors: Underwood AJ
Published: November 2005

The taxonomic positions and Australian distributions of 10 common species of intertidal prosobranchs from eastern Australia were established from museum collections and published records. Patellanax peroni (Blainville), Subninella undulata (Solander) and Littorina unifasciata Gray have a southern distribution (from latitude 43� 30'S.) reaching as far north as 26� S., but not to the tropic of Capricorn. Austrocochlea constricta (Lamarck), Nerita atramentosa Reeve and Bembicium nanum (Lamarck) have the same southern limit as the former species but extend northwards to the tropic of Capricorn. Montfortula rugosa (Quoy & Gaimard) and Cellana tramoserica (Sowerby) extend further north to northern Queensland (17�S.). Nodilittorina pyramidalis (Quoy & Gaimard) and Morula marginalba Blainville have a northern distribution, occurring throughout the Pacific, and extend southwards to southern New South Wales (37� 30'S.). These four types of distribution are briefly discussed in relation to the Australian faunistic provinces. Monthly samples from March 1972 to May 1973 of the ovaries of the 10 species were fixed for examination by light microscopy. The numbers of immature and mature oocytes were recorded to establish the times and seasonal duration of gametogenesis, vitellogenesis and spawning. The time of spawning for most species was confirmed from the presence on the shore of egg capsules or newly settled juveniles. The external appearance of male and female gonads proved unreliable for estimation of the phases of reproductive cycle. The 10 species showed a wide variety of pattern and timing of reproductive cycle at one locality, which did not correlate with their overall geographical distributions, zonation pattern on the shore or phylogenetic relationships. The possible importance of seawater and air temperatures as stimuli for initiation and cessation of phases of the reproductive cycles is discussed. Some species are influenced by temperature changes. The spawning periods of N. pyramidalis, L. unifasciata, M. marginalba and B. nanum fell within the period of maximum availability of phytoplankton (August to March). All these species have long-term planktotrophic larvae. With the possible exception of Nerita atramentosa, which breeds during the same period as the previous species, all the other species are archaeogastropods with short-term lecithotrophic larvae, which are independent of the availability of phytoplankton food sources. Austrocochlea constricta breeds throughout the year, Patellanax peroni either from June to September or from February to May. Cellana tramoserica breeds from March to October and Subninella undulata and Montfortula rugosa from October/November to May. All of the archaeogastropods, especially Patellanax peroni, retain unshed mature oocytes from one year to the next. Nodilittorina pyramidalis, Littorina unifasciata, Bembicium nanum, Nerita atramentosa and Morula marginalba all show cytolysis and resorption of unshed oocytes.
Reconnaissance limnology of Sub-Antarctic islands. II. Additional features of the chemistry of Macquarie Island lakes and tarns
Authors: Buckney RT , Tyler PA
Published: November 2005

Further analyses of waters from lakes and tarns on Macquarie Island, including some not previously
sampled, confirm conclusions of an earlier survey. Oceanic spray is a principal source of ions.
Geochemical influence is minimal in most lakes, but Square Lake and Waterfall Lake contain considerably more calcium than others and the cationic dominance order is changed from that of seawater.
Skua Lake is similarly affected though calcium concentrations are not so markedly increased. Magnesium enrichment does not occur. Though calcium and bicarbonate accrue in approximately equivalent amounts, more lakes are deflected from seawater anionic dominance order than the three with changed cationic orders. Despite equivalent accession of calcium and bicarbonate, Square Lake and Waterfall Lake occupy anomalous positions on a plot of calcium proportions against Oceanic Origin Factor. Seasonal variation in chemical composition is slight, but is greatest in Waterfall Lake and least in the shallow Square Lake where perhaps buffering by sediments is involved. Atmospheric supply of oceanic ions is commonplace on Sub-Antarctic islands.
Spawning, development and distribution of the southern pigmy perch Nannoperca australis australis Gunther from inland waters in eastern Australia
Authors: Llewellyn LC
Published: November 2005

Southern pigmy perch were bred in ponds on three occasions when water temperatures rose above 21.0�C at the surface and 19.3�C at the bottom during the months of September and October. Flooding was found not to be necessary as a breeding stimulus. The requirements for breeding and the embryological development of eggs and larvae were followed closely. The eggs were demersal, transparent, spherical, telolecithal and essentially non-adhesive; possessed a cluster of oil globules; varied from 1.16 mm to 1.35 mm in diameter; and were scattered randomly during spawning. They hatched after between 2 days 18 hr and 3 days 7 hr at temperatures fluctuating between 15.8�C and 25.3�C. The length of the recently hatched larvae varied between 3.18 and 3.92 mm. The pro-larval stage terminated at 5 days 23 hr at temperatures between 15.8 and 23.7�C. The largest adult recorded at Narrandera was 63 mm in length and weighed 3.48 g. Marked colour difference occurred between the sexes as the breeding season approached, the males possessing bright red fins with black edges. Fecundity of the females varied from 506 eggs at 40 mm length and 0.86 g weight to 4217 eggs at 63 mm length and 3.49 g weight. The gonosomatic index rose to 11.4 and 4.7 in females and males respectively prior to breeding. Fish 6 months, 18 months and 30 months old from a pond reached 3.0, 3.8 and 4.7 cm respectively. Some taxonomic problems of the Nannopercidae are discussed and the distributions of the different forms given. The breeding of .Edelia vittata and Nannoperca australis australis are compared.
Seasonal dynamics and productivity of Tanytarsus barbitarsis Freeman (Diptera: Chironomidae) in the benthos of a shallow, saline lake
Authors: Paterson CG , Walker KF
Published: November 2005

The chironomid Tanytarsus barbitarsis is the only abundant benthic species in Lake Werowrap, western Victoria, a small, shallow, highly alkaline lake in which high, fluctuating salinities (c. 36-56 g/l) impose an extremely low biotic diversity. Between successive Octobers in 1969 and 1970, the chironomids passed through about seven generations, attaining numerical densities in excess of 140,000/m². Seasonal fluctuations in density were attributed to emergence, available food, and predation by a dytiscid, Necterosoma penicillatum, occurring in high densities around the rocky marginal areas of the lake. Estimated annual net production, exclusive of mortality and first and second instar biomass, amounted to about 320 kcal/m²/yr. This is perhaps the highest estimate recorded for an inland aquatic macrobenthos community; it is especially remarkable in that evidence from salinity tolerance experiments suggests that the lake is not an optimal environment for the species.
A revision of Australian species of Agraptocorixa Kirkaldy and Diaprepocoris Kirkaldy (Heteroptera: Corixidae)
Authors: Knowles JN
Published: November 2005

A taxonomic revision of the Australian species of Agraptocorixa Kirkaldy, 1898, and Diaprepocoris Kirkaldy, 1897, is given. Five Australian species of Agraptocorixa are recognized and three of Diaprepocoris, including D. pedderensis sp. nov. Keys are provided for species identification of adult males.
Zinc, cadmium, copper, and manganese in species of finfish and shellfish caught in the Derwent Estuary, Tasmania
Authors: Eustace IJ
Published: November 2005

Thirty-nine marine species, including members of the Teleostorni and Elasmobranchii, were obtained from the River Derwent and analysed for four heavy metals known to be accumulated by certain species, particularly molluscs. Of the muscle tissues from edible Teleostomi and Elasmobranchii all contained levels of zinc, cadmium, and copper well below the maximum levels permitted by current Tasmanian food regulations. Manganese levels were also low. Small species differences for zinc and copper levels in muscle tissue are evident among these finfish. These are probably attributable to differences in feeding habits. Comparison of the metal levels in these species with levels reported by various overseas workers indicate no abnormal accumulation of heavy metals in muscle tissues. With some minor exceptions no relationships existed between the tissue metal levels and length of the fish. Two edible species of molluscs, the native oyster and the common mussel, contained much higher levels of the four metals. For both species levels of zinc and cadmium exceeded the levels specified by the food regulations. The data presented indicate that the ability of molluscs to accumulate certain metals, particularly zinc and cadmium, to abnormally high levels is not shared by finfish species. The fact that elevated metal concentrations in seawater are not reflected in the muscle tissues of finfish means that the monitoring of commercial fish species caught in the River Derwent would provide a much less sensitive index of pollution than would the monitoring of oysters or mussels.
Home range, homing and dominance in juvenile western rock lobsters.
Authors: Chittleborough RG
Published: November 2005

Home ranges of juvenile western rock lobsters (Panulirus longipes cygnus George), measured on a relatively uncrowded reef over a period of one year, did not exceed a radius of 15 m. Tagged juveniles transferred to similar reefs seldom remained on the new sites. Some found their way back to the home reef (from distances of up to 400 m), while many dispersed at random, travelling up to 8.3 km in 9 weeks. Dominance for food is displayed amongst juveniles (aged 2-5 years), especially under crowded conditions. The significance of these behaviour patterns is discussed in relation to research and management problems.
Aspects of the population dynamics of the western rock lobster, Panulirus cygnus George. I. Estimation of population density
Authors: Morgan GR
Published: November 2005

Breakdowns in the assumptions made by the Jolly (1965) method of estimating population size were detected in mark-recapture experiments with the western rock lobster. Using information gathered from sampling by both baited traps and by diving it was shown that, in particular, the assumptions of (1) a single population and (2) equal probability of capture of marked and unmarked rock lobsters, were not valid at all times in the 'population' studied, and this resulted in underestimates of population density. However, it was found possible to make suitable corrections to the raw data to arrive at apparently unbiased estimates of population density. In the cases studied, the calculated unbiased estimates of population density agreed well with unbiased estimates calculated from information gathered by marking and recapturing by different methods. Single census and the De Lury (1958) methods also grossly underestimated population density.
Aspects of the population dynamics of the western rock lobster, Panulirus cygnus George. II. Seasonal changes in the catchability coefficient
Authors: Morgan GR
Published: November 2005

The catchability coefficient, q, of a population of the western rock lobster P. cygnus was calculated monthly from November 1969 to January 1973 using measurements of catch, effort, population density, and area of reef. The catchability coefficient varied significantly during this time and was positively correlated with water temperature and water salinity, and negatively correlated with the percentage of rock lobsters in a premoult condition. A linear combination of these three factors was highly correlated with the catchability coefficient (P < 0.001) and appears to offer a method of adjusting the catchability coefficient and so leading to an improved stock assessment for this species.
A new species of Labidocera (Copepoda: Calanoida) from Tasmania and its postnaupliar developmental stages
Authors: Taw N
Published: November 2005

A new species of genus Labidocera, L. tasmanica sp, nov., found in the south-east inshore coastal waters of Tasmania, is described and figured. Its postnaupliar developmental stages are described and figured from the samples collected in the northern parts of D'Entrecastreaux Channel, Tasmania.
The abundance and size composition of trawled juvenile snapper Chrysophrys unicolor (Quoy and Gaimard) from Cockburn Sound, Western Australia
Authors: Lenanton RCJ
Published: November 2005

The abundance and size composition of juvenile snapper Chrysophrys unicolor trawled from Cockburn Sound, W.A., over a 20 month period is presented. 0+ year old snapper were first taken by the gear in April/May at a mean size of between 8 and 9 cm L.C.F. They continued to be caught until the following January/February when they were 1+ years old, and a mean size of between 14 and 15 cm L.C.F., after which they disappeared from the catch. The peak months of abundance were April/May. This is the first description of growth of juvenile snapper from Western Australia.
Morphology and benthos of three volcanic lakes in the Mt. Gambier district, South Australia
Authors: Timms BV
Published: November 2005

Lakes Valley, Leake and Edward are medium sized (< 65 ha) maars, 16, 4.5 and 7 m deep respectively. Each has a low shoreline development and a high volume development. Valley Lake supports at least 24 benthic species, Leake 12 and Edward 17. Austrochiltonia spp., Hemicordulia tau, Antipodrilus davidis, Procladius villosimanus, Chironomus duplex and Chaoborus sp. occur, some abundantly, in each, and in addition Cryptochironomus ?curtivalva is abundant and Sphaerium sp. common in Valley Lake and in Edward Ablabesmyia ?notabilis and Tanytarsus paskevillensis are present. Many species live at all depths, but some, e.g. Chaoborus sp., are restricted to greater depths and others, e.g. Austrochiltonia spp., to the littoral and sublittoral zones. Mean weighted biomass during winter was 16.8 g/m² in Valley Lake, 23.3 g/m² in Lake Leake and 8.7 g/m² in Lake Edward. In Lakes Valley and Edward there was a marked sublittoral maximum in the distribution of biomass with depth. These high values are in accord with the large amounts of organic matter (32-51 %) in the substrates and suggest that each lake is eutrophic, Leake particularly so.
Stratification and biogenic meromixis in Tasmanian reservoirs
Authors: Tyler PA , Buckney RT
Published: November 2005

Part of the Mersey-Forth hydro-electric scheme, Tasmania, Lakes Rowallan and Barrington are oligotrophic, slightly humic, warm monomictic reservoirs. Their flooded vegetation, shelter and deep V-section lead to pronounced clinograde oxygen profiles despite meagre autochthonous production. With surprising rapidity, Lake Barrington developed a monomolimnetic pool which, when destroyed by severe floods, soon reformed. Though crenogenic and triptogenic elements may participate, principal causes of this partial meromixis are flooded vegetation and basin morphometry. The monimolimnion exhibits unusually large temperature rises and considerable enrichment of such chemical species as iron, manganese, hydrogen suiphide and bicarbonate. Iron is a major factor in the meromixis and largely accounts for marked monimolimnetic rises in electrical conductivity. The sharp upper monimolimnetic boundary is an almost horizontal chemocline, above which the mixolimnion behaves as a warm monomictic lake. Winter ventilation of its hypolimnion is tardy but complete. The monimolimnion is therefore maintained by decomposition and basin morphometry, not climate. Attendant chemical phenomena of prolonged anoxia in hypolimnetic or monimolimnetic water pose alleviable problems when that water is used domestically, industrially or for power generation.
Studies on the ecology of the zooplankton of four estuaries in Victoria
Authors: Neale IM , Bayly IAE
Published: November 2005

Results are presented of quantitative studies on plankton in the Yarra, Maribyrnong, Werribee and Patterson River estuaries during the period February-July 1971. The horizontal and temporal distribution and abundance of 13 species of calanoid and cyclopoid copepods and of 28 other taxonomic groups are recorded. Differences in the species composition and mean total standing crop are discussed in relation to the apparent hydrological nature of the estuaries and the modifying influence of man. Results obtained are compared with those of similar studies elsewhere. The mean standing crop over the four estuaries is shown to be lower than in several previous estuarine studies, but distinctly higher than in Port Phillip Bay, into which all four estuaries discharge. he occurrence of Australomedusa baylii from a true open estuarine system (the Werribee) is reported for the first time, and some aspects of its feeding are noted.
Seasonal succession of phytoplankton at a coastal station off Sydney
Authors: Jeffrey SW , Carpenter SM
Published: November 2005

The seasonal succession of marine phytoplankton at the Port Hacking 100 metre coastal station was studied using living algae. The spring (September) bloom began with small chain-forming diatoms, mainly Asterionella, Thalassiosira, Skeletonema, Nitzschia and Chaetoceros species. These were succeeded by larger centric diatoms, the most abundant of which were species of Ditylum, Leptocylindrus, Eucampia, Rhizosolenia and Melosira, together with the pennate genus Thalassiothrix. Coccolithophorids, microflagellates (probably mostly chrysomonads) and dinoflagellates showed a first minor pulse in September, and became established in October and November. During late summer and early autumn, when diatom numbers were very low, the phytoplankton consisted mainly of dinoflagellates, coccolithophorids and microflagellates. A pulse of cryptomonads and silicoflagellates occurred in March and April respectively. A second diatom flowering took place in the autumn (May), dominated by species of Leptocylindrus, Thalassiothrix, Rhizosolenia etc., which were different from those which initiated the spring (September) bloom. Clear succession patterns were evident, in principle very similar to successions observed in temperate coastal waters in other parts of the world. These patterns may correspond, not to gross mineral enrichments, but to specific vitamin interrelationships among the algae.
Distribution and abundance of soft-bottom molluscs in Port Phillip Bay, Victoria, Australia
Authors: Poore GCB , Rainer S
Published: November 2005

The distribution of soft-bottom molluscs of Port Phillip Bay, Vic., is examined in terms of abundance, the distribution of feeding types and patterns of diversity, and related to environmental variables such as depth and sediment type. Six feeding types were distinguished among the 105 species collected. Infaunal suspension feeders dominated in marginal sandy substrates while surface deposit feeders dominated in the silt and clay sediments of the Central region and Corio Bay. Epifaunal suspension feeders, grazers, scavengers and predators were less abundant and were seldom dominant. Numbers of individuals and species, and diversity, varied widely but were generally higher in marginal areas. Four areas of the Bay were recognized on the basis of similarities in distribution patterns, the distribution of species numbers, of diversity and of the dominant feeding type: the Nepean sand banks, the deep water Central and Corio regions, marginal areas, and the shallow seagrass sand flats. The main determinants of mollusc distributions were substrate and food supply, while purely hydrological effects were limited to nearshore areas. Regional differences in diversity were related to sample size by correlation and regression; low faunal density caused diversity in the Exchange region to be considerably underestimated.
The hydraulics of the South Australian gulf system. I. Circulation
Authors: Tronson K
Published: November 2005

The steady state circulation equations are shown to be a valid first approximation of the circulation within the South Australian gulf system. These equations are solved using two different methods to emphasize different features of the circulation. A tentative estimate is made of the time constant for water to be replaced in the northern half of Spencer Gulf.
Ocean currents measured concurrently on and off the Sydney area continental shelf
Authors: Cresswell GR
Published: November 2005

Recording current meters, a GEK, and XBT'S were used to study on and off-shelf currents for a 10 day period. Oscillatory currents with frequencies 3-8 cph were observed quite frequently at a mid-shelf mooring (depth 140 m). They were perhaps due to internal waves and were often associated with sudden increases or decreases in current speed. On two occasions the speed increases occurred when meteorological fronts passed over. The horizontal oscillatory velocity components of two of the best wave examples showed clear evidence for clockwise polarization. At the edge of the shelf (180 m), current meters 10 and 50 m above the bottom, while not showing internal waves, showed a current somewhat variable in speed (mean: 20 cm/sec; maximum 50 cm/sec), but reasonably constant in direction (northward) for the experiment duration. At this time the main southward flowing core of the East Australian Current was 120 km out from the edge of the shelf, while the region out to 50 km from the shelf contained variable surface currents. The current in the deeper water at the edge of the shelf was tentatively labelled a counter current.
Heavy metals in cultivated oysters (Crassostrea commercialis = Saccostrea cucullata) from estuaries of New South Wales
Authors: Mackay NJ , Williams RJ , Kacprzac JL , Kazacos MN , Collins AJ , Auty EH
Published: November 2005

Results of a survey of metal levels in the Sydney rock oyster Crassostrea commercialis are reported. Concentrations of copper, zinc, cadmium, lead and arsenic in oysters sampled from the 19 important production areas in New South Wales are generally low, and in terms of the National Health and Medical Research Council recommendations for these metals there is little or no health risk to consumers. Evidence is presented which indicates that metal concentrations decrease with increasing age and wet weight of oysters. In oysters sampled from a single estuary, there is a gradient of increasing metal concentration with increasing distance upstream from the sea. Pollution may be the cause of the relatively high concentrations in oysters from this estuary, but further work will be required to verify this. The variability of metal concentrations in oysters is discussed, and a sampling method is suggested for future monitoring of metals in this species.
The influence of sampling intensity on the 'catchability' of marron, Cherax tenuimanus (Smith) (Decapoda: Parastacidae)
Authors: Morrissy NM
Published: November 2005

Sampling intensity is considered as one of the three factors contributing to the 'catchability' of animals. Theoretically, variation in 'catchability' between individuals, due to differences in 'vulnerability' ('inherent catchability'), may be magnified when sampling units are set 'non-competitively', since all the animals over the sampled area will not be equally exposed to capture; less active animals, i.e. with a lower 'vulnerability' to capture, may also be less exposed to capture because of, for example, habitat heterogeneity with respect to shelter where units cannot be placed. A model was proposed to describe the operation of a baited net, or trap, used to catch bottom dwelling crayfish or lobsters. This model was extended to describe the different relationships between catch number per sampling unit and density of units for non-competitive, partially competitive, and competitive degrees of sampling intensity. The results of an experiment using a known population of marron, Cherax tenuimanus (Smith), were used to quantify the above relationship for the range of net densities possible in a semi-artificial pond. After eliminating bias due to a number of causes of variability in 'catchability', it was shown that the competitive degree of sampling intensity, as described by the extended model, had been achieved. Total catch numbers derived from the use of different net densities covering this degree of sampling intensity should not be expressed 'per net', as is done for non-competitive sampling, for comparison of relative numbers of animals. Instead catch number should be expressed in terms of the area sampled, since catch number is independent of the number of nets used on the area. Mean 'catchability' tended to be positively correlated with seasonal water temperature. Marked differences in 'vulnerability' to capture, due to size and moult stage, could be inferred to exist between individuals. Previous capture also influenced 'catchability'.
A method for estimating mortality rates from tag recoveries when fishing is not constant
Authors: Lucas C
Published: November 2005

Maximum likelihood estimates for rate of survival and the rate of exploitation from tag recoveries when fishing is not constant are represented. A numerical technique for maximizing the likelihood function is presented. In it, trial values of the death rate parameters are selected until a maximum, if one exists, is located. The variances of the estimates are obtained using the information matrix.
The influence of tidal cycles on the distributional pathway of Penaeus latisulcatus Kishinouye in Shark Bay, Western Australia
Authors: Penn JW
Published: November 2005

The means by which Penaeus latisulcatus larvae in Shark Bay migrate from the offshore spawning areas to the inshore nursery grounds have been studied. It is generally accepted that penaeid larvae move at random and are carried into the nursery areas by ocean currents, but this was found to be impossible in Shark Bay. where the general movement of water is against the required direction of migration. Examination of the tidal flow during the hours of darkness revealed a yearly cycle with flood and ebb flow dominating for alternate halves of the year. This nocturnal tidal cycle and the reduced rate of tidal flow with increasing depth is shown to interact with the vertical diurnal movements of the larvae to provide a mechanism by which larvae can be transported a greater distance inshore at night than offshore during the day for the period March-August. This inshore displacement provides a means by which larvae can be moved inshore against the general movement of water within the embayment. Also the nocturnal tidal cycle during the summer, when ebb flow dominates, is shown to assist the offshore migration of juveniles. The presence of a comparable yearly cycle at Port Lincoln on the South Australian coast seems to indicate that the mechanism is not an isolated occurrence.
Larvae of the commercial scallop, Pecten meridionalis from Tasmania, Australia
Authors: Dix TG , Sjardin MJ
Published: November 2005

After fertilization in the laboratory, eggs (diameter 71 �m) of Pecten meridionalis developed to straight hinge veligers with a smallest shell length of 93 �m after 3 days at 13-15� C. The larval shell developed umbones at about 160 �m, pediveligers occurred at 180 fim and larvae began crawling at metamorphosis when the shell length was 220-240 �m 31 days after fetilization. The larval shells grew almost isometrically, and length (I) and width (w) (in �m) were described closely by the G.M. regression :
w = 0.9901-18.660.
The life histories of many of the stoneflies (Plecoptera) of south-eastern mainland Australia
Authors: Hynes HBN , Hynes ME
Published: November 2005

Collections of stonefly nymphs and adults were made at monthly intervals in 11 streams in Victoria throughout a year, and these were supplemented by collections from other streams. By following seasonal changes in the size distribution of the nymphs, and the occurrence of adults and cast skins, and by determining the length of development of the eggs under simulated stream conditions, the life cycles of 27 species were worked out in detail, and some information was obtained on a further seven species. The 34 species include representatives of all the four families that occur in Australia, and for several species the cycle was worked out in two or more streams. It is concluded that the life cycles in Australian species are generally much less rigid than those found in the northern hemisphere, and that they provide evidence of great adaptability to an uncertain climate. Each species therefore tends to occupy a broader ecological niche than do northern hemisphere ones and this possibly accounts fcr the relatively small number of species that are found in south-eastern Australia.
Larval development of the tiger prawn, Penaeus esculentus Haswell, 1879 (Decapoda, Penaeidae), reared in the laboratory
Authors: Fielder DR , Greenwood JG , Ryall JC
Published: November 2005

The four naupliar, three zoeal, three mysis, and first post-larval stages of the tiger prawn Penaeus esculentus were cultured in the laboratory and generally completed development within 200-220 h. These stages are described and figured, gross characters of potential diagnostic value being tabulated.
Tagging experiments with western king prawn Penaeus latisculatus Kishinouye. I. Survival, growth, and reproduction of tagged prawns
Authors: Penn JW
Published: November 2005

Two tags for adult western king prawns, Penaeus latisulcatus, have been field tested in an unexploited king prawn population in Cockburn Sound, Western Australia. Both toggle and Atkin tags have been found to cause little physical damage to the prawns apart from limited scarring at the points of entry and through the musculature adjacent to the tag. Long-term survival of both toggle- and Atkin-tagged prawns did not differ significantly from that of the untagged population, but a variable amount of initial tagging mortality occurred during the first 72 h after release due to both handling and tagging. Mortality related to size or sex was not evident for the toggle tags, but for Atkin tags there was a tendency towards smaller prawns having a better survival. Growth of all tagged prawns was found to be retarded during the first month from release, but in subsequent months appeared to be faster than the average control animals. Although the growth of tagged prawns recaptured during the spawning season was retarded, normal ovary development occurred and some females spawned while tagged. Some of the problems in the use of tag recapture data from penaeid prawn stocks have been discussed.
Slender tuna (Allothunnus fallai Serventy): first record of bulk catches, Tasmania, 1974
Authors: Wolfe DC , Webb BF
Published: November 2005

Purse seine catches of 230 tonnes of slender tuna in Tasmania were made in June 1974. The species has heretofore been regarded as rare in Australian waters, and relatively uncommon elsewhere. Surface water temperatures during commercial fishing ranged from 12.0 to 14.0�C. Age estimations by otoliths suggested 4+ to 6+ years for lengths 69.0-91.0 cm. The length-weight relationship was
W = 0.000004SL3.322.
The tuna were feeding mainly on pelagic Crustacea. Gonad inspection showed that spawning had occurred recently. Three internal parasites (Anisakis sp., Copepoda, Cestoda) were found in 89.3, 95.7 and 61.7% of the 46 fish examined. Fish flesh was extremely oily (10-50%), and mercury analysis gave readings from 0.1 to 0.2 mg/kg.
Mercury in fish in the Derwent Estuary, Tasmania, and its relation to the position of the fish in the food chain
Authors: Ratkowsky DA , Dix TG , Wilson KC
Published: November 2005

Total mercury concentrations are reported for 258 individuals representing 16 species of finfish from the Derwent Estuary, Tasmania. Mercury concentrations in the muscle tissue varied between undetectable levels and a value of 2.0 mg/kg in one specimen of a species of shark. Irrespective of species, the area encompassing Ralphs Bay contained a higher percentage of fish with mercury concentrations in excess of the Tasmanian Food Regulation limit of 0.5 mg/kg than any other area of the Estuary. RaIphs Bay is the area in which oysters were found in a previous study to contain extraordinarily high concentrations of other heavy metals, particularly zinc, cadmium and copper. The fish's position in the food chain appeared to be an important factor determining its mercury content. Approximately 51 % of individual fish of species whose diet consists predominantly of other fish had mercury concentrations in excess of 0.5 mg/kg. In contrast, 24% of invertebrate predators and only 7 % of individuals of herbivorous habit had mercury concentrations in excess of 0.5 mg/kg.
Seasonal variations in lipid content of eels (Anguilla australis)
Authors: Hopkirk G , Wills RBH , Townsend PR
Published: November 2005

Changes in the lipid content of short finned eels (Anguilla australis schimidtii Phillips) obtained from Lake Ellesmere, New Zealand, were determined. The lipid content of yellow eels increased once they resumed feeding after their winter 'hibernation' with the most rapid increase being in the first few weeks. The lipid content of silver eels was found to gradually decline with time.
A surface plankton sampler for the larval stages of the western rock lobster.
Authors: Phillips BF , Rimmer DW
Published: November 2005

A net capable of catching the larval stages, including the puerulus of Panulirus longipes* (MilneEdwards) in the surface plankton is described. The sampler has a square 0.25 m2 mouth, an overall filtering length of 140 cm and a 10 cm diameter PVC cod-end bucket. Towed from a short boom from the side of a small boat or from a longer boom out from the side of a larger vessel, the sampler has a bridle attached to two opposite corners and a weight at the bottom corner so that in operation it presents a relatively unobstructed diamond shaped opening to the water. A total of 112 puerulus stage larvae were caught with this sampler (fitted with a 2.5 mm mesh net) during five nights of sampling within the reef at Seven Mile Beach. The greatest number of larvae were found to be present in the surface plankton prior to midnight. Modified versions of this sampler with either 2.5 mm or 1.0 mm mesh net have been successfully used to sample puerulus and phyllosoma stages of western rock lobster larvae in the surface waters off the west coast of Western Australia.
Fluctuations of year-class strength and recruitment in the western rock lobster Panulirus longipes (Milne-Edwards).
Authors: Chittleborough RG , Phillips BF
Published: November 2005

Settlement of puerulus larvae on collectors composed of artificial seaweed and measurements of density of young juveniles on 'nursery' reefs show wide fluctuations in year-class strength, recent settlement from the spawning crop of 1973-74 being particularly high. Owing to restricted holding capacity of the shallow 'nursery' reefs (mainly due to limited food supply), density-dependent mortality reduces most year-class strengths to similar levels by the time juveniles reach 5 years of age. Particularly weak year-classes have been shown to be associated with poor catches from the coastal 'white' fishery at the opening of a fishing season. The applications of these findings to the management of the fishery are discussed. In theory, part of the wastage resulting from excess settlement of larvae in certain areas might be saved by transplanting to less crowded reefs or by mass-rearing in ponds, without diminishing recruitment from those left on the now overstocked reefs.
Observations on behaviour of the fish Meiacanthus nigrolineatus Smith-Vaniz (Blenniidae) in nature (Red Sea) and in captivity
Authors: Fishelson L
Published: November 2005

Meiacanthus nigrolineatus Smith-Vaniz is a nemophininae blenny, living sedentarily around the shallow-water corals of the Red Sea. Unlike intertidal blennies, individuals of this species feed and perform various types of behaviour in the open water above their rocky retreats or, as adults, above their territories. In this paper various types of behaviour are analysed.
Evidence of the South Tropical Counter-Current in the Coral Sea
Authors: Donguy JR , Henin C
Published: November 2005

In the Coral Sea, the mean dynamic topography of the sea surface indicates virtually zonal circulation with one westward flow and two eastward flows at 163� E. and two westward flows and one eastward flow at 158� E. One of the eastward flows may be defined as the South Tropical Counter-Current and its position suggests it originates in the western Coral Sea rather than north of New Guinea. However, the data of the abnormal years 1958 and 1972 point out only westward flow.
Effect of nocturnal illumination on catches of the puerulus larvae of the western rock lobster by collectors composed of artifical seaweed
Authors: Phillips BF
Published: November 2005

A method of illuminating collectors composed of artificial seaweed, and field experiments with them are described. Nocturnal illumination of the collectors resulted in increased catches of the puerulus larvae of the western rock lobster Panulivus longipes* (Milne-Edwards) by these collectors.