bluuebunny/crossref_metadata_2025 huggingface dataset:
Ontogenetic changes in the natural diet of the sandy shore crab, Matuta lunaris (Forskål) (Brachyura : Calappidae)
Authors: Perez OS , Bellwood DR
Published: November 2005

During June and July, 1984, the ontogenetic changes in the composition of the natural diet of M. lunaris from Pallarenda beach, Townsville, Australia, were investigated by analyses of foregut contents using the percentage occurrence and percentage point methods. M. lunaris was found to be a predator of small crustaceans and molluscs and a facultative scavenger. There were marked changes in the composition of its diet during ontogeny: small individuals fed primarily on small crustaceans such as sergestids and copepods; large individuals fed primarily on anomurans and gastropods. The possible influence of ontogenetic changes in chelae function upon the diet is discussed.
Seasonal and spatial variations in benthic macroinvertebrate communities of Magela Creek, Northern Territory
Authors: Outridge PM
Published: November 2005

This study examined seasonal and spatial patterns of benthic macroinvertebrate communities in four billabongs and a perennial stream riffle in the Magela Creek catchment, Northern Territory. Chironomids, coleopterans, trichopterans and hydracarina were the most diverse and abundant taxa, although the mussel Velesunio angasi contributed over 98% of total standing crop in most billabongs. Diversity and standing crop were usually higher in littoral than in profundal areas of two shallow billabongs, probably because of the presence of macrophytes. Diversity, abundance and biomass declined sharply over the dry season, from maxima in May-July to minima in December. Recovery in the early wet season was rapid, commencing after the first creek flows in December. The decline and recovery were closely associated with the availability of sediment organic matter, which reflected inputs of mainly allochthonous (terrestrial) detritus over the wet season followed by losses due to intense microbial breakdown. Microbial respiration also seemed related to declines in benthic communities in the latter half of the wet season, by producing hypolimnetic anoxia during periods of reduced creek flow.
Water quality variations during a flood event in the Annan River, North Queensland.
Authors: Hart BT , Day G , Sharp-Paul A , Beer T
Published: November 2005

Variations in water quality (conductivity, pH, suspended solids, Na, K, Ca, Mg, Cl, SO4, HCO3 and Si) during a major flood event that occurred in the Annan River, north Queensland, on 21 March 1985 are reported. Factor analysis showed that dilution of base flow concentrations by surface runoff was the dominant influence during the rising stage of the flood event, possibly with some flushing of ions from the surface layers of the catchment soils also occurring. At low river flow, the water quality was dominated by that in ground water and possibly interflow. Heavy metals were mostly transported in particulate forms (Fe 99%; Mn 95%; Pb, Zn, Sn c. 80%; Cu c. 60%). Filterable metal concentrations were low and changed little with flow.
Currents off south-eastern Australia: results from the Australian coastal experiment
Authors: Huyer A , Smith RL , Stabeno PJ , Church JA , White NJ
Published: November 2005

The Australian Coastal Experiment was conducted off the east coast of New South Wales between September 1983 and March 1984. The experiment was conducted with arrays of current meters spanning the continental margin at three latitudes (37.5�, 34.5�, and 33.0�S.), additional shelf moorings at 29� and 42�S. coastal wind and sea-level measurements, monthly conductivity-temperature-depth probe/expendable bathythermograph (CTD/XBT) surveys, and two satellite-tracked buoys. Over the continental shelf and slope, the alongshore component of the current generally exceeded the onshore component, and the subtidal (<0.6 cpd, cycles per day) current variability greatly exceeded the mean flow. Part of the current variability was associated with two separate warm-core eddies that approached the coast, causing strong (>50 cm sec-1), persistent (>8 days), southward currents over the continental slope and outer shelf. Temperature and geostrophic velocity sections through the eddies, maps of ship's drift vectors and temperature contours at 250 m, and the satellite-tracked drifter trajectories showed that these eddies were similar in structure to those observed previously in the East Australian Current region. Both eddies migrated generally southward. Eddy currents over the shelf and slope were rare at Cape Howe (37.5�S.), more common near Sydney (34.5�S.), and frequent at Newcastle (33.0�S.), where strong northward currents were also observed. Near Sydney, the eddy currents over the slope turned clockwise with depth between 280 and 740 m, suggesting net downwelling there. Repeated CTD sections also indicated onshore transport and downwelling at shallower levels; presumably, upwelling occurred farther south where the eddy currents turned offshore. Periodic rotary currents over the continental slope near Sydney and Newcastle indicated the presence of small cyclonic eddies on the flank of a much larger anticyclonic eddy. Between early October and late January, no strong southward currents were observed over the continental margin near Sydney. Data from this 'eddy-free' period were analysed further to examine the structure and variability of the coastal currents. Much of this variability was correlated with fluctuations in coastal sea-level (at zero lag) and with the wind stress (at various lags). The coherence and phase relationships among current, wind-stress, and sea-level records at different latitudes (determined from spectral analysis and frequency-domain empirical orthogonal functions) were consistent with the equatorward propagation of coastal-trapped waves generated by winds in phase with those near Cape Howe. Time-domain empirical orthogonal functions show that the current fluctuations decayed with distance from shore and with depth, as expected of coastal-trapped waves.
Microsporidiosis in prawns from Northern Australia
Authors: Owens L , Glazebrook JS
Published: November 2005

Two hundred thousand prawns from northern Australia were examined grossly for microsporidiosis. Ameson sp. was found infecting Penaeus semisulcatus, P. merguiensis and P. esculentus at low prevalence levels (<0.1%) across northern Australia. Thelohania sp, infected P. latisulcatus, P. longistylus and P. semisulcatus on the Great Barrier Reef, again at low prevalence levels (<0.1%). Histological attempts to find subclinical infections were unsuccessful. Ameson sp. infected the striated muscle bundles throughout the body, whereas Thelohania sp. infected mainly connective tissue, most organs and peripheral muscle bundles. Microsporidiosis is of concern, because it has been diagnosed from all areas where brood-stock females are collected for use in mariculture.
Genetic structure of barramundi (Lates calcarifer) stocks from northern Australia
Authors: Salini J , Shaklee JB
Published: November 2005

Barramundi, L. calcarifer, were collected from seven localities in the Northern Territory, the Daly, Finniss, Mary, Glyde, Roper and McArthur rivers and Blue Mud Bay, and from the Ord River in Western Australia. Barramundi were sampled seven times from the Daly and Finniss rivers over a 14-month period. In total, 46 loci were identified using starch-gel electrophoresis of enzymes and polyacrylamide electrophoresis of muscle proteins. Twelve loci were polymorphic at the P0.99 level. Most loci were in Hardy-Weinberg equilibrium. A contingency Χ2 analysis for homogeneity of alleles over all loci and all localities was highly significant (P < 0.001). Comparisons of data from adjacent pairs of localities revealed that the overall heterogeneity was attributable to heterogeneity among seven of the eight localities; the Daly and Finniss river areas were not significantly different from one another. No evidence of heterogeneity over time was found among the collections from the Daly River area. The considerable amount of heterogeneity observed suggests that each of these seven localities supports a genetically discrete stock of barramundi; this conclusion is consistent with the documented life history of Australian barramundi. The genetic heterogeneity of the stocks should be considered when management policies for L. calcarifer are being formulated.
Measuring abundance of juvenile abalone, Haliotis rubra Leach (Gastropoda : Haliotidae); Comparison of a novel method with two other methods
Authors: McShane PE , Smith MG
Published: November 2005

An underwater venturi-suction sampler is described, suitable for sampling fauna on structurally-complex sublittoral reefs. Abundance of juvenile Haliotis rubra was estimated from the samples collected with the suction sampler; this was compared with estimates obtained at the same time by two other methods, an anaesthetic method and a searching method. Off Sandpatch Point (south-eastern Australia) during January 1987, the mean number (s.e.) of H. rubra per square metre of substrate was 68.7 (s.e., 39.2) by the suction method, 25.6 (s.e., 16.1) by the anaesthetic method and 7.7 (s.e., 3.0) by the searching method. Off Cape Schanck, the respective numbers were 1.3 (s.e., 0.5), 1.2 (s.e., 0.5) and nil. Juveniles found in the population off Sandpatch Point were of a size range (430-1020 �m) consistent with recent settlement of H. rubra. The suction method has three main advantages over the other two methods: unlike the anaesthetic technique it is not destructive and is not restricted to removable substrate; it is readily applied to most reef substrata by one diver spending relatively little time under water; and the sampler is sufficiently powerful to remove all juvenile abalone from the reef surface.
Effects of hydrological change and the cessation of stocking on a stream population of Salmo trutta L
Authors: Davies PE , Sloane RD , Andrew J
Published: November 2005

The North Esk-St Patricks river system, northern Tasmania, was electrofished at 27 sites in 1985, 30 years after the same sites had been electrofished in a previous study on the survival of released brown trout. All sites were dominated by brown trout, Salmo trutta L. Before 1955, stocking of brown trout fry and yearlings had been heavy. Stocking ceased after 1956 and few releases were made to 1985. At all but 4 sites, the number and total biomass of brown trout were higher in 1985 than in 1955. The estimated total population of brown trout had increased by 63%, accompanied by a 55% increase in the number of fish of legal size (>22 cm). Previously described 'nursery streams' still maintained high densities of 0+ fish, despite considerable changes in the age composition at other sites. Little or no change had occurred in riparian habitat at 23 of 27 sites. Change in year-class strength was highly correlated with change in total annual river flow in the natal year. This is explained in terms of mortality in 'nursery streams' during periods of low river flow. At 19 sites out of 21, changes in age composition were related to relative changes in year-class strength due to interannual variability in river flow. Four sites where major changes in riparian habitat occurred exhibited decreased brown trout biomass but still showed changes in age structure due to variation in annual flow. Mean annual river flow had increased by three times since the 1950s and this was attributed to a doubling in the proportion of cleared land in the catchments. Effects of changes in river hydrology on the trout population are discussed. Growth of S. trutta was essentially independent of density. The number of anglers, total effort and the total harvest in 1985/86-1986/87 were significantly higher than in 1945/46-1953/54. A shift toward higher catch per season per angler was observed in 1985/86-1986/87 compared to the 1945/46- 1953/54 seasons, but catch per day had not changed. Total annual mortality remained at 70%. The effects of increased mean flow and interannual flow variability on the brown trout population of the North Esk river system are discussed.
Demography of Australian bass, Macquaria novemaculeata (Perciformes, Percichthyidae), in the Sydney Basin
Authors: Harris JH
Published: November 2005

A mark-recapture experiment showed Australian bass to be sparsely distributed through sheltered parts of their habitat, but no significant differences in population density among major habitat categories were detected by catch-per-effort analyses. Total mortality, estimated from the catch curve, was low (Z = 0.28). Tabular and graphical calculations of annual production in a lagoon resulted in similar low estimates (0.84 g m-2 year-1), and a strikingly low P/B (annual production/biomass) ratio (0.19) results from the bass' catadromous life history. Populations of bass in the Sydney Basin showed declining recruitment, distribution restricted by impoundments, and increasing mortality attributable to exploitation and habitat damage during the period 1977-82. Estimates of initial cohort abundance indicated that recruitment and subsequent year-class strength are positively related to the level of flooding in the spawning months, but flooding is suppressed by dams. Population declines and continuing environmental degradation give cause for concern over the status of bass populations.
Reproductive studies on Patiriella gunnii (Asteroidea : Asterinidae) in south-western Australia
Authors: Grice AJ , Lethbridge RC
Published: November 2005

Sea-star radius, gonadosomatic and pyloric indices, oocyte diameters and sperm development in Patiriella gunnii from intertidal rock platforfis near Fremantle, Western Australia, were monitored between November 1983 and June 1985. The reproductive events in male and female sea-stars were closely synchronized, and pyloric and gonadosomatic indices were inversely related. Both sexes exhibited a sharp peak in gonadosomatic indices (GSI) in March and April 1984, and in March 1985. GSI values declined to low levels in May and June, followed by a slow recuperation in females thereafter. Small and large maturing oocytes occurred together in the ovaries of females exceeding 13-15 mm radius between November 1983/April 1984 and November 1984/March 1985. Large mature oocytes were apparently shed in toto between March and May in each of the two successive breeding seasons. These data suggest that P. gunnii spawns in the late Southern Hemisphere summer through early autumn. Highly motile spermatozoa were usually present in males exceeding 11 mm in radius from at least January through to June. Large maturing oocytes were rarely observed in females less than 13 mm in radius. The pattern of reproductive events in P. gunnii is compared with that of other Patiriella species.
Recruitment patterns of scleractinian corals: a study of three reefs
Authors: Harriott VJ , Fisk DA
Published: November 2005

Racks of settlement plates were placed in forereef and backreef sites at three reefs offshore from Cairns (Green, Michaelmas and Upolo Reefs) during winter 1985, summer 1985/86, and winter 1986. Over 2200 spat were recorded on the summer plates, while 61 and 220 spat were found on the winter plates in the two years. Acroporid spat were generally dominant on summer plates, except for Upolo Reef where pocilloporid spat were the most abundant at all times of year. Most spat settling in winter at all reefs were of the family Pocilloporidae. Summer spat settlement showed significant variation in numbers between reefs and between forereef and backreef sites on each reef, with the greatest number on backreef sites. Highest recruitment was at Green Island reef despite the relatively depauperate adult fauna on that reef; this suggests that inter-reef dispersal may be the dominant factor in determining the number of recruits. Hypothesized dispersal paths of coral planulae in the region are derived from data on post- spawning oceanographic conditions, and testable predictions are made for future recruitment patterns in this reef set.
Age and growth of two commercially imported sharks (Carcharhinus tilstoni and C. sorrah) from Northern Australia
Authors: Davenport S , Stevens JD
Published: November 2005

The age and growth of Carcharhinus tilstoni and C. sorrah, the two most abundant shark species in commercial gill-net catches off northern Australia, were investigated by the examination of vertebral rings. Corroborating evidence for age and growth estimates was obtained from length-frequency distributions and tag-recapture data. To aid validation of these estimates, tetracycline was injected into sharks at the time of tagging. Growth is relatively rapid in the first year of life: vertebral ageing indicated 17 cm growth in total length (TL) for C. tilstoni and about 20 cm for C. sorrah during the first year after birth. By the time the sharks are 5 years old, growth has declined to 8-10 cm per year in C. tilsoni and 5 cm per year or less in C. sorrah. The von Bertalanffy growth parameters for C. tilstoni are L∞ = 194.2, K = 0.14, t0 = -2.8 for females, and L∞ = 165.4, K = 0.19, t0 = -2.6 for males; for C. sorrah the parameters are L∞ = 123.9, K = 0.34, t0 = -1.9 for females, and L∞ = 98.4, K = 1.17, t0 = -0.6 for males. The greatest recorded ages for C. tilstoni were 12 years for females and 8 years for males, and for C. sorrah, 7 years for females and 5 years for males. Sexual maturity is reached early: at 3 to 4 years in C. tilstoni and 2 to 3 years in female C. sorrah.
Behavioural responses of Polinices incei (Gastopoda : Naticidae) to diesel oil contamination in sediments
Authors: Chapman HF , Kitching RL , Hughes JM
Published: November 2005

The effects of diesel oil on burying and crawling behaviour in the intertidal gastropod Polinices incei are presented. Burying was examined by recording the number of animals buried after exposure to pollutant for 30 min and 24 h. Crawling activity was estimated by measuring the total length of track left in the sediment by a given number of snails over a set time. Both activities were reduced in the presence of diesel oil. Concentrations required to produce a significant response in terms of burial after 30 min and of crawling activity were greater than the 96-h LD50. Only the burying response after 24 h paralleled the 96-h LD50; its potential as an indicator of lethal effects is discussed.
Estimates of age and growth of ocean perch, Helicolenus percoides Richardson, in south-eastern Australian waters
Authors: Withell AF , Wankowski JW
Published: November 2005

Methods of age determination, age and the parameters of the von Bertalanffy growth function are described for ocean perch, Helicolenus percoides Richardson, from the continental slope in eastern Bass Strait. Comparison of scales and otoliths revealed the latter to be superior for age estimation. Annuli were used for age determination; 97% of whole otoliths with 2-15 annuli were readable, compared with only 37% of older (15 + annuli) otoliths. Of sectioned otoliths with 15 + annuli, 81% were readable and the oldest age estimated was 42 ( �3) years, compared with only c. 30 years from whole otoliths. For whole otoliths, the precision of intra-reader and inter-reader age estimates was, respectively, 89% and 79% within �1 annulus, and the average error was 4.6% and 5.0%. For sectioned otoliths, intra- and inter-reader precision was, respectively, 60% and 53% within k 1 annulus and the average error was 3.9% and 5.4%. Comparison of age estimates from whole otoliths and sectioned otoliths gave a precision of 84% within �1 annulus and average error of 2.8%. Precision of age determination decreased with increasing age for both methods. Age validation, using Petersen's length-frequency method and a marginal-increment method, was unsuccessful. Mean length-at-age and the values for the parameters of the von Bertalanffy growth function were estimated. For female and immature fish: K = 0.107 and L∞ = 44.68 fork length (cm), and for male and immature fish: K = 0.115 and L∞ = 43.19 fork length (cm). The growth of males and females was statistically different.
An analysis of two methods of fitting the von Bertalanffy curve to capture-recapture data
Authors: Maller RA , deBoer ES
Published: November 2005

The asymptotic inconsistency of the Fabens method of fitting the von Bertalanffy curve to capture- recapture data is proved under reasonably realistic assumptions on the growth of an animal, in the case of constant recapture intervals. The bias and inconsistency can be large, as is demonstrated by some simulations, and the unreliability of the estimates is also demonstrated by application to two data sets on the western rock lobster. A modified method proposed by Kirkwood and Somers suffers from the same deficiencies. It is concluded that, in general, neither method is trustworthy and a new method is required.
Diet and burrowing habits of the freshwater crayfish, Parastacoides tasmanicus tasmanicus Clark (Decapoda : Parastacidae)
Authors: Growns IO , Richardson AMM
Published: November 2005

Parastacoides tasmanicus tasmanicus, which burrows extensively into the peat soils of south-western Tasmania, is, like most freshwater crayfish, an omnivore. All food categories in the diet vary seasonally. Detritus, including unidentifiable material, is the major food type present in the gut contents, although root and algal material are also important. Less animal material is present in the diet than in the diet of open-water species, and the taxa consumed and size of prey differ between the adults and juveniles. Cannibalism occurred in less than 1% of the crayfish examined, an incidence considerably lower than that reported for any other crayfish species. Animal material was of comparatively little importance, but the low levels of mineral nutrients, bacteria and fungi in peat soils probably increase its importance as a protein source. The burrows of P. t. tasmanicus include blind, root-lined chambers beneath clumps of sedgeland plants. Larger animals occupy larger burrows and these have a higher proportion of their volume in the form of blind chambers. The animal appears to spend the majority of its time foraging within its burrow system, a behaviour that contrasts with most other crayfish.
Growth in the Australian freshwater crayfish, Cherax destructor Clark, under laboratory conditions
Authors: Geddes MC , Mills BJ , Walker KF
Published: November 2005

Small (0.08 to 6.1 g) crayfish were grown at 26�C under three treatments: held individually and fed 3% or 10% of body weight per day, or held communally and fed the higher ration. Moult increments, expressed as length or weight increment (%), were smaller and intermoult periods were longer in the crayfish held communally or, particularly, in crayfish fed low rations; this resulted in lower growth in these treatments. Crayfish from three geographically discrete populations held individually and fed the higher ration showed relationships between log moult increment in weight and log premoult weight; further, the length of the intermoult period increased with size for these populations. Models for average growth showed that C. destructor may grow from 0.1 g to 40 g in approximately 230 days. Growth may have been suppressed in the culture system because of the size of containers, the entirely artificial diet and the variable water quality.
Physical oceanography of the Exmouth Plateau region, north-western Australia
Authors: Holloway PE
Published: November 2005

This paper provides an introduction to the physical oceanography of the Exmouth Plateau, a shallow
region situated 250 km offshore of north-western Australia at latitude 20�s. Information is derived
from a 3-month intensive current-meter monitoring program run during Spring (August-October) 1978.
The currents, during the survey, are strongly influenced by semi-diurnal barotropic and baroclinic tidal
currents. Inertial period (35.2 h) currents are pronounced and strongest in the thermocline region.
Mean flow patterns are moderate in strength, highly variable in space and are poorly correlated to the
local winds. The observations are also marked by the intermittent presence of short-period (30 min)
baroclinic currents of substantial energy.
Nitrogen cycling in salt-marsh and mangrove sediments at Western Port, Victoria
Authors: Boon PI , Cain S
Published: November 2005

The metabolism of organic nitrogen compounds in sediments from salt-marsh (Sarcocornia quinqueflora) and mangrove (Avicennia marina) areas at Western Port, Victoria, was investigated. Organic nitrogen compounds were metabolized at potential rates of up to 3.9 �mol cmF3 day-1 for amino acids, 23 �mol cm-3 day-( for dipeptides, and 5 �mol cm-1 day-1 for an amide. These were higher than the rate of ammonium regeneration in the absence of added substrate (<0.08 �mol cm-3 day-1); this indicates that organic nitrogenous compounds play a major role in nutrient cycling in coastal sediments. Rates of some transformations were highly correlated with sediment organic-matter content, total nitrogen content or concentration of soluble reactive phosphorus in the sediments, but overall there were few significant correlations between metabolic rates and edaphic conditions. Degradation of organic nitrogenous compounds in these sediments is likely to be influenced strongly by the availability of phosphorus, the quantity and quality of detrital inputs, and the size and activity of microbial populations.
Diet of little penguins, Eudyptula minor, from Penguin Island, Western Australia
Authors: Klomp NI , Wooller RD
Published: November 2005

Between March 1986 and March 1987, the stomach contents of 236 little penguins on Penguin Island, Western Australia, were obtained using an emetic. The 1392 prey items identified included 16 fish species, one squid and one prawn, but four fishes comprised most of the birds' diet. Hyperlophus vittatus was taken throughout the year, Sardinops neopilchardus and Hyporhamphus melanochir mainly in winter and Spratelloides robustus during spring/summer. The penguins are largely opportunistic in their foraging and their diet appears to be similar to the fish species caught locally by commercial bait fishermen.
Reproductive cycles of the bivalve molluscs Anadara trapezia (Deshayes), Venerupis crenata Lamarck and Anomia descripta Iredale in the Sydney region
Authors: Hadfield AJ , Anderson DT
Published: November 2005

The female cycle of each species was described from gross gonad appearance, and quantitatively from oocyte counts. Males were assessed from external appearance and histological classification of the gonad. The timing of the male cycle is similar to that of the female in each species, Spawning in A. trapezia and A. descripta is associated with times of maximum phytoplankton availability. A. trapezia breeds during the summer when water temperatures are high; regeneration of the gonad takes place during winter and spring after a resting phase. A. descripta has two spawning peaks, a minor in summer and a major in autumn; regeneration of the gonad occurs from winter to late summer. V. crenata has a prolonged breeding season, with ripe animals occurring throughout the year, although activity decreases during the winter months; regeneration and maturation appear to occur cqntinuously with po resting phase. These reproductive patterns are discussed in the light of factors controlling reproduction in other bivalve species and strategies of other mollusc groups from the Sydney region.
Nutrient and gilvin levels in waters of coastal-plain wetlands in an agricultural area of Western Australia
Authors: Wrigley TJ , Chambers JM , McComb AJ
Published: November 2005

The Peel-Harvey catchment lies on a sandy coastal plain, largely cleared for agriculture, and drains into a eutrophic estuarine system. Sixty-eight wetlands in the catchment had total phosphorus concentrations of 0.4-7.8 mg I-1, the high values being atrributed to agricultural activity. Conductivity was 150-8770 �S cm-1, pH 4.1-9.3. Waters contained high concentrations of gilvin, up to 262 g440 m-1 with a mean ratio of 6.2. Particulate material contributed little to light absorption at lower wavelengths (400-450 nm) but governed absorbance at 600-700 nm. Wetlands with the largest concen- trations of gilvin were located in the grey Bassendean sands, leachates from which had gilvin levels up to 748 g440 m-1. NO phytoplankton blooms were observed, and it is suggested that high gilvin levels and the consequent reduction in light penetration are important in maintaining low phytoplankton biomass in these lakes.
Decapod Crustaceans of the North West Shelf, a Tropical Continental Shelf of North-western Australia
Authors: Ward T , Rainer SF
Published: November 2005

The North West Shelf is a tropical continental shelf with a highly diverse fauna of epibenthic decapod crustaceans. The 357 taxa of epibenthic crustaceans, including 308 decapods, recorded from four sites are more than reported from any other continental shelf. The dominant taxa were amphipods, portunid crabs, xanthid crabs, palaemonid shrimps, hermit crabs, crangonid shrimps, sergestid shrimps, and majid crabs, in decreasing order of abundance. The most diverse family was the leucosiid crabs, containing 39 species. The number of crustacean species collected was similar at both 40 m and 80 m depth, and only 35% of the most common species differed in abundance between the depths. The abundances of 30% of these common species appeared to be related to particle size of the sediment or to the biomass of large sedentary fauna. The abundance of 45% of the most abundant, mainly small, species differed between two sampling times 6 months apart. The abundance of many decapod crustacean species was related to depth, sediment type, bottom type, or sedentary fauna. It is concluded that the epibenthic decapod fauna at 40 and 80 m depth on the North West Shelf is a broadly distributed assemblage with high diversity, some environmentally determined pattern and, in smaller animals, significant seasonal variability.
Acute Cardio-respiratory responses of Spangled Perch, Leiopotherapon unicolor (Gunther 1859), to Sublethal concentrations of Zinc, Temephos and 2,4-D
Authors: Gehrke PC
Published: November 2005

Spangled perch, Leiopotherapon unicolor, were exposed to concentrations of 5.0, 10 or 20 mg 1-1 zinc, 0.1, 1.0 or 10 mg 1-1 temephos or 0.1, 1.0 or 10 mg 1-1 2,4-D at 25�C for 2 h, during which time ventilation rate, heart rate and oxygen consumption were continuously monitored. Fish exposed to 10 and 20 mg 1-1 zinc demonstrated a significant increase in ventilation rate; those exposed to 20 mg 1-1 also developed a significant bradycardia. Exposure to 10 mg 1-1 temephos caused an immediate reduction in ventilation rate and oxygen consumption, and also reduced heart rate during the second hour of exposure. Fish exposed to 10 mg 1-1 temephos died within 12 h. Responses of fish to 2,4-D gave no indication of toxic effects on the cardio-respiratory system. Cardio-respiratory responses to zinc are attributed to damage caused to the gill epithelium, which results in impaired gas exchange and lowered oxygen tension in arterial blood. Effects of exposure to temephos correspond to cholinesterase inhibition in nerves supplying the respiratory musculature and the heart.
Vertical distribution of Benthic Invertebrates in the Bed of the Thomson River, Victoria
Authors: Marchant R
Published: November 2005

The vertical distribution of the benthic fauna was studied at three sites on the Thomson River using a freeze-corer. Samples were taken over two years in early and late summer. At each site an average of 72 to 84% of the fauna was found in the 0-10 cm zone of the riverbed, 10-20% in the 10-20 cm zone and 6-8% in the 20-30 cm zone; flooding at one site was followed by an increase in the depth to which the fauna penetrated. Surface percentage abundances were probably underestimated because of the inability of the corer to sample surface rocks and their fauna consistently and because the coring operation disturbs the surface fauna to some extent before it can be frozen. Nevertheless, the results indicate that in the Thomson River the majority of the fauna is within the depth range (0-10 cm) of a Surber sampler.
Life histories of some Benthic invetebrates form streams of the Northern Jarrah Forest, Western Australia
Authors: Bunn SE
Published: November 2005

Life history patterns of thirteen species of invertebrates from streams of the northern jarrah forest were examined over a 1-year period. Five species had univoltine cycles with a single cohort and demonstrated a high degree of synchrony of larval development and a restricted period of adult emergence. Two species of Leptophlebiidae also had univoltine cycles but showed the more typical pattern of Australian mayflies, with extended recruitment, multiple overlapping cohorts and a long period of adult emergence. Uroctena sp., a small gammarid, had a generation time of 1 year but showed considerable spatial variation in the degree of synchrony of development. This appeared to be a result of differences in the constancy of stream discharge and was not attributable to differences in the temperature regime of the streams. At least three species demonstrated cohort splitting which resulted in an apparently bivoltine cycle. A life-history pattern of alternating long and short development times is described which, on average, would produce two generations every 3 years. This is considered to be a highly adaptive strategy for Australian stream insects with slow life cycles and can explain the extended periods of recruitment and adult emergence so often observed. Streams of the northern jarrah forest are depauperate compared with other Australian streams, despite predictable temperature and discharge regimes. The insular nature of the south-west Bassian region and its long period of isolation may be the principle cause of this reduced diversity. The invertebrate community of these streams is simple in structure and has a high degree of seasonality that is atypical of the temperate streams of Australia and New Zealand.
Optical properties, Nutrients and Phytoplankton of freshwater Coastal Dune Lakes in South-east Queensland
Authors: Bowling LC
Published: November 2005

Gilvin was the main attenuator of photosynthetically available radiation (PAR) in 26 freshwater coastal dune lakes, despite most being only slightly humic (range 0.000-27.866 m-1, median = 1.088 m-1). Most were also non-turbid [range 0.27-3.00 nephelometric turbidity units (NTU), median = 0.77 NTU] and had low concentrations of chlorophyll a (range 0.212-15.869 �g I-1, median = 3.285 �g I-1). Accordingly there was only slight to moderate attenuation of PAR in most lakes, the majority having mean downwelling vertical attenuation coefficients of less than 1.0 m-1. However, Secchi depths indicate that the lake waters were more transparent during this study than previously reported in the literature. The lakes were typically oligotrophic, acidic, and of low conductivity. Desmids and Peridinium spp. dominated the phytoplankton, although Dynobryon cylindricum Imhof. and various Chlorococcales were also common.
Mitochondrial DNA restriction site variation in Tasmanian populations of Orange Roughy (Hoplostethus atlanticus), a deep-water marine teleost
Authors: Ovenden JR , Smolenski AJ , White RWG
Published: November 2005

The orange roughy, Hoplostethus atlanticus, forms the basis of an important trawl fishery in Australia and New Zealand which is currently being over-exploited. To gain information about the stock structure of an Australian orange roughy population, ten restriction enzymes were used to survey the restriction- site variation in the mitochondrial genome of 23 individuals collected from the east coast and 26 individuals collected from the west coast of Tasmania. The mean diversity between all 49 genomes was a low 0.19%. Of the eleven haplotypes identified, only one was present in both the east and west coast samples. Four haplotypes were found only in the east coast sample and six were found only in the west coast sample. Eight haplotypes were related to the haplotype found on both coasts by the gain or loss of one restriction site. One haplotype collected in the east coast sample was related to one other east coast haplotype by one site change. One haplotype collected from the west coast was related to a west coast haplotype by one site change. If this pattern is confirmed by further mitochondrial DNA studies, it could be inferred that gene flow between the orange roughy populations on the east and west coasts of Tasmania is low.
Limnology of four groundwater-fed saline lakes in South-sestern Australia
Authors: Burke CM , Knott B
Published: November 2005

Salinity, temperature, dissolved oxygen (DO), pH and total alkalinity (TA) were measured in four saline
lakes of Yalgorup National Park, Western Australia, primarily over an 18-month period, July 1985 to
January 1987, but also during 1987 and in 1988. These lakes are shallow (<3 m) ground-water sinks
with no surface drainage. Rainfall and hence ground-water inflow to the lakes was highly seasonal and
occurred mainly between May and October. Lakes Hayward, North Newnham and South Newnham
were consistently hypersaline (e.g. Hayward 61-214 g L-1) and Hayward and North Newnham were
stratified from autumn to early summer. The bottom layer of water in Hayward was usually supersaturated
(to 430%) with respect to DO, because of the photosynthetic activity of the benthic microbial
communities (BMC). South Newnham did not stratify in 1985, but did so briefly in 1987 after a BMC
developed. The salinity of Lake Pollard varied from 19 to 51 g L-1 and the lake did not stratify
at all. During spring, extensive growth of the charophyte Lamprothamnium papulosum across the
sediments in Lake Pollard increased DO (from c. 100% to c. 140% saturation) and pH (from c. 8.5
to c. lo), but lowered specific TA (from 0.26 to 0.075 meq L-1 per unit salinity); later removal of
the L. papulosum by swans reduced DO to 50% saturation and pH to 7.5, and increased specific
TA to 0.15 meq L-1 per unit salinity. It is apparent that the processes controlling Hayward, North
Newnham and South Newnham are similar and are based on the activities of the BMC. South Newnham
is at an earlier stage of evolution. However, Pollard is controlled primarily by L. papulosum growth
and its subsequent removal by swans; this indicates a different evolutionary path for this lake.
Timing and location of spawning of Blue Grenadier, Macruronus novaezelandiae (Teleostei: Merlucciidae), In Australian Coastal Waters
Authors: Gunn JS , Bruce BD , Furlani DM , Thresher RE , Blaber SJM
Published: November 2005

The geographical distribution and ages of larvae of the blue grenadier, Macruronus novaezelandiae, based on ichthyoplankton surveys in southern Australian waters in 1984 and 1985, indicate that the species spawns primarily off the west coast of Tasmania in winter, and may spawn on a lunar cycle. Winter spawning off Tasmania is also suggested by adult gonad morphology: gonado-somatic indices peaked in winter, and mature and spent individuals were collected off the west coast of Tasmania. Small numbers of larval blue grenadier were also collected off north-eastern Tasmania, suggesting the occurrence of small-scale and sporadic spawning in that area. The date of first spawning differed by a month between 1984 and 1985, and was apparently related to broad-scale interannual differences in the oceanography of southern Australian waters. Use of oceanographic features to retrocast spawning dates for blue grenadier suggests that shifts in the date of first spawning of approximately one month are common in this species.
Continental shelf currents near the Abrolhos Islands, Western Australia
Authors: Cresswell GR , Boland FM , Peterson JL , Wells GS
Published: November 2005

Recording current meters were used to identify features of the circulation of the continental shelf near the Abrolhos Islands and Rottnest Island in 1973-75. In summer, from November to March, there was a mean northward drift of 0.1 m s-1; in winter, from April to August, the mean flow was southward at 0.2 m s-1, possibly due to the spread of the Leeuwin Current onto the shelf. In all seasons, the current records had superimposed upon them a variability with period from days to weeks. The several- day period variability in the along shore currents had peaks of up to 0.5 m s-1 and was strongly correlated with sea level and with phase-lagged alongshore wind at the nearby port of Geraldton. In summer, strong southerly wind events associated with the eastward passage of highs produced sea-level troughs and northward current pulses. In winter, northwesterly storms from lows passing over Cape Leeuwin produced sea-level crests and southward current pulses. Satellite drifter tracks confirmed the summer and winter behaviour revealed by the current meter records and, further, showed that the winter behaviour extended north of the Abrolhos Islands to 26�S.
Reproduction and feeding in the abalone Haliotis roei gray
Authors: Wells FE , Keesing JK
Published: November 2005

H. roei has a short period of intense spawning in July and August, followed by low levels of spawning until December. A few ripe animals are present throughout the year. Males were more common than females in a sample made at Waterman, Western Australia. The animals begin to mature at about 40 mm, but have few gametes at this size. Females of the maximum known size of 122 mm produce an estimated 8.6 million eggs. H. roei is herbivorous, feeding on a variety of macroalgae present in the drift. Algae consumed varied seasonally and between platforms. Volumes of gut contents were greatest in winter, corresponding with the time of maximum food availability.
Serious mortality in populations of giant clams on reefs surrounding Lizard Island, Great Barrier Reef
Authors: Alder J , Braley R
Published: November 2005

A survey of giant clams (family Tridacnidae) at Lizard Island fringing reefs on the Great Barrier Reef in July 1985 indicated that over the previous 6 weeks the combined total mortality for Tridacna gigas and T. derasa was 28% at Watson's Bay (WB) and 20% at the channel between Palfrey Island and South Island (P-S). Sporadic mortalities continued at intervals through to December 1985 when combined total mortalities at WB and P-S had reached 38% and 32%, respectively. By January 1987, mortality for these two species was 54% at WB and 51% at P-S. Deaths were not restricted to a particular size class and the average size of clams that died did not change with time during the study. Mortality rates for clams which had been previously biopsied for gonad condition and/or those induced to spawn with serotonin injection were not significantly different from controls. Distribution of dead clams was random to slightly clumped with respect to alive and dead clams within WB, and random within P-S. Results of heavy-metal analyses of tissues from moribund clams were similar to previous results for normal clams. The histopathology of tissues from six of eight moribund clams revealed an unidentified unicellular organism which was not found in Tridacna spp. from previous or subsequent samples from Lizard Island reefs or from other reef areas.
Age, growth estimates for pink ling, Genypterus blacodes (Schneider), and gemfish, Rexea solandri (Cuvier), from Eastern Bass Strait, Australia
Authors: Withell AF , Wankowski JWJ
Published: November 2005

Age and growth were estimated from counts of otolith annuli for pink ling (Genypterus blacodes) and gemfish (Rexea solandri). Sections of otoliths were preferable for age determinations of pink ling, whereas whole otoliths were preferable for gemfish. Validation of the assigned age classes was not achieved. Petersen's length-frequency method was unsuccessful and marginal increment methods were unsuitable for the species studied. Growth of males and females did not differ significantly for either pink ling or gemfish. Both species had a relatively slow growth rate, had a moderately long life-span and could reach body lengths in excess of 1 m. Maximum ages of pink ling and gemfish were, respectively, 21 and 13 years. Mean length-at-age and the von Bertalanffy growth functions were estimated. For pink ling (all individuals combined), K = 0.095 and L∞ = 135.5 cm. For gemfish the best estimates were K = 0.153 and L∞ = 112.3 cm. Precision of age determinations made independently by two readers for pink ling and gemfish, respectively, was 65% and 95% within �1 annulus; average per cent error, respectively, was 4.7% and 3.1%. Paired t-tests on ages assigned to each species by the two readers indicated no significant difference between ages assigned to gemfish, but there was a significant, albeit unbiased, difference for ages assigned to pink ling. However, for pink ling, estimates of the growth parameters derived separately from age determinations by the two readers were virtually identical.
Salinity tolerance of the eggs and larvae of the Australian grayling, Prototroctes maraena Gnnther (Salmoniformes : Prototroctidae)
Authors: Bacher GL , O'Brien TA
Published: November 2005

Eggs of the Australian grayling Prototroctes maraena were fertilized in the laboratory and the survival of eggs and larvae was investigated in salinities ranging from <0.1 to 30 g L-1. In salinities of <0.1, 5, 10 and 15 g L-1, most (81-90%) eggs survived to hatching; in salinities of 20, 25 and 30 g L-1, all eggs died. In salinities of <0.1 and 5 g L-1, all eggs that survived developed normally and the larvae survived for 21 d. In a salinity of 10 g L-1, all eggs that survived developed normally but the larvae were inactive and died within 6 h. In a salinity of 15 g L-1, many larvae were unable to emerge completely from the egg, were grossly deformed and died within 1 h of hatching. Newly hatched larvae were buoyant, positively phototropic and swam actively near the water surface. They survived in salinities ranging from <0.1 to 30 g L-1 for 21 d, at which time yolk absorption was complete. Death was probably the result of starvation.
Feeding in a Nocturnally active fish, Galaxias brevipinnis, in a New Zealand stream
Authors: Glova GJ , Sagar PM
Published: November 2005

To determine the diel feeding periodicity and diet of a lake-inlet population of Galaxias brevipinnis in New Zealand, samples of benthos, drift and fish were collected over a 24-h period in summer. Both numerically and gravimetrically, fish stomach contents revealed that feeding started some time after sunset, peaked towards midnight, and virtually ceased after sunrise. Benthic invertebrates were consumed almost exclusively, with ephemeropterans, trichopterans, and dipterans constituting 95% of the total foods eaten, a major proportion being chironomid larvae. Size of prey eaten compared with size of invertebrates in the benthos differed significantly during the night; this indicated that some size-selective feeding occurred. The benthic feeding habit of Galaxias brevipinnis appears to allow it to forage on relatively small prey during the night, a phenomenon that has been reported for other bottom-dwelling native fish species in New Zealand.
Applications of intervention analysis to model the impact of drought and bushfires of Water Quality
Authors: Welsh DR , Stewart DB
Published: November 2005

Intervention analysis is a rigorous statistical modelling technique used to measure the effect of a shift in the mean level of a time series, caused by an intervention. A general formulation of an intervention model is applied to water-quality data for two streams in north-eastern Victoria, measuring the effect of drought on the electrical conductivity of one stream, and the effect of bushfires on the flow and turbidity of the other. The nature of the intervention is revealed using exploratory data-analysis techniques, such as smoothing and boxplots, on the time-series data. Intervention analysis is then used to confirm the identified changes and estimate their magnitude. The increased level of electrical conductivity due to drought is determined by three techniques of estimation and the results compared. The best of these techniques is then used to model changes in stream flow and turbidity following bushfires in the catchment.