bluuebunny/crossref_metadata_2025 huggingface dataset:
An organic Geochemical analysis of Terrestrial biomarkers in a transect of the Great Barrier Reef Lagoon
Authors: Currie BR , Johns RB
Published: November 2005

Organic geochemical analyses of benthic sediments from a Northern Queensland coastal transect indicate that most terrestrial organic material is confined to near-shore sediments (<10 km offshore). Traces of higher plant material reach the inner fringes of the Great Barrier Reef, as indicated by the presence of pentacyclic triterpenoid alcohols (PTA) in near-reef sediments. A likely source of these alcohols is mangroves. PTA and long-chain normal alkanes appear to be the most reliable of the lipid biomarker classes analysed in assessing the distribution of terrestrial organic matter along the transect. Other terrestrial biomarker classes (sterols, normal fatty acids and fatty alcohols) present in the sediment do not show good correlation with distance from the land. This is believed to be due to the additional input of these biomarkers from planktonic sources.
Relationships between habitat characteristics and population abundance for Brown Trout, Salmo trutta L., and Blackfish, Gadopsis marmoratus Rich., in Tasmanian streams
Authors: Davies PE
Published: November 2005

Habitat relationships are described for Salmo trutta L, and Gadopsis marmoratus Rich. in Tasmanian streams. Multiple linear regression models were developed relating population abundance with habitat attributes for G. marmoratus but models describing a significant proportion of the variation in abundance of S. trutta could only be developed for streams of low hydrological variability. The derived model for S. trutta abundance (kg ha-1) was tested against data from sites affected by a variety of impacts. Interrelationships between habitat attributes are described in relation to hydrological variability and bank erosion. Problems associated with the development of models relating habitat attributes and fish abundance are discussed in the light of the effects of hydrological variability.
First records of Net-winged Midges (Diptera: Blephariceridae) from Papua New Guinea, with description of a new species
Authors: Zwick P , Hortle KG
Published: November 2005

Curupirina papuana sp. n. and an unnamed species of a probably new genus of Apistomyiini (Diptera : Blephariceridae) are described from the Ok Tedi, a tributary of the Fly River, Papua New Guinea. This is the first report of the family from the island; its zoogeographical significance is discussed with reference to the long-presumed role of the island in the evolution and dispersal of the tribe Apistomyiini.
Taxonomy and distribution of Shallow-water Lagenid Foraminiferida from the South-eastern coast of Australia
Authors: Albani AD , Yassini I
Published: November 2005

The taxonomy of 65 species of unilocular Foraminifera from 12 locations along the central and southern coast of New South Wales and in Bass Strait is discussed and all species illustrated. Thirty new species are described. A morphological key for the identified genera is also presented. Brief notes are added on their occurrence and distribution.
Seasonal dynamics of production, and nutrient accumulation and cycling by Phragmites asutralis (Cav.) Trin. ex Stuedel in a nutrient-enriched swamp in Inland Australia. II. Individual Shoots
Authors: Hocking P.J.
Published: November 2005

The seasonal dynamics of the growth of shoots of Pragmites australis, and the partitioning of dry matter and 12 mineral nutrients between shoot organs, were studied in a stand in a nutrient-enriched swamp in inland Australia. The stem accumulated over 75% of the total-shoot dry matter, the inflorescence less than 5%. About 26% of the shoot dry matter was redistributed to below-ground organs during senescence. K and N were the most concentrated macronutrients in shoots, followed by Cl>> Ca > S > P > Mg > Na. Micronutrient concentrations were in the order Mn > Fe >> Zn > Cu. Concentrations of most nutrients and total amino compounds were higher in leaves than stems. Concentrations of N, P and K were highest in young shoots and decreased throughout the season, whereas concentrations of Ca, Cl, Fe, Mn and Na increased during the life of the shoot. There were gradients of concentration of some nutrients in the stem and leaves from the base to the top of the shoot. The top of the shoot had the highest concentrations of nutrients. Ca and Mn accumulated mainly in the large leaves from the middle of the shoot. The stem contained the major proportion of the quantity of most nutrients in living shoots; however, leaves had over 55% of the total shoot content of N, Ca and Mn. The inflorescence usually had less than 10% of the quantity of a nutrient in the shoot, but had over 20% of the N and 32% of the P in the shoot. N, P and K were redistributed from senescing shoots to below-ground organs with over 60% efficiency, and S, Mg, Zn and Cu with between 17 and 38% efficiency. There was negligible redistribution of Ca, C1, Na, Fe or Mn from either leaves or stems. Nutrients were redistributed to a greater extent from leaves than from stems. There were leaching losses of some nutrients from exposed senescing shoots, especially with K, C1 and Na. Nutrients were leached more readily from leaves than from stems. Leaching losses of N were low (c. 5%). Shoots from part of the reed-bed burnt the previous winter were smaller, had fewer leaves, and had lower concentrations of most nutrients than those from the unburnt part of the reed-bed.
Phenology of the Cladophora-Stigeoclonium community in Two Urban Creeks of Melbourne
Authors: Entwisle TJ
Published: November 2005

Cladophora glomerata and Stigeoclonium tenue dominate lowland urban creeks in the Yarra River basin of south-central Victoria. In Darebin and Merri Creeks, Cladophora produces extensive mats in summer and autumn, and is mostly replaced by Stigeoclonium in winter and spring. Although Stigeoclonium can grow all year round, it only outcompetes Cladophora in winter and spring, when air temperatures range between a maximum of < 15� C and a nightly minimum of < 10� C (water temperature < 15� C, usually about 10� C). The seasonal composition and abundance of these macroalgae depend on temperature and on the severity of, and time since, the last floods, and the effect that these factors have on interspecific competition. Features of the microhabitat (e.g. photon irradiance, substratum stability and composition, and mean flow rates) determine the range of these variations. The biomass of both macroalgae fluctuates widely; this is due mainly to floods, which can remove almost the entire standing crop. In off-seasons, both species are maintained by small resilient plants or protected populations (in culture, plants remain viable after up to 6 months in complete darkness). Filaments of Cladophora readily produce zoospores and new vegetative growth following dormancy. The prostrate thallus of Stigeoclonium initiates new erect filaments before zoospores are produced. An understanding of the large local and seasonal variations in macroalgal biomass is essential for biological monitoring programmes.
Population genetics of two tropical sharks, Carcharhinus tilstoni and C. sorrah, in Northern Australia
Authors: Lavery S , Shaklee JB
Published: November 2005

The genetic structure of the Australian populations of Carcharhinus tilstoni and C. sorrah was investigated by starch gel electrophoresis. Tissue samples were taken from 1580 sharks from throughout the fishery, which extends from the North-West Shelf (off Western Australia) to the north-eastern coast of Queensland. From a total of 47 enzyme loci screened in each species, 13 proved to be polymorphic (P0.99) for at least one species, with only 5 loci for each species showing sufficient variation (P0.95) to be of use in the analysis of population structure. Mean heterozygosity values were relatively low: 0.037 for C. tilstoni and 0.035 for C. sorrah. A low level of population subdivision was found within each species, with FST values of 0.0094 for C. tilstoni and 0.0076 for C. sorrah. There was insufficient evidence to suggest that there is more than one population of either species of shark in Australian waters.
Effect of physical factors on the vertical distribution of Phytoplankton in Eutrophic Coastal waters
Authors: Gabric AJ , Parslow J
Published: November 2005

A new analytical model for the vertical distribution of phytoplankton in shallow, turbid waters is presented. The effects of vertical mixing, light-attenuated growth and algal-cell sinking rates are included. The two cases of a finite-depth water column and a mixed layer are investigated. The results for negatively buoyant cells suggest that concentration maxima can occur above the sea bed for either strong or weak mixing in a mixed layer but are always at the bed in finite-depth waters. Large-celled species with high sinking rates are least sustainable in stable water columns, especially a weakly mixed, mixed layer. Conversely, cell sinking rates have little effect on net growth rate when mixing is strong in finite-depth waters. The effect of turbidity on net growth is accentuated under weakly mixed conditions. Comparison with field data shows quite good agreement with the model predictions and underlines the fact that simple analytical tools are often quite adequate when dealing with a sparse experimental data base.
The freshwater Mussel, Westralunio carteri Iredale, as a Biological monitor of Organochlorine Pesticides
Authors: Storey AW , Edward DHD
Published: November 2005

The freshwater mussel Westralunio carteri was tested as a biomonitor of the organochlorine pesticides dieldrin, DDE, DDD and DDT. The mussel survived handling, transportation and being caged, and demonstrated significant bioaccumulation of the pesticides. Total DDT analogues at one site reached a maximum of 0.48 mg kg-1 wet whole tissue after 112 days and at a second site accumulated to 1.23 mg kg-1 wet whole tissue after 66 days. It is suggested that observed reductions in levels of bioaccumulated residues by aestivating mussels in an intermittent stream were the result of preferential utilization of stored lipids and release of associated pesticides.
Optical properties of Gas-vacuolate cells and colonies of Microcystis in relation to light Attenuation in a Turbid, Stratified Reservoir (Mount Bold Reservoir, South Australia)
Authors: Ganf GG , Oliver RL , Walsby AE
Published: November 2005

Profiles of downwelling and upwelling irradiance were measured in a stratified, turbid reservoir, when Microcystis aeruginosa formed a significant proportion of the phytoplankton community. The attenuation coefficient (Kd) was c. 2.1 m-1 and the reflectance (R) c. 0.03. Application of Kirk's simulation model relating apparent and inherent optical properties enabled calculation of coefficients of absorption (a; 1.3-1.6 m-') and scattering (6; 5-7 m-1). The asymptotic diffuse backscattering coefficient (0.2 m-1) was derived from the relationship b′b = 3.6 RaKd, a slight modification of Kirk's original equation. Turbidity measurements supported the general rule that nephelometric turbidity was numerically equivalent to the scattering coefficient. There was good agreement between the measured light profile and one reconstructed from inherent optical properties using the relationship between Kd, a and b. The optical properties of cells and colonies of Microcystis were investigated before and after the collapse of gas vacuoles. The Chla-specific absorption coefficient for cells (0.0138 m2 mg,-1 Chla) was higher than for colonies (0.0106 m2 mg,-1 Chla) at a depth equivalent to 0.2 m. Both coefficients decreased with increasing depth as the spectral composition changed. The Chla-specific scattering coefficient for vacuolate cells (0.14 m2 mg,-1 Chla) was greater than for colonies (0.11 m2 mg,-1 Chla), and a similar correspondence occurred for non-vacuolate cells and colonies (0.029 and 0.020 m2 mg,-1 Chla respectively). These measurements illustrate the package effect and also that c. 80% of light scattering is due to gas vacuoles. The relationship between pressure-sensitive turbidity and gas-vacuole volume suggested that 1 gL mL-1 was equivalent to a turbidity of 2 NTU. These optical characteristics, combined with the buoyant nature of Microcystis, suggest that it is a canopy species.
Nutrient concentration-Flow relationships and loads in the South Pine River, South-eastern Queensland. I. Phosphorus loads
Authors: Coser PR
Published: November 2005

Total P (TP), particulate P (PP), and total dissolved P (TDP) were monitored over 24 months in the South Pine River, south-eastern Queensland. The sampling interval ranged from 13-16 days during baseflow to less than 30 min duling stormflow. Baseflow TP concentrations were relatively constant at 0.03 mg L-1. During stormflow, concentrations of both TDP and PP increased significantly and were positively correlated with flow. TP loads were 8950 kg (56.7 kg km-2 year-1) and 3980 kg (25.2 kg-1 year-1) in 1984 and 1985 respectively. Annual load was influenced by both the absolute discharge volume and the relative proportion of stormflow. PP was the dominant P fraction, comprising 77% of the TP load. Approximately 86, 89 and 75% of the TP, PP and TDP loads, respectively, were carried in only 2.8% of the time (20 days) during three major storms (50.8% of total flow). Concentrations and exports were high relative to those reported in other Australian studies, suggesting that climatic factors, particularly rainfall intensity, are important in determining export. As a result of the variability in unit area export attributable to variations in runoff, unit area export coefficients are of negligible use for predictive purposes. However, by expressing load in terms of mass per unit runoff per unit area (kg mm-1 km-2), variance attributable to discharge is removed. When expressed in this form, stormflow export was relatively constant (0.46-0.54 kg mm-1 km-2). A method of predicting load from the flow record using this coefficient is proposed.
Mucus-secreting Glands in the Paragnaths and second Maxillipeds of the Banana Prawn, Penaeus merguiensis de Man
Authors: McKenzie LJ , Alexander CG
Published: November 2005

Glands are abundant in the paragnaths and distal endopod segments of the second maxillipeds of Penaeus merguiensis. Seven gland types have been identified and their secretions differentiated into acidic sulfated mucopolysaccharides and carboxylated mucopolysaccharides. In the paragnaths secretions are discharged through groups of pores on the oral and aboral surfaces, and in the second maxillipeds through a dense row of pores on the aboral surface at the propodus-dactylus articulation. Glands are not sexually dimorphic and glandular morphology does not change during the moult cycle. Glandular products probably have a role in feeding by lubricating large particles and entangling particulate matter in mucus.
Differences in growth rates between habitats of South-east Australian snapper (Chrysophrys auratus)
Authors: Francis RICC , Winstanley RH
Published: November 2005

Data on recaptured fish from two tagging experiments on south-east Australian snapper, Chrysophrys auratus, were analysed: 198 fish released in several Victorian locations between 1956 and 1962, and 118 fish released in Port Phillip Bay in 1971 and 1972. Movement data from both experiments were used to classify the fish into habitats (oceanic and bay) and stocks (western and eastern). Length increment data from the earlier experiment indicate that the major growth-rate differences in south-east Australian snapper lie within the western stock (between oceanic and bay habitats) rather than between stocks as suggested by an earlier analysis of the same data. The annual growth rates of 20-30-cm snapper in Port Phillip Bay and Western Port are 17-20% higher than for fish in the ocean. Oceanic growth rates in the western stock appear to be lower than those in the eastern stock. Procedural differences in length measurements at tagging and recapture can introduce a net bias in the length increment that, if ignored (as is conventional in tagging growth models), will bias growth rate estimates. In the earlier tagging experiment, this is shown to have caused a 10% positive bias in growth rate estimates.
Notes on the Biology of the Portunid Crab, Portunus sanguinolentus (Herbst), in Subtropical Queensland Waters
Authors: Sumpton WD , Smith GS , Potter MA
Published: November 2005

Trawl-caught Portunus sanguinolentus were more abundant in oceanic than estuarine waters in south- east Queensland. In samples, males outnumbered females by 1.7 : 1. Males attained a larger size than females and, for a given carapace width, weighed more than females. The smallest sexually mature male and female crabs had carapace widths of 83 and 74 mm respectively. Crabs recruited to the sampled population throughout most of the year except during winter, when moulting activity was also limited. April-May was a major mating period, and it is postulated that mature female crabs moved into deeper oceanic water to spawn.
Taxonomic Revision of the Family Pseudomugilidae (Order Atheriniformes)
Authors: Saeed B , Ivantsoff W , Allen GR
Published: November 2005

The genus Pseudomugil is revised and compared with its nominal sister groups. Popondichthys and Kiunga. which were previously placed within the family Melanotaeniidae . Pseudomugil, as a result of this study. is considered to belong to a distinct Old World atherinoid family. Pseudomugilidae. having two subfamilies. Pseudomugilinae and Kiunginae. with 13 species included in the first and 1 in the second . A key for and a full description of all the presently known species and their phenetic relationships are presented . P. helodes is no longer recognized as a member of the family Pseudo- mugilidae and is placed into the family of sailfin silversides, Telmatherinidae .
Partitioning of material discarded from Prawn Trawlers in Morton Bay
Authors: Wassenberg TJ , Hill BJ
Published: November 2005

Prawn trawlers in Moreton Bay, Queensland, discard about 3000 t of material each year. About 3% floats, and the rest sinks. The floating component is almost entirely fish. At night, floating discards are eaten by silver gulls (Larus novaehollandiae), crested terns (Sterna bergii) and, to a lesser extent, dolphins (Tursiops truncatus). There is little trawling during the day but the last discards are dumped overboard around dawn. At this time cormorants (Phalacrocorax varius) join the scavengers. Birds and dolphins scavenged only fish and cephalopods, and not crustaceans nor echinoderms. Birds are selective as to the size of fish they will eat, but most of the whole fish in the discards are below 50 g, and the largest fish that crested terns ate was 100 g. Dolphins are capable of taking the largest of the discarded fish. Most of the material that sinks is crustaceans (54%) and echinoderms (18%); the rest is elasmo- branchs and rubble. At night, about half of the fish that sink are eaten by diving birds and by dolphins. There was no indication of mid-water scavenging of sinking discards, except for cormorants and dolphins in the upper water column. Approximately 11% of the discards that reach the bottom comprise fish and crustaceans, which are eaten by crabs (Portunus pelagicus) and fish. The remainder- chiefly crabs, echinoderms and elasmobranchs-reach the bottom alive. Altogether, about 20% of discards are eaten by surface and bottom scavengers. Discards are probably important in maintaining populations of the major scavengers.
By-catch of the Prawn Fishery of Torres Strait; Composition and Partitioning of the discards into components that float of sink
Authors: Harris AN , Poiner IR
Published: November 2005

The quantity and composition of the by-catch from commercial prawn trawling in Torres Strait, Australia, were assessed from the results of seven trawl surveys and the fishery effort from log-book records, over 2 years. The total weight of by-catch caught in the fishery was estimated at 6930 t (�900 t) in 1985 and 4630 t (�710 t) in 1986. A wide range of marine organisms including cephalo- pods, crabs, rock lobsters, scallops, sharks, rays, snakes and turtles were caught, but teleost fishes were the largest component: 5520 t (�970 t) in 1985 and 2910 t (�510 t) in 1986. Nemipteridae and Synodontidae, the main teleost families, made up 15% and 13% of the teleost catch by weight, respectively. Apart from small quantities of shovel-nose lobsters (Thenus orientalis), rock lobsters (Panulirus ornatus) and squid, all the by-catch (approximately 99%) was discarded. There was little change in the composition of the fish by-catch between the 2 years but there was a noticeable change in the fish : prawn ratio from 5.1 : 1 in 1985 to 3.3 : 1 in 1986. Samples of the Torres Strait trawl by-catch from trawl surveys in 1988 were used to estimate the component of the by-catch which floated (available to surface predators) and that which sank (available to mid-water and demersal predators and scavengers). Most of the discards sank (-70%) but an estimated 40% of the teleost catch (1200-2200 t) floated. Of the teleosts, over 75% of the Apogonidae, Nemipteridae, and Monacanthidae floated, whereas all Synodontidae, Mullidae and Bothidae sank. Although for five fish families there was a difference in the proportion that floated when shallow water (= < 25 m) trawls were compared with deeper water (26-55 m) trawls, this did not affect the estimates of by-catch that floated or sank.
Fate of discards from Prawn Trawlers in Torres Strait
Authors: Hill BJ , Wassenberg TJ
Published: November 2005

A study was made of the fate of teleosts, non-commercial crustaceans and cephalopods discarded from trawlers in Torres Strait. These groups make up about 80% of the discards by weight, have a high mortality rate and are therefore the most likely animals to be eaten by scavengers. The remaining 20% of discards consists of animals such as turtles, sharks, bivalves and sponges, which are caught in low numbers and appear to have a low mortality from trawling. Fish made up 78%, non-commerical crustaceans 18%, and cephalopods 3% by weight of the material studied. Nearly all fish were dead when discarded, and about half sank. About half of the non-commercial crustaceans were alive when discarded and all sank when discarded. Few cephalopods (2%) were alive when discarded, and around 75% sank. Sharks and dolphins were the most common scavengers of floating discards at night. Birds (common and crested terns, and lesser and greater frigates) scavenged only during the day. Discards that sank did so rapidly, taking less than 5 min to reach 25 m depth. A high rate of loss of baits set for 10 min in the water column (24% in trawled area at night) indicated significant scavenging in mid- water-probably by sharks. Observations of baits set on the bottom showed that teleosts (nemipterids) and sharks ate most of the material that reached the bottom; scavenging by invertebrates was negligible. In an adjacent area that had not been trawled for 8 years, no dolphins and fewer birds were seen scavenging floating discards but there were more sharks. In this area, significantly fewer fish were attracted to a bait on the bottom at night compared with the trawled area. The cause of the difference in scavenging observed between the two areas is not known; while it may reflect learned behaviour by some scavengers such as birds and dolphins, there may also be intrinsic differences between the two areas unrelated to trawling. Discarding from trawlers has the effect of transferring large quantities of biological material from the bottom to the surface. This makes available to surface scavengers food that would otherwise be inaccessible.
Spatial and seasonal variation in Demersal Trawl Fauna associated with a Prawn Fishery on the Central Great Barrier Reef, Australia
Authors: Watson RA , Dredge MLC , Mayer DG
Published: November 2005

Regular monthly sampling at eight trawl sites in Great Barrier Reef waters identified variations in both species composition and the relative abundance of the more common species over a 2-year period. Faunal composition was affected more by the location of sample sites than by the time when samples were taken. Ordination analysis differentiated a 'nearshore' group of sites from a 'midshelf' and an 'inter-reef' group. The composition of 'inter-reef' fauna remained strikingly uniform below the 40 m depth contour regardless of proximity to coral reef formations. Classification of the samples also revealed weakly separated 'wet' and 'dry' season temporal groupings, with the former characterized by higher abundances of several 'nearshore' species.
Large-scale spatial patterns of abundance within the assemblage of fish caught by Prawn Trawlers in Northern Australian waters
Authors: Ramm DC , Pender PJ , Willing RS , Buckworth RC
Published: November 2005

Large-scale patterns of abundance within the by-catch of fish in the Northern Prawn Fishery of tropical Australia were investigated. Commercial catches were sampled from May 1988 to May 1989, between 128� and 138� E. Because sampling could not be stratified by fishing ground, depth, season and time of day, data on the abundances of 115 taxa of teleosts were restricted to: (1) 136 samples collected between 2000 and 0600 hours in depths of 18-49 m from four fishing grounds during August- November; and (2) 270 samples collected between 1800 and 0800 hours in depths of 18-76 m from seven fishing grounds throughout the period sampled. Pattern analyses indicated that samples clustered along geographic and bathymetric gradients, forming distinct western and eastern groups separated near 132� E, and shallow (<30 m) and deep (>30 m) water groups. Ten taxa had distributions centred east of 132� E, regardless of depth. A further 14 taxa had distributions centred east of 132� E and below 30 m. Nineteen taxa had distributions centred in the western region of the study area. Eight taxa occurred predominantly below 30 m throughout the area sampled, and 16 taxa had high catch per unit effort in shallow water (<30 m). Of the remaining species, seven were taken throughout the study area, and nine taxa were abundant on fishing grounds other than below 30 m in the Gulf of Carpentaria. Thirty-two taxa were rare. It was concluded that spatial patterns adequately described the abundance of taxa within the data, and that varying reports in the literature concerning the relative contribution of spatial and seasonal factors were dependent upon the scale of sampling.
Incidental capture and mortality of Sea Turtles in Australia's northern Prawn Fishery
Authors: Poiner IR , Buckworth RC , Harris ANM
Published: November 2005

Species composition, catch and mortality rates of sea turtles captured in the tiger prawn segment of Australia's northern prawn fishery were estimated from six prawn research surveys and three commercial catch monitoring programmes. Four species of turtles were captured in the research surveys: the flatback (Natator depressa, 43%) was the dominant species, although the loggerhead (Caretta caretta, 19%) and the olive Ridley (Lepidochelys olivacea, 15%) were common and the green turtle (Chelonia mydas, 4%) was occasionally captured. The size of the turtle catches varied with the duration of the trawl and water depth: the highest catch rates (turtles per standard net-h) were from trawls of 90 min or more in water less than 25 m deep: no turtles were captured in water deeper than 43 m. The rate of mortality amongst captured turtles also varied with trawl duration; there was no mortality recorded in trawls of less than 90 min, 5% mortality in trawls of 165 min, and 7% in trawls of 180 min. The incidence of capture in the commercial fishery was 0.045 (�0.006) turtles per 180-min trawl, with 0.0027 (�0.0014) turtles per 180-min trawl drowning in the nets. If it is assumed that these rates have been constant over the history of the fishery, then on the basis of the annual fishing effort, an average of 5730 (�1907) turtles have been caught per year [of which an average of 344 (�125) drowned]. Since the introduction of management measures in 1987 to reduce effort in the fishery, the number captured declined to about 4114 (�1369) turtles in 1988, of which an estimated 247 (k90) turtles drowned. It is concluded that the impact of trawl-induced drownings on the turtle populations is probably not of such proportions as to create immediate concern.
Variations in the fish catch composition in the Bay of St. Vincent, New Caledonia, as determined by experimental trawling
Authors: Kulbicki M , Wantiez L
Published: November 2005

An experimental trawl survey was conducted in the Bay of St Vincent between December 1984 and April 1986. In all, 85 hauls were performed during four cruises. The trawled fish represented 233 species and 59 families. Biomass and density estimates declined 13-fold between the first and last cruises. This decline is not due to the survey catch (less than 2% of the biomass of the bay), nor is it likely to be due to trawling-induced changes in habitat. Natural causes are the most likely reason for the decline. The r-type species (Leiognathidae, Lethrinus nematacanthus) had the largest population fluctuations, whilst longer living and later reproducing species (Saurida undosquamis, large Upeneus spp.) had the smallest. Trophic structure is studied using three expressions: number of species, biomass and density per trophic group. Number of species per trophic group was the most insensitive to changes in time and place, with density being the most sensitive. Study of the variations in trophic structure could help with the monitoring of major changes in fish populations caused by fishing or environmental changes.
Yield-per-recruit analysis of Eastern King Prawns Penaeus plebejus Hess, in Eastern Australia
Authors: Glaister JP , Montgomery SS , McDonall VC
Published: November 2005

The eastern king prawn, P. plebejus, has been commercially exploited for over 50 years. Controversy has arisen over the presumed effect of increasing fishing effort on reported declining catch per vessel and the need for further management of the fishery. The present study develops the information necessary to evaluate this presumption by analysing landing statistics, data developed from a log-book programme, commercial catch composition and data from a series of mark-recapture experiments conducted on part of the fishing grounds. Population parameters (growth, mortalities and other losses) were calculated via a series of tagging experiments. Recapture rates of tagged prawns were examined for each point release (local recapture) and for the state as a whole (sequentially applied effort), the difference providing estimates of emigration rate. Weekly values chosen for these parameters allowed calculation of yield-per-recruit estimates. For 1979 and 1980, respectively, fishing mortality estimates ranged between 0.04 and 0.08 per week, depending upon number of vessels per port; emigration was estimated to be 0.13 and 0.18 per week for the two years, tagging mortality (0.08 per week), and all other losses other than by tagging and emigration at 0.06 and 0.08 per week. A compartmented, time-lagged model of the fishery was used to predict changes in yield per recruit as a consequence of changes in management strategy and to describe the relationship between fishing effort and yield per recruit. The analyses suggested that limited benefits in terms of yield per recruit would eventuate from substantial increases in effort but that substantial decreases in catch per effort were likely.
Grazing on Bacteria by Zooplankton in Australian Billabongs
Authors: Boon PI , Shiel RJ
Published: November 2005

Five species of rotifer (Brachionus lyratus, Conochilus dossuaris, Keratella cochlearis, Keratella quadrata and Trichotria tetractis) ingested bacteria at a prey density of 5-7 × 109 cells L.-1, and a sixth (Keratella procurva) did so at a higher bacterial concentration of 4 × 1010 cells L-1. Gastropus minor, Polyarthra vulgaris, Synchaeta pectinata and Trichocerca similis were not bacteriovores. Fluorescent-stained (DATF or acridine orange) bacteria were not suitable for determining which rotifers were potential grazers. However, bacteriovory was detected easily with safranin-red or methylene-blue stained bacteria. Clearance rates for the zooplankton community larger than 51�pm, determined with 3H-thymidine labelled bacteria, varied from <0.1-71 mL L-1. H-1, but were usually <5 mL L-1 h-1. Significant grazing was detected in >200�m, 90-200�m and 51-90�m fractions: it was impossible to ascribe bacteriovory to discrete taxonomic groups, because zooplankton taxa were not completely separated by these mesh sizes.
Use of Allozyme Electrophoresis for identifying two species of Penaeid Prawn Postlarvae
Authors: Lavery S , Staples D
Published: November 2005

Allozyme electrophoresis was used to identify the postlarvae of two species of tiger prawns, Penaeus esculentus and P. semisulcatus, from the Gulf of Carpentaria, Australia. The two species were examined for genetic differences at 39 loci, in three developmental stages (adult, juvenile and postlarval). One locus, Gpi, was suitable for the routine species identification of postlarvae. The electrophoretic identification system developed, when applied to the identification of postlarvae taken by field sampling, was more reliable and efficient than standard morphological techniques.
Aspects of the Biology of the Perchlet Ambassis interrupta Bleeker (Pisces: Ambassidae) in the Sepik River, Papua New Guinea
Authors: Coates D
Published: November 2005

Ambassis interrupta enters the lower Sepik River and is found in or near turbid river channels. The species is considered to be a predominantly marine and/or estuarine spawner. A. interrupta feeds mainly on small aquatic insect larvae but also on insects from terrestrial sources and on small crustaceans. Low variability in the data for condition, fat deposition, reproduction and feeding is interpreted by the species' lack of affinity for the floodplain and the presumed transient nature of the population. Fecundity (F) is expressed by the formula F= - 12.3 + I5.3, where I is standard length (mm), and varied between 29 000 and 310 000 eggs per fish (70-105 mm standard length). Eggs are small (0.22 mm mean diameter) in comparison with known egg sizes for freshwater-spawning ambassids.
Lake Thetis, Western Australia: and example of Saline Lake Sedimentation dominated by Benthic Microbial Processes
Authors: Grey K , Moore LS , Burne RV , Pierson BK , Bauld J
Published: November 2005

Lake Thetis is a saline coastal lake in south-western Australia, a region of winter rainfall and summer drought. The lake demonstrates the close relationships between environmental variation and the nature of resident benthic microbial communities. Crenulate cyanobacterial mats occur in the low-lying areas adjacent to the lake. Lithified stromatolites with patches of living coccoid cyanobacterial mat characterize the littoral area, whereas a thick flocculent mat composed of phototrophic prokaryotes (principally purple sulfur bacteria) and diatoms has accumulated in the central lake basin. Lake Thetis is distinguished from other coastal saline lakes by the presence of the unusual flocculent mat and by the juxtaposition of this microbial community to the marginal lithified stromatolites. Further, some of the latter exhibit internal digitate columnar branching which, though common in Precambrian examples, is rare in modern environments.
Seasonal feeding on Zostera capricorni seeds by Juvenile Penaeus esculentus (Crustacea: Decapoda) in Moreton Bay, Queensland
Authors: Wassenberg TJ
Published: November 2005

The natural diet of juveniles of Penaeus esculentus Haswell (mean size 13.0 � 3.3 mm CL) collected from a seagrass (Zostera capricorni Aschers.) bed in Moreton Bay over 18 months was studied. There was a marked seasonal change in the occurrence of Z. capricorni seeds in their diet. These seeds made up to 1370 of the ash-free dry weight of the prawns' diet in November but disappeared completely from the diet between June and September. When seeds were not available, juvenile P. esculentus ate filamentous algae. Prawns less than 8 mm CL were not found with seeds in their foregut. There was no indication that prawns feed on seeds because of a shortage of other food items such as crustaceans or gastropods. Prawns studied in the laboratory removed seeds from the spathes and selected mature seeds. The seeds (each about 0.75 mg dry weight) had an energy content of 15.36 kJ g-1 dry weight. Seeds were found at densities of 456 m-2 in the seagrass beds. This study and other studies indicate that many species of juvenile penaeids incorporate vegetable material into their diet.
Spatio-temporal variability in surface Chlorophyll distribution in the Central Great Barrier Reef as derived from CZCS imagery
Authors: Gabric AJ , Hoffenberg P , Boughton W
Published: November 2005

A series of Coastal Zone Colour Scanner (CZCS) images has been used to compare the surface phytoplankton variation in the central Great Barrier Reef waters over the period 1979-81. Near- concurrent field data have been obtained for all the scenes so that approximate chlorophyll concentrations have been applied in the image classification. A consistent feature in the dry-season chlorophyll distribution is a cross shelf gradient with high chlorophyll levels inshore and lower levels in the mid-lagoonal waters increasing to higher concentrations in the reef matrix. The effects of higher nutrient loads in the wet season are also evident, although correlation between riverine discharge and phytoplankton abundance in the lagoon is problematic. In fact, a large scale 'bloom' event occurs before the start of the 1980-81 wet season and may be related to wind resuspension of sedimentary nutrients.
Diet of Nyctiphanes australis Sars (Crustacea: Euphansiacea)
Authors: Ritz DA , Hosie GW , Kirkwood RJ
Published: November 2005

The stomach contents of the euphausiid Nyctiphanes australis were analysed qualitatively on a monthly basis throughout a full year and for each stage of the life cycle. Dietary items occurring in decreasing order of frequency in stomachs were: inorganic matter including sponge spicules; diatoms; dino- flagellates; silicoflagellates; foraminiferans; and crustacean exuviae. Little change in the composition of the main dietary components between life stages was apparent. Minor seasonal changes in stomach contents occurred (i.e. greater prevalence of diatom resting spores and coccoliths during warmer months and greater prevalence of black particulate matter, thought to be zooplankton faecal pellets, in summer). Fluorescence of the full stomachs of adult N. australis was found to be linearly related to carapace length. Filtering rates calculated from this relationship and average levels of chlorophyll a present in south-eastern Tasmanian coastal waters suggest that N. australis could only satisfy about 25% of its carbon requirement from phytoplankton alone. Hence, it is concluded that this euphausiid needs to include detrital and animal matter in its diet.
Movement, Growth and natural mortality rate of the Red Spot King Prawn, Penaeus longistylus Kubo, from the Great Barrier Reef Lagoon
Authors: Dredge MCL
Published: November 2005

Movement, growth and natural mortality rate of the red spot king prawn, Penaeus longistylus, occurring in waters of the Great Barrier Reef off Townsville, Queensland, were investigated in a series of tagging experiments. Adult P. longistylus did not migrate after leaving nursery areas. Their growth rate was slower than that of the conspecific species P. plebejus, and significant inter-annual variation in growth parameters was observed. The natural mortality rate, assessed by sequential tagging experiments that eliminated the possibility of confounding with the rate of fishing mortality, was estimated to be 0.072 (week-1).
Seasonal changes in Ectoparasite infection of juvenile Yellowfin Bream, Acanthopagrus australis, (Gunther) (Pisces: Sparidae). from a small estuary in Northern NSW
Authors: Roubal FR
Published: November 2005

Seven monogenean, 1 digenean and 9 copepod species of ectoparasite were found on 179 juvenile Acanthopagrus australis collected bimonthly over two 12-month periods from a small estuary at Red Rock in northern New South Wales. The monogenean Allomurraytrema spari and the copepod Alella macrotrachelus showed a consistent cycle of spring-summer high and late summer-autumn low in prevalence and intensity of infection, whereas the digenean Prototransversotrema steeri was present only in winter. The monogenean Haliotrema spariensis was highly prevalent year-round, but other monogeneans were inconsistent in seasonal prevalence and intensity. The copepods Paraergasilus acanthopagri and Dermoergasilus acanthopagri showed inconsistent annual cycles, but their fluctuations in prevalence and intensity were nearly identical. The other species of ectoparasite had no consistent cycles or were rarely found. Temperature does not appear to directly regulate the abundance of ectoparasites on juvenile Acanthopagrus australis in Red Rock estuary.
Reproduction of the Slate Pencil Sea Urchin, Heterocentrotus mammillatus (L), in the Northern Red Sea
Authors: Dotan A
Published: November 2005

The annual reproductive cycle of Heterocentrotus mammillatus was studied in the northern Red Sea. Gametogenesis starts in January, and the abundance of ripe gametes gradually increases until, by May, they occupy most of the gonadal volume. Spawning occurs in June and July; the pattern suggested a lunar or semilunar cycle. Assays of KC1 injections suggest that these may be a better indicator of reproductive ripeness than conventional oocytes-ova analysis. A highly significant linear relationship between gonad weight and total body weight was observed at the period of maximal gonad size prior to spawning.
Composition, seasonality and distribution of the Ichthyoplankton in the Lower Swan Estuary, South-western Australia
Authors: Gaughan DJ , Neira FJ , Beckey LE , Potter IC
Published: November 2005

Paired conical nets (0.5 mm mesh) were used to sample ichthyoplankton at three sites in the lower
Swan Estuary in each month between May 1986 and April 1987. In all, 3948 fish larvae were caught,
representing 32 families and 60 species, of which 29 could be assigned species names. The Clupeidae
(20.2%), Engraulididae (10.4%), Callionymidae (8.7%) and Nemipteridae (6.8%) made the greatest
contributions to the total larval number, followed by the Pinguepididae (5.8%), Gobiidae (5.8%),
Terapontidae (5.7%) and Monacanthidae (5.4%). The most numerous of the identified species were
Engraulis australis (10.4%), Hyperlophus vittatus (8.9%), Callionymus goodladi (8.7%) and Sardinella
lemuru (7.4%). The 11 most abundant of the identified species included 2 that spawn in the estuary
(E. australis and Parablennius tasmanianus) and 2 that spawn at sea but are abundant as juveniles in
the estuary (Pelates sexlineatus and H. vittatus). The remaining 7 species are not common as either
juveniles or adults in any region of the Swan Estuary. The larvae of marine species collected just inside
the estuary mouth were very similar in size to those collected a further 7.2 km upstream, indicating
that they are transported rapidly through the lower estuary, presumably through tidal action. The
concentrations of both eggs and larvae of all fish collectively, and the concentrations of larvae of
most of the abundant identified species, peaked between late spring and midsummer (November-
January).
Interaction between the effects of Substratun, Velocity and location on Stream Benthos: and experiment
Authors: Barmuta LA
Published: November 2005

Patches of large and small pebbles were created in three riffles (fast current velocities) and three pools (slow velocities). It was expected that patches with different sizes of pebbles in the two velocity regimes would vary in the entrapment of fine sediments and organic matter, which in turn would result in differences in benthic community structure. This was not the case, for although deposition of fine material was greater in pools, there were appreciable location-specific differences in the fauna unrelated to the variables monitored in the experiment. Functional feeding groups did not respond predictably to the distribution of detritus. Generally, the community was least influenced by substratum size, with any differences being inconsistent across locations. Most other substratum effects were attributable to the presence of epilithon on undisturbed control patches. Velocity was the most influential factor, with riffles having higher total abundances and higher species richness. Some taxa showed strong location- specific differences. At the level of a small patch of pebbles, the colonization dynamics of the fauna are probably a mixture of species- and location-specific dispersal and selection mechanisms. At larger spatial scales, however, community structure is more predictable, with pools differing substantially from riffles.
Revision of the Australian cyclopidae, (Copepoda: Cyclopoida). II. Eucyclops Claus and Ectocyclops Brady
Authors: Morton DW
Published: November 2005

The Australian species of Eucyclops Claus and Ectocyclops Brady are revised and the following species are recognized: Eucyclops spatulatus sp. nov., E. australiensis sp. nov., E. nichollsi Brehm, E. baylyi sp. nov., E. ruttneri Kiefer and Ectocyclops rubescens Brady. All are described, figured and discussed, and keys are provided for their identification.
Reproductive Biology and Larval development of a Gizzard Shad, Nematalosa erebi (Gunther) (Dorosomatinae: Teleostei), in the River Murray, South Australia
Authors: Puckridge JT , Walker KF
Published: November 2005

The reproductive biology of the native Australian bony bream, Nematalosa erebi, resembles that of other gizzard shads. In the lower River Murray the species matures in its second or third year, spawns independently of flooding in December-January at temperatures of 21-23� C, and is highly fecund. Reproductive output increases with size. The ova and larvae are small, the yolk sac stage is brief, and development is typical of clupeids except for the fin-ray sequence. Sexual dimorphism does not occur, but females predominate in the largest size-classes. Catches of bony bream are increasing where other native species are in decline. This may indicate that bony bream larvae are not dependent on flooding for food, or that the species has an exceptional capacity for rapid population recovery.
Optimum and favourable temperatures for growth of Cherax tenuimanus (Smith 1912) (Decapoda: Parastoacidae)
Authors: Morrissy NM
Published: November 2005

The relationship between growth and water temperature for Cherax tenuimanus was described by fitting a multiple regression model employing a cubic polynomial equation in temperature and initial size to growth data obtained over the range 10-30� C. A physiologically based model for this relationship is unknown. The polynomial equation provides a mathematical method of defining features of the relationship that is preferable to curve-fitting by eye. Growth rate was dependent upon initial size and was suppressed by confinement of crayfish in individual compartments of a battery system. The lower temperature limits to growth were 11� C based on the minimum turning point of the growth-temperature curve, and 13� C based on the intercept of the lower limb of the curve on the temperature axis for the mean initial size of the test crayfish (0.82 g). The point of inflexion of the curve was at 18� C, and the optimum temperature for growth was 24� C based on the maximum turning point of the curve. The upper limit to the favourable range of temperature for growth and long-term survival was 30� C based on the intercept of the upper limb of the curve on the temperature axis for the mean initial size. The growth-temperature curves for three Australian Parastacidae- C. tenuimanus, C. destructor and C. quadricarinatus-all have a form similar to that for fish. This similarity further emphasizes the long-standing need for development of a physiologically based model for the relationship between growth and temperature for poikilotherms.