bluuebunny/crossref_metadata_2025 huggingface dataset:
Age and growth of a large tropical anchovy, Thryssa hamiltoni (Gray): A comparison of ageing techniques
Authors: Hoedt FE
Published: November 2005

Three principal ageing methods were used to describe the growth history of Thryssa hamiltoni, a large
tropical anchovy from the waters off Townsville, north-eastern Queensland. The study was undertaken
to compare ageing methods based on length-frequency analysis that are commonly applied in age and
growth studies of tropical clupeoids, with less commonly used methods based on daily and seasonal
growth rings in otoliths. A preliminary study suggested that seasonal growth rings in the sagittae of
T. hamiltoni were formed annually and were therefore useful for age estimations for this species.
Age and growth estimates derived from the three methods were consistent, with the results of each
method supporting the results of the others. Direct validation of daily growth increments in T. hamiltoni
by means of tetracycline marking experiments was unsuccessful due to the sensitivity of this species to
handling stress. The distribution of modes in length-frequency histograms, and age estimates based on
annual growth rings, both showed that male and female T. hamiltoni exhibit different growth patterns,
with females growing faster and attaining greater maximum lengths than do males. Although counts
of annual growth rings suggest a maximum longevity of 4 years for both males and females, lengthfrequency
data indicate that the population is largely comprised of fish up to 2 years of age.
Daily Otolith increments in juvenile tropical Parrotfishes and Surgeonfishes
Authors: Lou DC , Moltschaniwskyj NA
Published: November 2005

Otolith microstructure was examined in juvenile tropical herbivorous fish belonging to the families
Acanthuridae and Saridae at Lizard Island. Growth increments on the lapilli of 14 species were validated
by tetracycline marking in the laboratory. All species examined deposited growth increments on a daily
basis. Increment counts in left and right lapilli were compared for consistency in increment deposition.
Interobserver differences were examined as a possible cause of bias in age estimates for Ctenochaetus
binotatus and Scarus schlegeli. Given the precision of otolith increment counts by an observer, the
differences between counts of the left and right otoliths were acceptable, as were differences between
independent observers reading the same otoliths.
Age and growth of Murray Cod, Maccullochella peelii (Perciformes: Percichthyidae), in the Lower Murray-Darling Basin, Australia, from thin-sectioned Otoliths
Authors: Anderson JR , Morison AK , Ray DJ
Published: November 2005

Transverse thin sections (0.5 mm thick) of sagittal otoliths from 290 Murray cod up to 1400 mm
in total length and 47.3 kg in weight were used to establish the age and growth of cod in the lower
Murray-Darling Basin, including comparisons of recent (1986-91) and past (1949-51) growth rates and
growth in different waters. The maximum estimated age was 48 years. Quantitative and qualitative
analysis of the seasonal changes in otolith marginal increments showed that annuli in fish of all ages
were laid down each spring, and 1 October was assigned as the birthday. The thin-sectioning method
was validated by comparing age estimates for 55 Murray cod from Lake Charlegrark (age 0-21 years),
which had been validated by using burnt and polished half-otoliths. The new method had an accuracy
of 96.4% and it offers major advantages in ease of preparation, reading, and batch-handling of large
numbers of otoliths. The precision of the method, estimated as an average error for four readers,
was 5.4% (3.0% after ignoring discrepancies in relation to annuli on otolith edges). There was a linear
relationship between otolith weight and fish age and an exponential relationship between otolith weight
and fish length. Both otolith length and otolith width reached an asymptote at about 15 years, when
fish length also approached its maximum. However, otolith thickness continued to increase throughout
the life of the fish and, after about 15 years, contributed most to the increase in otolith weight.
This confirmed that otoliths continued to grow in thickness and that annuli were laid down throughout
life, and that cod could be aged reliably to the maximum age. The annulus pattern is very clear and
distinct, and the reading techniques are fully described, including recognition of 'larval' and 'false' rings.
Various differences were found in the growth rates, and the length-weight relationships for males and
females, for cod caught in 1986-91 and those caught in 1949-51, and various subpopulations are
discussed. The von Bertalanffy growth parameters (all individuals combined) were estimated at
L∞ = 1202 mm, k=0.108 and t0= -0.832. The availability of a reliable ageing method provides the
first opportunity to determine year of birth and thus to examine the age structure of populations and
to effectively manage cod populations that have declined in abundance.
Validation of the use of Otoliths to determine the ate and growth of Murray Cod, Maccullochella peelii (Mitchell) (Percichthyidae), in Lake Charlegrark, Western Victoria
Authors: Gooley GJ
Published: November 2005

The age and growth of Murray cod, Maccullochella peelii, in Lake Charlegrark, western Victoria, were
determined by using otoliths from fish sampled by beach-seine and gill-net, or caught by anglers,
between August 1978 and August 1982. Annulus formation was validated up to 11 + years by several
methods. Otoliths were examined from hatchery-bred fish of known age (up to 4+ years) that had
been stocked into local farm ponds. Analysis of incremental growth for all fish sampled from the lake
indicated that the mean edge-growth ratio was lowest, and the percentage of otoliths with an annulus
at the edge was highest, in October. A nominal birth date of 1 October was designated for the
population to enable calculation of the absolute age for each fish. Age-composition data for those fish
taken by gill-net and by anglers (up to 21 + years) revealed modal progression of strong year classes
(1970 to 1973 inclusive) during the sampling period. Length-frequency data for those fish taken by
beach-seine (up to 3 + years) revealed modal progression, on a seasonal basis, of two relatively strong
year classes (1978 and 1979) during the sampling period.
A von Bertalanffy growth curve was fitted to length and age data for all fish collected in the
lake (no sex difference, P>O.05), and growth parameters were estimated for the population (L∞ =
695 mm). This curve did not adequately describe the growth of fish older than 11 + years because the
majority of sampled fish (98.3%) were aged 11 + years or younger. The length-weight relationship for
the population was determined by using data from all fish collected in the lake (no sex difference,
P>0.05).
Growth of juvenile Coral Reef Damselfish: Spatial and Temporal variability, and the effect of population density
Authors: Pitcher CR
Published: November 2005

The growth rate of juvenile damselfish (Pornacentrus nagasakiensis) was estimated by daily ageing,
using otoliths, and constructing length-at-age curves or, due to a close relationship between otolith
radius and fish length, back-calculating the growth rates of individual fish. The growth of juvenile
P. nagasakiensis was not detectably affected by population density, whether naturally established or
manipulated. In one experiment, the presence of early recruits had no detectable effect on the growth
of subsequent recruits, and postsettlement growth rates even increased slightly with subsequent pulses
of settlement through the first half of the summer (as water temperature increased). However, in other
(nonexperimental) samples, there may have been an interaction between prior recruitment and falling
temperature that reduced growth rates. The rate of growth differed among habitats, but not in
proportion to the densities established at settlement-as might be expected if preference for habitats
conferring better growth had evolved. The growth of juvenile fish from different reefs within and
between different regions of the Great Barrier Reef also showed some significant differences. In all
analyses of variance, the residual natural variation accounted for most of the sums-of-squares, highlighting
the great plasticity of fish growth.
A new model accounting for seasonal cessation of growth in fishes
Authors: Pauly S , Soriano-Bartz M , Moreau J , Jarre-Teichmann A
Published: November 2005

A modified version of the von Bertalanffy growth function (VBGF) is proposed in which a sine wave
modifies a standard version of the VBGF, enabling a smooth transition between rapid summer growth
and a variable period of zero growth (in length) during winter or during the dry season for aestivating fishes.
The key features of a nonlinear routine for fitting this new model are also presented, with emphasis on the
estimation of the period of zero growth. Application examples, to Salmo salar and Trisopterus esmarkii,
are presented.
Shell growth checks are unreliable indicators of age of the Abalone Haliotis rubra (Mollusca: Gastropoda)
Authors: McShane PE , Smith MG
Published: November 2005

The results of tag-recapture studies on three Victorian populations of the abalone Haliotis rubra showed that the frequency of growth checks in the shells of individuals was not annual. The use of shell growth checks as a method for age determination of H. rubra is not reliable because of variation in the frequency of growth checks between populations and the inability to count growth checks in the shells of most individuals.
Effects of year-class strength on age determination
Authors: Kimura DK , Lyons JJ , MacLellan S , Goetz BJ
Published: November 2005

Little has been done to assess factors that can affect precision and accuracy in the fish age determination process. In this study, we examine how the presence of strong year-classes (i.e. foreknowledge of these year-classes) can affect the ages that are generated. It has been suggested recently that reader precision (i.e. reader repeatability) places limits on the accuracy of ages and that reader awareness of year-classes could both increase estimated precision and exaggerate the strength of strong year-classes beyond that which could be expected considering reader repeatability. That is, if reader repeatability was 60% at a given age, then a maximum of 60% of any strong year-class of that age could be expected to be aged correctly. However, consciously or subconsciously, age readers can be expected to tend to age toward strong year-classes. In order to examine these hypotheses, an otolith test sample was constructed for walleye pollock (Theragra chalcogramma) by combining samples that were collected in 3 adjacent years and that were known to include the strong 1978 year-class. Thus, the test sample gave the appearance of consisting of three neighbouring age-classes in nearly equal numbers. The age readers involved in this study had results that were better than might be expected, maintaining their reader precision even with this difficult sample. However, the results also appear to indicate that the 'dominant' year-class was spread to other ages in comparison with ages obtained when the age readers were aware of the strong year-class.
Effect of temporal changes in size composition on estimates of von Bertalanffy growth parameters for Gemfish, Rexa solandri (Cuvier), Gempylidae
Authors: Rowling K.R. , Reid DD
Published: November 2005

Estimates of von Bertalanffy growth parameters were made for mature (>3-year-old) gemfish (Rexea solandri), using otoliths sampled biennially from commercial catches between 1980 and 1986. During this period, there was a significant decline in the mean length of mature gemfish in the catch. Large variations in growth-parameter estimates were found over the period sampled (e.g. L∞ ranged between 87.3 and 130.3 cm for males and between 113.1 and 134.7 cm for females). Likelihood-ratio tests showed many of the growth-parameter estimates to be significantly different between the years sampled. Inclusion in the analyses of data for juvenile (1- to 3-year-old) fish considerably reduced both the standard errors of the parameter estimates and the significance of the variations between them. Comparison of parameters estimated by following the growth of individual cohorts spawned in 1975 and 1981 suggested that the variations in the parameters for the 1980-86 data were caused by differences in the length composition of the samples rather than by changes in the growth rate of the fish. The results suggest the need for care when comparing growth parameters estimated for different populations, especially when there are large differences in length composition. The best estimates of growth parameters for gemfish were considered to be those derived from the aggregate data for the whole of the period sampled, including the data for juveniles. For male gemfish these best estimates (with asymptotic standard errors in parentheses) were L∞ =97.5 (0.8) cm, K=0.212 (0.005) year-1 and to = - 0.54 (0.05) years, and for females the estimates were L∞ = 109.4 (0.6) cm, K= 0.180 (0.003) year-1 and to= -0.63 (0.04) years. Likelihood-ratio tests showed these estimates of L∞ and K to be significantly different between the sexes.
Movements and growth of tagged Blue Endeavour Prawns, Metapenaeus endeavouri (Schmitt 1926), in the Western Gulf of Carpentaria, Australia
Authors: Buckworth RC
Published: November 2005

Mark-recapture experiments, conducted near Groote Eylandt in the western Gulf of Carpentaria during 1984, were used to examine movements and growth of blue endeavour prawns, Metapenaeus endeavouri. The mean distance moved by tagged animals was only 12.7 (s.e.�1.0) km, but a few were recaptured > 100 km from their release sites. The mean time at liberty was 36.8 (�1.6) days, the maximum being 155 days. The distance and speed of movements were not related to the size or sex of tagged prawns. Nonuniform recapture patterns corresponded largely with fishing effort. Recaptures per unit effort (R/f analyses), used to account for nonuniform fishing effort, indicated that there was no directionality in movements. Thus, tagged specimens of M. endeavouri dispersed slowly across suitable adult habitat, with limited intermixing of adults from stocks around Groote Eylandt. Estimates of the von Bertalanffy growth parameters L∞ and K for each sex were obtained for data from summer and winter releases. The fit of the von Bertalanffy model to summer data was limited by the small number of recaptures. The fit of the model to winter data was improved by removing early recaptures, and these estimates are presented as the primary descriptors of growth in M. endeavouri. Parameter estimates did not differ significantly between seasons, but L∞ differed between sexes and K differed between sexes in winter. Predicted growth corresponded to the progression of modes in length-frequency data from commercial catches.
Recognizability of algae ingested by abalone
Authors: Foale S , Day R
Published: November 2005

Studies of the diet of abalone and other herbivorous gastropods, based on gut contents, may be biased against some species of algae, especially those that are most preferred. The blacklip abalone Haliotis rubra was fed for short periods on monospecific diets of eight algae, including red, brown and green species that span the range of preference. In addition, two preferred species were fed to abalone after one month's, one week's, or no starvation. The number of recognizable fragments of each alga per unit volume of crop contents was examined. Although key characters of some species remained recognizable even at an advanced stage of digestion, other algae were intrinsically less recognizable. Preferred red algae disappeared rapidly after one week's or no starvation but more slowly after one month's starvation. Less preferred algae were not eaten without a long starvation period and became unrecognizable relatively slowly, especially the least preferred brown algae Ecklonia radiata and Phyllospora comosa, which have high polyphenol contents. Thus, the gut contents of starved abalone in the field contain recognizable fragments of less preferred species for long periods, whereas well-fed abalone retain recognizable fragments of preferred species only for short periods.
Sizes at first maturity and at onset of breeding in female Jasus verreauxi (Decapoda: Palinuridae) from New South Wales waters, Australia
Authors: Montgomery SS
Published: November 2005

Two criteria were used to investigate the size at which female eastern rock lobsters (Jasus verreauxi) off New South Wales attain maturity. These were the presence of well developed setae on, or the presence of eggs attached to, the pleopods. Females having well developed setae on the pleopods and/or carrying eggs were found only in catches from Coffs Harbour and Crowdy Head, the two most northern localities sampled. There were no significant differences in carapace length (CL) between size at first maturity (SOM) and size at onset of breeding (SOB) within or between areas sampled or when data from different areas were combined. SOM and SOB values (with 95% confidence intervals) for combined areas were, respectively 170.1 mm CL (169.1-171 a2 mm CL) and 166.5 mm CL (166.1- 171.9 mm CL). The present legal minimum length for harvesting J. verreauxi (104 mm CL) is far shorter than these SOM and SOB values. It is suggested that if a legal minimum length is imposed to conserve the spawning stock, then it should be 166 mm CL.
Macroinvertebrate activity in the water column of backwaters in an upland stream in Victoria
Authors: O'Leary P , Lake PS , Marchant R , Doeg TJ
Published: November 2005

The activity of benthic invertebrates was monitored in the water column of slowly flowing backwaters of the Acheron River during summer. Samples were taken throughout 24 h on two occasions, and densities of fauna were compared with densities in drift samples taken concurrently in the main channel. Drift densities were generally higher than those in backwaters, but not by orders of magnitude. Also, drift densities displayed significant die1 variation, whereas densities in backwaters did not consistently show such a pattern. Species composition generally differed between the two habitats. This brief study demonstrates that benthic invertebrates do swim in the water column of stream backwaters and that they may use this opportunity for colonization.
Distribution and timing of spawning by the Australian pilchard (Sardinops sagax neopilchardus) off Albany, Western Australia
Authors: Fletcher WJ , Tregonning RJ
Published: November 2005

The pattern of abundance of eggs and larvae of the Australian pilchard, Sardinops sagax neopilchardus, collected by plankton tows in the region off Albany, Western Australia, was investigated. In 1989, surface tows were undertaken at five localities extending from the marine embayment of Princess Royal Harbour to the continental shelf just outside King George Sound. In 1990, oblique tows were undertaken at six localities extending from just inside King George Sound to beyond the edge of the continental shelf. Eggs and larvae of pilchards were found in many months, but peaks in egg numbers were found in July and December of both 1989 and 1990. There was, however, only one peak in larva abundance, during December. Most eggs and larvae were found in the region 2-8 km offshore from the entrance to King George Sound. Few were found either well inside King George Sound and Princess Royal Harbour or in outer-shelf localities. Spawning in the Albany region therefore occurred inshore of the main influence of the eastward-flowing tropical waters of the Leeuwin Current. The implications of this spawning activity in relation to the fishery for this species and the potential for stock separation along this coast are discussed.
Patterns of distribution and abundance of fishes in different habitats of a mangrove-lined tropical estuary, as determined by fish trapping
Authors: Sheaves MJ
Published: November 2005

Spatial and temporal patterns of distribution and abundance of large, demersal fishes in the deep-water
sections of Alligator Creek, in tropical northern Australia, were investigated. Small Antillean Z-style
fish traps were utilized to compare different estuarine habitats along the navigable length of the creek.
In particular, the traps were used to target the structurally heterogeneous 'snag' habitats provided by
areas of submerged mangrove prop roots and fallen timbers in the deeper areas of the estuary.
During the study, 962 fish of 23 species from 15 families were trapped over 1128 trapping days, at
an overall catch rate of 0.85 fish trap-1 day-1. Catches by numbers were dominated by two genera:
Acanthopagrus (Sparidae) (51.8%) and Epinephelus (Serranidae) (20.3%). Of the 23 species trapped,
eight had not been recorded during previous studies of Alligator Creek that used more conventional
netting methods to target fishes in shallow parts of the estuary.
In trap catches, the total number of fish, the number of species, and the numbers of individuals
of the most common species showed a general decline towards the upper areas of the estuary and
generally were higher in 'snag' habitats than in areas lacking such structures. No clear pattern of
temporal differences during the study was detected. Angling and seine-net catch data were used as
independent indicators of spatial patterns of distribution and abundance for comparison with the
patterns obtained from the catch data of traps. Data from all three sources demonstrated similar
spatial patterns.
Characteristics of coastal waters of the western Bay of Bengal during different monsoon seasons
Authors: Suryanarayana A , Murty CS , Rao DP
Published: November 2005

Physical characteristics of waters along the eastern coast of India up to offshore distances of 400 km have been investigated during the seasons of the north-easterly and south-westerly monsoons in light of relevant observed meteorological forcings. Analysis of wind data for five years (1980-84) showed high magnitudes of onshore-directed wind-stress impulse in the northern region throughout the year. Under the influence of this impulse, surface waters from offshore move towards the coast and sink along the shore under the direct wind setup. This feature is also indicated by negative values of the upwelling index. Fresh water, discharged through multiple outlets along the coast, mixes within the upper 50 m of the water column and spreads south-westward as a lens of low-salinity water. Further, fresh water advects offshore to distances of about 150 km. The transient, cross-shelf, haline frontal zones observed along the western margin of the Bay of Bengal separate the northern dilute waters from the southern saline waters.
Phosphorus sorption-desorption by some sediments of the Johnstone Rivers catchment, northern Queensland
Authors: Pailles C , Moody PW
Published: November 2005

Phosphorus (P) sorption-desorption characteristics were determined for 11 sediments from the Johnstone Rivers catchment, northern Queensland. Sediments were selected to cover a range in values of Bray extractable P from 0.1 to 10.4 mg P kg-1. P sorption curves were determined by using 0.01 M NaCl to simulate fluvial water conditions and, on a restricted number of sediments, 0.5 M NaCl to simulate sea water. The amounts of P released in 10 successive extractions for 30 min with 0.01 M CaCl2 were determined for each sediment. The amounts of P desorbed either declined to nondetectable levels or declined to a constant amount. These desorption curves were used to delineate 'rapidly desorbable' P from 'slowly desorbable' P. Bray extractable P and adsorption characteristics (equilibrium solution P concentration and P buffer capacity) were poorly correlated with 'rapidly desorbable' P. Most sediments in the suite would act as P sinks in both fluvial and marine environments because their equilibrium P concentrations are lower than the dissolved inorganic P concentrations of their respective water columns. For those sediments acting as potential sources (5 from 11 in 0.01 M NaC1, 2 from 6 in 0.5 M NaCl), amounts of P that could potentially be desorbed into the fluvial water column ranged from 0.1 to 3.9 mg P kg-1 sediment.
Associations and abundance of sea urchins and abalone on shallow subtidal reefs in southern New South Wales
Authors: Andrew NL , Underwood AJ
Published: November 2005

The densities of the abalone Haliotis rubra and the sea urchin Centrostephanus rodgersii were estimated at five localities on the southern coast of New South Wales. Abalone were most abundant at localities south of Eden but were patchy at all localities and sites. There was no clear pattern in the abundance of C. rodgersii among localities but there was considerable variation among sites within localities. Densities of abalone and sea urchins were negatively associated within 10-m2 transects at 20% of sites. At the smallest nearest-neighbour scale, the two species were segregated. The population structures of abalone differed considerably among sites; some populations consisted of single size cohorts, whereas others were much more complex. Abalone large enough to be collected legally were rare at all localities and comprised less than 10% of the total population. Possible reasons for the negative associations between H. rubra and C. rodgersii are discussed.
Enzyme variation in orange roughy, Hoplostethus atlanticus (Teleostei: Trachichthyidae), from southern Australian and New Zealand waters
Authors: Elliott NG , Ward RD
Published: November 2005

Orange roughy from six localities around the southern coasts of Australia showed no evidence of genetic subdivision when the products of 11 polymorphic enzyme loci were analysed electrophoretically. Samples ranged in size from 84 to 171 per locality. Gene frequencies were very similar in samples taken from New Zealand. The amount of total genetic diversity attributable to subdivision among samples is estimated at 0.55 to 0.22%, but bootstrapping procedures showed that much of this diversity could arise from sampling error. A minimum of around 200 migrants per locality per generation would be sufficient to maintain the observed genetic homogeneity, although actual numbers migrating are likely to be greater than this.
Blood gas transport and oxygen consumption in a supralittoral crab, Leptograpsus variegatus (Crustacea: Brachyura)
Authors: Greenaway P , Morris S , Sanders N , Adamczewska A
Published: November 2005

Routine oxygen consumption of Leptograpsus variegatus in air (MO2=6.12 mass (g)0.854 �mol h-1) was elevated from three to six times (depending on body size) following exhausting exercise (MO2= 42.8 mass0.608 �mol h-1). In addition, considerable capacity for anaerobic exercise was apparent and total body L-lactate rose 4.8 times during the exercise period (25-g crab). The respiratory pigment (haemocyanin) had a low affinity under normoxic resting conditions (P50=25 Torr, where 1 Torr = 101 325/760 Pa) but showed a large Bohr effect (Bohr factor = -0.78), a marked temperature sensitivity (ΔH= 67.4 kJ mol-1), and a large potentiating effect by L-lactate (lactate coefficient = - 0.205). These features are more characteristic of the haemocyanin of aquatic crustaceans than those of terrestrial crustaceans. The affinity of the haemocyanin of L. variegatus was also decreased by elevated PCO2. Haemocyanin was responsible for 92% of oxygen transport in both resting and exercised crabs. These features are discussed in relation to the degree of adaptation of L. variegatus to a terrestrial lifestyle.
Remote sensing of Australian wetlands: An evaluation of Landsat TM data for inventory and classification
Authors: Johnston RM , Barson MM
Published: November 2005

This study aimed to develop simple remote-sensing techniques suitable for mapping and monitoring
wetlands, using Landsat TM imagery of inland wetland sites in Victoria and New South Wales. A range
of classification methods was examined in attempts to map the location and extent of wetlands and their
vegetation types. Multi-temporal imagery (winter/spring and summer) was used to display seasonal
variability in water regime and vegetation status. Simple density slicing of the mid-infrared band (TM5)
from imagery taken during wet conditions was useful for mapping the location and extent of inundated
areas. None of the classification methods tested reproduced field maps of dominant vegetation species;
however, density slicing of multi-temporal imagery produced classes based on seasonal variation in
water regime and vegetation status that are useful for reconnaissance mapping and for examining
variability in previously mapped units. Satellite imagery is unlikely to replace aerial photography for
detailed mapping of wetland vegetation types, particularly where ecological gradients are steep, as in
many riverine systems. However, it has much to offer in monitoring changes in water regime and in
reconnaissance mapping at regional scales.
A coccolithophorid bloom in Jervis Bay, Australia
Authors: Blackburn SI , Cresswell G
Published: November 2005

A massive algal bloom of the coccolithophorid Gephyrocapsa oceanica Kamptner (Prymnesiophyceae)
developed in Jervis Bay, a coastal embayment at 34�s on the New South Wales coast, in mid December
1992. The bloom coloured the entire bay a dramatic milky blue-green, which was clearly visible from
aircraft and detectable in the visible band by the US satellite NOAA-11. The bloom, which reached cell
densities of 1.8 x 107 cells L-1, persisted for a month. Such high densities of coccolithophorids have
not been recorded before in Australian waters. Furthermore, it is the first record, world-wide, of a
large-scale mono-specific bloom of G. oceanica. The bloom is suggested to have been driven by an
intrusion of continental-slope water that continuously entered into the bottom of the bay.
The Leeuwin Current south of Western Australia
Authors: Cresswell GR , Peterson JL
Published: November 2005

Satellite images as well as data collected in situ were used to follow the seasonal changes of the Leeuwin
Current south of Western Australia (WA) in 1986-87. The current has two major sources: salty
subtropical water from west of WA, and fresher tropical water from north of WA. In summer, the
tropical waters are excluded by the strong equatorward wind stress. In autumn and winter, this wind
stress is reduced and tropical waters flood southward to dominate the flow. Nevertheless, salty subtropical
water is entrained en route, and so, whatever the season, the Leeuwin Current is more saline
than the 'local' subantarctic waters off southern WA. From a research vessel, observations were made
on the current and one of its offshoots in June 1987. The Leeuwin Current had a maximum surface
speed of more than 1 m s-1 just beyond the shelf edge. Its warm, low-salinity surface core rode on
a sheath of higher-salinity subtropical water that it had entrained upstream. The first survey of the
offshoot showed it to be 50 km across and 130 m deep (for water warmer than 17�C), and it extended
200 km seaward (as deduced from a satellite image). Velocities in the offshoot ranged up to 1 m s-1
southward and 1 m s-1 north-eastward on the western and eastern sides, respectively. Richardson
numbers were, in places, as low as 0.25. On a second survey two days later, the offshoot was found
to have pinched off and the remnant bulge on the edge of the parent stream to have moved 30 km
eastward. The flow around this bulge reached 1.6 m s-'. The offshoot/bulge was possibly first formed
in April, and it kept its identity at least until August. During this time, it moved eastward at speeds
between 2 and 15 km day-1. In June, the offshoot was estimated to contain water equivalent to five
days' transport of the parent current.
SST fronts in inverse estuaries, South Australia-indicators of reduced gulf-shlef exchange
Authors: Petrusevics PM
Published: November 2005

During the austral summer, the entrance to the South Australian gulfs exhibits sea surface temperature
(SST) fronts of between 3 and 3.5°C that are clearly discernible on NOAA/AVHRR imagery. The
surface fronts are formed by seasonal juxtaposition of relatively warm gulf and cooler bight water.
Field surveys indicate that the SST fronts coexist with and overlay strong benthic temperature and
salinity differentials of 74°C and 1.2-1.5, respectively. Density variation in the entrance to both gulfs
exhibits a density minimum at all depths and suggests bottom convergence of density currents that
effectively isolates gulf from shelf waters during the summer. Analysis of field temperature-salinity data,
using the 1-atmosphere equation of state, indicates that the density minimum is formed by mutual
compensation of the salinity and temperature dependent terms. The effect of the combined salinitytemperature
dependent terms is less but not insignificant. The value of satellite SST imagery as a tool
to signal periods of reduced communication between the gulfs and the shelf is revealed.
Resource enhancement of grazing mayfly nymphs by retreat-building caddisfly larvae in a sandbed stream
Authors: O'Connor NA
Published: November 2005

Over the summer-autumn low-flow period in the sandy upper and middle reaches of the Creightons
Creek system of northern Victoria, Australia, several different macroscopically visible substrate patch
types form on the streambed. Exploratory multivariate analyses revealed a distinct macroinvertebrate
fauna associated with each patch type. The major patch types were the thalweg, or pathway of main
flow, in which the substrate consisted of constantly shifting fine sand, and adjacent stable patches
of coarser sand, covered with larval retreats of the hydropsychid caddisfly Cheurnatopsyche sp.
(Trichoptera:Hydropsychidae). Although thalweg and Cheurnatopsyche patches contained a similar
interstitial macroinvertebrate fauna, the former lacked a surface-dwelling, or epibenthic, fauna. The
silken retreats of Cheurnatopsyche larvae entrained algal filaments and detritus, food of the grazing
mayfly nymph Baetis sp. Baetis nymphs recolonized plots containing Cheurnatopsyche retreats in higher
numbers than plots in which Cheurnatopsyche retreats and their entrained detritus had previously been
scoured away. Given the widespread distribution of the Cheurnatopsyche patch type in the system
during the low-flow period, it is hypothesized that the indirect interaction between these two species may
constitute a significant pathway in the energy budget of the stream.
Increased fecundity of the cladoceran Moinodaphnia macleayi on a diet supplemented with a green alga, and its use in uranium toxicity tests
Authors: Hyne RV , Padovan A , Parry DL , Renaud SM
Published: November 2005

The effects of two synthetic diets and four algal diets on the survival and fecundity of Moinodaphnia
macleayi for use in life-cycle toxicity tests were determined. The synthetic foods were a suspension of
blended cichlid fish pellets with powdered alfalfa, either prepared fresh or fermented in natural water
for 3 days. The algae, isolated from the habitat of M. rnacleayi in the Alligator Rivers Region, were
Selenastrum sp., Ankistrodesmus (falcatus?), Scenedesmus quadricauda and a Chlamydomonas sp.
Each alga was tested alone or as a supplement to the fermented synthetic food. The diet that supported
the greatest number of young and the highest survival rate over a 5-day period was a combination
of the fermented synthetic food and Chlamydomonas sp. Analysis of the fatty acid composition of
the lipid fraction of the four algal species showed that Chlamydomonas sp., Selenastrum sp. and
Scenedesmus quadricauda had significant concentrations of the highly unsaturated fatty acids 18 : 2(n-6),
18 : 3(n-6) and 18: 3(n-3). In terms of size and dry weight, Chlamydomonas sp. was the smallest of
the algal cells studied. The toxicity of uranium to M. macleayi survival, determined under standard
conditions, was a lowest-observed-effect concentration (LOEC) of 200 �g L-1 after 48 h and 25 �g
L-1 after 5 days.
Distribution and growth of juvenile mulloway, Argyrosomus hololepidotus (Pisces: Sciaenidae), in the Hawkesbury River, south-eastern Australia
Authors: Gray CA , McDonall VC
Published: November 2005

The distribution, recruitment, relative abundance and growth of juvenile mulloway,
Argyrosomus hololepidotus Lacepede, was investigated in the Hawkesbury River.
Otter trawling was used monthly between July 1986 and March 1988 at 12 sites
along a salinity gradient over 85 km of the estuary. The greatest numbers of juveniles
were caught at sites in the mid section of the estuary (20-40 km from the mouth) where
salinities were greatly reduced. No A. hololepidotus were caught at sites that were
permanently fresh water and few were caught at the marine-dominated sites closest
to the mouth of the estuary. The greatest numbers of juveniles were caught between
March and September (autumn-winter) and the fewest between October and January
(spring-summer). Juveniles with an estimated age of 2-6 months were caught between
February and July (late summer-winter) each year at a size of 30-150 mm total length.
Juveniles increased in length by 80-100 mm between March and October.
Facts and numerical artefacts in modelling the dispersal of crown-of-thorns starfish larvae in the Great Barrier Reef
Authors: Wolanski E
Published: November 2005

Existing models of the dispersal of crown-of-thorns starfish larvae in the
Great Barrier Reef suffer from problems with numerical algorithms,
unrealistic assumptions about open-boundary forcings, and unrealistic
parameterization of dispersion processes in the presence of salient
topography. These problems probably invalidate some of the published
model results, and these models should probably not be used for
management of the Great Barrier Reef Marine Park.
Limnological characteristics of two coastal Dune Lakes, Jervis Bay, South Eastern Australia
Authors: Norris RH , Moore JL , Maher WA , Wensing LP
Published: November 2005

Limnological features of two permanent, closed, coastal dune lakes that are
separated by only about 400 m are reported. The depth of Lake Windermere
fluctuated by about 7 m during this study (1982- 1988); however, fluctuations
up to 15 m were observed between 1970 and 1988. Lake Windermere is
exposed to wind mixing, is transparent and is usually mixed, or only weakly
stratified. Lake McKenzie is semi-perched, darkly coloured and strongly
stratified with an anoxic hypolimnion during summer. It is about one fifth
of the surface area and half the depth of Lake Windermere and protected
from wind mixing. Both lakes are acidic and have low salinity, and the
dominant ions are sodium and chloride probably from precipitation of
marine aerosols. Oxygen depletion in the hypolimnion of both lakes indicates
a substantial organic load, the source of which is allochthonous material from
the catchment rather than autochthonous material. Lake Windermere had higher
densities of zooplankton (mostly Calamoecia tasmanica) than Lake McKenzie,
but the latter lake had higher numbers of the predaceous Chaoborus sp. Lake
McKenzie had higher invertebrate densities than Lake Windermere and these
fluctuated widely between years, corresponding with variation in rainfall. Mayflies
and chironomids were numerically dominant in Lake McKenzie, and caddisflies
and chironomids were numerically dominant in Lake Windermere. Turtle and
odonate predators were more common in Lake McKenzie than in Lake Windermere.
It is postulated that biological interactions are more important in shaping the communities
in Lake McKenzie and physical factors such as wave action are more important in Lake Windermere.
Review of the Australian fish family Arripididae (Percomorpha), with the description of a new species
Authors: Paulin C
Published: November 2005

The family Arripididae contains one genus, Arripis Jenyns, with four species
endemic to areas within temperate Australian and New Zealand waters.
A. georgianus (Valenciennes), found throughout cool temperate Australia,
is identified by having more than 27 rakers on the lower limb of the first gill arch.
A. truttaceus (Cuvier), found in Western and South Australia, Victoria and
Tasmania, has fewer than 17 rakers on the lower limb of the first gill arch.
A. trutta (Bloch & Schneider), found in eastern Australia, Victoria, Tasmania
and New Zealand, has 20-24 rakers on the lower limb of the first gill arch and
a small caudal fin whose length is equal to or less than the length of the head.
A. xylabion sp, nov., found in northern New Zealand, Lord Howe Island, Norfolk
Island and the Kermadec Islands, is identified by having 20-25 rakers on the lower
limb of the first gill arch and a large caudal fin whose length is longer than that of
the head. A neotype is designated for A. trutta.
Invetebrate communities of Relict streams in the Arid Zone: the George Gill Range, Central Australia
Authors: Davis JA , Harrington SA , Friend JA
Published: November 2005

The George Gill Range (24�S,132�E) 220 km south west of Alice Springs in the
Northern Territory, lies within one of the driest regions of Australia. Diel and
seasonal temperature differences are extreme and the average rainfall is
250 mm per annum. The streams of the Range are the largest group within
the Central Ranges and are relatively pristine. Their flow regimes are episodic
but deep rock pools appear to act as reservoirs of surface runoff and may also
receive groundwater from the Mereenie aquifer.
The waterbodies of the Range and some nearby areas were sampled in July and
December 1986 to determine the composition of the macroinvertebrate communities
and biogeographical relationships with the fauna of lotic systems elsewhere in Australia.
Macroinvertebrate species richness at the Range was comparable with that of
other Australian streams but no Plecoptera, Isopoda or Amphipoda were collected.
The almost complete absence of shredders may reflect low allochthonous inputs,
because riparian vegetation in the arid zone is generally sparse. A small proportion of
the fauna of the Range appears to be a relictual stream fauna. Species of low vagility such
as the waterpenny, Sclerocyphon fuscus, would not be capable of dispersal across the large
tracts of arid land that now separate the Range from southern Australia, where it is also found.
The occurrence of new species at the Range suggests that it is also a site of allopatric
speciation within some groups. The conservation values of the streams of the George
Gill Range and other sites, such as Giles Springs in the Chewings Range, are extremely high.
They represent unique aquatic communities of both ecological and evolutionary importance in the arid zone.
Sexual maturity, reproductive season and fecundity of the spiny lobster Panulirus penicillatus from the Gulf of Eilat (Aqaba), Red Sea
Authors: Plaut I
Published: November 2005

Panulirus penicillatus Olivier (1791) (Decapoda: Palinuridae) is widely distributed in the Indian and
Pacific Oceans and is the most common spiny lobster in the Red Sea. Female lobsters (n =234), were
collected on four occasions in 1986 from the coral reef of Dahab, 110 km south of Eilat, Israel. Field
data and the gonadal index indicated that the reproductive season was from February to October,
during which the females spawned 2-4 times. In nature, females became sexually mature at a carapace
length (CL) of 50 mm. This result was confirmed by morphometric analysis of the regression between
pleopodal exopodite length and carapace length. The number of eggs per spawn (E) was related to CL
by the equation E=2.715 ×(CL)2.581. The incubation period of eggs was 35.5�1.0 days (�s.d.)
at temperatures of 24-27�C in the aquarium. The results are compared with data on P. penicillatus
from other parts of its geographic range, and the effect of geographic isolation on reproduction is discussed.
Limnology of rearing ponds for Australian fish larvae: Relationships among water quality, phytoplankton, zooplankton, and the growth of larval fish
Authors: Culver DA , Geddes MC
Published: November 2005

Fertilization of earthen ponds used to rear the larvae of golden perch, Macquaria ambigua, and
silver perch, Bidyanus bidyanus, resulted in phytoplankton blooms dominated by the cyanobacterium
Anabaena possibly because of a low N:P ratio. There was a zooplankton succession of rotifers
(mostly Brachionus), Moina, Boeckella and Mesocyclops, and then Daphnia. An increase in Daphnia
correlated with a decline in Anabaena, suggesting grazing on that cyanobacterium. Golden perch
larvae included copepods in their diet whereas silver perch did not, and this was reflected in lower
Boeckella numbers in the golden perch ponds. There was sufficient zooplankton forage, supplemented
by chironomid larvae in the later stages of the rearing ponds, for fish growth. The limnological conditions
and zooplankton communities in these ponds provide a model for evaluating nursery grounds for these fish.
Bioconcentration factors and kinetics of chlorobenzenes in a juvenile crab (Portunus pelagicus (L))
Authors: Mortimer MR , Connell DW
Published: November 2005

The uptake- and depuration-rate constants (k1 and k2 respectively), according to first-order kinetics,
were measured for a series of chlorobenzenes with juvenile crabs, Portunus pelagicus. These constants
were found to be related to the lipophilicity of the chlorobenzenes as expressed by the octanol-water
coefficient (log Kow), giving relationships similar to those observed with fish. However, the actual
magnitude of k1 and k2 on a lipid basis ranged from 720 to 5880 h-1 and from 0.492 to 0.0102 h-1
respectively, which is about ten times faster than those for fish. The bioconcentration factor (KB in wet
weight units) obtained from these rate constants was related to Kow, by the following expression.
log KB=-2.88+1.09 log Kow.

The empirical constants in this equation are similar to those observed with other aquatic organisms
except that the value of -2.88 is lower than that reported with the other organisms. This is probably
due to the relatively low lipid content of the crabs. It is suggested that the bioconcentration of essentially
nonbiodegradable lipophilic compounds occurs as a result of partitioning between biota lipid and water.
Other physicochemical properties (molar volume and aqueous solubility) and two molecular descriptors
(zero- and first-order Randik indices) exhibited good correlations with the bioconcentration characteristics
described above.
Aspects of spawner-recruit relationships, with particular reference to crustacean stocks: A review
Authors: Caputi N
Published: November 2005

The fundamental biological issue for fisheries management is undoubtedly the prevention of recruitment
overfishing, i.e. to prevent the spawning stock from being depleted by fishing to a level where it
significantly reduces the abundance of recruits. However, for many important fisheries, particularly
crustacean fisheries, the stock-recruitment relationship (SRR) is not known. In many cases, research
on recruitment has concentrated on short-term studies of recruitment processes to the exclusion of
research into the SRR which requires development of long term databases.
This paper examines techniques required to model the SRR, using case studies from Western Australian
crustacean fisheries. Outlines of potential problems such as errors and biases in the measurement of
stock and recruitment indices, the time series nature of the data, and lack of stationarity in the data, are
given with possible solutions. Environmental effects, which can greatly influence the abundance of recruits,
may need to be determined before the underlying SRR can be seen. Some of the advantages and possible
disadvantages of incorporating environmental variables in the SRR are examined. A thorough assessment of
SRRs also involves a study of the impact of fishing on the stock and the effect of stochastic variation using
simulations. The evaluation of the SRR requires a multi-disciplinary approach which includes the fields of
biology, environment, economics, population dynamics and statistics.