bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphorus metabolism in Coral Reef Communities: Dynamics in the Water Column
Authors: Sorokin YI
Published: November 2005

Phosphorus dynamics were studied in the coral reef waters of Heron and Wistari Reefs in the Capricornia group, Great Barrier Reef, Australia, using radioisotopic techniques. All studies were made during August-October 1986. Labelled phosphate (PO4 -33P) was used to measure total uptake as well as uptake by bacterioplankton alone. Rates of total PO4-P uptake by microplankton varied between 20 and 120 ng P L-1 h-1 at water temperatures of 20-24� C. The daily (24 h) uptake rate of PO4-P was 0.5-3.0 �g L-1. The ambient PO4-P content of water over the reefs was low (0.03- 0.3 �mol L-1, or 1-10 �g P L-1). Turnover time of PO4-P in the water column of these reef areas is therefore very short, being in the range of 2-8 days, even when its possible net consumption by bottom biota is ignored. Bacterioplankton, not phytoplankton, was found to be the major consumer of inorganic phosphorus in these waters. The percentage of total PO4-P uptake by bacteria varied from 50 to 90%. The results of these estimations are discussed in terms of the importance of active phosphorus dynamics in the water column to the nutrient budget of the coral reef ecosystem.
Productivity and growth rates of Coral Reef Bacteria on hard Calcareous Substrates and in Sandy Sediments in Summer
Authors: Moriaty DJW , Hansen JA
Published: November 2005

The growth rates and productivity of bacteria in the communities living on hard limestone substrate and sand were determined from the rates of incorporation of tritiated thymidine into DNA. Two reefs in the southern Great Barrier Reef, around Heron Island and One Tree Island, were studied during summer (January 1986). The specific growth rates varied on a diel cycle, being slowest at night, in both sand and hard substrate. They ranged from 0.005 h,-1 at night to 0.025 h-1 during the day in sand and from 0.002 to 0.01 h-1 in hard substrate. Productivity was also greater during the day than at night, ranging from 1 mg C m-2 h-1 at night to 5.5 mg C m-2 h-1 during the day in sand and from 0.5 to 2 mg C m-2 h-1 in hard substrate. Values were similar for both islands. The increase of four- to five-fold in bacterial growth rates in the sand and hard substrate on Heron Island during the daytime indicates that the heterotrophic bacteria rely mostly on organic matter exuded from the algae with which they are associated.
Protein Electophoresis for identification of Australasian fish stocks
Authors: Smith PJ
Published: November 2005

Gel electrophoresis, coupled with histochemical staining of specific proteins, is a powerful technique that has been applied widely in population biology. This paper outlines theoretical and practical aspects of the technique in relation to stock separation studies. The importance of protein variation and the limitations of protein electrophoresis are discussed. Laboratory methods and the genetic interpretation of gel phenotypes are described along with statistical methods for data analyses. Australasian examples of applications of the technique are given and include species and fillet identification as well as stock identification. Some theoretical and empirical problems arising from the use of the technique in stock separation studies are discussed.
Reappraisal of the use of parasites for fish stock identification
Authors: Lester RJG
Published: November 2005

Analysis of the geographical distributions of parasites is an excellent source of information about the movement of host fish. Occasionally such analysis can also allow us to discriminate between fish populations, though unequivocal discrimination usually requires methods with a genetic basis. In assessing fish movement, parasites have two advantages over conventional tags: they can more readily detect mass migration and, because the fish only have to be caught once, the data are usually cheaper to obtain. The most important criterion in selecting a parasite to be used as a tag is its longevity in the fish; short-lived parasites give information on short-term movements of the fish, long-lived parasites on more extensive migrations.
Copper bioavailability and amelioration of toxicity in Macquarie Harbour, Tasmania, Australia
Authors: Stauber Jennifer L. , Benning Rodney J. , Hales Leigh T. , Eriksen Ruth , Nowak Barbara
Published: November 2005

The 100-year operation of the Mount Lyell Mining and Railway Company
Limited’s copper mine in Queenstown, Australia, has resulted in the
deposition of over 100 million cubic metres of mine tailings, smelter slag and
topsoil into the King River and Macquarie Harbour. Apreliminary risk
assessment, together with chemical measurements of dissolved copper,
ASV-labile copper, copper complexing capacity and resin-adsorbed copper,
suggested that copper in mid-salinity harbour waters was potentially
bioavailable. However, toxicity tests based on inhibition of microalgal
(Nitzschia closterium) growth showed that copper in
these waters was not toxic, even though labile copper concentrations
(6–24 µg L−1) exceeded the
concentration of lowest observable effect for algae of 5 mg
L−1. Measurements of intracellular and
membrane-bound copper confirmed that cell division was not affected because
copper was not taken up intracellularly. Amelioration of copper toxicity was
due to binding of dissolved organic matter and/or other metals at the cell
membrane, preventing copper binding and uptake. An understanding of the
mechanism of copper toxicity and its amelioration is vital to assessing
various clean-up options for the harbour.
Age, growth and maturity of a New Zealand endemic shark (Mustelus lenticulatus) estimated from vertebral bands
Authors: Francis Malcolm P. , Maolagáin Caoimhghin Ó
Published: November 2005

Rig (Mustelus lenticulatus) specimens were aged by
counting growth bands in whole vertebrae that were illuminated laterally with
fibre-optic lights. Bands were counted by two readers who used information on
the diameter of the vertebrae of new-born young and 1-year-old juveniles to
identify the inner bands. The greatest estimated age was 12.1 years for a
female of 137 cm total length, but few rig were more than 8 years old. For
west coast South Island (WCSI) rig, there was no significant difference in
growth rates of males and females. After pooling both sexes, there was no
significant difference in growth rates between WCSI and east coast South
Island (ECSI) rig. The combined WCSI and ECSI von Bertalanffy growth curve was
Lt = 147.2 (1 – e
−0.119[t + 2.35]). This curve
agreed well with growth curves derived from length–frequency data, but
validation of the ageing technique is still required. WCSI males mature at
~85 cm and 5–6 years, and females at ~100 cm and 7–8
years. ECSI rig probably mature at similar lengths and ages. Tagged rig have
been recaptured after nearly 14 years at liberty. Longevity probably exceeds
15 years, and may exceed 20 years.
Genetic variation in the greenback flounder Rhombosolea tapirina GÜnther (Teleostei, Pleuronectidae) and the implications for aquaculture
Authors: van den Enden Tony , White Robert W. G. , Elliott Nicholas G.
Published: November 2005

Samples of the greenback flounder, Rhombosolea tapirina,
were collected from five Tasmanian sites and from one site each off Victoria
and New Zealand. Thirty enzyme-coding loci were analysed by gel
electrophoresis. Seventeen loci were variable, nine of which were polymorphic
in at least four samples. Average heterozygosity across all 30 loci was
relatively high at 0.086 ± 0.032. There were significant genetic
differences between the Australian and New Zealand samples, with a genetic
distance of 0.041, which was an order of magnitude larger than that observed
between any Australian samples. Samples from the west coast of Tasmania and
from Victoria were genetically isolated from each other and from the remaining
four Tasmanian samples; the latter showed little variation among themselves.
Reductions in genetic variation (heterozygosity and alleles) were observed in
two cultured cohorts when compared with the wild-caught samples, with
corresponding low estimates of effective population sizes compared with
putative breeding numbers. No genetic variation was detected between normal
and malpigmented individuals from the same culture cohort.
Simple morphometric characters, confirmed by gel electrophoresis, separate small juvenile banana prawns (Penaeus indicus and P. merguiensis)
Authors: Pendrey R. C. , Loneragan N. R. , Kenyon R. A. , Vance D. J.
Published: November 2005

The juveniles of red-legged banana prawns
Penaeus indicus and white banana prawns
P. merguiensis are difficult to distinguish. Gel
electrophoresis, with the enzyme malate dehydrogenase, clearly separated into
species both large and small prawns. Four morphological characters were
measured from juvenile prawns (identified using electrophoresis): three of
these provided reliable separation into species. The mean ratio of the
distance from the anterior-most dorsal rostral tooth (first tooth) to the tip
of the rostrum (L 1 ): to the distance between this
tooth and the second tooth (L 1,2 ) was higher for
P. indicus (3.16) than
P. merguiensis (1.56). All juvenile
P. indicus had the first tooth posterior to the
antennular peduncle, while it was anterior for all
P. merguiensis. More than 90% of
P. indicus had six rostral teeth behind the eye, while
over 90% of P. merguiensis had five teeth behind
the eye. Damage to the rostrum prevented measurements of the position of the
first tooth in 20 to 30% of juvenile prawns. Combining the measurements
of the ratio of L 1 : L 1,2 and
the count of the number of rostral teeth behind the eye meant that all prawns
could be unambiguously identified.
Effect of temperature and feeding rate on the growth and survival of early and mid-stage phyllosomas of the spiny lobster Jasus edwardsii
Authors: Tong Lennard J. , Moss Graeme A. , Paewai Megan P. , Pickering Timothy D.
Published: November 2005

Stage I J. edwardsii
larvae that had hatched from embryos held at one of three temperatures were
reared at 12˚C to 24˚C and fed 2–3 mm brine shrimps. Larvae
reared at 24˚, 21˚, 18˚, 15˚ and 12˚C moulted to
Stage II after 7, 8, 11, 17 and 33 days respectively. Larvae from 18˚ and
15˚C embryos reared at 24˚C had 40% and 100% survival
respectively. Larvae reared at 12˚C had 10–15% survival.
Stages II, IV, VI and VIII larvae were reared at three temperatures and fed 4,
8, 12, 16, 24 or 36 brine shrimp per day. At optimum feeding levels and at
24˚, 21˚ and 18˚C, Stage II larvae moulted after 6, 8 and 11
days respectively, Stage IV after 9, 10 and 12 days, Stage VI after 12, 14 and
17 days and Stage VIII after 18, 21 and 25 days. Survival was generally
>70% but at 24˚C when fed >16 brine shrimp survival was
<40%. For all stages, consumption rates increased but total
consumption decreased with increasing temperature. For Stages II, IV, VI and
VIII the intermoult period increased as the brine shrimp ration reduced.
Larvae were successfully reared up to Stage VI ~25% faster at 21˚
than at 18˚C.
Using sustainability indicators to manage fisheries: experiences on the Bay of Bengal
Authors: Chong Kee-Chai
Published: November 2005

Experience in the fisheries of the Bay of
Bengal has demonstrated that a key factor in the sustainability of the
resource is the involvement of whole communities. The degree to which this is
achieved can be assessed with reference to signs such as the attitude of the
resource users, the participation of the community in management, the
relationship of fishers with money-lenders and market intermediaries, and a
reduction in the degree of pollution deriving from the community. These can be
used as indicators to monitor trends in the use of fisheries resources in this
and similar regions.
Unexpected relationships between coral reef health and socio-economic pressures in the Philippines: reefbase/RAMP applied
Authors: Pollnac Richard B. , McManus John W. , del Rosario A. E. , Banzon A. A. , Vergara S. G. , Gorospe M. L. G.
Published: November 2005

The paper analyses variables hypothesized to
affect the health of coral reefs. These variables include fishing pressure as
measured by fisher density and land-based human activities as indicated by
population, relative wealth, waste disposal and aspects of land use. Findings
indicating that the healthiest coral reef areas are characterized by higher
fisher densities as well as greater increases in population density were, at
first, surprising. In retrospect, the results fit perfectly with human
ecological theory; where possible, people tend to migrate from resource-poor
to resource-rich areas. Any synchronic analyses of the interrelationships
between the condition of aresource and associated population size or density
will probably be confounded by the dynamics of the populations dependent on
the resource. Hence, there is a need to account for this dynamic when
researching anthropogenic effects on coral reefs. The findings also indicate
that less-healthy reefs are found in areas with a higher percentage of land
devoted to permanent crops; this appears to be related to observed high levels
of runoff from permanent crops.
Indicators for marine ecosystems affected by fisheries
Authors: Christensen Villy
Published: November 2005

The paper explores two types of indicators:
Odum’s 24 attributes for describing the state of an ecosystem based on
its maturity; and the fishing-in-balance (FIB) index for describing how
ecosystem exploitation changes over time. Application of the FIB index to the
Gulf of Thailand and the North Atlantic fisheries, describing the development
in fisheries catches and their trophic levels over time, reveals that the
index is straightforward to parameterize and adds an ecological dimension to
fisheries catch series; it is a useful indicator for assessing the impact of
fisheries on ecosystems.
Sustainability reference systems and indicators for responsible marine capture fisheries: a review of concepts and elements for a set of guidelines
Authors: Garcia S. M. , Staples D. J.
Published: November 2005

This review was prepared as a background
document for the Consultation on Sustainable Indicators for Capture Fisheries
held in Sydney, Australia, 18–22 January 1998. It aims to facilitate the
development and implementation of indicators and to serve as a basis for the
development of part of the series of Technical Guidelines in Support of the
FAO Code of Conduct for Responsible Fisheries. The paper reviews the concept
of sustainable development (‘sustainability’). Five sustainability
frameworks are suggested for developing and grouping indicators. A discussion
of the criteria that could be used to measure and monitor progress towards
sustainability includes the types of possible indicators, their use within the
sustainability concept, use of reference points on which to compare indicators
and their relation to planning and management. Sustainable Development
Reference Systems are introduced as a tool for grouping indicators and
representing the interrelationships among them. Visual methods of portraying
the human and environmental dimensions of sustainability and their indicators
can be broadened to permit temporal and spatial comparisons. These, combined
with systems to scale the different dimensions to reflect different societal
values of their importance, can assist policy makers, fisheries managers,
industries, non-governmental organizations and the general public in
understanding and assessing progress towards sustainable development of
capture fisheries.
Changes in quantum efficiency of Photosystem II of symbiotic dinoflagellates of corals after heat stress, and of bleached corals sampled after the 1998 Great Barrier Reef mass bleaching event
Authors: Jones Ross J. , Ward Selina , Amri Affendi Yang , Hoegh-Guldberg Ove
Published: November 2005

Pulse–amplitude–modulation chlorophyll fluorometry was used to
examine changes in dark-adapted
Fv/Fm
of endosymbiotic dinoflagellate microalgae within the tissues of the temperate
coral Plesiastrea versipora exposed to elevated seawater
temperature. The
Fv/Fm
was markedly reduced following exposure of corals to 28°C for 48 h. When
corals were returned to ambient (24°C) conditions,
Fv/Fm
increased in an initial rapid and then secondary slower phase. Tissue
discolouration (coral bleaching), caused by a significant decrease in the
density of algae, was observed during the first 2–3 days of the recovery
period. After 14 days,
Fv/Fm
was still significantly lower than in control corals. The recovery of
Fv/Fm
is discussed in terms of repair processes within the symbiotic algae, division
of healthy algae and also the selective removal of photo-damaged
dinoflagellates. Under field conditions, bleached corals sampled at Heron
Island Reef during a bleaching event had significantly lower
Fv/Fm
than non-bleached colonies; four months after the bleaching event, there were
no differences in F v
/F m or algal density in
corals marked as having bleached or having shown no signs of colour loss. The
results of this laboratory and field study are consistent with the hypothesis
that an impairment of photosynthesis occurs during heat-stress, and is the
underlying cause of coral bleaching.
Descriptions of immature stages of Neureclipsis napaea neboiss from Australia (Trichoptera : Polycentropodidae), with notes on biology
Authors: Cartwright DI
Published: November 2005

The larva and pupa of Neureclipsis napaea Neboiss from Australia are described. They conform in most characteristics with Neureclipsis McLachlan larvae and pupae from the northern hemisphere, although the Australian larva differs in the number of setae present on the venter of abdominal segment 9 and on the basal segment of the anal prolegs. N. napaea has been collected from larger upland rivers in south-eastern Australia, where the larva forms a loose silken net suspended between rocks.
Population dynamics of an ectoparasitic gastropod, Hypermastus sp. (Eulimidae), on the sand dollar, Arachnoides placenta (Echinoidea)
Authors: Crossland MR , Alford RA , Collins JD
Published: November 2005

The association between the sand dollar, Arachnoides placenta, and the eulimid gastropod, Hypermastus sp., was investigated at Pallarenda Beach, Townsville, Queensland. Hypermastus sp. is a temporary ectoparasite of A. placenta that penetrates the latter's test to ingest gonad tissue and coelomic fluid. The infestation rate normally varies between 8 and 15% but increases in winter to 26%. This seasonal increase in the infestation rate appears to be due to an increase in the duration of attachment of female parasites. Hypermastus sp. is sexually dimorphic, with males being, on average, 0.6 times the size of females. Individuals may be protandric sequential hermaphrodites.
Genetic variation and population stucture in the blacklip abalone, Haliotis rubra
Authors: Brown LD
Published: November 2005

Populations of blacklip abalone (Haliotis rubra) from southern Australia have been investigated genetically using protein gel electrophoresis. Allele frequency and genotype distributions were analysed to provide information on population structure, gene flow patterns and genetic differentiation among local populations. Breeding populations appear to be large. Measures of genetic distance reveal an 'isolation by distance' broad-scale population structure, although significant genetic heterogeneity can occur between sites < 3 km apart. Reasons for this apparent contradiction are discussed. It is concluded that zones of about 500 km of coastline, corresponding to 'neighbourhood size', could be recognized for the conservation of regional gene pools, but that stock-recruitment relationships need to be established on a localized basis.
Active and passive dispersal of Centroberyx affinis (Berycidae) and Gonorynchus greyi (Gonorynchidae) larvae on the Sydney shelf
Authors: Smith Kimberley A.
Published: November 2005

Distributions of small and large larvae of
Centroberyx affinis (Berycidae) and
Gonorynchus greyi (Gonorynchidae) were examined along a
shore-normal transect across the Sydney continental shelf, south-eastern
Australia during January and April 1994. Both species were abundant, and 3016
individuals of C. affinis and 3184 individuals of
G. greyi were taken. Distributions of small and large
C. affinis reflected hydrographic variability and
suggested passive dispersal. Previous observations of high year-class
variability for this species may therefore reflect oceanographic variability
during the larval stage. In contrast, the distributions of
G. greyi only partially reflected hydrography and
appeared to be influenced by larval behaviour at both sizes. Size
distributions during each month indicated protracted spawning periods for both
species. Spawning by C. affinis may have occurred over
the inner shelf although the location was unclear because of the complexity of
nearshore currents. Spawning by G. greyi probably
occurred over the outer shelf. An increasing influence of larval behaviour
with larval size on the distribution of G. greyi
restricted larger individuals to the shelf break; this may have been a
response to higher productivity in this region.
A new technique for tagging abalone
Authors: Prince JD
Published: November 2005

A new technique for individually marking abalone in situ uses a nylon rivet to attach a numbered disc to the trema. In trials with Haliotis rubra, there was an initial loss of 4-16% and an annual rate of tag shedding of approximately 4-35%. Rates of tag loss depended on the positioning of the tag. The ease with which this technique can be used under water, the speed of application, and the low level of irritation expected to result from its use make this a useful addition to the range of techniques available for the study of abalone.
Foraging areas of southern elephant seals, Mirounga leonina, as inferred from water temperature data
Authors: Hindell MA , Burton HR , Slip DJ
Published: November 2005

Fourteen time-depth-temperature recorders were recovered from adult southern elephant seals (Mirounga leonina) returning to Macquarie Island to breed or moult. The resulting temperature/depth profiles indicated that all four males spent most of their time in waters lying over the Antarctic Continental Shelf, whereas only one of the ten females spent any time there. Five of the females foraged just off the Antarctic Continental Shelf. and the other five remained near the Antarctic Polar Front.
The fate of lead from duck shooting and road runoff in three western Australian wetlands
Authors: Lund M , Davis J , Murray F
Published: November 2005

This investigation examined whether lead shot from duck shooting was acting as a source of lead in an alkaline wetland ecosystem typical of popular duck-shooting areas in Western Australia. A polluted urban wetland and a pristine wetland were also studied for comparison. Lake Wannamal receives an estimated 82 kg of lead shot per year from duck shooting and no lead from any other known source. Lake Monger was estimated to receive 138 kg of lead per year from road runoff, leachate from a sanitary landfill site, and lead from aerosols. Thomsons Lake has no known source of lead from human activities. Lead concentrations in sediments did not differ significantly (P < 0.05) between Lake Wannamal and Thomsons Lake and apparently represent natural background levels. Lake Monger sediments were contaminated (mean: 192 � 82 �g Pb g-1 dry weight); the main source appeared to be runoff from a nearby freeway. Lead concentrations in Baumea articulata Blake, Typha orientalis Presl and Schoenoplectus validus Love were generally low; concentrations in the roots were higher than those in the leaves, suggesting that lead is poorly translocated. Lead concentrations in submerged macrophytes and in sediments were similar, which may be attributable to periphyton on the plants binding lead in seston resuspended by water turbulence. The cyanobacterium Microcystis sp. accumulated lead to low concentrations, believed to be from soluble lead in the water column. Macroinvertebrates accumulated lead to low concentrations, but no evidence was found of biomagnification. Lead concentrations were only slightly higher in macroinvertebrates in Lake Monger than in macroinvertebrates in the other lakes, indicating that lead uptake was poor even in a contaminated lake.
Nutrient and plankton distribution near a shelf break front in the region of the Bass Strait cascade
Authors: Gibbs CF , Arnott GH , Longmore AR , Marchant JW
Published: November 2005

Nutrient enrichment of surface water to the east of a shelf break front at the eastern end of Bass Strait occurs in winter. This area of enrichment is more than 100 nautical miles (E-W) by 150 nm (N-S). From east of Banks Strait (40� 45'S,148�E), some of the nutrient-rich water is carried northwards with the northward flow of Bass Strait water which later forms the well-known 'cascade' below the warmer waters of the Tasman Sea. In September 1984, the chlorophyll a concentration increased along the line of this northward flow, producing a maximum off the Victorian coast near where the cascade occurs. In contrast to nutrient and chlorophyll a distributions, zooplankton biomass (dry weight) was higher in the shallow water of Bass Strait than over the continental slope. This suggests that the plankton growth observed in shallow Bass Strait waters in late winter had ceased by September, but was continuing to the north-east and over the slope in waters with a shallow mixed depth. We propose that the northward flow of water along the shelf break maintains plankton in a nutrient-rich environment, so that they continue to grow until they are carried below the photic zone by the cascade.
Growth, mortality and recruitment rates of giant clams, Tridacna gigas and T. derasa, at Michaelmas Reef, central Great Barrier Reef, Australia
Authors: Pearson RG , Munro JL
Published: November 2005

Growth, recruitment and mortality rates of a population of giant clams (Tridacna gigas and T. derasa) were monitored between 1978 and 1985 in a 2.7 ha study area on Michaelmas Reef, Great Barrier Reef. The initial 1978 census revealed the presence of 1166 T. gigas and 44 T. derasa. For T. gigas, the Fabens method provided growth-parameter estimates of L∞ = 85.7 cm, K = 0.07 and to = 0.732 year. The generated von Bertalanffy growth curve was a relatively poor fit to an empirical growth curve. A better description of growth was obtained for younger clams by using a forced value of L∞, = 80 cm, yielding K = 0.105 and to = 0.145 year. There was marked variability in the growth rate of individual clams, which has implications for the aquaculture industry. Average annual mortality rates in two census intervals (1978 to 1980-81 and 1980-81 to 1985) were 3.4 and 10.7% respectively. A comparison of the calculated size structure (assuming constant recruitment) with the observed size structure clearly suggested that recruitment was not constant and had declined drastically from a peak in the 1950s. For the much smaller population of T. derasa, the Fabens routine yielded estimates of L∞ = 46.91 cm, K= 0.108 and to = -0.188 year. The average annual mortality rate was 4.4%. Trends in recruitment could not be determined because of the small sample size. This study has highlighted the need for follow-up studies of this and other populations of giant clams if we are to understand more fully the processes of growth, recruitment and mortality in wild stocks and the implications for stock management and aquaculture.
Reproductive behaviour and early development of the honey blue-eye, Pseudomugil mellis Allen and Ivantsoff 1982 (Pisces : Pseudomugilidae), from the North-east Coast Divison, south-eastern Queensland, Australia
Authors: Semple GP
Published: November 2005

Specimens of Pseudomugil mellis larger than 15 mm standard length (SL) showed sexual dichromatism as well as dimorphism in fin and body shape. Pairing occurred diurnally, with multiple releases of eggs amongst submerged vegetation between late morning and early afternoon when increasing water temperature reached 28� C. Eggs were demersal, adhesive and spherical (1.29-1.64 mm diameter) and had adhesive fibres (0.5-2.0 mm long) distributed (0.2-0.3 mm apart) over the chorion. Oil droplets (0.01-0.35 mm diameter) persisted throughout egg and larval development. Eggs hatched 112-190 h after spawning when they were incubated at 25-27�C. Yolk-sac larvae were 3.60-5.00 mm SL at hatching and began feeding at the surface after absorption of the yolk and oil droplets (3-80 h after hatching). All fin rays were developed in 9.0 mm SL fry, which feed at any depth. Aquarium-reared fish first spawned at 20 mm SL, when they were 95 days old. Features of Pseudomugil reproduction as they relate to a specific survival strategy and to taxonomy are discussed briefly.
Recolonization dynamics of benthic macroinvertebrates after artificial and natural disturbances in an Australian temporary stream
Authors: Brooks SS , Boulton AJ
Published: November 2005

The effects of substratum particle size (cobbles, coarse gravel and medium-fine gravel) on recolonization by benthic macroinvertebrates after disturbance was investigated in small plots (0.05 m2) in the Finniss River, an intermittent stream in South Australia. Six weeks after flow resumed, the intermediate particle size (coarse gravel) supported the greatest densities of taxa and individuals. Experimental disturbance reduced species richness by 83% and numbers of individuals by 97%. Rapid recolonizers (e.g. mayfly and stonefly nymphs) showed little substratum specificity and attained predisturbance densities within one day. Slow recolonizers (e.g. chironomid hatchlings) favoured gravel substrata and had not reached predisturbance densities within 4 days. Recolonization of small plots appeared to be by surface movement from neighbouring intact areas. A spate on Day 7 prevented further sampling, destroying all experimental plots, but this permitted a study of macroinvertebrate recolonization following a natural disturbance at a larger spatial scale. The spate reduced species richness by 45% and numbers of individuals by 70%. Vertical migration rather than drift appeared to be the major source of recolonizing fauna. Our data show that results from small-scale experiments can not be extrapolated to large-scale disturbance because the scale of disturbance strongly influences the rate and pathways of recolonization as well as the sources and faunal composition of the recolonists.
Aspects of the limnology of Yeppen Yeppen Lagoon, central Queensland
Authors: Mackey AP
Published: November 2005

Aspects of the morphometry and physical and chemical limnology of Yeppen Yeppen Lagoon, in tropical Australia, have been investigated. The lagoon is a channel billabong lying in the old bed of the Fitzroy River. It has a relatively small, shallow and elongated basin. Seasonal variations in water temperature, light regime, oxygen concentration, pH and conductivity suggest that the lagoon exhibits a warm monomictic pattern of thermal stratification rather than a continuous warm polymictic one. The annual heat budget was 3294 calories cm-2 year-1. Maximum work of the wind was 238.8 g-cm cm-2, and maximum stability was 34.5 g-cm cm-2. Despite the apparently low stability of stratification, the lagoon remained thermally stratified for much of the year. Analysis of wind-distributed heat suggested that slow mixing was taking place even during periods of relatively high stability, although this mixing was insufficient to reoxygenate the hypolimnion, which remained anoxic for much of the year. Yeppen Yeppen Lagoon is likely to prove eutrophic, and it is suggested that primary productivity will be high because a large volume of the lagoon's water is well lit and a large sediment surface area is in contact with the epilimnion. Notes on the biota of Yeppen Yeppen Lagoon are also given.
Characterization of organic matter at the air-sea interface, in subsurface water, and in bottom sediments near the Malabar sewage outfall in Sydney's coastal region
Authors: Nichols PD , Espey QI
Published: November 2005

The lipid and related-chemical compositions of samples from the air-sea interface, subsurface water and sediments collected adjacent to Sydney's Malabar nearshore sewage outfall during January and February 1990 were analysed in detail. A novel sampling scheme made use of a rotating-drum microlayer sampler, a towed Seastar sampler for filtration and extration of subsurface water in situ, and sediment collection in Teflon bags by divers. Particulate and dissolved organic matter was examined for four distinct aquatic environments: the surface microlayer in a no-slick zone (ML), the microlayer in a plume slick (PS), the microlayer in a banded slick (BS) and subsurface waters (SS). The concentrations of lipid classes and of many individual components in particulate matter from water samples generally followed the trend PS > ML > BS > SS, although in several instances the sequence began with ML > PS. A similar pattern was seen for the dissolved organic fractions. The composition of the ML sample differed from the compositions of the other water samples for several of the lipid classes analysed; the very high relative abundance of cholesterol and the presence of significant portions of long-chain saturated and monounsaturated fatty acids indicate a substantial marine origin for the lipids in the ML sample. The concentrations of most components were generally an order of magnitude higher in sediment 0.5 km from the Malabar outfall than in sediment 0.85 km away (Long Bay). The faecal indicator coprostanol was present in all samples at concentrations ranging from 0.1 to 7 �g L-1 in water and from 0.1 to 1.1�g g-1 in sediments. Petroleum contamination was also apparent in all samples, based on a number of distinctive features of the hydrocarbon profiles: the occurrence of a high abundance of unresolved complex material, little or no odd-over-even predominance in the distribution of n-alkanes, and the presence of hopanes and steranes characteristic of crude oil. Polycyclic aromatic hydrocarbons (PAHs) derived from combustion sources were detected in sediments at both distances from the outfall. PAH concentrations in water samples were at the limits of detection of this study. With the commissioning of deep-water outfalls to replace the nearshore ones, a decrease in nearshore contamination is expected. This study provides baseline chemical data for future comparative examination of the efficacy of Sydney's deep-water sewage outfalls.
Catching characteristics of four fish-trap types on the North West Shelf of Australia
Authors: Whitelaw AW , Sainsbury KJ , Dews GJ , Campbell RA
Published: November 2005

Commercial catch rates for the North West Shelf trap fishery, at up to 10 kg trap-1 h-1, are considerably greater than those reported for similar trap fisheries elsewhere. Two fish-trapping experiments were conducted off Lowendal Island (north-western Australia) to study the catch rates of four trap types (O-, S- and Z-shaped and rotational) and two bait types (pilchard, Sardinops neopilchardus, and emperor, Lethrinus choerorynchus) over various soak times (ranging from 1 to 24 h). Total catches varied significantly with soak time. Catches increased rapidly for the first 3 h, levelled off, and then decreased steadily to 16 h; there was a slight increase at 24 h. The species composition of the catch did not vary significantly with soak time. There was no significant difference in catch rates between trap types. The traps did not appear to cause fish to die by being confined in the traps for extended periods. A fairly large amount of suitable bait (about 4 kg) was necessary for effective trapping of fish. The catch rates of the pilchard bait were significantly higher than those of the emperor bait. Over extended soak times (more than 3 h), pilchard bait was lost at a rate of about 6% h-1. whereas there was no detectable loss of emperor bait.
Growth, development and behaviour of artificially reared larval Pagrus auratus (Bloch & Schneider, 1801) (Sparidae)
Authors: Pankhurst PM , Montgomery JC , Pankhurst NW
Published: November 2005

Pagrus auratus eggs were obtained from wild broodstock with naturally and artificially ovulated fish. Larvae were cultured for periods of up to 1 month on a diet of marine rotifers, Brachionus plicatilis. Small yolk-sac larvae hatched without functional eyes, mouth or digestive tract and for 3 days spent long periods at rest. Growth was initially rapid but slowed by 3 days as yolk reserves were nearing depletion. By Days 4-5, the mouth had opened, eyes were pigmented, yolk was depleted, and a rudimentary gut had formed. Larvae were now able to maintain a horizontal swimming mode and were actively searching for and attacking prey. First-feeding was observed in some larvae. Growth was retarded during the transition from endogenous to exogenous nutrition and then increased, probably as feeding proficiency improved with experience. Larvae starved from hatching did not survive for longer than 8 days.
Body lengths and maximum gut food-particle sizes of the dominant cladocerans and calanoid copepods in Wallerawang Reservoir, New South Wales
Authors: Kobayashi T
Published: November 2005

Body length influences the maximum gut food-particle size of the dominant cladocerans and calanoid copepods in Wallerawang Reservoir. For the Wallerawang cladocerans, a linear regression equation, similar to the Northern Hemisphere equivalent, relates food-particle and body sizes. The larger cladoceran species ingest larger food particles than do the smaller species they displace, thus seemingly supporting the size-efficiency hypothesis. On the other hand, the competitive ability of the Wallerawang calanoid copepods cannot be explained simply by the observed differences in the upper food-particle size limit of these species.
Dietary and spatial overlap between stream populations of a native and two introduced fish species in New Zealand
Authors: Glova GJ , Sagar PM
Published: November 2005

Benthic and drifting invertebrates as well as fish were sampled in a lake-inlet stream over a 24-h period in summer in order to investigate interactions for food and space between a native fish species (Galaxias brevipinnis, Galaxiidae) and juveniles of two exotic fish species (Salmo trutta and Oncorhynchus mykiss, Salmonidae) in New Zealand. Galaxias brevipinnis fed almost exclusively at night on the benthos, whereas both trout species fed mostly during the day on drifting and benthic prey. Larvae of Deleatidium (Ephemeroptera), Hydrobiosis and Oxyethira (Trichoptera), and Austro-simulium and Chironomidae (Diptera) were the major prey in the diets of all three fish species. Small prey made up a greater proportion of the diet of G. brevipinnis than for either trout species. All three species of fish were found primarily in riffles and runs in water depths of 0.1-0.3 rn, with G. brevipinnis frequently being in faster-flowing areas (water velocity 0.8-1.1 m s-1) than was either trout species (water velocity 0.4-0.7 rn s-1). These differences in pattern of die1 feeding and micro- habitat use no doubt lessen the interaction between the galaxiid and salrnonid fish species.
Distribution of metals in the Linggi River Basin, Malaysia, with reference to pollution
Authors: Nather  Khan ISA , Lim RP
Published: November 2005

Pollution inputs into the Linggi River Basin comprise domestic sewage, agroindustrial effluent (especially from rubber factories and palm-oil mills), and effluent from animal-husbandry activities. Total metals were analysed at eight sampling stations located at three highly polluted sub-basins: Linggi, Simin and Kundor. Dissolved metals were analysed occasionally at 21 major tributaries. The following concentrations were found (mg L-1; d.l., detection limit): Na, 0.93-117.73; K, 0.88-77.03; Ca, 1.89-24.00; Mg, 0.30-14.78; Fe, 0.47-12.2; Zn, 0.06-5.12; Cu, < d.l. -2.88; Mn, < d.l.-0.18. Pb, Ni and Cr were not detectable in their dissolved or total forms. Organic sewage inputs greatly increased the concentration of metal ions in reaches just downstream of discharge points. Ion concentrations generally decreased, but not substantially so, in the recovery reaches. Various pollutants contributed differentially to the concentrations of specific metal ions; rubber-factory effluent contributed slightly lower amounts of these ions than did industrial, urban, or palm-oil-mill effluents. No seasonal changes can be readily detected because of the influence of rainfall patterns, variable effluent discharges, and a complex combination of physical, chemical and biological processes occurring in the river.
Influence of Bass Strait water on the Tasman Sea thermocline
Authors: Villanoy CL , Tomczak M
Published: November 2005

Volumetric analysis of the Tasman Sea Central Water for different temperatures and salinities was used to determine the degree of influence of the seasonal outflow from Bass Strait on the observed strong positive anomalies in the Tasman Sea thermocline. The absence of a systematic decrease of salinity and Bass Strait Water content away from the coast suggests that the observed high-salinity anomalies are not entirely manifestations of Bass Strait Water alone and that some local processes may be involved in modifying the water properties. It is suggested that the seasonal Bass Strait Water intrusions may act as a trigger to overturn the environment, entraining high-salinity water from the upper layers by double-diffusive convection.
Effect of experimentally increasing concentration of suspended sediment on macroinvertebrate drift
Authors: Doeg TJ , Milledge GA
Published: November 2005

The effect of artificially elevating concentrations of suspended sediment on macroinvertebrate drift was studied in the Acheron River, 100 km north-east of Melbourne. Two experimental channels were established in the stream, and suspended sediment was introduced into one channel over a period of 1.5 h. The second channel was left undisturbed as a control. The concentration of suspended sediment was altered every 15 min, rising and falling to imitate concentrations reported during natural flood events. Drift was collected from two nets at the downstream end of each channel during each 15-min period. Collections were made for three 15-min periods before the introduction of the sediment and for three periods after the release.
The addition of suspended sediment at a mean concentration of 133.4 mg L-1 over a 15-min period
(compared with around 20 mg L-1 in the control channel) resulted in a sevenfold increase in the total
number of drifting invertebrates. At lower concentrations (both before and after this peak concentration),
drift densities were more similar to prerelease conditions. The number of drifting taxa also
showed an increase during the period of high release.
Although the experiment did not conform strictly to a full experimental design, the results indicated
that there may be a threshold level of suspended sediment that initiates macroinvertebrate drift, and
this experiment represents an appropriate starting point for future investigations.
Beyond BACI: Experimental designs for detecting human environmental impacts on temporal variations in natural populations
Authors: Underwood AJ
Published: November 2005

Biological effects of environmental impacts are usually defined simplistically in terms of changes in the mean of some biological variable. Many types of impact do not necessarily change long-run mean abundances. Here, designs for detection of environmental impact are reviewed and some of their shortcomings noted. New sampling designs to detect impacts that cause changes in temporal variance in abundance of populations, rather than their means, are described. These designs are effective at distinguishing pulse and press episodes of disturbance and could be used for other variables of interest (size, reproductive state, rate of growth, number of species, etc.) for monitoring. The designs require sampling different time-scales before and after a proposed development that might cause impact. Cases are discussed in which there is a single control location. Inadequacies of this approach for detection of environmental impact are mentioned, with some discussion of the consequences for management of impacts that cause temporal change rather than alterations of the mean abundance of a population.
Chemistry of trace elements, humic substances and sedimentary organic matter in Macquarie Harbour, Tasmania
Authors: Carpenter PD , Butler ECV , Higgins HW , Mackey DJ , Nichols PD
Published: November 2005

A broad range of physical and chemical parameters was measured in waters of the Gordon and King Rivers and Macquarie Harbour, Tasmania, along with sedimentary organics at three sites. Most concentrations of dissolved heavy metals in the Gordon and upper King Rivers were similar to those found in normal coastal sea waters, but such concentrations were up to 100 times higher in the harbour waters and were higher still in the lower King River. Much of the large particulate load in the lower King was removed during estuarine mixing. In the harbour, low dissolved oxygen (< 175�M) was found in intermediate waters at two sites, accompanied by higher heavy-metal and lower iodate concentrations. Strong copper-complexing capacities were proportional to humic concentrations but were always exceeded by concentrations of dissolved copper. Total dissolved iodine was conservative, whereas dissolved iodate was reduced to iodide or organo-iodine in waters with salinities of less than 15. Humic substances were conservative and originated almost entirely from the Gordon River. The sedimentary lipid profiles were dominated by higher-plant-derived compounds, whereas microbial communities were largely prokaryotic, with biomarkers indicative of anaerobic microorganisms. Sediment near the mouth of the King River contained substantial amounts of anthropogenic petroleum-derived hydrocarbons.
Avoidance of inundated floodplain habitat by larvae of golden perch (Macquaria ambigua Richardson): Influence of water quality or food distribution?
Authors: Gehrke PC
Published: November 2005

Golden perch (Macquaria ambigua) larvae were studied in a pond and an adjoining inundated floodplain to determine the influence of water quality and prey density on larval dispersion. Mean catches in both pump and light-trap samplers were greatest at midnight (4.08 and 11.58 larvae per sample, respectively), with relatively few larvae caught at dawn, midday and dusk. A total of 1421 larvae were collected in 320 samples from the pond (4.4 larvae per sample), whereas only 354 larvae were caught in 480 samples (0.7 larvae per sample) from the floodplain. Neither total plankton density nor the density of specific size classes of plankton were correlated with the distribution of golden perch larvae. Dissolved-oxygen concentrations were higher in the pond than on the floodplain and were significantly correlated with the spatial distribution of golden perch larvae. Tannin and lignin concentrations were also greatest on the floodplain. These results suggest that water quality may exert a greater influence than does food availability on the distribution of native fish larvae in artificially inundated floodplain habitats.
An assessment of genetic differentiation among feral Australian tilapia populations
Authors: Mather PB , Arthington AH
Published: November 2005

Feral populations in Australia of the introduced cichlid, tilapia, were compared by using cellulose- acetate electrophoresis to examine degrees of genetic differentiation among the disjunctive populations. Evidence was obtained to support the recognition of three morphs: two 'good' species (Oreochromis mossambicus and Tilapia mariae) and a third morph that is a potential interspecies hybrid between O. mossambicus and one or more of the related Oreochromis species O. honorum, O. niloticus and O. aureus. Distributions of the three morphs are described, and their likely origins and potential impacts on native fauna are discussed.