bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrological stucture and phytoplankton distribution in the region of a warm-core eddy in the Tasman Sea
Authors: Scott BD
Published: November 2005

The distribution of temperature, salinity, density, dissolved oxygen, phosphate, silicate, and nitrate to 2000 m depth, and phytoplankton to 150 m depth is described in the region of an anticyclonic mesoscale eddy located in the Tasman Sea. Vertical discontinuities in the hydrological properties showed that the eddy had entrained several surrounding water types at the surface and at depths of up to 500 m. In particular, Bass Strait water normally found among the slope waters along the New South Wales coast was entrained by the eddy and transported to positions 200 km from the coast. The temperature and salinity of the eddy appeared to have been increased below the core of the eddy at depths of 300-600 m. due to the entrainment of and mixing with Bass Strait water. The distribution of density, oxygen, nutrients and phytoplankton in the central portion of the eddy between 60 and 240 m depth showed differences between adjoining positions which were attributed to vertical water movements within the eddy core. These movements appeared to be responsible for increases of phytoplankton biomass within the eddy, of up to 10 times that of the surrounding ocean.
Dispersal of tropical marine fauna to the Great Australian Bight by the Leeuwin Current
Authors: Maxwell JGH , Cresswell GR
Published: November 2005

A tropical element in the demersal and pelagic fauna of the Great Australian Bight has been observed. The fauna includes benthic invertebrates, such as the basket star, Euryale aspera (Lamark), and the holothurians Pentacta anceps (Selenka) and Pentacta quadranguiaris (Lesson), and tropical pelagic tuna, such as the oriental bonito, Sarda orientalis (Temminck and Schlegal). It is suggested that the Leeuwin Current, which flows southward to Cape Leeuwin and then eastward, is responsible for the existence of tropical fauna in the Bight. The low salinity waters of the Leeuwin Current were observed for the first time to round Cape Leeuwin.
Limnology of Perched Lake, south-west Tasmania
Authors: King RD , Tyler PA
Published: November 2005

Perched Lake is one of the few lakes of lowland parts of south-west Tasmania. It is a warm monomictic lake, stratifying for 7-8 months each summer and, unlike most other bodies of standing water in the south-west, is only moderately dystrophic. Oxygen concentrations of the hypolimnion decline late in the stratification period but do not fall below 20% saturation, indicating low areal productivity. Though only moderately dystrophic, there is sufficient organic colour to cause marked attenuation of photosynthetically active radiation, particularly in the blue wavelengths. Its water chemistry is that of dilute seawater. Certain thermal and chemical anomalies are possibly explained by subsurface inflows of artesian water. The plankton of Perched Lake is dominated by chrysophytes and chlorophytes, with no well-defined seasonal change of biomass or species composition. An unusual dinoflagellate with marine affinities. probably Phalacroma sp., occurs in the lake.
Estimation of the scattering coefficient of natural waters using underwater irradiance measurements
Authors: Kirk JTO
Published: November 2005

Certain relationships between irradiance reflectance (R), average cosine (μ) and the ratio of the scattering and absorption coefficients (b/a), previously derived by Monte Carlo simulation of underwater light, have been used as the basis for a new method of estimating the scattering and absorption coefficients of natural waters from irradiance measurements made within the water body concerned. Standard curves are presented from which, given R at a certain optical depth, the values of μ at that depth and b/a for the water may be read off. The product of μ and the vertical attenuation coefficient, KE for net downward irradiance, (Ed - Ea, provides an estimate of a; this multiplied by b/a then gives the value of b. When applied to published data for Lake Pend Oreille the method gives a value for b differing by only 5% from that which may be calculated by subtracting the absorption coefficient from the beam attenuation coefficient for that lake. Values for scattering coefficient have been calculated by the new method for five water bodies in the southern tablelands of New South Wales for various dates over a 3-year period. The values of b correlate very closely with nephelometric turbidity, an independent measure of light scattering. The new procedure gives higher values than those obtained by an earlier method, but is considered to be more accurate.
Nutrients and phytoplankton in three shallow, freshwater lakes of different tropic status in Western Australia
Authors: Gordon DM , Finlayson CM , McComb AJ
Published: November 2005

The trophic status of three shallow, freshwater lakes on the Swan coastal plain near Perth, Western Australia, was assessed from February 1975 to January 1976. Loch McNess is in a National Park, Lake Joondalup is in an area becoming urbanized, and Lake Monger is in a suburb near the centre of Perth. Monthly measurements were made of phytoplankton numbers and environmental parameters, including forms of nitrogen and phosphorus. Populations tended to be high when lake levels were low. Phytoplankton numbers were dominated by blue-green 'algae' in summer in each lake, with the lowest numbers in Loch McNess. Green algae were most prominent in autumn and winter. Diatoms were present at relatively lower numbers throughout the year. Phytoplankton numbers were strongly correlated with phosphorus levels, particularly for blue-green algae, and less so with nitrogen. Green algae were also strongly correlated with water conductivity. Nearly 80% of variance in phytoplankton numbers was accounted for in multiple linear regression by temperature, sunlight hours, depth, pH, conductivity and phosphate, organic phosphorus, ammonia, nitrate-nitrite, and organic nitrogen concentrations. Much of the variance was accounted for by the nutrients alone. Comparisons with data in the literature suggest that Lakes Joondalup and Monger are eutrophic by world standards, and are far more eutrophic than Loch McNess.
Shallow dredging as a strategy for the control of sublittoral macrophytes: a case study in Tuggerah Lakes, New South Wales
Authors: Collett LC , Collins AJ , Gibbs PJ , West RJ
Published: November 2005

The effects of dredging the nearshores of the Tuggerah Lakes, on the central coast of New South Wales, to depths of 1.0, I.4 and 1.8 m, were investigated as a means of controlling aquatic macrophytes. The effects of this management strategy on the macrobenthic fauna and macrophyte growth were also evaluated.Recolonization of dredged plots by most of the 63 zoobenthic species present in control plots had occurred within 8 months of the treatment. All species of macrophytes had re-established in the shallowest (1.0 m) plot within 4 months but had failed to colonize the deeper plots up to 12 months after dredging. The removal of growing macrophytes from the water by dredging as a means of enhancing the shoreline is discussed, as are constraints relating to this method.
Experimental studies on the settlement and growth of bryozoa in the natural environment
Authors: Vail LL , Tranter DJ
Published: November 2005

A rack of six panels of roughened black Perspex was placed in Port Hacking, Sydney, for a period of 34 weeks. Some panels were screened and the rack was examined each week for accumulation of Bryozoa. Some colonies were allowed to grow for the complete study period; some panels were scraped free of all organisms each week; some were scraped free of all organisms except Bryozoa; and some panels which had been screened were returned to the environment unscreened. Sizes of colonies were noted and are presented in tabular form. Results show that there is a marked variation in the growth of Bryozoa, even extending to the same species on the same panel. No rigorous statistical analysis of the growth is attempted. Environmental variables such as rainfall, salinity and temperature were monitored at stations close to the panel site and are discussed in relation to bryozoan growth.
Growth of the saucer scallop, Amusium japonicum balloti Habe, in central eastern Queensland
Authors: Williams MJ , Dredge MCL
Published: November 2005

Tag-recapture data were used to determine growth and movement of A. japonicum balloti. The von Bertalanffy growth model was found to be suitable for describing growth in the latter half of the size range for A. japonicum balloti, and estimated S∞ of scallops varied with year and area. A. japonicum balloti grows rapidly, being recruited to the commercial fishery at about 6 months of age in some cases. Recapture data indicated that A. japonicum balloti does not undergo long-distance displacements in its post-larval stage.
Flushing of salt from mangrove swamps
Authors: Wolanski E , Gardiner R
Published: November 2005

Both tidal inundation and groundwater flow help flush salt from mangrove swamps.
Water circulation and shelf waves in the northern Great Barrier Reef lagoon
Authors: Wolanski E , Ruddick B
Published: November 2005

Currents and sea levels were measured at a number of locations in the Great Barrier Reef (GBR) lagoon from about 10 to 13� S., during the period October-December 1979. A strong non-tidal, low-frequency modulation of all sea-level and current data was found. The currents nearshore were driven northward by the wind, and then at least partially blocked by the dense network of reefs to the north of 10� s. The water then flowed southward in deeper water adjacent to the reef, driven by a longshore pressure gradient. The low- frequency sea-level data, though not the current records, showed northward phase propagation at speeds characteristic of a first-mode shelf wave trapped in the lagoon between the shore and the reef. Data are presented revealing the intrusion of low-salinity water, through Bligh Entrance, in the GBR lagoon, as a result of river discharges in the Gulf of Papua. It is suggested that low-frequency longshore currents may periodically flush these river plumes from the GBR lagoon and enhance interaction between reefs. In the Coral Sea in front of reef passages, the large horizontal velocities may result in forces upwelling by selective withdrawal and jet entrainment.
Field and laboratory studies on salinty tolerance and osmotic behaviour in the polychaete Galeolaria caespitosa (Serpulidae)
Authors: Tait NN , Atapattu D , Browne R
Published: November 2005

G. caespitosa is an osmoconformer surviving within the range of 100-60% seawater. However, at lower salinities, the worms are able to maintain high body-fluid osmotic concentrations, for a limited period, by behavioural osmoregulation. Thus, G. caespitosa is largely confined to the open coast of its geographic distribution, while also being able to survive estuarine conditions where periodic flooding is of limited duration and extent. Populations of G. caespitosa can survive greater excursions into estuarine conditions, provided suitable substrates are available. Here, however, they can be subjected to high mortality from time to time. and reconstitution of these populations must take place by subsequent settling of larvae from more permanent populations.
Respiratory responses of the pea crab, Pinnotheres hickmani (Guiler)
Authors: Elliott NG
Published: November 2005

The respiration rates for various developmental stages of the Australian pea crab, P. hickmani, were obtained at three temperatures, representing the normal environmental range, and in light and dark conditions. The free-living hard stages of both the males and the females, show marked variation in oxygen uptake compared with the pre- and post-hard commensal stages. Oxygen requirements increase as the female matures to the stage-V form. Results obtained indicate that, under normal conditions, the presence of P. hickmani within a host mussel, Mytilus edulis planulatus, would present no undue burden on the host's available oxygen. Under conditions of low oxygen tension, P. hickmani shows the ability to build up an oxygen debt, again providing no undue burden on its host. It is proposed that P. hickmani is an obligatory commensal within M. e. planulatus.
Studies of the relationship between the ascidian Diplosoma virens and its associated microscopic algae. II. Aspects of the ecology of the animal host
Authors: Van Thinh L , Griffiths DJ , Ngan Y
Published: November 2005

The numbers of colonies of the ascidian D. virens (Hartmeyer) occurring on a reef flat in the vicinity of Townsville, undergo pronounced seasonal fluctuations. The maximum colony numbers were recorded in October-November, with a smaller peak in May; colonies were almost entirely absent from the reef flat during the summer months. Observations of the rate of increase of colony numbers, both on the reef flat and on artificial substrates, showed that the organism proliferates by repeated division of the colonies, accompanied by movement of the daughter colonies along the substrate. In the laboratory, colonies of D. virens move at rates of 4.3-8.0 mm per day. The direction of movement is strongly influenced by light. Observation of the life span of the colonies on the reef flat, supported by measurement of the photosynthetic activity of the contained symbiotic algae, give some indication of the probable major factors influencing colonization of the reef flat by D. virens.
Seasonal upwelling along the south-eastern coastline of South Australia
Authors: Lewis RK
Published: November 2005

The hydrology of the south-eastern waters of South Australia over the period 1973-77 is described with particular reference to a wind-induced summer upwelling. The nitrate concentration of upwelling water is found to be 30 (surface) to 70 (50m depth) times greater than the average background levels of 0.1-0.9 mmol m-3. The horizontal distribution of temperature and salinity shows that upwelling along the shelf region is not uniform but has a number of localized centres. During January 1976 centres of upwelling water were found at three locations along the coastline.
Observations on nitrate, phosphate and silicate in Cleveland Bay, northern Queensland
Authors: Walker TA , O'Donnell G
Published: November 2005

Results of a year-long study of nitrate, phosphate and silicate concentrations at a station in Cleveland Bay are reported. Silicate concentrations in local rivers were consistently high and in the sea were greatly increased during the wet season. Silicate was not considered to be limiting to phytoplankton growth during the year. Nitrate and phosphate concentrations were generally low and not strongly correlated with salinity. They were, however, strongly correlated with Secchi disc transparency changes throughout the year. indicating that release of nutrients occurred during periods of bottom sediment resuspension. Nutrient enrichment experiments with seawater showed that only addition of nitrogen stimulated phytoplankton growth. although addition of nitrogen plus phosphorus gave maximum growth. The results suggest an unusual system in which the chemical and biological processes in the lagoon waters of the Great Barrier Reef are coupled to benthic processes by intermittent, wind-driven bottom resuspension events.
Geographic differentiation of eastern Australian penaeid prawn populations
Authors: Mulley JC , Latter BDH
Published: November 2005

The geographic differentiation of Metapenaeus bennettue. M. macleuyi and Penueus plebejus has been examined by electrophoretic techniques. Differences between localities were detected in M. bennettae and M. macleayi. but not in P.plebejus. The observations for M. bennettae and P. plebejus are consistent with what has previously been revealed by ecological investigations. Despite the existence of detectable genetic heterogeneity in M. bennettae and M. macleayi, the differences in gene frequency are in almost all cases of a minor order, and the overall degree of divergence between populations is quite small. The comparative measures of geographic differentiation for the three species M. bennettae. M. macleuyi and P. plebejus are Φ* = 0.051. 0.014, and 0.007 respectively.
Monthly variation in recruitment, infection, size, fecundity and mating of Naobranchia variabilis (Copepoda : Naobranchiidae) parasitic on the gills of toadfish Tetractenos hamiltoni from Moreton Bay, Australia
Authors: Roubal F. R. , Graham D.
Published: November 2005

Naobranchia variabilis on the gills of
Tetractenos hamiltoni were sampled monthly from July to
June. Recruitment began in August, peaked in October, and was low from
January. Most late juveniles occurred in November. Numbers of subadults
declined from July, with none in October; intensity peaked during
November–December. Adult prevalence and intensity declined from August,
to consist only of large, mature individuals in October with many large eggs
and with a large percentage of these adults shedding eggs. Adult prevalence
and intensity peaked in January; average adult size and number of eggs were
consistent after January. The presence of small adults from November reduced
the average number and size of eggs. Adults produced at least two batches of
eggs, and eggs were produced and shed all year round. At least 75% of
the female N. variabilis had no male attached, but
numbers of males and females in each age class were correlated. Most males on
late-juvenile and subadult females occurred during the period of greatest
recruitment, but was later for adult females because of the preference of
males for pre-adult stages.
Responces of Typha domingensis to salinity and high levels of maganese in the rooting medium
Authors: Hocking PJ
Published: November 2005

The response of T. domingensis, a large emergent macrophyte, to salinity and manganese was studied under glasshouse conditions. Plants were grown in saline solutions ranging in concentration from 0.5 to 100 mM NaCI. and in manganese sulfate solutions ranging in concentration from 0.01 to 10 mM. Growth was reduced slightly at 50 mM NaCl and severely at 100 mM NaC1, suggesting that T. domingensis is moderately salt tolerant. Plant parts had highest chloride levels at 25 mM NaCl and highest sodium levels at 100 mM NaCl. The highest sodium chloride treatment reduced the level of potassium in the rhizomes, but not in roots or leaves. Sodium chloride had no effect on the concentration of nitrate in organs, but total nitrogen levels in roots and rhizomes increased at 100 mM NaCI. Sodium was considered to be more toxic than chloride. Growth in manganese solutions was unaffected except at the highest concentration used. Manganese accumulated quickly in leaves to levels which would be toxic to livestock; leaves retaining over 70% of the total manganese in the plant. Manganese applied at high concentrations substantially reduced the levels of calcium, magnesium and phosphorus in the leaves. In a field experiment, there were seasonal changes in the levels of selected elements in the leaves of T. domingensis. During leaf senescence. concentrations of sodium, manganese and calcium increased by 20-80%, but levels of phosphorus, nitrogen, potassium and maganesium fell by 65-84%. The results are discussed in relation to the use of T. domingensis in Hastewater reclamation.
Metabolic activity of zooplankton from the Antarctic Ocean
Authors: Ikeda T , Fay EH
Published: November 2005

Eight species of live zooplankton were transported from the Antarctic Ocean to a tropical laboratory in
Queensland, Australia. Their respiration and ammonia excretion rates measured at - 0.5� C were in the
order of 0.15-0.55 �l O2/mg dry wt. h and 0.002-0.06�g N mg dry wt. h, respectively. As an indirect
estimate enzyme activity of the respiratory electron transport system (ETS) was determined on frozen
specimens of 15 zooplankton species brought back from the Antarctic Ocean. The ratio of ETS activity to
respiration rate measured in this study was 1.863 � 0.738 (n = 12). The respiration rates thus directly and
indirectly obtained were in agreement with results of previous workers.
Effect of temperature on respiration and ammonia excretion rates were examined on two selected animal
groups of zooplankton- copepods belonging to the family Calanidae and euphausiids of the genus
Euphausia- and the results were compared with those for species from other seas where the temperature
varies from 5.0 to 27.6�C. From this comparison, acceleration of the rate (standardized to 1 mg dry wt of
body) by the increase of temperature (expressed as a Q10 value) was 2.18 for respiration rate and 2.58 for
ammonia excretion rate.
Cirolanidae (Crustacea : Isopoda) of Australia: diagnoses of Cirolana Leach, Metacirolana Nierstrasz, Neocirolana Hale, Anopsilana Paulian & Debouteville, and three new genera—Natatolana, Politolana and Cartetolana
Authors: Bruce NL
Published: November 2005

The taxonomy of Cirolana and a description and diagnosis to the genus are given. The genera, Metacirolana, Neocirolana and Anopsilana are defined. and three new genera. Nutarolana, Politolana, Curtetolana created.
A list of the species of each genus is provided. Those species that cannot be referred to any of the given genera are retained for the present within Cirolana. All but eight species previously placed in Cirolana have been reallocated. The relationships and distributions of the genera are discussed; and synonymies are provided.
Diet and growth of rainbow trout, Salmo gairdneri Richardson, in two streams on the New England Tableland, New South Wales
Authors: Pidgeon RWJ
Published: November 2005

The diets and growth rates of rainbow trout in the Wollomombi and Guy Fawkes Rivers in northern New
South Wales were examined. The growth rate of trout in the Wollomombi River was much higher than that
of fish in the Guy Fawkes River. Spearman rank correlation coefficients indicated that stream type was more
important than fish size in determining the composition of the diet of the trout. Benthic invertebrates formed
the largest component of the diet in both streams: 66.0 and 63.0% of ash-free dry weight (AFDW) in the
Wollomombi River and the Guy Fawkes River, respectively. Trout in the Wollomombi River consumed
more nektonic prey (33.3% of AFDW) than fish in the Guy Fawkes River (3.7% of AFDW). In contrast,
surface food (aquatic imagines and terrestrial insects) made up a much higher proportion of the diet of trout
in the Guy Fawkes River (33.9% of AFDW) than in the Wollomombi River (0.6% of AFDW). Crayfish
were a major component of the diet (in terms of AFDW) in both streams, their proportions increasing with
fish size. The significance of crayfish in relation to fish growth is discussed.
Dependance of phytoplankton chlorophyll on bottom resuspension in Cleveland Bay, northern Queensland
Authors: Walker TA
Published: November 2005

In relatively shallow regions of the lagoon of the central Great Barrier Reef. phytoplankton chlorophyll a
concentrations are dependent on intermittent resuspension of bottom sediment by wind-generated waves.
This results in a strong inverse correlation between chlorophyll a levels and transparency over a period of
time. Bottom resuspension and resettling cause a mide transparency range to occur at any given station. but
the mean Secchi disc depth increases linearly with water depth across the lagoon.
Annual temperature cycle in Cleveland Bay, Great Barrier Reef province
Authors: Walker TA
Published: November 2005

Weekly temperature measurements have been taken over a 55-month period at a 10 m deep station in
Cleveland Bay. Temperature at the surface ranged from 19.3 to 30.9�C with a mean monthly minimum of
20.9�C in July and a mean monthly maximum of 29.0�C in January. The water-temperature curve lagged
behind the 0900 h air-temperature curve by an average of 10 days. Differences between the present data and
other published temperature data for Great Barrier Reef waters are discussed.
Sponge masking and related preferences in the spider crab Thacanophrys filholi (Brachyura : Majidae)
Authors: Woods Chris M. C. , Page Mike J.
Published: November 2005

Spider crabs, Thacanophrys filholi, collected from
Kaikoura, New Zealand, were predominantly masked with four species of sponge:
Lissodendoryx sp.,
Iophon laevistylis, Paresperella
sp. and Dysidea sp. Other species of sponge, as well as
ascidians, brachiopods, anomiid bivalves and tube-dwelling polychaetes, were
also part of the extensive epifauna covering the crabs. The act of masking is
described, and the location of the hooked setae that allow attachment of
material to the crabs exoskeleton is mapped. When crabs in the laboratory were
simultaneously offered equal volumes of the four main sponge species with
which they masked in the field, they masked equally with
Lissodendoryx sp. and Dysidea sp.
in preference to I. laevistylis and
Paresperella sp. These masking preferences were
influenced by the relative volumes in which each species of sponge was
presented to the crabs.
A method for quantifying hand-net samples of stream invertebrates
Authors: Marchant R. , Hehir G.
Published: November 2005

Quantitative sampling using a hand-net can be accomplished by taking three
successive catches of invertebrates from the same point on the streambed. This
is a form of removal sampling. By plotting the decline in number of
individuals in each catch against the total previously caught, the total
population at the sampling point can be estimated. From this, the probability
of capture in a single catch (p) can be calculated. For
Agapetus, other trichopteran, leptophlebiid, caenid and
gripopterygid larvae from a site on a tributary of the Acheron River in
southern Australia, p varied from 0.66 to 0.81.
Additional data for a species of Gammarus from the
Credit River in Ontario gave a p value of 0.67. In three
successive catches the overall probability of capture exceeded 95% for
all taxa, indicating that with this degree of effort most individuals present
were caught.
Labile forms of iron in coastal seawater: Otago Harbour, New Zealand
Authors: Croot Peter L. , Hunter Keith A.
Published: November 2005

The horizontal distribution and speciation of
iron in the Otago Harbour, New Zealand, a shallow, vertically well mixed
estuary, was investigated on six occasions from April to November 1993. Iron
speciation was determined by a suite of analytical methods focussing on the
chemical reactivity of iron. The dominant source of iron into the water column
in these waters was resuspension of bottom sediments, particularly under windy
conditions. The only important freshwater source of iron to the harbour, the
Water of Leith, appeared to be a major source of iron to Otago Harbour only
under conditions of high stream flow. However, the influence of the Water of
Leith was often detectable down harbour by the presence of more
reactive/labile iron phases. Prolonged periods of strong winds also
appeared to supply large concentrations of reactive iron to the water column,
possibly by mixing and resuspension of sediment material from below the redox
boundary. Experiments on natural samples from Otago Harbour revealed that at
pH 4.0 ascorbic acid was able to reduce Fe(III) oxyhydroxides more effectively
than was hydroxylamine hydrochloride. This difference may reflect either
different mechanisms for the reduction of iron oxyhydroxides or differences in
the crystallinity of these oxyhydroxides.
Aggregation dynamics in penaeid fisheries: banana prawns (Penaeus merguiensis) in the Australian Northern Prawn Fishery
Authors: Die David J. , Ellis Nick
Published: November 2005

In the Gulf of Carpentaria, banana prawns
(Penaeus merguiensis) form dense aggregations that are
targeted by trawl vessels with the help of small aeroplanes and colour
sounders. Such aggregating behaviour is rare in penaeids and may lead to a
change in catchability when stock abundance changes. Commercial logbook data
containing trawl-tow records have been used to identify the location, time of
capture and biomass of over 600 banana prawn aggregations during
1991–92. The number of aggregations decreased by 83% in the first
three weeks of the fishing season. The average biomass of an aggregation
decreased even more rapidly than the number of aggregations and, after three
weeks of fishing, it had been reduced by 93%. The apparent decrease in
the biomass of aggregating prawns during the first three weeks of the season
is, therefore, in the order of 99%. This is considerably greater than
the 66% decrease that can be estimated from catch per unit of effort
data. It also suggests that catchability is directly related to stock
abundance. Assessment models that assume that catchability is independent of
stock size may not be appropriate for the assessment of the status of common
banana prawns in this fishery.
Effects of salinity acclimation on oxygen consumption in the freshwater blenny, Salaria fluviatilis, and the marine peacock blenny, S. pavo
Authors: Plaut Itai
Published: November 2005

The effect of salinity on standard metabolic rate was studied in a freshwater
blenny, Salaria fluviatilis, and a marine congener,
S. pavo. These blennies tolerate both fresh water (FW,
<30 mOsm L −1 ) and full-strength sea water
(SW, 1000 mOsm L −1 ). Fish of both species were
acclimated to FW, iso- osmotic concentration (IOC, 375 mOsm L
−1 ) and SW at 21 2±2°C for three
months before oxygen consumption rates were measured. Slopes of the
regressions relating oxygen consumption rates to body mass did not differ
significantly between species and among salinity treatments. Oxygen
consumption rates of S. fluviatilis in FW were
significantly higher than in IOC and SW, whereas oxygen consumption rates of
S. pavo were similar in IOC and SW salinity but were
significantly lower in fish in FW. These results do not seem to be accounted
for by different costs of osmoregulation or by different concentrations of
oxygen in the water among different salinities, and they may demonstrate
reduction in metabolic activities as a reaction to chronically unfavourable,
sub-optimal environmental conditions.
Temporal population dynamics of the swarming shrimp, Acetes sibogae australis, in a tropical near-shore system
Authors: Omundsen S. L. , Sheaves M. J. , Molony B. W.
Published: November 2005

Acetes sibogae australis, a small swarming crustacean,
is an important component of near-shore systems in eastern Australia. It is
considered that densities of A. s. australis are highly
variable. However, this variability has never been tested on a fine temporal
scale. In this study, densities of A. s. australiswithin
swarms, as well as swarm length and width, were recorded once a week for seven
months at one locality in Townsville, Australia, and once a fortnight for
seven months at two other localities in the region. Length frequency of a
sub-sample of individuals caught at each sample time was also recorded.
Density of A. s. australis fluctuated significantly
during the seven months, with numbers per replicate varying between 0 and 1000
individuals. Swarm width and length were significantly correlated with
density, contributing to large-scale differences in overall abundance. Length
frequencies revealed at least three dominant cohorts present during the seven
months, although appearance and disappearance of these did not correspond to
density changes. Patterns recorded were similar at the three spatially
separate localities. The large fluctuations in
A. s. australis abundance over time are likely to have
important effects on the near-shore system of Townsville.
A tagging study on tailor (Pomatomus saltatrix) in Western Australian waters: their movement, exploitation, growth and mortality
Authors: Young Glen C. , Wise Brent S. , Ayvazian Suzanne G.
Published: November 2005

Recreational anglers fishing for tailor
(Pomatomus saltatrix) around Perth, Western Australia,
have expressed concern over declining catches during the early 1990s. A total
of 3949 undersize (below the legal minimum length of 250 mm), 1015 sub-adult
and 143 adult tailor were tagged between November 1994 and August 1996 at 24
sites along 1200 km of Western Australian coastline. Undersize tailor were
recaptured at lower rates than sub-adult tailor, and were, on average, at
liberty for longer periods. Modelling indicates that fishers under-report
undersize fish, probably because of the legal minimum length requirement, and
that the natural loss rate is higher for undersize than sub-adult fish. The
majority of recaptured undersize and sub-adult fish had moved <25 km,
remaining in sheltered estuarine and marine areas. In contrast, recaptured
undersize and sub-adult tailor that had become adults while tagged displayed
behaviour consistent with a northward or offshore winter movement. Comparisons
between tag returns and the annual commercial catch of tailor suggests that
recreational fishers take the majority of the total catch of tailor in Western
Australia. Growth estimates between 0.41 ± 0.19 and 0.44 ± 0.12
mm day −1 suggest that tailor reach legal size in
18–22 months.
Are mean size data adequate to monitor freshwater eel fisheries?
Authors: Francis R. I. C. Chris , Jellyman Don J.
Published: November 2005

As the biomass of a fish population is reduced by fishing, the mean size
(length or weight) of individuals in the population can be expected to
decrease. Thus, it should be possible, in principle, to detect changes in
fishing pressure by monitoring mean size. A simulation experiment was carried
out to see whether this might work in practice with New Zealand freshwater eel
fisheries. Information on the dynamics of eel populations was used to
construct a simulation model of a fishery with a range of exploitation
scenarios. It was found that size data, by themselves, could be useful for
detecting large long-term changes in stock status, but are not likely to be
good indicators for use in year-to-year management. Natural variations in eel
recruitment cause substantial year-to-year variations in the mean size of
eels, even when fishing pressure is constant. This makes it difficult to
detect changes in size caused by long-term changes in fishing pressure. Even
without sampling error, biomass would need to drop by more than 40% (or
more, if the drop is gradual) before this change could be reliably detected.
The presence of typical levels of sampling error makes this detection even
harder.
Length at maturity of the greeneye spurdog shark, Squalus mitsukurii (Elasmobranchii : Squalidae), from the SW Atlantic, with comparisons with other regions
Authors: Lucifora Luis O. , Valero Juan L. , García Verónica B.
Published: November 2005

Size at maturity is analysed for Squalus mitsukurii from
the SW Atlantic. Males mature between 51 and 55 cm total length and females
between 52 and 60 cm total length. Hence, S. mitsukurii
appears to be intermediate in size at maturity among the SW Atlantic squalid
sharks. This analysis adds evidence of the plasticity of
S. mitsukurii in size at maturity. The
length–weight relationship did not differ between sexes in the SW
Atlantic population, whereas it differed in one population from the NW
Pacific. Intersexual differences in size at maturity in the present study were
lower than those reported for other regions.
Laboratory study of the accumulation and distribution of cadmium in the Sydney Rock oyster Saccostrea commercialis (I & R)
Authors: Ward TJ
Published: November 2005

The Sydney rock oyster (S. commercialis) was exposed to a control and four concentrations of cadmium (nominally 0, 10,25,50 and 150�g I-1) in a flowing seawater system in the laboratory. Oysters from the 10 and 50 �g 1-1 groups were briefly exposed to 109Cd, then frozen in liquid CO2 and sectioned. The thin sections of whole oyster were apposed to X-ray film. The resulting images showed that 109Cd accumulated mainly in the gut, kidney and gill, with little in the gonad and glycogen storage areas of the visceral mass. Oysters from all water concentrations of cadmium were removed after 1,4,8 and 16 weeks of treatment with cadmium. The visceral mass, gill, mantle, muscle and heart-kidney were analysed for total cadmium. All groups of oysters rapidly accumulated cadmium. The heart-kidney attained the highest concentration and the muscle invariably displayed the lowest concentration. The visceral mass contained the greatest amount of cadmium in all oysters. The gill changed its position in the ranking of the organ concentrations of cadmium, increasing with increasing water concentrations of cadmium. The results suggest that the gill may be the critical organ during a challenge with cadmium-at both lethal and sublethal concentrations. The long-term nature of this experiment reveals that the accumulation of cadmium in S. commercialis is non-linear at some water concentrations of cadmium.
Intertidal community offshore from the Werribee sewage-treatment farm: an opportunistic infaunal assemblage
Authors: Dorsey JH
Published: November 2005

The upper intertidal sediments and infauna between two effluent drains at the Werribee sewage-treatment farm were sampled during the late spring of 1979. Sediments were of fine sands, little mud and varying amounts of shell debris. Species diversity was low, but abundance very high. Densities of individuals at the two drains ranged from about 300 000 to 400 000 individuals per square metre. The fauna was characterized by opportunistic species which included spionid, capitellid and nereid polychaetes and corophiid amphipods.
The genus Drepanopus (Copepoda : Calanoida): a review of species in Antarctic and Sub-Antarctic waters, with a description of D. bispinosus, sp. Nov
Authors: Bayly IAE
Published: November 2005

The definition of Drepanopus is revised. Some taxonomically significant features of D. pectinatus Brady are described for the first time. D. bispinosus, sp. nov. is described from close inshore waters of the Vestfold Hills region of Antarctica. It differs from other species of Drepanopus (and from most genera in the Clausocalanidae) most strikingly in having only two spines on the outer edges of the terminal exopodal segments of the second to fourth pairs of swimming legs. A summary is presented of existing information on the abundance and distribution of D. pectinatus, D. forcipatus Giesbrecht and D. bispinosus.
Life spans of two species of tropical mayfly nymph (Ephemeroptera) from Magela Creek, Northern Territory
Authors: Marchant R
Published: November 2005

The nymphs of Cloeon fuviatile and a species of Tasmanocoenis were common in the shallows (< 1 m) of two
billabongs in Magela Creek, Northern Territory. Monthly estimates of abundance and length frequency
showed that growth and reproduction occurred continuously. Estimates of the ratio of annual production to
mean biomass (PIB) were calculated with the size-frequency method, using different values for nymphal life
span; these estimates, when compared with P/B values predicted from the literature, suggested that the
nymphs had a life span of about 1 month. Such a rapid life cycle is at least in part the result of the high mean
temperature (30°C) in the shallows.
Phosphorus and nitrogen loads in waters associated with the River Murray near Albury-Wodonga, and their effects on photoplankton populations
Authors: Walker KF , Hillman TJ
Published: November 2005

This is part of a survey carried out to assess the likely impact on the River Murray of urban development at Albury-Wodonga. The study area included two impoundments, Lake Hume and Lake Mulwala, the tributary Mitta Mitta, Kiewa and Ovens Rivers, and the River Murray. Phosphorus and nitrogen loads were examined over 4 years, incorporating a high flow period, 1974-75, and a low flow period, 1976-77. Loads varied directly with stream flow, although loadings to the two impoundments were generally high and above levels considered indicative of eutrophy elsewhere. Phytoplankton biomasses did not reflect this situation, howeyer, and averaged below 2000 mm3 m-3 Phytoplankton growth, and hence nutrient assimilation, probably were restricted by low light penetration resulting from high turbidities. This is supported by preliminary laboratory experiments involving nutrient enrichments over a range of turbidities. Under low flow conditions, nutrient inputs to the impoundments were reduced and underwater light penetration increased, due to settling of abiogenic suspended material. Nutrient enrichment experiments in Lake Mulwala supported the proposition that availability of nutrients, particularly phosphorus, could limit phytoplankton biomass under those conditions. The results generally indicate that pro rata inputs from Albury-Wodonga need to be reduced as the urban population grows, if the risk of nuisance algal blooms during low flow periods is to be minimized.
Feeding of Holothuria atra and Stichopus chloronotus on bacteria, organic carbon and organic nitrogen in sediments of the Great Barrier Reef
Authors: Moriarty DJW
Published: November 2005

Organic carbon and nitrogen and bacterial biomass were measured in the sediments and gut contents of H. atra and S. chloronotuson the Great Barrier Reef. Organic carbon averaged from 3.4 to 4.7 mg g-1, organic nitrogen from 0.20 to 0.31 mg g-1 and muramic acid from 1.4 to 3.3�g g-1 dry weight of surface sandy sediments. Bacterial biomass, determined by muramic acid measurements, averaged 3-8% of organic carbon in the sediments; blue-green algae accounted for 3-7% of muramic acid. Significantly higher values of organic carbon and nitrogen and muramic acid were found in foregut contents of the holothurians, indicating selective feeding on organically rich components of the sediment. Carbon values were 16-34% higher in the foregut than in the sediment. nitrogen values 35-111% higher and muramic acid values 33-300% higher. These values indicate that bacteria and nitrogenous components of the organic matter were selectively eaten. Values for organic carbon and nitrogen and muramic acid were generally lower in the hindgut than in the foregut, due to digestion and assimilation. Assimilation efficiencies averaged 30% for organic carbon, 40% for organic nitrogen and 30-40% for muramic acid (bacteria). Detritus (non-living matter) probably constituted 60-80% of the organic matter in the sediment and thus the food of the holothurians.
Studies on southern Australian abalone (Genus Haliotis). III. Mortality of two exploited species
Authors: Shepherd SA , Kirkwood GP , Sandland RL
Published: November 2005

The natural mortality of populations of H. laevigata and H. ruber was measured at two sites off the South Australian coast, West Island and Tipara Reef, which were closed to commercial fishing for the duration of the experiment. Abalone were individually marked with numbered tags and censuses taken of the marked populations periodically over several years. Examination of the data for H. laevigata at West Island showed that there was no significant age dependence in mortality, and that the probability of sighting an animal was independent between successive visits. The average annual natural mortality rate for H. laevigata at West Island was estimated to be 0.26 (s.e. 0.06) and at Tipara Reef to be 0.22 (s.e. 0.10). The mortality rate estimates for H. ruber were 0.36 (s.e. 0.28) at West Island and 0.21 (s.e. 0.10) at Tipara Reef.
Plankton of the lower River Murray, South Australia
Authors: Shiel RJ , Walker KF , Williams WD
Published: November 2005

Seasonal changes in the composition of plankton in the lower River Murray reflect disproportionate contributions from the Murray and its major tributary, the Darling River. Flows in the Murray are closely regulated, whereas Darling flows are relatively unimpeded. Typically, Murray flows carry blooms of Cyanobacteria (Anabaena and Anacystis spp.) in summer, and diatoms (Melosira and Cyclotella spp.) in winter and spring. The zooplankton, dominated by endemic microcrustaceans, is derived principally from upstream reservoirs. The most common taxa are eurytopic. although there are seasonal occurrences of cold stenothermal species. The Darling flows typically have a high abiogenic turbidity. low algal biomass, and zooplankton dominated by warm stenothermal pantropical rotifers. Of 133 zooplankton taxa recorded from the lower Murray in 1976-80, more than half were pseudoplanktonic or littoral incursions. Of the dominant potamoplankters, more than half were endemics. Plankton density and diversity were distributed contagiously across- and down-river. Mean zooplankton density at Mannum, S.A., was 119 plankters I-1, and average community species composition was 14.4 rotifers, 6.0 cladocerans and 2.4 copepods. Most common zooplankters were eurytopic and indicative of eutrophic conditions; some were influenced by changes in temperature, turbidity and salinity.
Seasonal variations in the macroinvertebrate fauna of billabongs along Magela Creek, Northern Territory
Authors: Marchant R
Published: November 2005

The littoral zone of five permanent billabongs along Magela Creek was sampled monthly over 1 year for macroinvertebrates. In three shallow billabongs, greatest numbers of taxa (about 45) and of individuals (about 1000 individuals per minute) were caught in the late wet season and early dry season (April-July); by the end of the dry season (December) these values had decreased to about 18 taxa and about 200 individuals per minute. Fluctuations were not so marked in two deep (or channel) billabongs: rarely were there fewer than 30 taxa and 400 individuals per minute present, and maximal values were similar to those in the shallow billabongs. These changes appeared to be associated with the growth of macrophytes, which occurred during the wet season in all billabongs. There was little variation between billabongs in the mean composition of the fauna.
Taxonomic revision of Australian species of Atyoida Randall (Crustacea : Decapoda : Atyidae), the genera Atyoida and Atya Leach
Authors: Smith MJ , Williams WD
Published: November 2005

A reconsideration of the diagnostic characters of Atya Leach and Atyoida Randall supports their generic separation. Accordingly, Atyoida is reinstated as a full genus of which the distinguishing features are slender third peraeopods with a relatively short merus, a tapering endopod in the male first pleopod and protandry. It includes three species, A. bisulcata Randall from the Hawaiian Islands, A. pilipes (Newport) widespread in the Indo-Pacific area, and A. striolata (McCulloch & McNeill) found only in Australia. A. striolata is fully redescribed. Morphological variation throughout its range is slight; no subspecies are distinguishable. It is suggested that larvae hatch in estuaries and that protandry is an adaptive life-cycle strategy.
Population dynamics and feeding ecology of juvenile Australian salmon (Arripis trutta) in Westren Port, Victoria
Authors: Robertson AI
Published: November 2005

Juveniles (0 + age group) of both subspecies of the Australian salmon were captured over eelgrass meadows in Western Port at various times between October 1974 and February 1976. The western subspecies and the eastern subspecies were present from August through April, and December through May, respectively. The western subspecies always fed on benthic-dwelling prey including fishes, crabs and shrimps, and the eastern subspecies fed on prey which inhabited the water column (crustacean larvae, insects and epitokous polychaetes) in December but switched to benthic-dwelling prey (fishes, small squid, benthic crustaceans and polychaetes) in May. The role of different gill-raker number and morphology in effecting dietary separation of the subspecies is unclear.
Water movement and salinty in the Yarra and Maribyrnong estuaries
Authors: Beckett R , Easton AK , Hart BT , McKelvie ID
Published: November 2005

Water movement and salinity studies have shown that the distance of salt-water penetration up the Yarra estuary is dependent upon the magnitude of the flow of the incoming Yarra River. During June, July and August 1977, salinity, temperature and current profiles showed that the Yarra and Maribyrnong estuaries had distinct stratification, the Yarra being classified as a 'salt-wedge' estuary and the Maribyrnong as a 'partially mixed' estuary. The residence time of water in the Yarra estuary was estimated to vary between 1 day and several weeks, depending upon the river flow at the time. The influence of freshwater discharge, tidal state and weather conditions are discussed.