bluuebunny/crossref_metadata_2025 huggingface dataset:
The New South Wales Trawlfishery: Review of Past Course and Examination of Present Condition
Authors: Houston TW
Published: November 2005

The past course of the New South Wales mixed trawlfishery is reviewed mainly on the basis of the available catch and fishing effort statistics. The size composition of tiger flathead landings from 1946-47 to 1953-54, and the age composition for certain post-war years, are analysed in conjunction with catch per unit effort data. The results suggest that 1943-44, 1944-45, 1947-48, and 1948-49 were relatively poor brood years, and 1945-46 and 1946-47 relatively good. The fluctuations in availability of tiger flathead (Neoplatycephalus macrodon (Ogilby) ) are accounted for after making certain valid assumptions. It is considered probable that the unexpectedly low catches of tiger flathead in the immediate post-war years were due to inefficiency of the few steam trawlers then working, and that Danish seiners were unable to exploit fully the available V+ and higher age-group fish. An examination of the present situation indicates that the New South Wales stock of tiger flathead is at a low level and is likely to reach even lower levels in the future if fishing intensity remains as high as in 1953-54. An improvement of the existing catch per unit effort would be expected if fishing intensity was reduced to the level of the middle nineteen-thirties (i.e. approx. 3500 trawler-tons) . Other regulative measures would need to be introduced to bring about an improvement in the annual catch of tiger flathead. These measures should aim at ensuring a more favourable weight-length relation.
Puberty, Physical Maturity, and Relative Growth of the Female Humpback Whale, Megaptera nodosa (Bonnaterre), on the Western Australian Coast
Authors: Chittleborough RG
Published: November 2005

At puberty the mean body length of the female humpback whales on the Western Australian coast is 38.60 � 0.18 ft. It is demonstrated that this length gives a reliable means of calculating the proportion of sexually immature females in a series where the lengths are known. Sexual maturity (based upon the first pregnancy) may either follow immediately upon puberty or be delayed for a further year. At the approach of physical maturity (when epiphysial fusion begins) the mean body length is 45.08 � 0.29 ft. At this stage an average of 19 ovulations have occurred. On the available material, physical maturity is reached at a mean length of 44.34 � 0.72 ft, when close to 30 ovulations have occurred. Growth in body length of sexually mature females becomes very slow even before epiphysial fusion begins. The significance of the high number of ovulations before the attainment of physical maturity is discussed. The proportion of physically mature individuals amongst the females in recent catches off the Western Australian coast is extremely low (1.8 per cent. of 457 females examined). The lengths of male and female humpback whales at puberty, at the approach of physical maturity, and at physical maturity are compared.
The Movements and Migrations of Mullet (Mugil cephalus L.)
Authors: Thomson JM
Published: November 2005

The mullet school (Mugil cephalus L.) has a real entity. The same fish
remain associated in a group for a considerable period. Some emigration from
(and inferentially immigration to) the school takes place. Some schools remain
in one locality (within a river system) for some months. Others appear to
move more or less continually. A sojourn in fresh water does not appear to be
essential though many fish are found there. It is impossible to generalize about
age preferences for salinity. Fish of all age groups can be found at all times
of year from fresh water to the lower saline estuaries.
Some seasonal difference in the direction of movement is evident in
Moreton Bay, Qld.; but this movement lacks the persistence of the seaward
spawning migration of adult fish in late summer and autumn. There is some
evidence to support the hypothesis that the majority of mature fish do not
migrate every spawning season, but at greater intervals.
Population Studies on the Toheroa, Amphidesma ventricosum Gray (Eulamellibranchiata)
Authors: Cassie RM
Published: November 2005

The ecology, distribution, and commercial importance of the toheroa, Amphidesma ventricosum Gray, are discussed. The habitat favoured by that portion of the population at present known is a beach fully exposed to heavy surf, with a fine sand and sufficient residual moisture to prevent desiccation at low tide. Frequent dense blooms of phytoplankton are necessary to provide an adequate food supply. Estimates of numerical abundance for various beaches are given, showing that violent fluctuations in numbers may occur, sometimes, but not always, with epidemic mortalities. The sampling technique for estimat- ing numerical abundance is described and discussed. The growth rate has been estimated for several different beaches, both by interpreting the annual growth-rings of the shell, and by analysis of length frequency data. The South Island toheroa have a significantly lower growth rate than those in the North Island. It is shown that the distribution of age classes on the beach is inconsistent with the assumption that the species is confined to the littoral region. In particular, the younger toheroa are almost invariably fewer in numbers than would be expected in a self-contained popula- tion. From this, and from the extreme fluctuations in numbers which occur from time to time, it is concluded that some part of the population is located in the sublittoral. The spatial distribution of the beach toheroa shows a high degree of over-dispersion (or aggregation) which is mainly attributable to variations in environmental conditions. Vertical and horizontal zonation of size groups may sometimes occur, but the contributing factors are obscure. Statistical aspects are discussed in appendices.
The Southern Bluefin Tuna, Thunnus thynnus maccoyii (Castelnau), in Australian Waters
Authors: Serventy DL
Published: November 2005

This paper deals with the results of the investigations of the Division of Fisheries,
C.S.I.R.O., into the biology of the southern bluefin tuna (Thunnus thynnus maccoyii
(Castelnau)), a representative in southern Australia and New Zealand of the tunny
of Europe and the bluefin tuna of California.
A comparative description of the morphology of the ,Australian form is given with
a detailed study of its occurrence in Australia, including a discussion of the possible
presence of local breeding stocks. The growth rate is considered from a study of length
frequency data.' Considerable variations have been found in the growth rate of the
younger age classes, as well as fluctuations in their relative abundance and their
migratory movements along the eastern Australian coastline. Reference is made to
the feeding habits in various areas.
The Marine Algae of Kangaroo Island. IV. The Algal Ecology of American River Inlet
Authors: Womersley HBS
Published: November 2005

An account is given of the marine ecology of American River inlet on the north
coast of Kangaroo Island, S.A. The plant and animal associations are described, with
emphasis on the marine algae, and an attempt is made to relate levels of zones to
tidal means.
A Portable Recording Tide Gauge
Authors: Hodgkin EP
Published: November 2005

The gauge is pressure-operated. A copper bellows is connected by plastic tubing
to the water, and both bellows and tube are filled with water. Movements of the free
end of the bellows are transmitted through a lever system to a marker recording on
a revolving drum. The weight of the water is counterbalanced by suspending appropriate
weights from the free end of the bellows. Waves are damped by inserting a capillary
in the tubing. The instrument records on a scale of 1 in, to 1 ft (the maximum tidal
range on the coast of south-western Australia is 5 ft) and it is sensitive to changes
of water level of less than 1 in. It is readily portable.
Additional Microplankton from Australian Late Mesozoic and Tertiary Sediments.
Authors: Cookson IC
Published: November 2005

New Australian Late Mesozoic species of Gymnodinium and Deflandrea (Dinoflagellata)
and Odontochitina and Palaeotetradinium (Incertae Sedis) have been described.
A new species of Wetzeliella from a South Australian Eocene deposit has thrown light
on the taxonomic position of the genus. Hystrichokolporna cinctum Klumpp (Hystrichosphaeridae)
has been recorded from Victorian Tertiary deposits.
Studies in Australian Estuarine Hydrology. II. The Swan River
Authors: Spencer RS
Published: November 2005

The physiography of the Swan River is described, with particular reference to the drowned valley basin which is connected to the sea across a shallow sill. The climatological features of the region are discussed, together with the tidal characteristics of the basin. Drought conditions prevail during the summer, effective rainfall being confined to the winter months. Density stratification in the basin
is intense and prolonged, because of the weakly developed tidal mixing. Changes in the mean water level of the basin are correlated with variations in barometric pressure; the amplitude of these changes sometimes exceeds that of the lunar tides. This fact has a significant bearing on hydrological conditions within the basin.
The distribution and the seasonal cycles of temperature, chlorinity, and oxygen saturation are compared with those of a tidal-dominated estuary situated at the same latitude In eastern Australia. Most of the differences in these cycles can be attributed to the tidal regimes of the two systems. Nutrient cycles within the Swan River basin are discussed with particular reference to the recovery period following the development of stratification. In the later stages of the investigation this period was studied intensively, and from the information obtained several theories are advanced to explain the circulatory features of the basin region.
An attempt is made to classify the Swan River estuary.
The Ecology and Distribution of Intertidal Organisms on Certain Islands off the Queensland Coast
Authors: Endean R , Stephenson W , Kenny R
Published: November 2005

The species composition and general ecology of intertidal organisms present
at Heron Island, a coral cay in the Capricorn Group, are recorded in this paper. It
was found that the general zonation picture on this Great Barrier Reef island differed
markedly from that found previously at localities on the Queensland mainland
(Endean, Kenny, and Stephenson 1956). In particular the mainland upper barnacle
(Chthamalus) zone was not represented at Heron I., and the species forming the
mainland lower barnacle zone (Tetraclita squamosa (Bruguiere) ) was replaced by a
different species (Tetraclita vitiata Darwin). Also the characteristic algal zone of
mainland localities was replaced by a lithothamnion-zoanthid-coral zone.
In order to investigate the possibility of a gradual transition from the mainland
type zonation to that found on the Great Barrier Reef, as exemplified by Heron I.
zonation, the species composition and general ecology of intertidal organisms inhabiting
a series of continental islands lying off the Queensland coast between lat.
16� and 22� S. were investigated. The fauna of these islands was found to be closely
allied to that of the mainland. There was, however, an intrusion of corals and
zoanthids on the more exposed of the islands visited which lie between lat.
20� and 22�S., and also on the more northerly of the islands visited. The biogeographical
implications of these findings are discussed, and it is noted that the
results of the present investigation support the contention of Whitley (1932) that
a longitudinal division of the Queensland marine fauna into "Solanderian" and
"Banksian" elements is warranted.
Accounts are also given of the major environmental factors that might affect
specific composition and zonation patterns at the localities investigated. Analyses
of these have given much information on the general ecology and distribution of
many Queensland intertidal species. Thls information is discussed. Of particular
interest was the finding that the Peronian barnacle Tetraclita rosea (Krauss) has
extended its range,to the north of the biogeographical boundary situated near lat.
25� S. by colonizing the more exposed of the continental islands.
A Critical Survey of the Marine Algae of Southern Australia. I. Chlorophyta
Authors: Womersley HBS
Published: November 2005

This paper is a survey of all the known marine Chlorophyta of southern
Australia, from the south-west corner of Western Australia to about the Victoria-
New South Wales border, and including Tasmania. Full references to each species
are given, all established synonomy, the type locality of each species and where the
type specimen is deposited, and a summary of the known distribution. Critical
notes on many species are given also.
Biological Studies of Economic Significance of the Yellow-Eye Mullet, Aldrichetta forsteri (Cuvier & Valenciennes) (Mugilidae)
Authors: Thomson JM
Published: November 2005

This species attains a relatively small size (40 cm maximum) and an age of
7 years. The smallest fish recorded with mature gonads were 22 cm length to caudal
fork (male) and 24.5 cm (female). The species matures at the end of the third year.
Two races are distinguishable, a summer-spawping group in Victoria and Tasmania
and a winter-spawning group in Western Australia. Fecundity varies from 125,000
eggs in a female 24.5 cm long to 630,000 in one 39.1 cm long. The condition factor
increases markedly in fish with ripening gonads.
In Western Australia only 3.3 per cent. of yellow-eye mullet in market
samples were less than the legal minimum size. Mesh tests show that 24 in. mesh
is sufficient to permit escape of undersized fish.
The species feeds on any small organic material, plant, animal, or detrital.
Existing management policies are effective in maintaining stocks.
Interpretation of the Scales of the Yellow-Eye Mullet, Aldrichetta forsteri (Cuvier & Valenciennes) (Mugilidae)
Authors: Thomson JM
Published: November 2005

The yellow-eye mullet scale is of the typical percomorph type, feebly ctenoid in most cases, but cycloid in the mid-flank region, which provides the best scale for age and growth determinations. The annual "break" is more obvious in the posterior sector than in the anterior. Above a length of 5 cm (length to caudal fork) there is a straight-line relationship between increments in dimensions of scale and increments in length of the fish. The scales of Victorian and Tasmanian fish are smaller than those of Western Australian fish, which is in accord with the rather larger number of scales in eastern fish. The annual "breaks" become apparent in spring when growth recommences after the winter cessation. As western fish are winter spawners and eastern fish summer spawners, the age and size attained at the time of formation of tho annuli differs in the two stocks. Females grow faster than males. Lengths (cm) attained each winter average as follows:
Year I II III IV V VI VII
Western fish 11 18-19 24-25 29-32 32-35 38 39
Eastern fish 5 12-13 19-21 24-27 30
The Petersen method of modal progression gives rather higher readings in the first and second years, probably as a result of mesh selection.
The Respiratory Metabolism of Dendrostomum cymodoceae Edmonds (Sipunculoidea)
Authors: Edmonds SJ
Published: November 2005

The consumption of oxygen of Dendrostomum cymodoceae at 22'C in aerated
sea-water varied from 4-5-5.5 μl/g (wet weight)/hr for adults to 20-31 μ/g/hr for
juveniles. The production of carbon dioxide was 13-17 μ/g/hr (juveniles) and the
R.Q. varied from 0.55 to 0.67 (juveniles). The rate of consunlption of oxygen
decreased as the tension of the dissolved oxygen decreased. The oxygen combined
with the pigment of the blood was 2.1 vols. of oxygen per 100 vols. of blood and the
ratio of blood volume (ml) to total weight (g) of the animal was 0.47. D. cymodoceae
was able to live under anaerobic conditions in sea-water for as long as 5 days and
in paraffin oil for 4 days. The haemerythrin in the blood of animals kept under
oil was found to be reduced after about 6 hr. Lactic acid was identified as one of
the end-products of anaerobiosis. The concentration of lactic acid in the blood of
animals living under anaerobic conditions increased after 60 hr from 7-12 to 46-61
μg/ml of blood. The ability to revert to anaerobiosis may have survival value for
the species.
The Ascidians of Australia. II. Aplousobranchiata Lahille: Clavelinidae Forbes & Hanly and Polyclinidae Verrill
Authors: Kott P
Published: November 2005

An account is given of 39 species of Australian ascidians of the families
Clavelinidae and Polyclinidae, of which 14 are new. The larvae of certain species
are considered in relation to specific and phylogenetic patterns within the genera
and families. The geographical distribution of species is discussed.
Trout Populations and Habitats in New South Wales
Authors: Lake JS
Published: November 2005

Surveys of most of the trout waters in New South Wales have been made.
Relevant data of the trout areas are given in respect to geography, generalized
topography, and climate. Chemical and physical conditions of the waters are
tabulated. Growth rates of trout and quantitative data on the bottom fauna of
some streams have been determined. It is shown that the biological, chemical, and
physical characteristics of the trout habitats are related and interdependent to a
marked and consistent degree. The waters are separated into three groups on the
basis of trout growth. The data suggest that the majority of waters in New South
Wales often provide conditions which are limiting for trout.
Preliminary population and mortality studies have been made on small
sections of nine rivers and on one small lake. The results of a creel census are given.
The information from these sources confirms conclusions obtained from the habitat
surveys. In addition evidence is presented indicating that certain management
procedures should be modified. These include legal length, closed season, and
stocking of streams. It is suggested that some of these modifications would have
the additional benefit of reducing predation, and that hatchery-reared trout could
be utilized on a much wider basis than at the moment for cold-water fish farming.
Observations on the Biology of the Greentail Prawn, Metapenaeus mastersii (Haswell) (Crustacea Decapoda: Penaeidae)
Authors: Dall W
Published: November 2005

The ecology, growth, and behaviour of Metapenaeus mastersii from the Brisbane River, Qld., are described. Postlarval stages were found to favour a warm sheltered locality with abundant algal cover and salinity below 20‰. Salinity tolerance range of all stages was from almost fresh to sea-water, and activity was at a minimum when the average temperature fell to 16�C. Carapace length was found to be as reliable a measure of size as overall length or volume. Progression
of the modes of length frequency distributions was unsatisfactory for finding growth rate, but showed a steady downstream movement as growth progressed. From the growth rate of captive prawns, age at sexual maturity was estimated as 12-15 months at 16 mm carapace length (males) and 20 mm (females) (76 and 95 mm overall). Males were less tolerant of low salinity than females, but
did not migrate as far downstream. Fertilization occurred in the lower reaches of the Brisbane River, but spawning occurred outside. The length-volume relationship of prawns above 10 mm carapace length (48 mm overall) did not conform to the curve: volume = k × (length)³. This deviation was interpreted as due to change of growth characteristics during winter. A reversed respiratory current
and other adaptations to burying in the mud, and a possible associated diurnal
rhythm are described.
Reproduction in Australian Pearl Oysters (Lamellibranchia). III. Pinctada albina (Lamarck): Breeding Season and Sexuality
Authors: Tranter DJ
Published: November 2005

Plnctada albina breeds continuously throughout the year, but most actively
during April and May when sea temperatures begin to fall. Thus the species resembles
the majority of tropical marine invertebrates in the former respect but differs from
them in the latter. The heaviest spatfalls occur from June to August when sea
temperatures are at a minimum.
This species is hermaphrodite, with a, general tendency toward protandry.
Both male-female and female-male sex changes, and the bisexual condition which
sometimes prevails during change-over, have been observed. Sex change in bivalves
is discussed, and it is suggested that the phenomenon can best be explained in terms of
a weak hereditary sex-determining mechanism, and germ cell rudiments responsive to
the food reserve level in the body such that male differentiation is favoured at lower
levels and female differentiation at higher levels.
A Monograph of the Freshwater Mussels (Mollusca: Pelecypoda) of the Australian Region
Authors: McMichael DF , Hiscock ID
Published: November 2005

This monograph incorporates a systematic revision of the freshwater mussels
of the Australian Region (Australia, New Zealand, New Guinea and the Solomon
Islands). Previous systematic works are revised and discussed. Details of the
taxonomic procedures used in the present work are presented. One aberrant New
Guinea genus, Haasodonta, with two species is referred provisionally to the family
Unionidae Fleming, subfamily Rectidentinae Modell. The remainder of the Australasian
species are assigned to the family Mutelidae Gray. Four subfamilies, Velesunioninae Iredale, Lortiellinae Iredale, Hyridellinae Iredale, and Cucumerunioninae Iredale, are recognized. These include eight genera, Velesunio Iredale, Alathyria Iredale, Weatralunio Iredale, Microdontia Tapparone Canefri, Lortiella Iredale, Hyridella Swainson, Cucumerunio Iredale, and Virgus Simpson. The genus Hyridella includes four subgenera, Hyridella s.s., Protohyridella Cotton & Gabriel, Nesonaia Haas, and a new subgenus for H. menziesi Gray. These eight genera
include 27 species, three of which are polytypic. Three additional species are
considered of doubtful validity and two nominal species are listed as nomina dubia.
Each taxon is redescribed and all available data of shell morphology, soft anatomy,
larval stages, distribution, and type material are presented. The distribution of the
Australian and New Guinea species in relation to the fluvifaunal provinces of Iredale
and Whitley is considered and a new name is proposed for the fluvifaunula of
southern New Guinea. The evolutionary relationships of the Australasian freshwater
mussels are discussed and it is suggested that, with one exception, they arose from a
single ancestral stock and have subsequently differentiated into four subfamilies
within this region. This view is supported by the close anatomical similarity between
them.
The Status of the 'White' Crayfish in Western Australia
Authors: George RW
Published: November 2005

The pale-coloured "white" marine crayfish which occur seasonally along the
southern part of the Western Australian west coastal shelf are recently moulted
immature crayfish, and are stages in the development of the Western Australian
commercial crayfish Panulirus longipes. It is suggested that individuals which
reappear as whites the following season have failed to mature in the intervening
period. During these phases, the average annual increment is about 0.3 in. in
carapace length. Crayfish in this phase had carapace lengths from 2 3/8 to 3 3/4 in.
The Gastropod Genus Bembicium Philippi
Authors: Anderson H
Published: November 2005

A history of the nomenclature of the littorinid genus, Bembicium Phllippi,
1846, and its characters are given, and the anatomy of species of the genus is discussed.
Three species are recognized and redescribed: a reef-living species, B. nanum
(Lamarck); an estuarine species, B. auratum (Quoy & Gaimard); and the species B. melanostoma (Gmelin) which normally inhabits sheltered bays and inlets. Although all are intertidal animals, and show some measure of adaptability, each appears to be best suited to a particular habitat. B. melanostoma and B. nanum are usually found where the chlorinity of the water is close to that of the sea. B. auratum can withstand considerable variation in the chlorinity of its environment for periods of time which are not likely to be exceeded in its normal habitat. B. melanostoma mostly lives at higher tidal levels than B. nanum. In the aquarium B. nanum proved the most susceptible to desiccation.
The egg masses of B. melanostoma contain fewer and larger eggs than those of B. auratum. In the laboratory spawning of B. auratum occurred during the spring and early summer. Under the same conditions specimens of B. melanostoma deposited eggs in October. The differences between the eggs and their development, and between the times of spawning of the two species collected from different littoral regions are also discussed.
The Absorption of Phosphate by Estuarine Bottom Deposits
Authors: Jitts HR
Published: November 2005

Experiments were made on the effects of pH, phosphate concentration, particle size, iron, and organic matter on the adsorption of phosphate by estuarine bottom deposits in as natural a state as possible. Measurements of the ability of the silt to adsorb phosphate were made by isotope dilution, using 32P. The silt was separated into four fractions by sedimentation.
The ability of silts to adsorb phosphate was directly related to the ratio of their contents of iron to organic matter. Organic matter depressed phosphate adsorption.
Suspensions of silts (2.99g/1250ml) adsorbed 80-90 per cent. of the phosphate in solutions containing 0.55 to 2.55 mg of phosphate P. This suggested that adsorption caused estuarine silts to trap phosphates during run-off periods.
Factors Influencing the Settling of the Principal Marine Fouling Organisms in Sydney Harbour
Authors: Wisely B
Published: November 2005

The macrofouling organisms most commonly encountered during intermittent
plate exposures in Sydney Harbour over 10 years (1947-57) comprised a barnacle
(mainly Balanus (Balanus) amphitrite var. cirratus Darwin), several serpulids and
bryozoans (Hydroides norvegica Gunnerus, Spirorbis sp.; Bugula neritina L., Bugula
avicularia L., Watersipora cucullata (Busk)), a mussel (Mytilus planulatus Lamarck),
and an oyster (Crassostrea commercialis Iredale & Roughley). With the exception
of the mussel, settlement was heaviest during the summer months. Surface water
temperatures averaged from about 15°C in midwinter to 24� in midsummer and
were over 20°C for 6 months of the year. Two cases where freshwater dilution
apparently affected biological populations are recorded. The effects of colour,
surface texture, depth, aspect, and horizontal distance on settling were investigated
using paired series of plates. The results were treated statistically and compared
with those reported by others. It is suggested that during antifouling raft tests
at this locality the control plates for any group of experimental plates need to be
placed at the same site, same depth, facing the same way, and 5-10 ft apart
horizontally. Providing the most common macrofouling organisma settling at the
station were considered as a whole, this arrangement seemed to give a reasonably
accurate assessment of their settling intensity at the test site.
The Distribution of Intertidal Crabs in the Brisbane River
Authors: Snelling B
Published: November 2005

This paper records investigations made on the ecology of intertidal crabs of the Brisbane River. Traverses were made at selected localities extending from the river mouth upstream to points beyond the limit of tidal influence. Twenty-three species of crabs were found, two of which extend 37 miles upstream. The population was found to fall into four clearly defined vertical zones: (1) sesarmine zone, H.W.N. upwards, (2) ooypodine zone, H.W.K. to M.S.L., (3) upper macrophthalmine zone, M.S.L. to L.W.X., and (4) lower macrophthalmine zone, L.W.N. to L.W.S. After drought, species not usually found in the river were present in the lower reaches. Freshwater flooding caused disappearance of these from the river and reduced the upstream penetration of one species. Comparisons with work in other parts of the world show that the estuarine crab distribution in the Brisbane River is similar to that in South Africa and Java. It is suggested that salinity is the most important factor controlling the distribution of estuarine crabs.
The Australian Portunids (Crustacea : Portunidae). III. The Genus Portunus
Authors: Stephenson W , Campbell B
Published: November 2005

Thirteen species of the genus Portunus Weber are recorded from Australia, including one new species and five new records. These species are described and illustrated, and a key is given to known Indo-West-Pacific species. First pleopods of males are considered in detail and a key based on their features is included.
The problems of designating subgenera are discussed and the relevance of a knowledge of the structure of first male pleopods is indicated.
The Status of the School Shark Fishery in South-Eastern Australian Waters
Authors: Olsen AM
Published: November 2005

The maximum yield of the school shark fishery in south-eastern Australian waters was 4.09 million lb in 1949. The catch has fluctuated since then about a declining trend to 3.18 million lb in 1956.
In 1944, 7.3 hooks were required to catch a shark of mean weight 14.7 lb. In 1956 the number of hooks required was almost doubled: 13.6 hooks were needed to catch sharks of mean weight 13.7 lb; the catch per hook dropped from 2.01 to 0.99 lb. Whereas the catch per boat-month remained relatively stable at 4765 lb for 1944 and 4643 for 1956, the number of hooks used per boat-month increased from 2366 to 4668 hooks in 12 years.
Throughout this period the mean weight of sharks in eastern Bass Strait remained fairly steady (11-13 lb) whereas there was a drop of 3 lb from a mean weight of 17-20 lb in the predominantly mature portion of the stock in western Bass Strait. Fishermen in South Australia have reported a comparable drop in the mean weight of sharks in their catches. During the period 1941-46 there was unrestricted inshore fishing of juveniles and pregnant females with a consequent severe drop in the inshore population. The subsequent decline in the annual total catch is believed to be due not
only to a too intensive offshore fishery but also to the resultant reduced recruitment and depressed reproductive potential caused by the earlier destruction of juveniles and pregnant females.
In the data presented in this paper there is evidence that the school shark fishery, which is operating on a single stock of sharks with a slow growth rate, a late sexual maturity, and a low fecundity, shows trends which are suggestive of depletion. Because similar trends in the soupfin shark fishery of California and in the dogfish fishery of British Columbia were followed by depletion, it has been inferred that regulations to protect the vulnerable phases of the life history of the school shark of
Australia may be required. Measures for conservation are discussed.
Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. I. General Introduction
Authors: Baas Becking LGM , Thomson JM , Wood JF
Published: November 2005

In the period 1883-98 Lake Macquarie was the principal source of fish for
Sydney and Newcastle. Since 1930 it has been only tenth or eleventh of New South
Wales estuaries in fish production. The number of commercial fishermen in 1920
was 110, but today is only 35. Allegations of depletion prompted this investigation,
the results of which are discussed in this series of papers.
Lake Macquarie is a coastal lake with a small freshwater inflow estimated
to be only 4 per cent. of its volume. Attempts to improve the channel connecting
the lake with the sea have failed repeatedly. A seemingly permanent result of the
dredging is a great enlargement of the unproductive sand flat at the inner end of
the channel. The soils of the lake's catchment area are poor in minerals. The land
vegetation is mainly sclerophyllous forest with isolated patches of rain-forest and
Melaleuca swamp.
The population has increased since the first settlement in 1825 until it is
now over 50,000, but the lake is also a recreation area for the much larger population
of Newcastle (over 200,000).
Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. IV. Bacterial and Fungal Studies
Authors: Wood EJF
Published: November 2005

Bacterial communities in Lake Macquarie show several peculiarities including
the paucity of cellulose digesters and agar digesters, and the presence at times of
anaerobic sulphur bacteria in waters containing considerable oxygen.
The Eh of the lake bottom is frequently positive, negative potentials being
recorded from decomposing Zostera patches and from the microbially rather inert
blue muds. The latter show little or no active sulphate reduction, though Desulphovibrio
may be present. Photosynthesis controls the pH on the sea-grass flats, values
as high as 9.7 having been recorded off Swansea flat on a sunny afternoon.
Bacterial populations are relatively low, especially in the muds, and there is
no marked seasonal variation.
Contamination by faecal pollution of the lake waters could not be demonstrated,
either during the summer holiday season or during a typhoid epidemic at
Swansea.
Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. V. Chlorophyll Distribution
Authors: Davis PS
Published: November 2005

The chlorophyll a in samples from five stations in Lake Macquarie was determined
over the period July 1955 to November 1956. The mean surface value for
the four stations within the lake proper was 1.26 mg/m³. The vertical profile at
one station was studied and the mean of these profile values was 1.23 mg/m³.
Throughout the period of the survey chlorophyll concentrations in the lake varied
from 0.1 to 4.0 mg/m³. The lowest values were found in the late winter and early
summer (November) and the peaks during spring and autumn.
The chlorophyll concentration in the surface waters of Lake Macquarie was
shown to be significantly higher than that of the marine water entering the lake,
but lower than that of a comparison station in the Hawkesbury River.
One series of light penetration measurements made in December 1956 showed
that all the water in the lake, and all but one section of Dora Creek, lay within the
euphotic zone.
Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. VI. Plant Communities and their Significance
Authors: Wood EJF
Published: November 2005

There are four plant communities in Lake Macquarie: the see-grass community, the reef community, the mud bottom community, and the phytoplankton community. Biologically, the sea-grass community is regarded as being the most important. The epiphytes on the sea-grasses are largely used as food by phytophagous fish and other animals.
The reef community consists of larger brown algae which are not of themselves of great importance, and of felts of blue-green algae such as Ectocarpus, and other filamentous forms which are important.
Photosynthetic organisms are sparse in the mud bottoms, except for the tapetic organisms in the sea. Phytoplankton is relatively abundant.
Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. VII. The Benthic Macrofauna.
Authors: MacIntyre RJ
Published: November 2005

The benthic zone of Lake Macquarie, passing from shallow to deep water, consists of weed, slope, and mud zones, occupying respectively 23.5, 16.0, and 60.5 per cent. of the lake area. The biomasses of the invertebrate macrofauna of the zones are respectively 94 156 g, 180 � 12 g, and 10.6 � 9.4 g per m2. Each zone has its typical fauna. A variety of species occurs in the weed and slope zones, but only two species occur in number in the mud zone.
A number of mollusc species was represented only by dead shells of recent origin, suggesting some catastrophe such as production of anaerobic conditions. There is no evidence that the mussel Trichomya hirsuta was affected, and experimentation revealed that this species can survive long periods of immersion under anaerobic conditions.
A Study of Condition (Weight for Length) of Australian Barracouta, Thyrsites atun (Euphrasen)
Authors: Blackburn JP
Published: November 2005

Regression of weight in the round (w) on length to caudal fork (I) was calculated
for 6571 barracouta from southern Victoria and 2711 from south-eastern
Tasmania. The equations for the regressions, which differ significantly in position
but not in slope, are respectively w = 0.0572 l2.360588 w = 0.1064 l2.239524 The values of the exponents are unusually low.
A condition factor Kn was obtained for each fish by dividing the observed weight by the weight estimated from the regression, and geometric mean Kn was calculated for each month for each of the two regions. The mean for southern Victorian fish varied within the year in much the same way in each of three successive years, with three highs and three lows from early spring through early
winter, but was consistently higher in 1950-51 than at the corresponding period of the year in 1949-50 or 1951-52. A similar pattern of within-year variation is suggested by the scantier data for other years, and likewise for south-eastern Tasmanian fish. All changes in mean Kn are closely paralleled by those in mean Kn,c the corresponding factor for beheaded eviscerated fish. It is also shown that changes in density of the fish are negligible. Thus the rises and falls in mean Kn represent true increments and decrements of growth in weight and volume of trunk muscle (edible flesh), unassociated with growth in length.
There is a tendency for fish with filling gonads to have better condition than ripe, spent, recovering, or immature individuals, but it does not explain the major part of the variation in condition observed. Neither is there any apparent relationship between mean Kn and percentage of the monthly sample affected by the sporozoan Chloromyxum or the cestode Tetrarhynchus, which cause the conditions
known as "milky" and "wormy" and are the only parasites of barracouta that occur in the trunk musculature. It seems most likely that the changes in mean Kn signify a complex interplay between assimilation on the one hand and the energy demands of migratory and food-seeking activity on the other.
Oil content as a percentage of original (wet) weight was determined separately
for fillet (edible flesh), viscera, and head of each of 66 south-eastern Tasmanian
barracouta. There is a highly significant correlation between the oil content of
each portion and the Kn of the fish. Regressions are given, and indicate that oil
contents for fish of average condition (Kn = 1.000) are 4.39, 8-08, and 7.98 per
cent. for fillet, viscera, and head respectively.
Observations on the Settling Behaviour of Larvae of the Tubeworm Spirorbis borealis Daudin (Polychaeta)
Authors: Wisely B
Published: November 2005

Aspects of natural and experimental settling of Spirorbis borealis on the seaweed Fucus serratus L. were compared. Under natural conditions S. borealis appeared to settle preferentially in the concave grooves flanking the midribs, and less commonly on the flatter parts of the fronds. Settlement seldom took place on the convex midrib. The centres of individuals of dense populations, which were spaced along the grooves, were 1-2 mm from those of their nearest neighbours; none of the 2582 examined were closer than 0.5 mm. Experiments showed that larvae tended to avoid settling on P. serratus bearing adults of their own species, or similar shaped objects, when the density of these exceeded 10 per cm² and if alternative settling surfaces of Fucus were provided. Direct observations showed that larvae tended to explore concave areas of the fronds more intensively than other areas and turned away from nearby round, protruding objects during their final settling movements. However, larvae withheld from suitable settling surfaces for increasing periods of time showed a successive abbreviation of the pattern of searching behaviour. When they had been prevented from settling for 8 hours or more they settled on or very close to the point where they first alighted, apparently regardless of the surface contour or the presence of nearby objects. The most densely settled populations encountered naturally in the area (Menai Straits, North Wales) ranged from 12 to 33 individuals per cm² and averaged 21, but experimental densities of 64 to 322 individuals per cm² were obtained readily when larvae competed for limited settling spaces on F. serratus under laboratory conditions. Analysis of the settlement behaviour and its modification with the passage of time indicated how the pattern of settlement observed in nature could result.
The Intermediate Depth Waters of the Tasman and Coral Seas. I. The 27.20 σt Surface
Authors: Rochford DJ
Published: November 2005

The distribution of salinity, dissolved oxygen, and phosphates on the 27.20 σt surface of the Tasman and Coral Seas is examined. Their distribution patterns and the relations of salinity and phosphate values on this σt surface are explained by the horizontal mixing of three water types. These originate, one at the Antarctic Convergence, one in the western equatorial region of the Pacific, and one in the south-west Pacific. From the distribution of these water types and the topography of the 27.20 σt surface, general features of the intermediate depth circulation of the Tasman and Coral Seas are deduced.
Sea-Levels around Australia during the International Geophysical Year
Authors: Hamon BV , Stacey FD
Published: November 2005

The variations in mean sea-level observed at Australian tide-recording
stations during the International Geophysical Year are presented in graphical form
and compared with the changes in density of sea-water measured near some of the
stations. The observations are in general but not detailed agreement with the isostatic
hypothesis according to which sea-level and water density are directly related.
Area of Distribution, and Movement of the Western Subspecies of the Australian 'Salmon', Arripis trutta esper Whitley
Authors: Malcolm WB
Published: November 2005

Evidence provided by the commercial fishery, tagging operation, and direct
observation of the schools is used to give a general account of the area of distribution
and movements of this subspecies. A study of some aspects of the reproductive
cycle has furnished evidence on the location of the spawning area. Some
age data are used, but conclusions regarding age are exceedingly tentative and are
not essential to the general account. The implications of this account with regard
to the total area of distribution and the magnitude of the entire stock are discussed.
The Development of the Embryo and Membranes of the Humpback Whale, Megaptera nodosa (Bonnaterre)
Authors: Stump CW , Robins JP , Garde ML
Published: November 2005

The material consists of 20 embryos (5-30 mm) and two foetuses (63 mm and
90 mm) collected at whaling stations on Moreton and Norfolk Islands (latitude
27� 11'S. and 29� 5' S. respectively) during late August, September, and early
October in 1952-53-54 and 1956. The consecutive series permitted the study of
membrane formation and organogenesis.
Younger embryos are found in grooves between the folds of endometrium in a
constant site in that uterine horn associated with the ovary containing the recent
corpus luteum.
Older embryos and the early foetus are adapted to lie freely in the uterine fluid,
and are devoid of any mechanism for apposition or attachment to the endometrium.
Variation in the sequence of the association of the components of the umbilical
cord provides suspensory structures for the amnion and yolk sac, and for the embryo
a bifid ligament, retained in the early foetus for attachment of the foetal membranes.
In the younger foetus the allantoic duct drains the nephric secretion into the
uterine cavity. In the older foetus chorionic villi are present. The bifid suspensory
ligament forms the major part of the distal region of the umbilical cord. The allantoic
duct is reunited with the allantoic sac.
Amniogenesis is by folding. During the embryonic period the chorio-amniotic
connection forms a suspensory ligament. The yolk sac, attached by a novel ligament
to the amnion, is large and functional in the embryo. In the foetus vascular splanchnopleure
is present in a tubular form.
A rete system develops in the embryo.
Distribution and abundance of giant sea anemones (Actiniaria) in subtropical eastern Australian waters
Authors: Richardson Darren L. , Harriott Vicki J. , Harrison Peter L.
Published: November 2005

Five of the 10 known Indo-Pacific giant anemone species were recorded on
subtidal reefs within the eastern Australian subtropics (26°37′S to
30°56′S) during surveys between 1993 and 1995. Giant anemones had a
patchy distribution among the 30 localities sampled, and species richness did
not display any latitudinal trends within this province. Spatial distribution
patterns and abundance of anemones were assessed from total counts and from
line-intercept and belt transects. Anemone abundance was significantly higher
on reefs to the leeward of the prevailing swell than on more exposed sites, at
Julian Rocks and North Solitary Island, northern NSW. Significant reductions
in anemone cover were detected among years within shallow reefal sites at
North Solitary Island, coinciding with two major storm events. The abundance
of the widespread Entacmaea quadricolor at North
Solitary Island was the highest reported worldwide. Significant differences
were detected between two morphological types of
E. quadricolor in terms of microhabitat type, oral disk
size and spatial distribution patterns. Important factors influencing the
distribution, abundance and spatial patterns of giant anemones over both large
and localized spatial scales appear to be water temperature, wave disturbance
and water depth.
Uptake and depuration of organochlorine compounds in Sydney rock oysters (Saccostrea commercialis)
Authors: Scanes Peter R.
Published: November 2005

Field experiments were done to determine the rates of uptake and depuration of
chlordane, dieldrin, heptachlor epoxide, PCBs, DDT, DDD and DDE in Sydney rock
oysters (Saccostrea commercialis). Oysters from a clean
source were placed in a contaminated location and concentrations of
organochlorines determined in samples collected at a number of times during
the deployment. After 209 days (which was long enough for equilibrium to have
been reached), the oysters were moved to an uncontaminated location and
concentrations of the compounds were determined at various times. Mean weight
of the oysters changed during the study, but not in any consistent manner.
Mean content of lipids did not change significantly during the study.
Detectable concentrations of all organochlorines were present after 3 days.
Times to equilibrium and biological half-lives were calculated using kinetic
models. Generally, rates of depuration were of the same order, but slower,
than rates of uptake. There was a strong correlation between percentage lipid
and organochlorine concentration, but little difference in times to
equilibrium and biological half-lives derived from concentrations per wet
weight and those per weight of lipid. The experiments show that times to
equilibrium for each compound differ and that this should be taken into
account when designing a programme to monitor these compounds.