Port Hacking Research Articles

A New Species of Hatschekia (Copepoda: Dichelesthiidae) Parasitic on Leopard Coral Trout in the Great Barrier Reef, Australia

Hatschekia plectropomi sp. n. is described based on the specimens taken from Plectropomus leopardus (Lacepede) collected from Wistari Reef, Heron Island, and Lizard Island of the Great Barrier Reef, Australia. There are two known records of Hatschekia reported from Australia, but none from the Great Barrier Reef. Heegaard (1962) described H. elongata, which he (1964) renamed H. thompsonii, from Brachaluteres jacksonianus washed ashore at Cronulla Beach, near Port Hacking, New South Wales, and Kabata (1965) described H. modesta from Upeneichthys porosus (Cuvier et Valenciennes) which was collected east of Albany, Western Australia. Specimens of the new species treated below were collected by Dr. K. Rohde, while director of the Heron Island Research Station, Queensland, Australia. We would like to thank Dr. Rohde for his kindness and generosity in placing his collection of copepod parasites at our disposal. Hatschekia plectropomi sp. n. (Figs. 1-11) Material examined: 87 ovigerous and juvenile 9 9 on gills of Plectropomus leopardus (Lacepede). From Wistari Reef: 12 ovigerous and 3 juveniles from a 58 cm long host, 4 November 1973; 3 ovigerous and 2 juveniles from a 63 cm long host, 4 November 1973; 17 ovigerous and 2 juveniles from a 45 cm long host, 11 November 1973 (holotype, USNM 170547, and 10 paratypes, USNM 170548, selected from this collection are deposited in the U.S. National Museum of Natural History, Smithsonian Institution, Washington, D.C.); 8 ovigerous and 1 juvenile from 62 cm long host, 4 December 1973; 8 ovigerous from a 50 cm long host, 5 January 1974; 1 ovigerous from a 50 cm long host, 29 May 1974. From Heron Island: 6 ovigerous (no host length recorded), 2 Received for publication 27 January 1978. *Department of Biology, California State University, Long Beach, California 90840. t Boston University Marine Program, Marine Biological Laboratory, Woods Hole, Massachusetts 02543. September 1973; 3 ovigerous from a 68 cm long host, 4 December 1973; 10 ovigerous from a 78 cm long host, 28 January 1974. From Lizard Island: 8 ovigerous from a 31 cm long host, 23 April 1975. Female: Body (Fig. 1) long, with flattened ventral surface. Head wider than long, with a rounded margin extending posteriorly into trunk. Distinct cuticular ribs on dorsal surface of head. First and second pedigerous somites short and incompletely fused. Third and fourth pedigerous segments completely fused to form a long trunk bearing a prominent lateral swelling on either right or left side. Genital segment (Fig. 2) small, attached to ventral surface of trunk. Egg sacs attached to posterodorsal surface of genital segment. Abdomen (Fig. 2) distinctly wider than long, bearing a pair of small setules on posterodorsal surface. Caudal ramus about 3 times longer than wide, armed with 6 unequal setae (3 plumose, 3 naked). First antenna (Fig. 3) 3-segmented, with stout basal portion covered by a semi-transparent membrane. Armature of these segments being: 9, 10, and 12 + 1 aesthete. Second antenna (Fig. 4) a strong prehensile apparatus bearing numerous microtubules on its huge second segment. These tubules appear as minute scales on surface of cuticle. Terminal segment a simple recurved hook. Base of second antenna lacking papilla. Mandible (Fig. 5) stubby, bearing 3 stout teeth. Maxilla (Fig. 6) small, consisting of 2 lobes, each bearing 2 processes. Maxilliped (Fig. 7) long, slender, and 4-segmented; second and third segments each bearing a seta; terminal segment bearing a break on its cuticle and a forked tip. Both leg 1 (Fig. 8) and leg 2 (Fig. 9) biramous, with 2-segmented rami bearing rows of spinules only on their anterior surfaces. Armature on these legs as follows: Leg 1 Protopod 1-1 Exopod 1-0; 6 Endopod 0-0; 5 Leg 2 Protopod 1-0 Exopod 1-0; 5 Endopod 0-1; 5 Leg 3 (Fig. 10) represented by a small lobe tipped with 2 plumose setae and leg 4 (Fig. 11), with 1 plumose seta. Measurements (in Ium):

A study of copper, lead and cadmium speciation in some estuarine and coastal marine waters

The potential of a heavy metal speciation scheme to reflect differences in metal distributions within a water mass was evaluated in a study of soluble copper, lead and cadmium speciation in water samples from five stations in the Port Hacking Estuary (Australia) and one coastal Pacific Ocean station. The observed metal distributions were found to be consistent with the other measured physical and chemical properties of the sampled waters. In all samples, the percentages of metals associated with colloidal matter were high, amounting to 40–60% of total copper, 45–70% of total lead and 15–35% of total cadmium. The scheme was used to follow changes in metal speciation under different sample storage conditions. Storage at 4 °C in polythene containers was shown to prevent losses or changes in speciation of the metals studied.

Nutrient Cycling and Primary Production in Port Hacking, New South Wales

The changes in the concentrations of nitrate, phosphate and silicate in a marine-dominated estuarine basin are described and related to the changes in the physical properties of the water and the primary production. The consumption of oxygen and nutrient regeneration in the lower water column were directly related to density differences in the lower water column, and to the primary production. The regeneration of nutrients was related to the consumption of oxygen, with seasonal differences in the regeneration of nitrate and silicate. Increased rates of nutrient regeneration during salinity stratification after heavy rain were attributed to increased sedimentation rates.

Phytoplankton Distribution and Light Attenuation in Port Hacking Estuary

The distribution of phytoplankton in a marine dominated estuary is described in terms of in vivo chlorophyll fluorescence, phytoplankton photosynthesis rates at constant irradiance, and the attenuation of solar irradiance by the water column. The phytoplankton distribution was consistent with the physiography and water circulation in the estuary. A method is described for estimating the proportions of suspended sediments, introduced with runoff from the land, which are removed from the estuary by tidal exchange or by sinking. Estimates of the proportions of phytoplankton and detritus in the water column are derived from the relationship of chlorophyll concentration to the extinction coefficient.

The bedrock topography of the botany basin, New South Wales

Abstract The bedrock topography of the Botany Basin has been determined from seismic‐sparker records made in Botany Bay and Bate Bay, and from seismic‐refraction and gravity measurements on the Kurnell Peninsula. Supplementary information has been obtained from boreholes both on land and in the sea. The Cooks and Georges Rivers formerly constituted the main drainage of the Basin and flowed generally southeastwards (beneath the present Kurnell Peninsula) and joined the Port Hacking River east of Cronulla. The depth of the bedrock channel of the former Georges River is 75–80 m b.s.l. at Taren Point, 90–95 m beneath the Kurnell Peninsula and 110–115 m at its junction with the Port Hacking River channel. The bedrock channel of the former Cooks River is about 30 m b.s.l. at Kyeemagh, its present entrance to Botany Bay, and it joined the Georges River at a location now 90 m b.s.l. beneath the Kurnell Peninsula. A second drainage system existed in the north and east of Botany Bay and generated the present mouth ...

Long-term variability of oceanographic data at the Port Hacking 50-metre station

Measurements of water temperature, salinity, dissolved oxygen, nitrate and inorganic phosphate have been made at the Port Hacking 50-m station which is about 30 km south of Sydney and 5 km offshore. This paper reports an analysis of the data obtained between 1942 and 1972. Mean seasonal cycles of each of these variables have been evaluated for the time interval, as well as the annual means for each year. Shorter period fluctuations are studied by cross correlating the monthly anomalies of the various oceanographic variables.

Direct measurement of dissolved organic carbon release by phytoplankton and incorporation by microheterotrophs

It is now possible to divide particulate primary production into algal and heterotrophic components without physical separation. This depends on two innovations, the introduction of isotope in the form of labelled dissolved product(s) of primary production and the employment of a data analysis specifically designed for tracer kinetic incorporation experiments. The 14C technique described by Steemann Nielsen (1952) is inapplicable in the analyses of certain classes of systems and kinetic tracer incorporation experiments must be employed instead. We show that measurement of PDOC production rate requires such kinetic tracer analyses. Measurements made in the laboratory on water taken from 2 m depth in South West Arm of the Port Hacking estuary showed that: (1) the steady-state rate of PDOC production was 0.10 to 0.13 mg C.m-3.h-1; (2) the rate of PDOC incorporation into microheterotroph particulate organic carbon was 0.10 to 0.12 mg C.m-3.h-1; (3) the rate at which PDOC was respired to CO2 was 0.001 to 0.003 mg C.m-3.h-1. (4) the PDOC makes up only about 0.1% of the total dissolved organic carbon. The size class of particles associated with PDOC production differed from the size class responsible for uptake of PDOC. More than 50% of the PDOC production was associated with particles having a nominal diameter range of 20 to 63 μm, while this fraction was responsible for <10% of the incorporation.

Ecology of Botany Bay. I. Growth of Posidonia australis (Brown) Hook. f. in Botany Bay and other bays of the Sydney basin

The distribution, biomass and density of various beds of P. australis have been determined for Botany Bay (N.S.W.). Comparisons have been made with sites at Broken Bay, Port Hacking and Jervis Bay and these include observations of other seagrass beds (Zostera capricorni, Heterozostera tasmanica, Halophila ovalis and Halophila decipiens). The P. australis plants observed were all of the broad-leaved (1.0-1.2 cm) variety. The length of leaves appears to be correlated with depth and with degree of exposure to wave action. The distribution of P. australis in Botany Bay is almost entirely restricted to the southern side and is limited to a maximum depth of - 3 m compared with -7 to -9 m at other sites. The growth of plants in well-established beds seems to be as vigorous in Botany Bay as elsewhere but flowering is poor and infrequent and the overgrowth of epiphytes is very great at certain seasons. Clearing experiments in Botany Bay indicate that recolonization by surrounding plants or seedlings is extremely slow. Transplant experiments indicate that mature plants will survive transplanting to cleared sites on both the northern and southern sides of the Bay. Evidence for a much more extensive distribution of P. australis in Botany Bay in times past and the possible effects of pollution are discussed.

A schema of the nitrogen cycle off Port Hacking, New South Wales

The Port Hacking 100 m Station represents a continental shelf situation where periodic enrichment occurs from below without the classical upwelling sequence, but with profound biological effects. The Station receives irregular influxes of low-salinity, high-nitrate slope water intruding onto the continental shelf. Vertical mixing distributes nitrate into the upper illuminated depths and an increase in algal growth ensues. The resulting algal population is generally confined to the layer above the pycnocline. It is probable that nutrient exhaustion limits the ultimate algal population which then becomes subject to attrition by grazing and sinking. The nitrogen introduced as nitrate in the slope water intrusions moves offshore as biological nitrogen. The latter remineralizes at subsurface depths giving an effectively closed nitrogen cycle.

Seasonal succession of phytoplankton at a coastal station off Sydney

The seasonal succession of marine phytoplankton at the Port Hacking 100 metre coastal station was studied using living algae. The spring (September) bloom began with small chain-forming diatoms, mainly Asterionella, Thalassiosira, Skeletonema, Nitzschia and Chaetoceros species. These were succeeded by larger centric diatoms, the most abundant of which were species of Ditylum, Leptocylindrus, Eucampia, Rhizosolenia and Melosira, together with the pennate genus Thalassiothrix. Coccolithophorids, microflagellates (probably mostly chrysomonads) and dinoflagellates showed a first minor pulse in September, and became established in October and November. During late summer and early autumn, when diatom numbers were very low, the phytoplankton consisted mainly of dinoflagellates, coccolithophorids and microflagellates. A pulse of cryptomonads and silicoflagellates occurred in March and April respectively. A second diatom flowering took place in the autumn (May), dominated by species of Leptocylindrus, Thalassiothrix, Rhizosolenia etc., which were different from those which initiated the spring (September) bloom. Clear succession patterns were evident, in principle very similar to successions observed in temperate coastal waters in other parts of the world. These patterns may correspond, not to gross mineral enrichments, but to specific vitamin interrelationships among the algae.

Changes in the characteristics of 26.00 Sigma-t water off Port Hacking (1943-1968)

Bottom waters at a 50 m station off Port Hacking (34�05'S., 151°13'E.) with a sigma-t of 26.00, have in general increased in salinity, decreased in oxygen, and increased in phosphate and nitrate in the 25 year period 1943-1967. In seeking an explanation of this trend, changes in upper 25 m column water temperatures, slope water characteristics and surface temperatures, and salinity characteristics off east Australia during this same period have been discovered. The year 1943 at the beginning of this 25-year trend had an exceptionally cold and dry winter. Cause and effect relationships are difficult to prove but an explanation based upon transport variations of the East Australian Current, with minimum transport in the early 1940's and maximum in the late 1950's, is favoured.

Variation in silicate concentration at Port Hacking station, Sydney, in relation to phytoplankton growth.

Data are presented to show the variation in silicate concentrations in surface waters at a station in the Western Tasman sea, over two annual cycles. The area is characterized by low silicate concentrations in the surface (0-20 m) waters over the whole year with a maximum of 40 �g/litre occurring at very brief intervals in mid-winter. In spring and summer values frequently fall below detectable limits. The subsurface waters (20-60 m) are also usually low in silicate, but show a series of periodic intrusions in which concentrations go as high as 120 �g/l. These variations in silicate concentration are discussed in relation to the known variations in phytoplankton populations and the hydrology of the area.

Phytoplankton numbers and species at Port Hacking Station and their relationship to the physical environment

During 1965-66 the phytoplankton numbers at the Port Hacking 100 m Station varied from below 10 to 2.25 × 104 cells per litre, with maximum numbers occurring in a series of blooms between September and December. The dominant species were Asterionella japonica, Leptocylindrus danicus, Navicula sp., Nitzschia longissima, Rhizosolenia alata, and Rhizosolenia stolterforthii. Statistical analysis showed that abundance was correlated with total phosphorus and oxygen content of the surrounding water, but not with nitrate concentration. Using agglomerative classification techniques a number of phytoplankton communities were distinguished, and these were related to water movements off the Australian coast.

Underfit stream of the osage type: head of the port hacking river

Underfit stream of the osage type: head of the port hacking river

Seasonal changes in the hydrological and biological environments off Port Hacking, Sydney

Data obtained over 10 yr at the Port Hacking 100-m station show an annual cycle in some properties. In May the continental shelf is dominated by high salinity subtropical water from the western Pacific. From June to August, cooling and vertical mixing decrease temperatures and salinities at all depths. From September, tropical water of northern origin penetrates southwards, increasing temperatures and decreasing salinity at 10 and 50 m. This tropical water exerts its maximum influence in March. From September to March other offshore water from deeper than 100 m rises onto the shelf, decreasing temperature, salinity, and oxygen, but increasing nitrate. In addition there is probably a continual land drainage influence on the hydrological regime. Algal blooms occur from August to April, in association with the penetration of nitrate-rich water onto the shelf.

The intermediate depth of waters of the Tasman and Coral Seas. III. Succession of water types east of Port Hacking in 1957–1959 : Rochford, D. J., 1962. Aust. J. Mar. Freshwater Res., 13 (1): 61–88

The intermediate depth of waters of the Tasman and Coral Seas. III. Succession of water types east of Port Hacking in 1957–1959 : Rochford, D. J., 1962. Aust. J. Mar. Freshwater Res., 13 (1): 61–88

The Intermediate Depth Waters of the Tasman and Coral Seas. III. Succession of Water Types East of Port Hacking in 1957-1959

The seasonal occurrences of three water types on the 27.20 and 26.80 σt, surfaces on a section east of Port Hacking, 153-160� E., and at certain stations north of this line are discussed. On the 27.20 σt, surface it is shown that the Pacific Equatorial Intermediate is found in maximum intensity during September-October at longitude 158-160� E. Subsequently it moves west and during April-June it occurs at longitude 153-157� E. The South-West Pacific Intermediate appears at maximum intensity during March-July at 158-160� E. but in September-February it moves west to longitude 152-154� E. The Antarctic Intermediate is only about 30% of the water type mixture and occurs at the eastern end of the section during December to April and at the western end (152-154� E.) during March-April. On the 26.80 σt, surface the Subtropical formed between 30 and 75% of the water type mixture and was the principal water type, though it was not possible to distinguish between the part formed by local vertical mixing and that formed by actual movement from the Subtropical Convergence. No seasonal cycle could be determined for the Upper Antarctic Intermediate which varied between 0 and 55% of the water type mixture. The Upper Equatorial Intermediate varied from 5 to 45% of the mixture and showed no seasonal cycle.

The Effects of the Orientation of Clutch Material on the Setting of the Sydney Rock Oyster

In 1945–46 in Port Hacking, N.S.W. there was some spawning over the entire year, but successful spat-falls occurred only over the summer, with the greatest number in November and again in March. On every 12-in. length of fibrocement slat approximately 24 oyster spat were present (on all faces) 12 months after the slats were set out. Thus on the average a four foot slat carried 96 oysters or approximately four oysters every five square inches of surface. A greater number of oysters settled when the slats were less than half an inch apart than when the slats were an inch apart. When the slats were one inch apart the central portion of the slats carried more oysters than the ends, but when the slats were within half an inch of each other the numbers at the ends and on the middle section were about the same. When the slats are within half an inch those oriented with the long axes parallel with the current show greater catches than those perpendicular to the current. However, when the slats are further apart the reverse is the case. The horizontal portion of the broad surface supplies the highest catches, but the catch is more evenly distributed when they are vertical, and this would permit better growth. The ratio of the catches on upper horizontal, lower horizontal, and vertical surfaces is similar to the ratio found by Schaeffer for O. gigas, which is a similar type oyster to O. commercialis. There is a horizontal gradient on the vertical surface across the batteries such that the number of oysters on the surface facing a particular direction increases on the columns more remote from that direction. There is a vertical gradient on the vertical and upper surfaces such that the number of oysters caught increases on the lower rows of vertical surfaces, but the evidence is anomalous for the horizontal surfaces. The discussion of the possible factors causing the pattern of set reveals that the reaction to light could be an explanation. But there are other explanations which are equally valid, and the experimental design was not such as to reveal the true causes. The practice in Australia of using closely bundled cultch material is a good one; but there is a possibility that better total catches would ensue if the cultch set out in spring were removed to growing areas in January and new cultch set out to catch the autumn spat fall.

Scientific and Industrial Research in Australia

THE thirteenth annual report of the Council for Scientific and Industrial Research, Commonwealth of Australia, covers the year ending June 1939 (Canberra: Commonwealth Gov. Printer, 4s. 6d.). The Council was established in 1926 by the reorganization of the existing Institute of Science and Industry, and the powers and functions of the Council are defined by the Science and Industry Research Act, 1920–39. They include the initiation and carrying out of research in connexion with, or for the promotion of, primary and secondary industries, the training of research workers,the making of grants-in-aid of pure research, the testing and standardization of scientific apparatus and instruments, the carrying out of scientific investigations connected with standardization and the establishment of a Bureau of Information relating to scientific and technical matters. The report refers to progress in the erection of the National Standards Laboratory and the Aeronautical Research Laboratory. The erection and equipment of a laboratory for the Fisheries Section was completed during the year at Port Hacking, south of Sydney. Reference is made in some detail to investigations on plant introduction, pasture plant breeding and investigations on pastures. Other investigations of the Division of Plant Industry cover experiments planned for a period of five years on the root rot of wheat, as well as seed-bed experiments on the control of downy mildew of tobacco which refer to the successful results obtained with benzene vapour and also with Shirlan compounds and alum-lead acetateas cover dressings. Studies on the nature of the virus diseases of Australian potatoes have also been continued by the Division.

Fisheries Research in Australia

THE 138-ton motor ship Warreen (an aboriginal name for the sea), built for the fisheries section of the Australian Council for Scientific and Industrial Research, has been launched in Melbourne. The vessel will be used for the study of pelagic fish in the waters around Australia, commencing in the south-eastern seas. The headquarters of the section will be at Port Hacking, some eighteen miles south of Sydney, on a reserve beautifully situated for the purpose. Plans have been drawn for a laboratory to cost £12,000, which should be finished by the end of the year.