Light traps were used to sample presettlement larval fishes simultaneously at Lizard Island and Davies Reef, located 500 km apart on the Great Barrier Reef (GBR). At Lizard Island, three traps were moored on both the windward and leeward side, whilst at Davies Reef two traps were placed off the back reef in open water (approximately 25 m deep). On both reefs, traps were moored 200 m apart, and placed at least 100 m from the nearest reef to ensure that fish were not attracted from the reef substratum. The light traps were deployed during the nights of 19 to 23 December, 1987. All traps at both localities were set to fish for 3 hours each night (21.00 to 22.00 hrs, 12.00 to 01.00 hrs, and 03.00 to 04.00 hrs), to minimise the influence of tide on catches. Traps were cleared daily and samples were returned to the laboratory. Fish that could be identified to species immediately, were preserved in 99% ethanol. Those that had not developed sufficient pigmentation to allow identification were placed in aquaria with live coral, to initiate the development of pigmentation, which usually occurred within 12 hours. Fish were then identified and preserved. The dominant species from these samples, Chromis atripectoralis and Pomacentrus coelestis, were chosen for further study. Post-settlement individuals of these two species were collected using the fish anaesthetic quinaldine and small hand-nets. Fish of both species were collected from Lizard Island on 6-7 January 1988. Chromis atripectoralis was collected from Davies Reef on 17 January 1988, and Pomacentrus coelestis from Lodestone Reef on 20 January 1988. Fifty pre-settlement and 40 post-settlement individuals of both species, from each locality, were used for otolith examination. Otoliths were teased out the brain tissue with tungsten needles, placed on a microscope slide and dehydrated by baking at 60°C for 6 hours in an oven. The dried otoliths were mounted in Euparal, covered with a cover-slip, and left for at least one month before reading, as growth increments were noticeably clearer after this time. Analysis was confined to the lapilli of both species, as growth increments were much clearer than on the sagittae. Otoliths were viewed under a compound microscope at 250 or 400 x magnification using polarized transmitted light. A high-resolution video-camera was mounted on the microscope, which was in turn connected to a video-screen on which increments were counted. The system was also interfaced with a personal computer for measurement of otolith diameter.Live fish collected from light traps at Lizard Island were used to validate the daily periodicity of growth increments after settlement. Fish were immersed in a 0.25 g/l solution of oxytetracycline overnight, and then kept in aquaria with live coral for 12 days and 11 nights under ambient light and temperature conditions. Lapilli were dissected out of ten fish of each species after this period, and viewed under fluorescent UV light. The number of increments between the fluorescent band (corresponding to the time of tetracycline treatment) and the edge of the lapillus was then enumerated. Daily periodicity of increment formation was confirmed for both species during this time. It was not possible to validate the periodicity of increments before capture, and it was assumed that they too were daily. This research was undertaken to:1. determine if length of larval life in Chromis atripectoralis and Pomacentrus coelestis varies intra- or inter-specifically within and/or between localities on the GBR and to determine if size at settlement varies similarly2. determine if otolith dimensions are related to size in these species and if these relationships are consistent between pre- and post-settlement fishes, and between localities3. determine if any of the above characteristics are related to pre- and/or post-settlement growth rates at these localities

Chemical cycling and energetics of the coral reef system at Lizard Island, North Queensland were studied during September-October 1975 by the LIMER (Lizard Island Metabolic Exchange on Reefs) expedition, a cooperative investigation by 8 institutions. Calcification, primary production, the nitrogen cycle, the sulphur cycle, zooplankton distribution, and water currents of the reef system were investigated.Patterns of water movement at ebb and flood tides was measured using Woodhead current drogues deployed 10 cm below the surface.Calcification activity rates were based on the alkalinity-anomaly approach; areas measured were the algal crest on the seaward reef flat, a large pinnacle at the entrance channel to the lagoon, a transect across the central-leeward reef flat, a sandy algal bottom with small coral heads, and a sandy reef flat with extensive algal filming. Replicate samples of a foraminifera (Marginopora vertebralis), a common coral (Acropora), crustose and foliate algae (Lithothamnian and Halimeda spp.) were also measured experimentally in a laboratory for their rates of calcification. Sulphate reduction and ammonia accumulation rates in reef and lagoon sediments were assessed. The nitrogen cycle was investigated using in situ and experimental measurements. Concentrations of nitrate on the algal crest, the lagoonal reef flat and oceanic front of the reef were measured and rates of nitrate exportation into the lagoon calculated. Nitrogen fixation was measured using the C2H2 assay technique.Primary production was estimated using measurements taken along a transect from the windward edge of the reef to the lagoon. Light attenuation was measured in the lagoon and in the ocean in front of the entrance.Zooplantkon were sampled during the day and at night, in the water column at different depths, and from reef and lagoonal sediments. Both micro and macro-zooplankers (amphipods, cumaceans, large copepods, polychaetes, shrimp and fish larvae) were measured from 6 stations. To examine metabolic processes and gain a better understanding of reef metabolism and function. A separate metadata record is available for the LIMER II expedition.

1689 symbionts from 1114 crinoids of the Central Great Barrier Reef were assigned to 46 taxa from 5 invertebrate classes. Crinoid specimens were collected from 46 sites (24 sites on 12 reefs, 2 sites per reef, and 22 sites at Davies Reef, see separate metadata record).Species abundance and species richness were recorded and Cramer values applied. In addition, 46 taxa were identified as symbiotic associates of the crinoids. To provide ecological information on crinoid communities of the Great Barrier Reef.First large-scale study of the structure and composition of crinoid communities on the central Great Barrier Reef. Symbiont taxa: Crustacea (Amphipoda: sp.1, sp.2; Isopoda: Carteolania integra); ecapoda (Natantia: Athanas ornithorhynchos, Palaemonella pottsi, Parapontonia nudirostis, Periclimenes affinis, Periclimenes albolineata, Periclimenes amboinensis, Periclimenes attenuatus, Periclimenes commensalism, Periclimenes tenuis, Pontiniopsis comanthi, Synalpheus carinatus, Synalpheus demani, Synalpheus stimpsoni, Synalpheus tropicocactylus, unidentified shrimps); astropoda (Annulobalcis sp., Bittium sp., Chrysallida sp., Columbellidae sp., Curvculima spp. 1-11, Pyrene sp., Stiliferina sp., Triphora sp., Triphoridae sp., Turridae); Myzostomata; Ophiuroidea; and Polychaeta.Host crinoid species: Amphimetra laevipinna, Antedonid sp., Capillaster multiradiatus, Cenometra bella, Clarkcomanthus albinotus, Clarkcomanthus littoralis, Clarkcomanthus luteofuscum, Comanthina schlegeli, Comanthus alternans, Comanthus gisleni, Comanthus parvicirrus, Comanthus wahlbergi, Comaster brevicirrus, Comaster gracilis, Comaster multifidus, Comaster pulcher, Comatella maculate, Comatella nigra, Comatella sp., Comatella stelligera, Comatula pectinata, Comatula purpurea, Decametra laevipinna, Decametra sp.a, Dorometra nana, Euantedon polytes, Himerometra bartschi, Himerometra magnipinna, Himerometra robustipinna, Iconometra intermedia, Liparometra articulate, Oligometra serripinna, Oxycomanthus benetti, Oxycomanthus comanthipinna, Oxycomanthus exilis, Oxycomanthus mirus, Oxycomanthus perplexum, Petasometra clarae, Stephanometra indica, Stephanometra oxyacantha, Stephanometra spicata, Stephanometra spinipinna, Tropiometra afra.

Examined the effect of artificial light on the nearshore trajectories of turtle hatchlings dispersing from natal beaches. Green turtle (Chelonia mydas) hatchlings were tagged with miniature acoustic transmitters and their movements tracked within an underwater array of 36 acoustic receivers placed in the nearshore zone. A total of 40 hatchlings were tracked, 20 of which were subjected to artificial light during their transit of the array. At the same time, we measured current speed and direction which were highly variable within and between experimental nights and treatments. Artificial lighting affected hatchling behaviour, with 88% of individual trajectories oriented towards the light and spending, on average, 23% more time in the 2.25ha tracking array (19.5 ± 5 mins) than under ambient light conditions (15.8 ± 5 mins). Current speed had little to no effect on the bearing (angular direction) of the hatchling tracks when artificial light was present, but under ambient conditions, it influenced the bearing of the tracks when current direction was offshore and above speeds of ~32.5 cm s-1. This is the first experimental evidence that wild turtle hatchlings are attracted to artificial light after entering the ocean, a behaviour that is likely to subject them to greater risk of predation. The experimental protocol described in this study can be used to assess the effect of anthropogenic (light pollution, noise etc.) and natural (wave action, current, wind, moonlight) influences on the in-water movements of sea turtle hatchlings during the early phase of dispersal.

Six blocks of mangrove sediments, measuring 30 cm x 30 cm x 15 cm, complete with crab burrows and root fragments were collected one metre within the edge of a Rhizophora stylosa forest adjacent to Cocoa Creek, Cape Cleveland, North Queensland. Sediment blocks were placed in individual plastic bins to form temporary mesocosms. Seawater was added to the mesocosms at 15 and 23 hours daily and siphoned off after one hour to simulate tidal cycles. Light conditions were kept low and shade cloth covers were used to inhibit growth of an algal mat which might alter oxygen conditions in the sediments.Magnesium peroxide powder, an oxygen release compound, (3.14 g dry weight) was evenly distributed along a 13 cm long and 4 cm deep cut into three of the mesocosms. After 40 hours, vertical oxygen profiles were measured down to the aerobic-anaerobic zone interface in 100 µm increments at three sites along the centre line of the buried compound in each mesocosm.In each of the three remaining mesocosms three pre-disturbance vertical oxygen profiles were measured along a 13 cm long and 4 cm deep cut in the sediment. An airstone was then placed into the 4 cm deep cut, with its flat upper surface approximately 2 cm below the surface and completely buried. Air was administered to the sediments via the airstone at a rate of 1L/min at 400 kPa. Following aeration treatments for 40 hours, the aerobic zone was described in reference to the airstone. Oxygen concentration of sediments was measured for several profiles taken vertically from the surface. The first profile was taken near the centre, immediately adjacent to the airstone, and 3.5 cm from the input end. Each successive profile was taken 5 mm further away from the previous, perpendicular to the airstone, until they resembled pre-disturbance profiles. Air flow continued whilst measurements were taken. To establish whether burial of the airstone might influence the oxygen profiles, an additional three profiles were measured after burial of the airstone and before aeration in one of the mesocosms.Field trials of forced aeration were conducted in a Rhizophora stylosa mangrove forest at Fishermans Landing, near Gladstone. The procedures, described earlier, for positioning the airstone in sediments and the depth of burial and measuring oxygen saturation, were repeated in this trial. The delivery of air was pulsed in field trials since this was considered sufficient to aerate sediments based on observations made during mesocosm trials. The pulse cycle used was 60 minutes airflow and 60 minutes off, repeated for around 40 hours prior to measurements being taken. As the majority of hydrocarbons introduced to sediment in an oil spill initially reside on the surface, availability of oxygen in this layer is critical for biodegradation by the more active aerobic microbes. The objective of this series of experiments was to determine whether forced aeration and/or magnesium peroxide (an oxygen release compound) might provide significant increases in molecular oxygen saturation in the surface aerobic layer of sediments under common tropical mangrove trees.

Water sampling was carried out at the channel mouth of Coral Creek, Missionary Bay, Hinchinbrook Island to determine the transport and exchange of carbon and nitrogen in particulate organic carbon (POC), the component of particulate organic matter consisting of finely divided materials which range in size from 10 µm to 2 mm. Samples were taken during 13 tidal cycles over a 2-year period. Beginning at low tide, water samples were collected from three depths (surface, mid-depth (4-5 m) and at 0.5 m above the creek bed) at half-hour intervals during the complete 12 hour tidal cycle. Initially, samples were taken at three different points across the channel and later only from a single central station, which was adequate to monitor exchanges.Analysis of POC was carried out using the wet digestion method. On two runs, concurrent samples were filtered through 25-mm GFC filters and analysed with a Perkin Elmer analyser to obtain the C : N ratio of the material and to verify the wet digestion method for POC analysis. Concurrent sampling for ATP and chlorophyll analyses was also carried out on two tidal cycle sampling runs, to obtain information on the character of the particulate matter.During each sampling run, regular measurements of tidal depth at the mouth of the channel were made. The volume of water entering or leaving the basin during any time period was calculated from the tide height measurements and the survey data. The average POC concentration during the same time period was interpolated from the graphs of the average POC (average of the three depths) versus time and the amount of POC passing through the mouth of the creek during that time period was calculated. Summation of the individual fluxes for the entire cycle gives the net import or export of POC for that tidal cycle. To check the accuracy of the calculated volume-time data, a bank of Salvonius-type current meters, with automated data logging, were placed in a 3 X 3 matrix across the channel mouth. These meters measured the current flow every 5 min during a continuous series of tidal cycles for 4 days and the average current was determined as a function of time. This research was undertaken to establish carbon and nitrogen budgets for a mangrove system for which litter fall statistics were available. The mangrove forests surrounding Coral Creek have been extensively surveyed to provide detailed information on topography, and to allow estimation of areas inundated at various tidal heights, and the corresponding volumes of water contained in the basin. Except during infrequent tidal runs greater than 3·2 m, all of the water entering and leaving the basin flows through the mouth of Coral Creek and hence all of the observations of the tidal water were monitored at this point.

Presence information for sharks and fish fitted with acoustic transmitters on reefs in the Townsville region. Acoustic receivers are deployed on: Bramble (4), Rib (4), Kelso (2), John Brewer (4), Lodestone (4), Helix (4), Keeper (2), Glow (3), Cotton Shoal (1), Arc (1), Grub (4), Yankee (3), Centipede (2), Wheeler (5), Davies (2), Pinnacle (1) and Little Broadhurst (2) reefs. Transmitter life ranges from 12-30 months. Transmitters report depth data to indicate position of the animal in the water column. To date transmitters have been deployed in: grey reef, blacktip, bull, silvertip, sliteye and hammerhead sharks, common coral trout, bluespot coral trout, redthroat emperor, giant trevally and spanish mackerel in this region. To monitor the presence and movement of fish and elasmobranch species within and between reefs in the Townsville reef region. These data are collected as part of NERP funded research, but the data will also be contributed to the AATAMS facility within IMOS and as such are part of a broader national framework. Data from this research is also housed in the AATAMS data repository and publicly available on line.

Water, sediment, algae and coral samples were collected between July 1980 and March 1981, over a wide range of sites at Davies Reef in the central Great Barrier Reef for phosphorus and nitrogen analyses.Water column samples were collected in 4 liter Niskin bottles. Subsamples for phosphorus (as soluble reactive P), nitrate, nitrite and ammonium analyses were filtered through a 20 µm plankton net into 100 ml acid-washed polythene bottles and stored at -20°C until analysis using a Technicon AutoAnalyzer II system. Samples for arsenic analysis were collected in bottles containing As-free HCl and stored at 3°C until analysis using a Varian model AA6 atomic absorption spectrophotometer.Sediment samples from the deeper waters outside the reef were collected with a van Veen grab. Inside the reef, surface sediment samples, to a maximum depth of 10 cm, were collected in labelled plastic bags by SCUBA divers. Deep cores, to 5 m, were taken from the large lagoon in a polyvinyl chloride casing tipped with a stainless steel corer and driven hydraulically. Samples of young, calcified Halimeda tips as well as young growing coral tips were collected from various locations and either immediately bleached or frozen in dry ice for transport to the laboratory.Sediment, coral and Halimeda samples were dried and ground to pass through a 50 µm sieve. Duplicate 0.5 g subsamples were analyzed for total phosphorus, after digestion, using a standard colorimetric method. For arsenic determination, 0.5 g of sediment was dissolved in 10 ml of Merck 318 HCl, heated at 80°C for 5 minutes and diluted to 50 ml. 5 ml aliquots were then analyzed as described for water analyses.Redox potential of the sediments at a large number of sites was measured in situ using a Pt/SCE combination electrode connected to a millivoltmeter sealed in a waterproof housing. Samples of sediment water were collected using aquarium stones, buried beneath the sediment surface and connected via Tygon tubing to 50-ml polythene syringes. Water samples were also obtained by extracting freshly collected small sediment cores, which were collected by inserting 50 ml syringes, with one end removed, into the sediment and manipulating the plunger to draw sediment into the tube. The syringes were excavated and sealed before final removal from the sediment. Extraction with 10 ml of seawater was carried out within 1 hour. The sediment and seawater mixture was shaken for 1 minute, centrifuged, and the cleared water decanted and stored frozen until analysis. All sediment water samples were analyzed for inorganic nitrogen and phosphorus by the methods described for water analyses.Algal samples were collected from the reef front and crest. The types of algae collected were: calcifying algae (Halimeda sp. dominant), other macroalgae, blue-green algal mats and turf algae. The samples were sorted at the reef and frozen in sealed containers until analysis. Duplicate 3 mg subsamples of finely ground algal material were analyzed for total C and N in a Perkin-Elmer model 240 elemental analyzer. This research was undertaken to determine whether any significant differences in the phosphorus and nitrogen content of water or sediments could be detected over a range of varying conditions such as water depth, water residence times, types and abundances of benthic organisms, and composition of sediment.

A fluorometric procedure was applied to measure changes in phosphatase activity in seawater flowing across reef flats at Bowl and Hopkinson Reefs on the central Great Barrier Reef. Seawater samples were collected at 50 m intervals across the reef flat during low tide, commencing at the reef front using a volume transport method and a time-distance-depth record was maintained allowing measurements to relate to the distance a water mass had flowed across the coral reef flat. Water samples were collected below the surface using a dip-scoop, filtered through 10 µm mesh and stored in the dark before being assayed.Fluorescence was measured on 2 ml filtered (Nucleopore, 0.2 µm) and unfiltered subsamples on addition of 50 µl of a 5.0 mM solution of the enzyme substrate (4-methylumbelliferyl phosphate) and then at hourly intervals. An 8 hour period of incubation was required to determine statistically significant rates of hydrolysis from oligotrophic water samples. This research was initiated to examine the importance of the hydrolysis of organophosphates by alkaline phosphatase enzymes as a source of inorganic phosphate, a nutrient essential for primary production. The assay used was able to determine low levels of enzyme phosphatase activity in marine waters based on the enzymatic hydrolysis of the fluorogenic substrate, 4-methylumbelliferyl phosphate.

Acetes sibogae australis, a planktonic sergestid shrimp was collected at night with light traps suspended about 2 m deep in the harbour off Townsville, north Queensland, as well as in shallow water off the nearby beach and transferred to aquaria at the Australian Institute of Marine Science.Experiments were conducted in unaerated aquaria (15 x 22 x 60 cm) and water was changed every 2 days. Each aquarium was illuminated from both sides, by fluorescent light and the backs and bottoms of the tanks were painted black to make the transparent shrimps more visible. The front pane was marked at 5 cm intervals to estimate swimming speed and distance. Between 8 and 12 shrimps were placed in each aquaria and they were fed on Artemia, prior to commencement of experiments.During experiments, diced banana prawns (Penaeus merguiensis) or freshly killed and crushed Acetes, soaked in fluorescein dye were dropped into the aquariums and left to sink to the bottom, leaving thin trails of highly visible dye in the water. The movement patterns and swimming speed of the shrimps in response to the presence of trails was recorded. Additional experiments were carried out using meat and meat extract. Sensitivity to these food odours was also monitored over the time that individuals were exposed to the scent trails.The sensitivity of Acetes sibogae australis to specific chemical stimuli also was tested with pieces of blotting paper soaked in saturated solutions of 17 different L-amino acids.The importance of vision in following trails was tested by providing undyed meat and undyed blotting paper soaked in millipore filtered prawn juice as food stimuli. To determine whether Acetes sibogae australis generally swims downward when following a vertical trail or if they follow a chemical gradient, dyed meat tied to a string near one side of the aquarium was lowered and then slowly pulled it up near the opposite side and the response of the shrimps recorded.Experiments were also carried out to determine the anatomical location of the chemoreceptors on the shrimp. The role of the antennules was investigated by testing the behavioural response of shrimp to dyed stimuli, 18 hours after their antennules were excised. Other possible receptor sites, such as the setae in antennae were identified after ultrastructure analysis. This research was undertaken to investigate the importance of chemosensitivity to planktonic animals. Using the planktonic sergestid shrimp, Acetes sibogae australis, experiments were conducted to examine behavioural responses to scent trails and the precision with which this species can follow these trails.