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Identifying mechanisms that drive population divergence under varying geographic and ecological scenarios can inform our understanding of evolution and speciation. In particular, analysis of genetic data from island populations with known colonisation timelines allows us to identify potential source populations of diverging island subspecies and current relationships among populations. Silvereyes (Zosterops lateralis) are a small passerine that have served as a valuable study system to investigate evolutionary patterns on both large and small geographic scales. We examined genetic relatedness and diversity of two silvereye subspecies, the mainland Z. l. cornwalli and island Z. l. chlorocephalus, and used 18 077 single nucleotide polymorphisms (SNPs), to compare locations across southeast Queensland, Australia. Although silvereyes are prolific island colonisers our findings revealed population divergence over relatively small spatial scales was strongly influenced by geographic isolation mediated by water barriers. Strong genetic connectivity was displayed between mainland sites, but minimal inter-island connectivity was shown despite comparable sampling distances. Genetic diversity analysis showed little difference in heterozygosity between island and mainland populations, but lower inbreeding scores among the island populations. Our study confirmed the range of the Z. l. chlorocephalus subspecies throughout the southern Great Barrier Reef. Our results show that water barriers and not geographic distance per se are important in driving incipient divergence in island populations. This helps to explain the relatively high number of phenotypically differentiated, but often geographically proximate, island silvereye subspecies compared to a lower number of phenotypically less well-defined Australian continental subspecies. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef Marine Park was established to provide for conservation and ecologically sustainable multiple use of 344,400 km of a large marine ecosystem. Management is based on multiple use, with zoning as a fundamental component of marine spatial planning. The legislative framework, including a specific Act and Regulations, address the objectives of ecosystem-based, integrated management of human uses and impacts consistent with best contemporary understanding of biological diversity. Zoning is one of a suite of management tools that include other spatial and temporal management tools and non-spatial measures including public education, community engagement, codes of environmental best practice, industry partnerships and economic instruments. The first section of the Great Barrier Reef Marine Park came into operation in 1981 and the most recent zoning came into operation in mid 2004. The paper discusses some common misunderstandings about zoning and identifies lessons that appear relevant for others addressing management and use of marine ecosystems and natural resources. [ABSTRACT FROM AUTHOR]

The integration of social and ecological knowledge has been identified as one of the key issues and research priorities in landscape ecology. However, research into the tools and processes that support knowledge integration for planning sustainable land- and sea-scapes is largely lacking. To fill this gap, Bohnet and Smith (Landsc Urban Plan 80:137–152, ) developed a social-ecological planning framework based on a holistic landscape concept which I applied in the Tully–Murray basin to test the framework’s transferability and effectiveness for knowledge integration in a water quality improvement planning context in the Great Barrier Reef (GBR) region, Australia. In this paper I present the context in which the Tully Water Quality Improvement Plan (WQIP) was developed, the tools and processes applied during the three planning stages to achieve knowledge integration, and the results from this exercise. I then discuss the transferability and effectiveness of the framework using criteria identified to assess collaborative planning processes, outputs and outcomes, such as collaborative science and social and political capital. While many social outcomes such as the creation of partnerships between multiple-stakeholders, including Traditional Owners, local farmers, industry, government, community groups, schools, and the wider public, have been achieved, the research also highlights some of the challenges related to multiple-stakeholder relations. Further research into the roles and responsibilities of multiple-stakeholders for knowledge integration in developing and managing sustainable land- and sea-scapes is recommended. [ABSTRACT FROM AUTHOR]

Reef corals form associations with an array of genetically and physiologically distinct endosymbionts from the genus Symbiodinium. Some corals harbor different clades of symbionts simultaneously, and over time the relative abundances of these clades may change through a process called symbiont shuffling. It is hypothesized that this process provides a mechanism for corals to respond to environmental threats such as global warming. However, only a minority of coral species have been found to harbor more than one symbiont clade simultaneously and the current view is that the potential for symbiont shuffling is limited. Using a newly developed real-time PCR assay, this paper demonstrates that previous studies have underestimated the presence of background symbionts because of the low sensitivity of the techniques used. The assay used here targets the multi-copy rDNA ITS1 region and is able to detect Symbiodinium clades C and D with >100-fold higher sensitivity compared to conventional techniques. Technical considerations relating to intragenomic variation, estimating copy number and non-symbiotic contamination are discussed. Eighty-two colonies from four common scleractinian species (Acropora millepora, Acropora tenuis, Stylophora pistillata and Turbinaria reniformis) and 11 locations on the Great Barrier Reef were tested for background Symbiodinium clades. Although these colonies had been previously identified as harboring only a single clade based on SSCP analyses, background clades were detected in 78% of the samples, indicating that the potential for symbiont shuffling may be much larger than currently thought. [ABSTRACT FROM AUTHOR]

Evidence shows that in the modern ocean, coral reefs are disappearing, and these losses are tied to climate change. However, research also shows that coral reefs can adapt rapidly to changing conditions leading some researchers to suggest that some reef systems will survive future climate change through adaptation. It is known that there were changes in the area covered by coral reefs in the past. Therefore, it is important to investigate the long-term response of coral reefs to environmental changes and high sea-surface temperatures (SSTs). However, because of diagenetic issues with SST proxies in neritic, metastable carbonate-rich environments, there is an incomplete and sometimes even incorrect understanding of how changes in SSTs affect carbonate reef systems. A good example is the Queensland Plateau offshore northeast Australia next to the threatened Great Barrier Reef. In the Late Miocene, between 11 and 7 Ma, a partial drowning caused the reef area on the Queensland Plateau to decline by ~ 50% leading to a Late Miocene change in platform geometry from a reef rimmed platform to a carbonate ramp. This reef decline was interpreted to be the result of SSTs at the lower limit of the modern reef growth window (20–18 °C). This article presents a new Late Miocene—ased SST record from the Coral Sea based on the TEX86H molecular paleothermometer, challenging this long held view. Our new record indicates warm tropical SSTs (27–32 °C) at the upper end of the modern reef growth window. We suggest that the observed temperatures potentially exceeded the optimal calcification temperatures of corals. In combination with a low aragonite supersaturation in the ocean, this could have reduced coral growth rates and ultimately lowered the aggradation potential of the reef system. These sub-optimal growth rates could have made the coral reefs more susceptible to other stressors, such as relative sea-level rise and/or changes in currents leading to reef drowning. Given that these changes affected coral reefs that were likely adapted to high temperature/low aragonite saturation conditions suggests that reefs that have adapted to non-ideal conditions may still be susceptible to future climate changes due to the interaction of multiple stressors associated with climate change. [ABSTRACT FROM AUTHOR]

Few studies have considered linkages of mobile predators across large spatial scales despite their significant and often critical role in maintaining ecosystem function and health. The bull shark (Carcharhinus leucas) is a large, widespread coastal predator capable of undertaking long-range movement, but there is still limited understanding of intra-regional differences in movement and habitat connectivity across latitudes within the same coastline. This study used acoustic telemetry data and network analyses to investigate long-range movements, residency patterns and seasonal habitat linkages of sub-adult and adult C. leucas along the east coast of Australia. Our results revealed that C. leucas tagged in Sydney Harbour were mainly present within this temperate estuary in summer and autumn; the rest of the year individuals were detected in tropical and subtropical habitats from southern and central Queensland. In contrast, the detection probability of C. leucas tagged in the Townsville Reefs (central Great Barrier Reef) peaked in spring, with a portion of the tagged population migrating south during the summer months. Differences in residency time between tagging locations were also detected, as all C. leucas tagged in Sydney Harbour were absent between June and November, but 35% of the tropical-reef tagged population remained resident year-round. Network analyses complemented these findings by revealing different seasonal habitat use between regions, thus highlighting complex seasonal-habitat linkages of C. leucas along the coast. Our findings support the hypothesis that the timing, duration, and drivers involved in the long-range movements and connectivity of sub-adult and adult C. leucas vary between latitudinal regions, most likely driven by the interaction between seasonal temperature changes, foraging and reproduction. [ABSTRACT FROM AUTHOR]

Historical water quality datasets from the Fitzroy Basin, a large river system that receives mine-affected water from more than 40 mines, and drains into the Great Barrier Reef Lagoon, were analysed. There is great public and environmental interest in these waters that are used for agriculture, recreation and raw drinking water supplies. Aside from one AMD-impacted area, waters were generally alkaline. Turbidity data regularly exceeded the regional water quality objective (< 50 NTU), indicating the presence of particulates that may accumulate or transport metal contaminants within the waters. Analyses of data for 14 metals showed dissolved Cu and Al, followed by Zn, were the parameters that were most often greater than Australian toxicant guideline values. Analysis of coal mine-affected water samples and the receiving creek data, showed that median turbidity was greater downstream than upstream of the mine water release points, suggesting release-water may contain particulate-bound metals. Median dissolved Al and Cu concentrations were lower downstream than upstream and were above guidelines. Preliminary modelling using WHAM7 suggested downstream dissolved Cu (2–5 µg/L) was bound to fulvic acid and was likely not bioavailable. Dissolved Al (170–550 µg/L) may have existed as Al(OH)4−. Overall, suspended particulate matter appeared to be a water quality parameter of interest in this mine-affected river basin. Further targeted sampling, direct measurement of particulate-bound metals and multivariate statistical analysis are needed to help better understand metal partitioning in these turbid, alkaline waters. [ABSTRACT FROM AUTHOR]

Coral spawning in Western Australia (WA) occurs predominantly in the austral autumn in contrast to the Great Barrier Reef (GBR) on Australia's east coast where most spawning occurs in spring. Recent work, however, suggests a second spawning period in northern WA with at least 16 Acropora spp spawning in spring or early summer. This discovery has initiated a re-examination of reproductive seasonality in northern WA, particularly on inshore reefs adjacent to large development projects, such as the site of this study in Mermaid Sound, in the Dampier Archipelago. Three locally abundant taxa, Porites spp, Pavona decussata and Turbinaria mesenterina were sampled monthly from September 2006 to May 2007 to determine sexuality, the mode of reproduction and the time of gamete maturity. All three taxa were gonochoric broadcast spawners. Porites spp. colonies were mature in November and December, P. decussata in March and April. In contrast, most colonies of T. mesenterina contained mature gametes for up to 5 months beginning in November, suggesting either individuals are releasing gametes on multiple occasions, or they retain mature gametes for more than 1 month. Field surveys to determine the reproductive status of the remaining coral assemblage were conducted prior to the full moon in October 2006 and March 2007. Only four species contained mature gametes in October 2006. In contrast, 55 species contained mature gametes in March 2007. We conclude that the major spawning season of corals on shallow-inshore reefs in the Dampier Archipelago is autumn, although taxa that spawn in spring and summer include Porites spp., Acropora spp . and possibly T. mesenterina that are numerically dominant at many of these sites. Consequently, management initiatives to limit the exposure of coral spawn to stressors associated with coastal development may be required in up to five months per year. [ABSTRACT FROM AUTHOR]

Careful analysis of gut contents has resulted in the reclassification of several species of grazing fish as detritivores, shifting the trophodynamic assignment of many prominent reef grazers. Combtoothed blennies, which are among the most numerous grazing fish of the Great Barrier Reef, have been shown to target the detrital component of the epilithic algal matrix (EAM). It has been suggested that blennies have specialized dental morphology that allows them to comb through fronds of algae, collecting detritus, while leaving the algal component intact. In this study, we analysed the capability of a common reef flat blenny, Salarias fasciatus, to remove algae by (i) examining oral morphology for evidence of wear and adaptations for abrasion, and (ii) a short-term EAM feeding experiment. Examination of S. fasciatus teeth with scanning electron microscopy (SEM) showed evidence of macrowear (changes in tooth height or shape), microwear (surface chips and striae), and tooth replacement that suggests abrasion on the substrate. Energy Dispersive X-ray Spectrometry (EDS) revealed that oral teeth incorporate mineral iron. When fed artificial substrata with a developed EAM layer S. fasciatus removed 57% of photosynthetic material and 38.5% of organic biomass. Although studies have found that blenny gut contents consist predominantly of detritus, blennies are still likely to contribute to the removal of algae on coral reefs. [ABSTRACT FROM AUTHOR]

We have characterised the northern Pacific undescribed sponge Haliclona (? gellius) sp. based on rDNA of the sponge and its associated microorganisms. The sponge is closely related to Amphimedon queenslandica from the Great Barrier Reef as the near-complete 18S rDNA sequences of both sponges were identical. The microbial fingerprint of three specimens harvested at different times and of a transplanted specimen was compared to identify stably associated microorganisms. Most bacterial phyla were detected in each sample, but only a few bacterial species were determined to be stably associated with the sponge. A sponge-specific β- and γ-Proteobacterium were abundant clones and both of them were present in three of the four specimens analysed. In addition, a Planctomycete and a Crenarchaea were detected in all sponge individuals. Both were closely related to operational taxonomic units that have been found in other sponges, but not exclusively in sponges. Interestingly, also a number of clones that are closely related to intracellular symbionts from insects and amoeba were detected. [ABSTRACT FROM AUTHOR]

Patterns of abundance, age structure and recruitment of coral trout (Plectropomus leopardus) and snapper (Lutjanus carponotatus) were described in different environments, which varied in benthic cover, in a 12-yr study at One Tree Island. It was hypothesized that both taxa would show strong preferences to different environments and benthic cover and that patterns would be consistent through time. Plectropomus leopardus were abundant on the reef slope and seaward edge of the lagoon, where live coral cover was high, and recruitment was generally low, in all environments. The population was sustained by a trickle of recruits, and total abundance varied little after 10 to 25 yr of protection in a no-take area, suggesting P. leopardus had reached an environment-related carrying capacity. Protogynous P. leopardus recruited to shallow environments at sites with 20% or more hard live coral and age data indicated the abundance of fish on the reef slope was from redistribution. Most recruits of gonochoristic L. carponotatus (<150 mm Standard length, SL) were found in the lagoonal environments, and adults were rare on the reef slope. Abundance of recruit L. carponotatus and P. leopardus did not correlate with percent cover of live and soft coral within environments. Recruits of L. carponotatus were usually rare in all lagoonal environments, but in 2003, many recruits (80 to 120 mm SL) were found in lagoonal environments with low and high hard live coral cover. A substantial proportion of the population (age max 18 yr) was from strong recruitment events. In 2003 and 2004, total abundance of L. carponotatus was supported by 1 year class 51.7 and 41% respectively. The utilization of environments and types of substrata varied among taxa and in some cases among lifehistory stages. There was also temporal variation in the importance of some environments (e.g. Lagoon Centre). [ABSTRACT FROM AUTHOR]

Physiological responses to environmental stress are increasingly well studied in scleractinian corals. This work reports a new stress-related skeletal structure we term clypeotheca. Clypeotheca was observed in several livecollected common reef-building coral genera and a two to three kya subfossil specimen from Heron Reef, Great Barrier Reef and consists of an epitheca-like skeletal wall that seals over the surface of parts of the corallum in areas of stress or damage. It appears to form from a coordinated process wherein neighboring polyps and adjoining coenosarc seal themselves off from the surrounding environment as they contract and die. Clypeotheca forms from inward skeletal centripetal growth at the edges of corallites and by the merging of flange-like outgrowths that surround individual spines over the surface of the coenosteum. Microstructurally, the merged flanges are similar to upsidedown dissepiments and true epitheca. Clypeotheca is interpreted primarily as a response to stress that may help protect the colony from invasion of unhealthy tissues by parasites or disease by retracting tissues in areas that have become unhealthy for the polyps. Identification of skeletal responses of corals to environmental stress may enable the frequency of certain types of environmental stress to be documented in past environments. Such data may be important for understanding the nature of reef dynamics through intervals of climate change and for monitoring the effects of possible anthropogenic stress in modern coral reef habitats. [ABSTRACT FROM AUTHOR]

Rising sea temperatures may potentially affect the dispersive larval phase of sessile marine invertebrates with consequences for the viability of adult populations. This study demonstrated that the planktonic larvae of Rhopaloeides odorabile, a common Great Barrier Reef sponge, survived and metamorphosed when exposed to temperatures up to 9°C above the annual maximum (~29°C). Planktonic larval duration of 54 h, at ambient temperatures (~28°C), were reduced to 18 h for larvae exposed to elevated temperatures (32-36°C). Moreover, at ambient temperatures larvae began metamorphosing after 12 h, but at 32-36°C this reduced to only 2 h. Larvae survived and could still metamorphose at temperatures as high as 38°C, but were no longer functional at 40°C. These results imply that predicted increases in sea surface temperature may reduce planktonic larval duration and dispersal capabilities, thereby contributing to population subdivision of the species. [ABSTRACT FROM AUTHOR]

The deposition and cycling of carbon and nitrogen in carbonate sediments located between coral reefs on the northern and central sections of the Great Barrier Reef were examined. Rates of mass sediment accumulation ranged from 1.9 kg m-2 year-1 (inshore reefs) to 2.1- 4.9 kg m-2 year-1 (between mid-shelf reefs); sedimentation was minimal off outer-shelf reefs. Rates of total organic carbon decomposition ranged from 1.7 to 11.4 mol C m-2 year-1 and total nitrogen mineralization ranged from 77 to 438 mmol N m-2 year-1, declining significantly with distance from land. Sediment organic matter was highly reactive, with mineralization efficiencies ranging from 81 to 99% for organic carbon and 64-100% for nitrogen, with little C and N burial. There was no evidence of carbonate dissolution/precipitation in short-term incubation experiments. Rates of sulfate reduction (range 0-3.4 mmol S m-2 day-1) and methane release (range 0-12.8 μmol CH4 m-2 day-1) were minor or modest pathways of carbon decomposition. Aerobic respiration, estimated by difference between total O2 consumption and the sum of the other pathways, accounted for 55-98% of total carbon mineralization. Rates of ammonification ranged from 150 to 1,725 μmol NH4 m-2 day-1, sufficient to support high rates of denitrification (range 30-2,235 μmol N2 m-2 day-1). N2O release was not detected and rates of NH4 + and NO2- efflux were low, indicating that most mineralized N was denitrified. The percentage of total N input removed via denitrification averaged ≈75% (range 28-100%) with little regenerated N available for primary producers. Inter-reef environments are therefore significant sites of energy and nutrient flow, especially in spatially complex reef matrices such as the Great Barrier Reef. [ABSTRACT FROM AUTHOR]3- efflux were low, indicating that most mineralized N was denitrified. The percentage of total N input removed via denitrification averaged ≈75% (range 28-100%) with little regenerated N available for primary producers. Inter-reef environments are therefore significant sites of energy and nutrient flow, especially in spatially complex reef matrices such as the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

Coral communities were monitored at Pandora Reef, nearshore Great Barrier Reef from 1981 to 2005 using photography and videography. In the 1980s, regional elevation of land-based nutrients in coastal waters (ca. 2-6 times pre-European levels of early 1800s) did not prevent overall recovery of coral cover and diversity following a sequence of environmental disturbances in the 1970s. However, prospects for a repeat of such resilience following catastrophic mortality from high-temperature bleaching in 1998 and a cyclone in 2000 are not clear. Different coral communities around the reef varied greatly in relation to impacts and recovery. Fore-reef communities dominated by acroporids (fast growing branching and tabular Acropora and foliose Montipora) recovered strongly in the 1980s following apparently severe impacts by cyclone, food and heat wave disturbances in the 1970s, attaining 60-90% cover by stabilizing rubble and outgrowing macro-algae in <10 years. In the back-reef, by contrast, poritid-dominated communities (massive and finger Porites and columnar Goniopora and Alveopora) had more stable trajectories and smaller impact from recent disturbances: recovery was well underway in 2005. The contrasting trajectories of different parts of the reef reflect differential survival of more persistent versus more ephemeral taxa, notably poritids and acroporids, respectively, both major contributors to framework and cover on reefs globally. A repeat of earlier resilience appears possible in the shallow fore-reef, but unlikely in the deeper fore-reef, which had few viable fragments or recruits in 2005. The main limits on recovery may be (1) reduced supply of coral larvae due to widespread regional losses of coral brood stock and (2) the reduced intervals between disturbances associated with global climate change. The presence of a high abundance of Acroporidae is a major pre-disposing risk factor for climate change impacts. [ABSTRACT FROM AUTHOR]

Aipysurus laevis and Emydocephalus annulatus typically occur in spatially discrete populations, characteristic of metapopulations; however, little is known about the factors influencing the spatial and temporal stability of populations or whether specific conservation strategies, such as networks of marine protected areas, will ensure the persistence of species. Classification tree analyses of 35 years of distribution data (90 reefs, surveyed 1-11 times) in the southern Great Barrier Reef (GBR) revealed that longitude was a major factor determining the status of A. laevis on reefs (present = 38, absent = 38 and changed = 14). Reef exposure and reef area were also important; however, these factors did not specifically account for the population fluctuations and the recent local extinctions of A. laevis in this region. There were no relationships between the status of E. annulatus (present = 16, absent = 68 and changed = 6) and spatial or physical variables. Moreover, prior protection status of reefs did not account for the distribution of either species. Biotic factors, such as habitat and prey availability and the distribution of predators, which may account for the observed patterns of distribution, are discussed. The potential for inter-population exchange among sea snake populations is poorly understood, as is the degree of protection that will be afforded to sea snakes by the recently implemented network of No-take areas in the GBR. Data from this study provide a baseline for evaluating the responses of A. laevis and E. annulatus populations to changes in biotic factors and the degree of protection afforded on reefs within an ecosystem network of No-take marine protected areas in the southern GBR. [ABSTRACT FROM AUTHOR]

Radiocarbon dating of seven drill cores from both the windward Lizard Island fringing reef and the windward and leeward margins of MacGillivray platform reef, Northern Great Barrier Reef Province, reveal the Holocene evolution of these two mid shelf coral reefs. The windward margin at Lizard Island started growing approximately 6,700 calendar years before present (cal yr BP) directly on an assumed granite basement and approached present day sea level approximately 4,000 cal yr BP. Growth of the windward margin at MacGillivray Reef was initiated by 7,600 cal yr BP and approached present day sea level by approximately 5,600 cal yr BP. The leeward margin at MacGillivray was initiated by 8,200 cal yr BP also directly on an assumed granite basement, but only approached sea level relatively recently, between 260 and 80 cal yr BP. None of the cores penetrated the Holocene-Pleistocene unconformity. The absence of Pleistocene reefal deposits, at 15 m depth in the cores from MacGillivray Reef, raises the possibility that the shelf in this region has subsided relative to modern day sea level by at least 15 m since the last interglacial [125,000 years ago (ka)]. [ABSTRACT FROM AUTHOR]

The dynamics of carbon and nitrogen in carbonate mud were examined in the lagoons of Arlington and Sudbury Reefs, Great Barrier Reef. Most (89-93%) of the organic carbon and total nitrogen depositing to the carbonate mud zones was mineralized over a sediment depth of 1 m, with ∼50% of CO2 produced during microbial decomposition involved in carbonate precipitation/dissolution reactions. There was proportionally little burial of organic carbon (10-11%) or nitrogen (7-10%). Nitrogen budgets suggest rapid turnover of porewater inorganic N pools on the order of hours to a few days. Incubation experiments indicate carbonate dissolution in surface deposits (≤ 20 cm depth) and carbonate precipitation in deeper sediments. Depth-integrated reaction rates indicate net carbonate precipitation of 7-10 mol CaCO3 m² year-1 over a depth of 1 m. Budget calculations at the whole-reef scale imply that deposition of CaCO3 in the mud zones of both lagoons may equate to 50-90% of total reef carbonate production, with organic carbon fluxes equating to nearly all net primary production on each reef. These biogeochemical estimates point to the functional importance of carbonate mud zones in the lagoons of the shelf reefs of the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

Patterns of bioerosion of dead corals and rubbles on the northern Great Barrier Reef were studied by using blocks of the massive coral Porites experimentally exposed at six sites, located on an inshore–offshore profile, for 1 year and 3 years. Rates of microbioerosion by microborers, grazing by fish, and macrobioerosion by filter-feeding organisms were simultaneously evaluated using image analysis. Microbioerosion, grazing, and total bioerosion were lower at reefs near the Queensland coast than at the edge of the continental shelf (1.81 kg m−2 and 6.07 kg m−2 after 3 years of exposure respectively, for total bioerosion). The opposite pattern was observed for macrobioerosion. Bioaccretion was negligible. These patterns were evident after 1 year of exposure, and became enhanced after 3 years. Microborers were established and were the main agent of bioerosion after 1 year of exposure, and as the principal support for grazing, continued to be the main cause of carbonate loss after 3 years. Full grazing activity and establishment of a mature community of macroborers required more than 1 year of exposure. After 1 year, macroborers and grazers were the second most important agents of bioerosion on both inshore and offshore reefs. However, after 3 years, grazers became the main agents at all sites except at the inshore sites, where macroborers were the principal agents. Because the contribution of microborers, grazers, and macroborers to bioerosion varies in space and time, we suggest that the estimation of reef carbonate budgets need to take in account the activities of all bioerosion agents. [ABSTRACT FROM AUTHOR]

To study the effects of terrigenous inputs on rates of bioerosion by grazers and micro- and macroborers, two inshore sites, one mid-shelf site, two outer barrier sites, and one site located in the Coral Sea were selected along a cross-shelf transect (200 km from onshore to offshore) on the northern Great Barrier Reef. At each site, two grids were firmly attached to the substrate on which replicate experimental blocks, cut from live colonies of Porites sp., were laid in order to study the intra-site bioerosion variability as well as the variation between sites. After 1 year of exposure, rates of bioerosion were estimated using petrographic sections, scanning electron microscopy, and image analysis. Sites differed significantly. The lowest rates were found at the inshore sites (0.46-0.14 kg CaCO[sub3] m[sup-2] year[sup-1]), while the highest rates were found at the outer barrier sites (3.6-0.52). The pattern of bioerosion exhibited at these six sites varied also, mainly due to different levels of bioerosion by grazers and microborers. Rates of macrobioerosion were low. We suggest that this was due to varying levels of terrigenous inputs, hydrographic patterns, and interactions between agents of bioerosion. [ABSTRACT FROM AUTHOR]

Assesses the changes in reef assemblages of corals and fishes following a tropical cyclone in the Great Barrier Reef, Queensland. Decrease of mean coral cover due to the cyclone; Abundance and species richness of adult damselfish assemblages; Magnitude and spatial extent of cyclonic storm damage to coral reefs.

Presents a study that investigated the demographic basis of differences in the size structure of coral reef fishes in the Great Barrier Reef in Queensland. Spatial analysis of the demographic patterns of Chlorurus sordidus and Scarus frenatus; Differences in the growth profile of the reef fishes; Assessment of the age structure of the reef fishes.

Focuses on the microbial symbionts of the sponge Candidaspongia flabellata found in the Australian Great Barrier Reef, Queensland. Diversity of the microbial community associated with the sponge; Use of 16S ribosomal RNA gene sequencing of the microbial symbionts for phylogenetic characterization; Presence of various morphotypes of bacteria on C. flabellata.

Investigates whether the culturable microbial assemblage of the sponge Rhopaloeides odorabile in the Great Barrier Reef is constant or varied among individuals in a single location, between dispersed geographic locations or at different sampling periods. Isolation and enumeration of bacteria; Localization of the designated strain NW001 by cell separation; Fluorescence in situ hybridization.

Analyzes the bleaching response of coral colonies on the Great Barrier Reef in Queensland. Differences in bleaching response between sites, depth and taxa; Relation between spatial distribution in assemblage response and the taxonomic composition of reef sites.

Presents a study which evaluated the dietary resources available to, and selected by, blennies of the tribe Salariini to assess their trophic status on the Great Barrier Reef. Materials and methods; Results; Discussion.

Presents information on a study which examined the vertical and horizontal movements and activity patterns of black marlin caught off the Great Barrier Reef, Queensland, and the diurnal effects of these behaviors. Usefulness of the vertical and horizontal movements of black marlin to fisheries' management; Materials and methods; Results of the study.

Studies asexual reproduction by fission in populations of Holothuria (Halodeima) atra, H. (H.) edilis and Stichopus chloronotus in the Great Barrier Reef. When asexual reproduction occurred; Popularity of cloning by asexual reproduction; Details on the study.