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The paper 'Biodiversity values of remnant freshwater floodplain lagoons in agricultural catchments: evidence for fish of the Wet Tropics bioregion, northern Australia', published in Aquatic Conservation: Marine and Freshwater Ecosystems in 2015, has contributed in several ways to the integration of freshwater wetland science within new catchment management policies and practices for Great Barrier Reef (GBR) sustainability.The Tully–Murray biodiversity study developed novel protocols to sample larval, juvenile, and adult fish life‐history stages in floodplain lagoons using a combination of boat‐based backpack electrofishing and fyke netting. In addition, hydrological and hydrodynamic models were applied in a completely new way to quantify the timing, extent, and duration of water connectivity across floodplain streams, cane drains, and wetlands. Combining the two novel approaches enabled an analysis of lagoon fish assemblage patterns in relation to environmental gradients, especially floodplain hydrology, connectivity patterns, and measures related to agricultural land use.In demonstrating the importance of different levels of connectivity for different biodiversity outcomes in freshwater floodplain lagoons of the Tully–Murray catchment, the subject paper established that floodplain connectivity needs to be taken into consideration in wetland management practices.The timing of the subject publication was fortuitous. It coincided with the preparation of the evidence‐based 2017 Scientific Consensus Statement on land‐based water quality impacts on the GBR. As one of the few freshwater wetland ecology publications for the catchments of the GBR at that time, this paper played an important role in demonstrating freshwater wetland values, fish conservation options, and management imperatives to sustain wetland ecological health and services in GBR catchments.By advancing the understanding of factors driving biodiversity patterns, and the importance of connectivity and ecohydrological processes in freshwater floodplain wetlands of the GBR catchment, the Tully–Murray study helped to drive new policy directives for the protection and restoration of catchment, floodplain, and estuary functions, and connectivity, now embedded in the Reef 2050 Long‐Term Sustainability Plan 2018, an overarching strategy for managing the GBR over the next 35 years, and complementary Queensland environmental legislation. [ABSTRACT FROM AUTHOR]

This paper proposes using an adaptive management approach to achieve water quality improvement in large catchments with multiple diffuse pollutant issues. Adaptive management involves attention to process, and commitment to continually improving knowledge and practice. It also requires an appreciation of differences in understanding of various stakeholders and an ongoing commitment to learning. Based on research with the Burdekin Dry Tropics regional Natural Resource Management group, the paper shows how the acquisition of knowledge about Water Quality Management can be an aim in itself, rather than an activity peripheral to the planning process. To this end, the paper describes the methods used to elicit stakeholders’ understandings, explores the variation in understandings between key stakeholders, and describes a process used to incorporate the various views in an adaptive management framework for managing water quality. The research findings reveal the importance of process and participation for adaptive management and suggest that success can be judged in terms of learning outcomes. [ABSTRACT FROM AUTHOR]

This paper describes the role of the autonomous underwater vehicle (AUV) Sirius on a research cruise to survey drowned reefs along the shelf edge of the Great Barrier Reef in Queensland, Australia. The primary function of the AUV was to provide georeferenced, high-resolution optical validation of seabed interpretations based on acoustic data. We describe the AUV capabilities and its operation in the context of the multiple systems used in the cruise. The data processing pipeline involved in generating simultaneous localization and mapping–based navigation, large-scale, three-dimensional visualizations, and automated classification of survey data is briefly described. We also present preliminary results illustrating the type of data products possible with our system and how they can inform the science driving the cruise. © 2010 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The north-east Australian margin is the largest modern example of a tropical mixed siliciclastic/carbonate depositional system, with an outer shelf hosting the Great Barrier Reef (GBR) and an inner shelf dominated by fluvially sourced siliciclastic sediment wedges. The long-term interplay between these sediment components and sea level is recorded in the Queensland Trough, a 1–2 km deep N–S elongate basin situated between the GBR platform and the Queensland Plateau. In this paper, 154 samples from 45 surface grabs and six well-dated piston cores were analysed for total carbonate content, carbonate mineralogy and Sr concentration to establish spatial and temporal patterns of carbonate accumulation in the Queensland Trough over the last 300 kyr. Surface carbonate contents are lowest on the inner-shelf (<5%) and in the trough axis (<60%) because of siliciclastic dilution. Carbonate on the shelf is mostly Sr-rich aragonite and high-Mg calcite (HMC), whereas that in the basin is mostly low-Mg calcite. Once normalized to remove the effects of siliciclastic dilution, surface Sr-rich aragonite and HMC abundances decrease linearly to background levels ≈ 100 km seaward of the shelf edge. Core samples show that, over time, normalized aragonite and Sr abundances are greatest during periods of shelf flooding and lowest when sea level drops below the shelf edge. This is consistent with changes in the production of coral and calcareous algae, and the shedding of their debris from the shelf. Interestingly, normalized HMC concentrations on the slope peak during periods of major transgression, perhaps because of maximum off-shelf transport from inter-reef areas or intermediate water dissolution. After accounting for siliciclastic dilution, there are strong similarities in both spatial and temporal patterns of carbonate minerals between slopes and basins of the north-east Australian margin and those of pure carbonate margins such as the Bahamas. A limited set of basic processes, including the formation and breakdown of carbonate on the shelf, the transport of carbonate off the shelf and eustatic sea level, probably controls carbonate accumulation in slope and basin settings of tropical environments, irrespective of proximal siliciclastic sediment sources. [ABSTRACT FROM AUTHOR]

Reducing nutrient runoff from sugarcane production into the Great Barrier Reef (GBR) has become a major policy focus for the Queensland and Australian Governments. This study explores consumer willingness to pay (WTP) to achieve higher environmental standards for sugar originating from the GBR catchments, through the use of a GBR‐safe ecolabel. A Best‐Worst Scaling (BWS) and a Contingent Valuation (CV) experiment are conducted on a random sample of 1,100 Australian residents. The BWS experiment reveals that personal health considerations are more important than sustainability and environmental factors, including impacts on the GBR. Results of the CV experiment show that respondents are more likely to pay a premium to support Reef‐friendly sugar if they are living in urban areas, plan to visit the GBR in the future, think that the GBR condition has declined, and are generally concerned about keeping a healthy diet. We estimate that the average WTP is $24.5/year/household, which only represents 0.34 per cent of the average weekly grocery bill of Australian households. This small contribution through increased sugar prices could conservatively raise $46.9M/year in support of sugar producers to improve water quality in the GBR. Based on these results, we recommend policy‐makers consider instruments that further involve sugar consumers. [ABSTRACT FROM AUTHOR]

New regionalism encompasses a diversity of approaches to address regional planning problems. Within Australia, the Great Barrier Reef Water Quality Protection Plan was developed to enhance water quality within the World Heritage-listed Great Barrier Reef, and the plan gave responsibility to regional, natural resource management bodies to undertake several actions. This paper evaluates these initiatives in the light of the emerging theory of new regionalism and highlights six main lessons: up-scaling of the catchment approach to a reef-wide approach is essential in order to improve water quality, but must be complemented by cross-regional collaboration; new governance and institutional arrangements and strengthened partnerships must be effectively integrated; culture and history are important in determining the most effective management approaches; pilot projects must move to comprehensive and strategic implementation; science is important but needs to incorporate other branches of knowledge; and economic incentives are important in encouraging the implementation of best practices, but delivery needs to be flexible. We conclude that the new regional approach is appropriate for addressing complex, multi-scale problems such as water quality, and has incorporated several key principles of new regionalism, but that the process must move quickly to a higher level of commitment and application. [ABSTRACT FROM AUTHOR]

Presents a paper on gonad development and evidence of protogyny in the red-throat emperor Lethrinus (L.) miniatus on the Great Barrier Reef, Queensland. Concurrent degeneration of all oocytes and proliferation of spermatocysts near lamellae in transitional L. miniatus; Implications of the presence of spermatocysts in the females; Unusual characteristics of transitional L. miniatus.

The Great Barrier Reef World Heritage Area in Queensland, Australia contains globally significant seagrasses supporting key ecosystem services, including habitat and food for threatened populations of dugong and turtle. We compiled 35 years of data in a spatial database, including 81,387 data points with georeferenced seagrass and species presence/absence, depth, dominant sediment type, and collection date. We include data collected under commercial contract that have not been publicly available. Twelve seagrass species were recorded. The deepest seagrass was found at 76 m. Seagrass meadows are at risk from anthropogenic, climate and weather processes. Our database is a valuable resource that provides coastal managers and the global marine community with a long‐term spatial resource describing seagrass populations from the mid‐1980s against which to benchmark change. We address the data issues involved in hindcasting over 30 years to ensure confidence in the accuracy and reliability of data included. [ABSTRACT FROM AUTHOR]

Human activities threaten reef ecosystems globally, forcing ecological change at rates and scales regarded as unprecedented in the Holocene. These changes are so profound that a cessation of reef accretion (reef 'turn-off') and net erosion of reef structures is argued by many as the ultimate and imminent trajectory. Here, we use a regional scale reef growth dataset, based on 76 core records (constrained by 211 radiometric dates) from 22 reefs along and across the inner-shelf of the Great Barrier Reef, Australia, to examine the timing of different phases of reef initiation ('turn-on'), growth and 'turn-off' during the Holocene. This dataset delineates two temporally discrete episodes of reef-building over the last 8500 years: the first associated with the Holocene transgression-early highstand period [∼8.5-5.5 k calibrated years (cal y)]; the second since ∼2.3 k cal y. During both periods, reefs accreted rapidly to sea level before entering late evolutionary states - states naturally characterized by reduced coral cover and low accretion potential - and a clear hiatus occurs between these reef-building episodes for which no records of reef initiation exist. These transitions mimic those projected under current environmental disturbance regimes, but have been driven entirely by natural forcing factors. Our results demonstrate that, even through the late Holocene, reef health and growth has fluctuated through cycles independent of anthropogenic forcing. Consequently, degraded reef states cannot de facto be considered to automatically reflect increased anthropogenic stress. Indeed, in many cases degraded or nonaccreting reef communities may reflect past reef growth histories (as dictated by reef growth-sea level interactions) as much as contemporary environmental change. Recognizing when changes in reef condition reflect these natural 'turn-on'- growth -'turn-off' cycles and how they interact with on-going human disturbance is critical for effective coral reef management and for understanding future reef ecological trajectories. [ABSTRACT FROM AUTHOR]

An Integrated Risk Assessment for Climate Change (IRACC) is developed and applied to assess the vulnerability of sharks and rays on Australia's Great Barrier Reef (GBR) to climate change. The IRACC merges a traditional climate change vulnerability framework with approaches from fisheries ecological risk assessments. This semi-quantitative assessment accommodates uncertainty and can be applied at different spatial and temporal scales to identify exposure factors, at-risk species and their key biological and ecological attributes, critical habitats a`nd ecological processes, and major knowledge gaps. Consequently, the IRACC can provide a foundation upon which to develop climate change response strategies. Here, we describe the assessment process, demonstrate its application to GBR shark and ray species, and explore the issues affecting their vulnerability to climate change. The assessment indicates that for the GBR, freshwater/estuarine and reef associated sharks and rays are most vulnerable to climate change, and that vulnerability is driven by case-specific interactions of multiple factors and species attributes. Changes in temperature, freshwater input and ocean circulation will have the most widespread effects on these species. Although relatively few GBR sharks and rays were assessed as highly vulnerable, their vulnerability increases when synergies with other factors are considered. This is especially true for freshwater/estuarine and coastal/inshore sharks and rays. Reducing the impacts of climate change on the GBR's sharks and rays requires a range of approaches including mitigating climate change and addressing habitat degradation and sustainability issues. Species-specific conservation actions may be required for higher risk species (e.g. the freshwater whipray, porcupine ray, speartooth shark and sawfishes) including reducing mortality, preserving coastal catchments and estuarine habitats, and addressing fisheries sustainability. The assessment identified many knowledge gaps concerning GBR habitats and processes, and highlights the need for improved understanding of the biology and ecology of the sharks and rays of the GBR. [ABSTRACT FROM AUTHOR]

The article presents a study on predictive modeling of coastal seagrass habitats in the Great Barrier Reef World Heritage Area (GBR) in Queensland. It applies a planning element to be used as a pattern to the Bayesian belief network predictions. It involves several predictor variables integrated in the model for coastal seagrass distribution, which include season, sea surface temperature, and tidal range. Results of the study show a tentative dependence on bathymetry and tidal range.

Aim This study examines the importance of geographic proximity, host life history and regional and local differences in environment (temperature and water clarity) in driving the ecological and evolutionary processes underpinning the global patterns of diversity and distribution of symbiotic dinoflagellates. By comparing and contrasting coral–algal symbioses from isolated regions with differing environmental conditions, we may assess the potential of coral communities to respond to significant changes in climate. Location Indian Ocean. Methods Community assemblages of obligate symbiotic invertebrates were sampled at numerous sites from two regions, the north-eastern Indian Ocean (Andaman Sea, western Thailand) and the western Indian Ocean (Zanzibar, Tanzania). Molecular genetic methods, including denaturing gradient gel electrophoresis analysis of the ribosomal internal transcribed spacers, DNA sequencing and microsatellite genotyping, were used to characterize the ‘species’ diversity and evolutionary relationships of symbiotic dinoflagellates (genus Symbiodinium). Host–symbiont specificity, geographic isolation and local and regional environmental factors were evaluated in terms of their importance in governing the distribution and prevalence of certain symbiont taxa. Results Host-generalist symbionts ( C3u and D1-4, formerly D1a now designated Symbiodinium trenchi) frequently occurred alone and sometimes together in hosts with horizontal modes of symbiont acquisition. However, the majority of Symbiodinium diversity consisted of apparently host-specific ‘species’. Clade C Symbiodinium were diverse and dominated host assemblages from sites sampled in the western Indian Ocean, a pattern analogous to symbiont communities on the Great Barrier Reef with similar environmental conditions. Clade D Symbiodinium were diverse and occurred frequently in hosts from the north-eastern Indian Ocean, especially at inshore locations, where temperatures are warmer, water turbidity is high and large tidal exchanges commonly expose coral populations to aerial desiccation. Main conclusions Regional and local differences in cnidarian–algal combinations indicate that these symbioses are ecologically and evolutionarily responsive and can thrive under various environmental conditions. The high temperatures and turbid conditions of the north-eastern Indian Ocean partly explain the ecological success of Clade D Symbiodinium relative to Clade C. Phylogenetic, ecological and population genetic data further indicate that Clade D has undergone an adaptive radiation, especially in regions around Southeast Asia, during the Pleistocene. [ABSTRACT FROM AUTHOR]

Aim To determine whether the diversity of resident and transient coral-dwelling fish responds differentially to gradients in regional species richness. Location Three regions in the Indo-Pacific (Red Sea, western Indian Ocean, Great Barrier Reef) which contain increasingly larger regional diversities of reef fish. Methods I surveyed fish residing within branching coral species. Fish species were a priori categorized as resident or transient based on the degree of affiliation between the fish and live coral. To compare among regions that differ in coral diversity I used a modified species–volume relationship (SVR). Each point in the SVR represents the total number of fish species, resident or transient, found within the cumulative volume of a specific coral species. Empirical SVRs were further compared with random-placement null models. Results For transient species, I found that the observed SVRs did not differ consistently from those expected from random samples drawn from the corresponding regional species pools. In addition, for a given volume of coral, more fish species were found in richer regions, indicating strong regional influences on local diversity. In contrast, resident richness was lower than that expected from random samples of the species pool, and richness in rich regions was reduced comparably more than in poor regions. The SVRs of resident species were similar among regions with different regional diversities. Main conclusion These results suggest that, within coral species, transient fish richness is mostly influenced by stochastic allocation of species from the regional pool. Conversely, richness of resident species within a coral species is limited, making it independent of regional diversity. Since higher regional diversity of resident fish was not accompanied by higher richness per coral species or by decreased niche breadth, higher regional diversity of resident fish species must be rooted in higher coral richness. Consequently, ecological interactions between functional groups (coral and fish) can be powerful drivers of regional biodiversity. [ABSTRACT FROM AUTHOR]

There is a growing concern that increased nutrient and sediment runoff from river catchments are a potential source of coral reef degradation. Degradation of reefs may affect the number of tourists visiting the reef and, consequently, the economic sectors that rely on healthy reefs for their income generation. This study uses a contingent behaviour approach to estimate the effect of reef degradation on demand for recreational dive and snorkel trips, for a case study of the Great Barrier Reef in Australia. Results from a negative binomial random effects panel model show that the consumer surplus current reef visitors derive from a diving or snorkelling trip is approximately A$185 per trip. Furthermore, results indicate that reef trips by divers and snorkellers could go down by as much as 80 per cent given a hypothetical decrease in coral and fish biodiversity. This corresponds to a decrease in tourism expenditure by divers and snorkellers on full-day reef trips in the Cairns management area of the Great Barrier Reef Marine Park of about A$103 million per year. [ABSTRACT FROM AUTHOR]

The sources and fluxes of sediment to the Great Barrier Reef lagoon from north-eastern Australian rivers have been the subject of much concern and study, with the large catchments of the Burdekin and Fitzroy Rivers thought to be the key sources at present. Here, the utility of newly developed magnetic ‘fingerprinting’ methods for identifying sediment provenance, both onshore and offshore, and in association with individual large flood events, is investigated. Within the Burdekin catchment, sediments are mobilized from different subcatchments by runoff generated by intense, localized rainfall events. Magnetic measurements were made on untreated and acid-treated samples of river channel sediments within the Burdekin River subcatchments and from the estuarine and inner shelf depocentres of Burdekin River sediments. The acid treatment removes all discrete magnetic particles and coatings, and leaves magnetic inclusions (protected within host silicate grains) as the basis of the measured magnetic signature of a sample. The magnetic properties of the acid-treated samples display statistically distinct sediment provenance groupings. Sand samples from the Upper Burdekin River appear magnetically distinct from samples from tributaries of the Burdekin (e.g. Hann Creek, Fanning River) and also from nearby coastal rivers, including the Haughton. Suspended sand samples from a Burdekin flood event in 2000 appear to have a different source compared with those from floods in 1998 and 1999. Comparisons of the terrestrial, acid-treated sand fractions with the same, acid-treated, sand-size fractions from transects taken offshore suggest that the surface sediments in Upstart Bay and Bowling Green Bay have different sources. Some of these sources are as yet unidentified but may represent the unsampled, lower-discharge south-western Burdekin subcatchments, and/or along-shore drift of sand from the south, perhaps even from the Fitzroy River, over millennial timescales of cyclone pumping. The magnetic inclusion method precludes any obfuscation or confounding of sediment source, which might arise from hydraulic sorting and/or post-depositional magnetic diagenesis or authigenesis. [ABSTRACT FROM AUTHOR]

The historical exploitation of marine resources in Queensland has only been partially documented. In particular, the history of the commercial fishing of dugongs and marine turtles has received comparatively little scholarly attention. Since European settlement in Queensland, various human activities have exploited these resources. We present documentary and oral history evidence of the scale of those industries. Based on extensive archival and oral history research, we argue that diverse fishing practices occurred and that the sustained exploitation of dugongs, green turtles, and hawksbill turtles led to observable declines in the numbers of these animals – now species of conservation concern. [ABSTRACT FROM AUTHOR]

Morphological development of the larvae of the Ambon damselfish Pomacentrus amboinensis from the Great Barrier Reef, Australia, is described from 34 reared specimens (2·5–13·0 mm standard length), and two wild settlement-stage larvae (10·8–11·3 mm) captured in light traps. Reared larvae emerged from demersal eggs at c. 2·5 mm, underwent notochord flexion at 4·0–4·5 mm, and settled at 11–13 mm at 19–21 days after hatching (within the known range for wild larvae). Reared larvae grew at 0·3 mm day−1 (preflexion) to 0·5 mm day−1 (postflexion). Development was direct with few specializations for pelagic existence and was typical of pomacentrids. Head spination consisted of very weak spines on the preopercle, opercle, interopercle, subopercle and supracleithrum. Development of the olfactory system and retina are also described. A summary of published descriptions of early life-history stages of pomacentrid damselfishes is provided ( n= 15% of known species). Larvae of several genera ( e.g. Abudefduf, Chromis and Stegastes) are deeper-bodied and more ‘hunchbacked’ than P. amboinensis. Larvae of other genera ( e.g. Amblyglyphidodon, Chrysiptera and Neoglyphidodon) are similar to P. amboinensis. Larvae of only three other Pomacentrus species have been described, and they are similar to P. amboinensis in body morphology, pigmentation and head spination. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A spatially structured simulation model of the population dynamics and line fishing exploitation of common coral trout,Plectropomus leopardusLacepède, was used to evaluate the effects of infringement and different amounts and arrangements of marine reserves on the Reef Line Fishery of the Great Barrier Reef, Australia. With no marine reserves and under a constant future effort level equal to that for 1996, the size of the population was reduced and the biomass stabilised at about 40% of pre-exploitation levels. Marine reserves were ineffective at conserving biomass when limited infringement was allowed throughout an entire reserve. When infringement was absent altogether or limited to the edges of reserves, larger marine reserves lead to lower total catches and higher overall biomass. When infringement was limited to reserve edges, a single large closure was more effective at conserving biomass than more fragmented arrangements. Simulations suggested that marine reserves might lead to better conservation of a fishery-targeted species if infringement is negligible or limited to reserve margins. Even where infringement occurred only at the edges of reserves, a network of small reserves may be less effective at conserving a targeted species than a smaller number of larger reserves. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At Heron Island reef, Great Barrier Reef Australia, biomass densities and mean wet mass of Ward's damselfish Pomacentrus wardi and the jewelled blenny Salarias fasciatus were not significantly different at 2·37 v. 2·95 g m−2 and 8·7 v. 7·9 g, respectively. Whereas S. fasciatus significantly exceeded P. wardi in (1) total number of bites per day (3427 v. 1155), (2) the mass of epilithic algal community consumed per bite (2·19 v. 0·14 mg) and (3) total organic carbon consumed per day (487·31 v. 35·46 mg C m−2 day−1). Territorial behaviour differed also between the two species. Pomacentrus wardi chased from their territories a smaller proportion of blennies than roving grazers ( i.e. scarids, acanthurids, siganids and pomacentrids) relative to S. fasciatus. Salarias fasciatus chased c. 90% of other blennies from their territories, while chasing only c. 20% of all damsels that entered. Both P. wardi and S. fasciatus rarely chased non-grazers. The chasing behaviour of S. fasciatus was size dependent, with resident fish chasing only individuals of its own family ( i.e. Blenniidae) that were the same or smaller size. Pomacentrus wardi may have tolerated S. fasciatus grazing within its territory, as it contributes to territory defence from other blennies. The possibility that the interaction between the two species is facilitative, rather than competitive, is discussed. It was concluded that salariine blennies play an important, and previously underestimated role in coral reef trophodynamics. [ABSTRACT FROM AUTHOR]

Symbiotic relationships have contributed greatly to the evolution and maintenance of biological diversity. On the Great Barrier Reef, species of obligate coral-dwelling fishes (genus Gobiodon) coexist by selectively recruiting to colonies of Acropora nasuta that differ in branch-tip colour. In this study, we investigate genetic variability among sympatric populations of two colour morphs of A. nasuta (‘blue-tip’ and ‘brown-tip’) living in symbiosis with two fish species, Gobiodon histrio and G. quinquestrigatus, respectively, to determine whether gobies are selecting between intraspecific colour polymorphisms or cryptic coral species. We also examine genetic differentiation among coral populations containing both these colour morphs that are separated by metres between local sites, tens of kilometres across the continental shelf and hundreds of kilometres along the Great Barrier Reef. We use three nuclear DNA loci, two of which we present here for the first time for Acropora. No significant genetic differentiation was detected between sympatric colour morphs at these three loci. Hence, symbiotic gobies are selecting among colour morphs of A. nasuta, rather than cryptic species. Significant genetic geographical structuring was observed among populations, independent of colour, at regional (i.e. latitudinal separation by <500km) and cross-shelf (<50km) scales, alongside relative homogeneity between local populations on within reef scales (<5km). This contrasts with the reported absence of large-scale genetic structuring in A. valida, which is a member of the same species group as A. nasuta. Apparent differences in biogeographical structuring between species within the A. nasuta group emphasize the need for comparative sampling across both spatial (i.e. within reefs, between reefs and between regions) and taxonomic scales (i.e. within and between closely related species). [ABSTRACT FROM AUTHOR]

Sundberg, P., Gibson, R. & Olsson, U. (2003). Phylogenetic analysis of a group of palaeonemerteans (Nemertea) including two new species from Queensland and the Great Barrier Reef, Australia. —Zoologica Scripta, 32, 279–296. Based on 18S rDNA nucleotide sequences and morphological characters, we reconstruct the phylogeny for a group of palaeonemerteans estimated to be monophyletic. Two new palaeonemertean species from Queensland and the Great Barrier Reef, Australia are included in the phylogenetic analysis. The results confirm that one of the species, Cephalothrix queenslandica sp. n., is part of the Cephalothrix–Cephalotrichella–Procephalothrix group. These genera are redefined phylogenetically under the name Cephalothrix based on the cladistic analysis. The other species, Balionemertes australiensis gen. et sp. n., is placed in a new genus which forms a sister taxon to Cephalothrix . The morphology of both new species is described in detail. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef (GBR) shelf contains a range of coral reefs on the highly turbid shallow inner shelf, where interaction occurs with terrigenous sediments. The modern hydrodynamic and sedimentation regimes at Paluma Shoals, a shore-attached ‘turbid-zone’ coral reef, and at Phillips Reef, a fringing reef located 20 km offshore, have been studied to document the mechanisms controlling turbidity. At each reef, waves, currents and near-bed turbidity were measured for a period of ≈1 month. Bed sediments were sampled at 135 sites. On the inner shelf, muddy sands are widespread, with admixed terrigenous and carbonate gravel components close to the reefs and islands, except on their relatively sheltered SW side, where sandy silty clays occur. At Paluma Shoals, the coral assemblage is characteristic of inner-shelf or sheltered habitats on the GBR shelf (dominated by Galaxea fascicularis, up to >50% coral cover) and is broadly similar to that at Phillips Reef, further offshore and in deeper water. The sediments of the Paluma Shoals reef flats consist of mixed terrigenous and calcareous gravels and sands, with intermixed silts and clays, whereas the reef slope is dominated by gravelly quartz sands. The main turbidity-generating process is wave-driven resuspension, and turbidity ranges up to 175 nephelometric turbidity units (NTU). In contrast, at Phillips Reef, turbidity is <15 NTU and varies little. At Paluma Shoals, turbidity of >40 NTU probably occurs for a total of >40 days each year, and relatively little time is spent at intermediate turbidities (15–50 NTU). The extended time spent at either low or high turbidities is consistent with the biological response of some species of corals to adopt two alternative mechanisms of functioning (autotrophy and heterotrophy) in response to different levels of turbidity. Sedimentation rates over periods of hours may reach the equivalent of 10 000 times the mean global background terrigenous flux... [ABSTRACT FROM AUTHOR]

Lithofacies analysis, pollen assemblages and radiocarbon age dates oF 20 stratigraphic drill holes are used to develop an evolutionary history for late Quaternary sedimentation in two coastal embayment landward of the central Great Barrier Reef. Different physiographic settings of the embayment result in two contrasting styles of sedimentary sequence: (a) an exposed, moderate energy, beach barrier--lagoon system (Wyvuri Embaymeat) and (b) a protected, low energy, muddy inlet fill sequence (Mutchero Inlet). Despite sharp contrast in sequence style, similar depositional cycles occur in both embayments in response to late Quaternary sea level fluctuations including: (1) a last interglacial high stand (+2 m; c. 125 000 yr bp) beach barrier (Wyvuri); (2) an early to mid-Holocene (8000-6100 yr ap) transgressive beach barrier lagoon (Wyvuri) and estuarine infill (Matchero); and (3) mid-Holocene to present high stand beach barrier (Wyvuri) and estuarine (Mutchero) progradation. Preservation of such cycles in the stratigraphic record would produce a series of vertically stacked and offset linear barrier sands surrounded by lagoonal mud and fine grained shore face sediment juxtaposed to muddy, estuarine infills. Sea level elevations are well recorded by the upward transition from Rhizophora-dominated intertidal mangrove mud to freshwater swamp (clearly identified by pollen analysis) and by the basal contacts of beach barrier sediments which sharply overlie the upper shore face. Transgressive sedimentation is interrupted in both embayments by a constructional beach barrier (Wyvuri) and abbreviated progradation (Mutchero) corresponding to a -- 5 m pause in relative sea level rise at c 6800 yr BP. Sea level control of fine scale coastal sedimentation patterns is beginning to be widely recognized and provides an accurate analogue for stacked ancient sequences. [ABSTRACT FROM AUTHOR]

Investigates holocene reef development by coring on Britomart Reef in the central Great Barrier Reef, Queensland. Mineralogical and geochemical analyses; Conversion of magnesian calcite and aragonite to low magnesium-calcite below the Holocene-Pleistocene disconformity; Partial replacement of aragonite by calcite; Radiocarbon dating.

Reports various developments pertinent to the science of geology as of March 2002. Magmatic intrusion at Mammoth Mountain in the eastern Sierra Nevada; Reconstruction of a primitive sea cow at the Florida Museum of Natural History in Gainesville, Florida; Evidence of the age of Australia's Great Barrier Reef.