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Summary: Crowdsourcing methods facilitate the production of scientific information by non‐experts. This form of citizen science (CS) is becoming a key source of complementary data in many fields to inform data‐driven decisions and study challenging problems. However, concerns about the validity of these data often constrain their utility. In this paper, we focus on the use of citizen science data in addressing complex challenges in environmental conservation. We consider this issue from three perspectives. First, we present a literature scan of papers that have employed Bayesian models with citizen science in ecology. Second, we compare several popular majority vote algorithms and introduce a Bayesian item response model that estimates and accounts for participants' abilities after adjusting for the difficulty of the images they have classified. The model also enables participants to be clustered into groups based on ability. Third, we apply the model in a case study involving the classification of corals from underwater images from the Great Barrier Reef, Australia. We show that the model achieved superior results in general and, for difficult tasks, a weighted consensus method that uses only groups of experts and experienced participants produced better performance measures. Moreover, we found that participants learn as they have more classification opportunities, which substantially increases their abilities over time. Overall, the paper demonstrates the feasibility of CS for answering complex and challenging ecological questions when these data are appropriately analysed. This serves as motivation for future work to increase the efficacy and trustworthiness of this emerging source of data. [ABSTRACT FROM AUTHOR]

Information about several papers discussed at the Great Barrier Reef (GBR) Restoration Symposium held in 2018 which brought together restoration practitioners, scientists, engineers, environmental managers is presented. Topics include the need to address climate change to maintain existing management activities and to harness adaptation and restoration techniques to enhance the recovery and increase resilience of the GBR..

Aim Increasingly frequent and intense disturbances of many kinds are reducing the populations of habitat-forming species. For example, disturbances, including coral bleaching, storms and cyclones, coral disease and Crown-of-Thorns starfish (CoTS) outbreaks, have been important contributors to the global decline of coral populations. Understanding these the effects of such disturbances is challenging but necessary for their effective management. In this paper, we provide a novel spatially and temporally explicit perspective on the role of multiple and interacting disturbances on population dynamics. Location Great Barrier Reef (GBR), Australia. Time period 1995-2011. Major taxa studied Acropora species. Methods A semi-parametric Bayesian hierarchical model was used to estimate the form and strength of the cumulative effects of multiple disturbances that have affected coral populations at different locations, frequencies and intensities, and in different orders over 16 years. Boosted regression trees and random forest models were used to rank the relative importance of four types of disturbances in reducing the ability of coral populations to recover following disturbance. Results We show that while all the disturbance agents examined had clear negative impacts, coral predation by CoTS was the strongest contributor to the decline of coral cover and resilience of coral populations. The effects of multiple disturbances on individual reef sites were overwhelmingly additive. Main conclusions Reduction of coral predation through control of CoTS could substantially reduce the severity of disturbances along the GBR and promote greater resilience, and thereby recovery, of coral populations. [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 food selection of hawksbill turtles, Eretmochelys imbricata, using reefs of the Far Northern Section of the Great Barrier Reef Marine Park (nGBR) during 2006 and 2007. A total of 467 gastric lavage and 71 buccal cavity ingesta items were collected from 120 individual E. imbricata, comprising adult female and immature turtles of both sexes. Nineteen E. imbricata that were captured in 2006 were recaptured and sampled again in 2007. Within the total pooled buccal and lavage sample (n = 538), the occurrence of food items was dominated (72.7%) by only three algal taxonomic divisions: Rhodophyta (red algae; 53.7%, n = 289); Chlorophyta (green algae; 11.0%, n = 59) and algae from the division of Phaeophyceae (brown algae; 8.0%, n = 43). The remaining total (buccal and lavage) ingesta sample comprised sponges (10.4%, n = 56), soft corals and a wide variety of possibly nutritionally important invertebrate species (12.6%, n = 68), and a small percentage (5.4%, n = 22) of inorganic material. Generally, E. imbricata were considered to be primarily a sponge-feeding specialist and secondarily an omnivorous species; within coral reef habitats and in various parts of the world this is the case. However, this study has shown that E. imbricata found foraging on reefs of the nGBR are primarily algivorous and secondarily omnivorous. A feeding strategy that relies on a predominantly algal diet may infer important benefits to the species if the impacts of climate change and ocean acidification inhibit coral growth, while promoting algal density and distribution within the Great Barrier Reef ecosystem. [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]

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]

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.