Ongoing effects of no-take marine reserves on commercially exploited coral trout populations on the Great Barrier Reef

Networks of no-take marine reserves (NTMRs) are widely used for managing marine resources. Because they restrict fishing, managers need to monitor reserves to reassure stakeholders that they are achieving the intended results. In 2004, the Great Barrier Reef (GBR) Marine Park was rezoned and the area of NTMRs was greatly increased. Using manta tow we assessed the effectiveness of the new NTMRs in conserving coral trout (Plectropomus and Variola spp.), the principle targets of the GBR reef line fishery. Over a six year period, we sampled regional groups of matched pairs of similar reefs, ones closed to fishing under the rezoning and ones that remained open. Coral trout populations were significantly higher in NTMRs. While coral trout populations declined on reefs open to fishing, stocks were maintained in NTMRs, highlighting the ongoing benefits of marine reserves.     

Seismic and stratigraphic evidence for reef expansion and onset of aridity on the Northwest Shelf of Australia during the Pleistocene

Modern reef (the Great Barrier Reef and Ryukyu Reef) distribution in the Indo-Pacific region is strongly controlled by warm currents (East Australian and Kuroshio Currents) that radiate from the Indo-Pacific Warm Pool. The modern distribution of reefs (south of 15°S) on the Western Australian shelf is related to the presence of the warm Leeuwin Current. However, the age of the reefs south of 15°S, and hence their temporal relationship to the Leeuwin Current, has been largely unknown. Seismic and subsurface stratigraphic data show that reef growth and expansion on the Northwest Shelf of Australia began in the Middle Pleistocene (∼0.5 Ma). The oldest ooids in the region are approximately synchronous with reef growth. We suggest a two stage process for the spread of reefs to higher latitudes on the Western Australian coast; first an increase in Leeuwin Current activity at approximately 1 Ma brought warm waters and a tropical biota to the region; and second, increased aridity after ∼0.6 Ma led to a decline in clastic input and increased alkalinity, triggering ooid formation and reef expansion to higher latitudes associated with the switch to higher amplitude glacio-eustatic cycles at the end of the Middle Pleistocene Transition. The timing and mechanisms for reef expansion south along the Western Australian coast has implications for the origin of the Eastern Australian Middle Pleistocene Great Barrier Reef, the New Caledonia Barrier Reef and Japanese Ryukyu Reef systems.     

Effect of agricultural activity on levels of organochlorine pesticides in hard corals, fish and molluscs from the Great Barrier Reef

An organochlorine baseline study of selected corals, fish and molluscs has established that lindane is the only consistently detectable persistent pesticide in Great Barrier Reef organisms sampled. Samples taken during 1976–1977 from twenty reefs between Heron Island and Lizard Island provide evidence from the distribution of lindane that the contamination is related to agricultural usage in the coastal sugar cane growing regions. Consideration is given to the possible mode of transport of lindane to the reef environment. No polychlorinated biphenyls were detected in any of the samples and only scattered samples contained levels of residues other than lindane. Inner marginal shelf reefs of the Great Barrier Reef may be the most pristine environment yet reported for organochlorine pollutants.     

A wave model for the Great Barrier Reef

A new wind wave generation model, WAMGBR, is presented that has been adapted from WAM especially for use in the complex geometry of the Great Barrier Reef. A technique (reef parameterization) has been presented that incorporates sub-grid scale dissipation caused by coral reefs. Three other improvements to WAM have been proposed. An explicit/implicit finite difference scheme has been implemented that allows for more efficient modelling (longer time steps) while maintaining diffusive characteristics that are at least as good as those of WAM. An offset in discrete angles creates more uniform diffusive characteristics. And, a transformed spherical coordinate system allows for more efficient grid sizes and smaller grid dependent refraction. Comparisons between modelling techniques and between model and measured data show that WAMGBR produces very good results in the difficult challenge of modelling both non-cyclonic and tropical cyclone waves in the geographically complex environment of the Great Barrier Reef.     

The value of recreational fishing in the Great Barrier Reef, Australia: A pooled revealed preference and contingent behaviour model

Given the focus on protecting natural assets in the Great Barrier Reef Marine Park in Australia, it is important for managers and policy makers to understand the value of recreational fishing in the area, and how changes in management may affect those recreational values. Travel cost methods were used to estimate the value of recreational fishing in the Capricorn Coast in Central Queensland using data from on-site surveys conducted at boat ramps. The study also uses contingent behaviour models to estimate the change in the value of recreational fishing as conditions vary. Results indicate that there are high values associated with recreational fishing activity along the Capricorn Coast, and that the demand for recreational fishing is inelastic and that values are relatively insensitive to changes in catch rates.     

Holocene reef growth — One Tree Island,Great Barrier Reef

Data from investigations at One Tree Reef and from other sources suggest that post-glacial coral reefs in the Great Barrier Reef probably date from only about 9,000 years ago. They are likely to have grown on the elevated parts of an irregular karst surface, their general morphology having been largely determined by the shape and depth of this surface. Growth has been dominantly vertical because of the rapid sea-level rise, with lateral modification being quite recent and dominantly in a leeward direction.     

Recreational fishing and boating: Are the determinants the same?

The research uses household survey data collected from 656 people in Townsville (adjacent to the Great Barrier Reef, Australia) within a hurdle model to investigate key factors influencing both the probability of participating and the frequency of (a) boating trips which involve fishing; (b) boating trips which do not involve fishing; and (c) land-based fishing trips. The findings suggest that there are differences in determinants, highlighting the importance of disaggregating the fishing/boating and boat/land-based experience (an uncommon practice in the literature) if wishing to obtain information for use in the design of monitoring programs, policy and/or for developing monitoring and enforcement strategies relating to fishing and boating.     

Developing a long-term outlook for the Great Barrier Reef,Australia: A framework for adaptive management reporting underpinning an ecosystem-based management approach

The Great Barrier Reef Outlook Report 2009 was the first produced in response to a newly legislated requirement for five-yearly reports on the status of and outlook for the Great Barrier Reef. It adopted an ecosystem approach, assessing all habitats and species, ecosystem processes and major uses. By then considering the factors affecting the ecosystem, coupled with an assessment of management effectiveness, it provided a risk-based forward-looking projection for the ecosystem. Rarely has such a comprehensive, ecosystem-based report been produced to guide government action. With no pre-determined path to follow for interpreting the legislative requirements, the Great Barrier Reef Marine Park Authority (GBRMPA) developed a repeatable structure and method for Great Barrier Reef Outlook Reports that impartially and consistently considers the evidence and clearly presents the findings. The GBRMPA worked closely with relevant Australian and Queensland Government agencies as well as researchers, industry representatives and the community while developing the report. That such a report must be produced every five years allows an overview of the effectiveness of management responses to be regularly assessed. It also provides a transparent means of highlighting and tracking emerging risks facing the Great Barrier Reef.     

The need and practice of monitoring, evaluating and adapting marine planning and management—lessons from the Great Barrier Reef

An increasing number of scientists and resource managers recognise that successful marine management approaches, including marine spatial planning (MSP), cannot occur without effective monitoring, evaluation and adaptation. These basic components are necessary to ensure that any marine planning or marine management measures are both effective and efficient. While a number of fundamental principles for marine monitoring, evaluation and adaptive management exist, there are varying levels of understanding about how these should be undertaken and what they may achieve. Challenges include the development of realistic and measurable objectives and indicators against which effectiveness can be practically measured. The matter becomes even more complicated as the focus of marine planning and management strategies changes from ‘single species’ to ‘habitats’ and ‘ecosystems’ that may enable a diversity of permitted uses consistent with a variety of overall objectives. Over the last 30 years, the Great Barrier Reef Marine Park (GBRMP) has successfully established a multiple-use spatial management approach that allows both high levels of environmental protection and a wide range of human activities. Drawing on this unique long-term experience in the GBRMP, this article discusses key aspects of effective monitoring and evaluation, and summarises lessons learned from over two decades of adaptive management.     

Responses and adaptation strategies of commercial and charter fishers to zoning changes in the Great Barrier Reef Marine Park

Fishers' responses to changes in resource access through the imposition of marine protected areas can be a critical factor influencing the likelihood of achieving management objectives.Face-to-face interviews with 114 commercial and charter fishers were conducted to investigate their responses and adaptation strategies to the increase in the size and number of no-take zones imposed by the 2004 Great Barrier Reef Marine Park zoning plan. Despite holding positive attitudes towards marine biodiversity protection, fishers were generally unsupportive of the new zoning plan 5 years after its implementation. Fishers' lack of support was related to the perception that they had not been adequately engaged in the rezoning process and the perception of significant impacts of the zoning plan on fishing businesses. Fishers generally believed that the new zoning plan had a negative impact on their access to productive fishing areas, the numbers of fish they catch, the profitability of their fishing business, and their personal income. In response to the new no-take zones, fishers tended to redistribute their fishing activity to locations closer to their home port, and to locations already known to them through their previous fishing, resulting in an increase in high density fishing locations within the park. Despite the impacts that fishers experienced, most reported that they have adapted their fishing activity and fishing business at least moderately well to the new zoning plan, suggesting that many of the impacts experienced by fishers might be short-term and may decline over time as fishers learn to adapt to the new zoning system. The information provided should prove valuable as a baseline for continued monitoring of the costs and benefits of the Great Barrier Reef Marine Park rezoning into the future.     

Aliphatic hydrocarbons in Great Barrier Reef organisms and environment

This investigation was undertaken to assess the chemical nature, occurrence, and possible origin of petroleum hydrocarbons in the Great Barrier Reef ecosystem. Aliphatic hydrocarbons in surface sediments, water, and a suite of seven species from widely separated coral reefs in the Great Barrier Reef area were analysed by gas chromatography, and by gas chromatography coupled with mass spectrometry. The hydrocarbons found were substantially of biogenic origin. The major components were n-pentadecane, n-heptadecane, pristane and mono-alkenes based on heptadecane, and were believed to originate from benthic algae and phytoplankton. There was no evidence to suggest that lipid content had any influence on hydrocarbon content. Hydrocarbons from the organisms and sediments have characteristic composition patterns which would be altered by the presence of petroleum hydrocarbons. An unresolved complex mixture, usually considered indicative of petroleum contamination, was found in greater than trace amounts only in Holothuria (sea cucumber) and Acropora (coral) from the Capricorn Group, and in some sediment samples from the Capricorn Group and Lizard Island area.     

Enhancing fish stocks with wave-powered artificial upwelling

Ocean fisheries are declining worldwide due to overexploitation. Productivity could be enhanced and the problem alleviated by pumping nutrient-rich deep ocean water (DOW) to the surface to feed phytoplankton, the bottom end of a marine food chain, mimicking natural upwelling which sustains the most productive ocean fishing grounds in the world. Various pump types and power sources have been proposed for this purpose. The present article proposes a simple wave-powered pump to demonstrate the concept cost-effectively at prototype scale. Possible solutions to the problems of dilution and plunging of dense, nutrient-rich DOW are discussed. Two further possible benefits of this proposal are discussed: by extracting wave energy, relatively calm fishing grounds may be created close to markets, and by pumping up very large quantities of cold DOW, the surface temperature could be lowered enough to reduce coral bleaching on parts of the Great Barrier Reef.     

New evidence for drowned shelf edge reefs in the Great Barrier Reef,Australia

We present four new high-resolution multibeam bathymetry datasets from the shelf edge of the northern Great Barrier Reef (GBR). Analysis of these data, combined with Chirp sub-bottom profiles and existing submersible observation data provides a fresh insight into the detailed morphology and spatial distribution of submerged reefs and terraces at the shelf edge. An extensive and persistent line of drowned shelf edge reefs exist on the GBR margin in about 40 to 70 m. They appear as barrier reefs up to 200 m wide and comprising twin parallel ridges of rounded pinnacles. Subtle yet consistent terrace and step features lie between 78 and 114 m seaward of the shelf edge reefs in the southern study area. Submersible observations confirm that the drowned reefs now provide a favorable hard substrate for live soft corals and algae. They form a consistent and extensive seabed habitat that extends for possibly 900 km along the GBR shelf edge. The submerged reef and terraces features may reflect a complex history of growth and erosion during lower sea-levels, and are now capped by last deglaciation reef material.     

Effective governance of a large and complex cross-jurisdictional marine protected area: Australia's Great Barrier Reef

Australia's Great Barrier Reef is the largest coral reef ecosystem on earth. The governance of such a large and iconic area is complex due to the overlapping federal and state (Queensland) jurisdictions. Since 1975 this globally significant area has been protected by pioneering federal legislation which enabled the ‘reasonable use’ of natural resources to co-exist with conservation, thus introducing the concept of a multiple-use marine park. In 1981 the Great Barrier Reef was listed as a UNESCO World Heritage Area. Today a federal multiple-use Marine Park covers 99% of the Great Barrier Reef Region and World Heritage Area, with the remaining areas under state jurisdiction. A close working partnership between the federal and state governments has evolved over 37 years and includes complementary legislation, joint field management and joint permits. In the face of increasing pressures, management of the Great Barrier Reef continues to be effective for a range of reasons, including a sound governance/legislative framework together with complementary federal/state legislation; integrated management with relevant federal and state agencies; and the application of ecosystem-based management principles both inside and outside the area of the marine park's jurisdiction. This integrated and comprehensive management model is widely regarded as effective by marine and coastal managers around the world.     

Algivory in hawksbill turtles: Eretmochelys imbricata food selection within a foraging area on the Northern Great Barrier Reef

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.     

Artificial marine habitats in the Arabian Gulf: Review of current use, benefits and management implications

The use of artificial reefs in the Arabian Gulf have a history extending back over a century, when date palm trunks, stones, pottery and other materials were sunk in coastal areas to enhance fish catch. Historically, such artificial reefs formed an important component of the socio-economic development of coastal fisheries. In comparison, modern artificial reefs have taken on a variety of forms. The most widely recognized are purpose-build modular artificial reefs designed for the enhancement of fisheries yield, diving, and various other benefits. However, far more common within the Gulf are the large-scale unplanned artificial reefs that have been formed as a result of human activities in the marine system, such as large-scale coastal breakwaters, seawalls, jetties, pipelines, and oil and gas infrastructure. Although there is limited information on the role of these constructions in structuring Gulf marine communities, increasing evidence suggests that abundant and diverse communities of reef fish, coral and other benthos can develop on these structures, with important ecological implications in urbanized coastal areas in the Gulf. However, due to a variety of unintended consequences of artificial reef development such structures may also pose challenges to coastal marine management. We review the current published literature on artificial reefs in the Gulf in order to improve our understanding of the role that these structures play in Gulf coastal ecosystems, and to further develop regional management of artificial reefs. We explore the various types of artificial reef that exist in the Gulf and examine the benefits and challenges that these structures represent for coastal ecology and economics. Such information is essential for our improved understanding and management of these increasingly important ecosystems in the Gulf.     

Photochemical activity in waters of the Great Barrier Reef

Photochemical activity in waters of the Great Barrier Reef was investigated through studies on the vertical, horizontal and temporal distribution of hydrogen peroxide and factors influencing its generation and decay processes. Surface hydrogen peroxide concentrations varied from 15 to 110 nM and generally decreased with depth, though a number of anomalies were detected. Photochemical activity decreased with increasing distance from the coast reflecting the positive influence of terrestrial inputs to the hydrogen peroxide generation and decay processes. Increases in photochemical activity were observed in the proximity of coral reefs. Hydrogen peroxide concentrations in the region were influenced by wind-induced mixing processes, atmospheric inputs, anthropogenic activity and seasonal light regimes.     

Benefits and opportunity costs of Australia's Coral Sea marine protected area: A precautionary tale

The paper analyses the benefits and costs of the Coral Sea Marine Reserve which, together with the contiguous Great Barrier Reef World Heritage Area, creates the largest marine protected area in the world. The benefits are found to be minimal, in both anthropocentric and ecocentric terms. Nevertheless establishment and management costs could be in the order of $A20 million and $A13 million, respectively. Meanwhile, serious depletion of the vital fish stocks of the largest tuna fishery in the world in the Western and Central Pacific Ocean—in which Australia is a management partner—continues, as does the rapid erosion of the unique and outstanding values of the Great Barrier Reef. It is concluded that current investment in the creation and management of the Coral Sea Reserve—in the face of the demonstrably urgent needs for investment in the management of marine resources in the near region and in Australia – is problematic.     

Spatial substitution strategies of recreational fishers in response to zoning changes in the Great Barrier Reef Marine Park

Understanding fishers’ responses to marine spatial closures is important for both resource users and managers. Fishing is a major recreational activity in Australia, and recreational fishers are key local resource users within the Great Barrier Reef Marine Park. In 2004, implementation of a new zoning plan in the park resulted in a reduction in the amount of area available to recreational fishing. A combination of phone, mail, and face-to-face surveys was used to investigate recreational fishers’ choices and spatial redistribution strategies in response to the reduction in fishing area. Approximately 56% of fishers reported losing at least one of their regular fishing locations under the new zoning plan. Fishers generally compensated by shifting their fishing effort to other areas they knew to be good fishing locations, and by finding new areas that they had not exploited previously. Potential implications of these spatial changes in recreational fishing effort for both the marine park and recreational fishers include changes in fishing frequency and satisfaction, reduced fishing quality, restricted access to areas considered to be of high quality for recreational fishing, increased crowding in areas that remain open to fishing, and increased likelihood of localized depletions in popular recreational fishing locations. Identification of the drivers of the spatial distribution of fishing effort, factors affecting fishers’ choices of locations, and adaptation strategies adopted by fishers provide a valuable tool to help understand the impact of spatial fishing closures on fishers and resources.     

Grazing on coral reefs facilitates growth of the excavating sponge Cliona orientalis (Clionaidae,Hadromerida)

Although bioerosion is among the most destructive forces on coral reefs, indirect effects influencing the bioerosion dynamics are understudied. Here, I assess the hypothesis that coral reef grazers indirectly facilitate proliferation of bioeroding sponges by removing epibiotic fleshy seaweeds from the Great Barrier Reef. This study quantifies the degree of spatial correlation between the distribution of bioeroding sponges and the distribution of grazing pressure, as evidenced by the abundance of seaweed and parrotfish bite marks. While the sponge tissue area was negatively correlated with seaweed coverage, the number of parrotfish bite marks was associated with less algae and more sponge tissue. Several factors derived from grazing on seaweeds may facilitate sponge growth: increases in the availability of light may favor primary production by symbiotic zooxanthellae and thereby increase growth of bioeroding sponges; on the other hand, sponge settlement may be facilitated on grazed substrates. All these factors are likely related, and contribute to an increasing erosion of coral reefs. Similar processes have recently been described in Mediterranean ecosystems, suggesting that the interactions I document here, could be widespread.