A robust operational model for predicting where tropical cyclone waves damage coral reefs

International audienceTropical cyclone (TC) waves can severely damage coral reefs. Models that predict where to find such damage (the 'damage zone') enable reef managers to: 1) target management responses after major TCs in near-real time to promote recovery at severely damaged sites; and 2) identify spatial patterns in historic TC exposure to explain habitat condition trajectories. For damage models to meet these needs, they must be valid for TCs of varying intensity, circulation size and duration. Here, we map damage zones for 46 TCs that crossed Australia's Great Barrier Reef from 1985–2015 using three models – including one we develop which extends the capability of the others. We ground truth model performance with field data of wave damage from seven TCs of varying characteristics. The model we develop (4MW) out-performed the other models at capturing all incidences of known damage. The next best performing model (AHF) both under-predicted and over-predicted damage for TCs of various types. 4MW and AHF produce strikingly different spatial and temporal patterns of damage potential when used to reconstruct past TCs from 1985–2015. The 4MW model greatly enhances both of the main capabilities TC damage models provide to managers, and is useful wherever TCs and coral reefs co-occur

Coral restoration effectiveness: multiregional snapshots of the long-term responses of coral assemblages to restoration

Coral restoration is rapidly becoming a mainstream strategic reef management response to address dramatic declines in coral cover worldwide. Restoration success can be defined as enhanced reef functions leading to improved ecosystem services, with multiple benefits at socio-ecological scales. However, there is often a mismatch between the objectives of coral restoration programs and the metrics used to assess their effectiveness. In particular, the scales of ecological benefits currently assessed are typically limited in both time and space, often being limited to short-term monitoring of the growth and survival of transplanted corals. In this paper, we explore reef-scale responses of coral assemblages to restoration practices applied in four well-established coral restoration programs. We found that hard coral cover and structural complexity were consistently greater at restored compared to unrestored (degraded) sites. However, patterns in coral diversity, coral recruitment, and coral health among restored, unrestored, and reference sites varied across locations, highlighting differences in methodologies among restoration programs. Altogether, differences in program objectives, methodologies, and the state of nearby coral communities were key drivers of variability in the responses of coral assemblages to restoration. The framework presented here provides guidance to improve qualitative and quantitative assessments of coral restoration efforts and can be applied to further understanding of the role of restoration within resilience-based reef management

Priority species to support the functional integrity of coral reefs

Ecosystem-based management on coral reefs has historically focussed on biodiversity conservation through the establishment of marine reserves, but it is increasingly recognised that a subset of species can be key to the maintenance of ecosystem processes and functioning. Specific provisions for these key taxa are essential to biodiversity conservation and resilience-based adaptive management. While a wealth of literature addresses ecosystem functioning on coral reefs, available information covers only a subset of specific taxa, ecological processes and environmental stressors. What is lacking is a comparative assessment across the diverse range of coral reef species to synthesise available knowledge to inform science and management. Here we employed expert elicitation coupled with a literature review to generate the first comprehensive assessment of 70 taxonomically diverse and functionally distinct coral reef species from microbes to top predators to summarise reef functioning. Although our synthesis is largely through the lens of the Great Barrier Reef, Australia, a particularly data-rich system, it is relevant to coral reefs in general. We use this assessment to evaluate which taxa drive processes that maintain a healthy reef and whether management of these taxa is considered a priority (i.e. are they vulnerable?) or is feasible (i.e. can they be managed?). Scientific certainty was scored to weight our recommendations, particularly when certainty was low. We use five case studies to highlight critical gaps in knowledge that limit our understanding of ecosystem functioning. To inform the development of novel management strategies and research objectives, we identify taxa that support positive interactions and enhance ecosystem performance, including those where these roles are currently underappreciated. We conclude that current initiatives effectively capture many priority taxa but that there is significant room to increase opportunities for underappreciated taxa in both science and management to maximally safeguard coral reef functioning

Chapter 5 Priority Species to Support the Functional Integrity of Coral Reefs

Ecosystem-based management on coral reefs has historically focused on biodiversity conservation through the establishment of marine reserves, but it is increasingly recognised that a subset of species can be key to the maintenance of ecosystem processes and functioning. Specific provisions for these key taxa are essential to biodiversity conservation and resilience-based adaptive management. While a wealth of literature addresses ecosystem functioning on coral reefs, available information covers only a subset of specific taxa, ecological processes and environmental stressors. What is lacking is a comparative assessment across the diverse range of coral reef species to synthesise available knowledge to inform science and management. Here we employed expert elicitation coupled with a literature review to generate the first comprehensive assessment of 70 taxonomically diverse and functionally distinct coral reef species from microbes to top predators to summarise reef functioning. Although our synthesis is largely through the lens of the Great Barrier Reef, Australia, a particularly data-rich system, it is relevant to coral reefs in general. We use this assessment to evaluate which taxa drive processes that maintain a healthy reef, and whether or not management of these taxa is considered a priority (i.e. are they vulnerable?) or is feasible (i.e. can they be managed?). Scientific certainty was scored to weight our recommendations, particularly when certainty was low. We use five case studies to highlight critical gaps in knowledge that limit our understanding of ecosystem functioning. To inform the development of novel management strategies and research objectives, we identify taxa that support positive interactions and enhance ecosystem performance, including those where these roles are currently underappreciated. We conclude that current initiatives effectively capture many priority taxa, but that there is significant room to increase opportunities for underappreciated taxa in both science and management to maximally safeguard coral reef functioning

A dynamic understanding of coral reef health informs resilience-based management of the Great Barrier Reef

Coral reefs are among the most sensitive ecosystems to climate change. Managing coral reefs at a time when changing sea temperatures, levels and chemistry are already negatively affecting the capacity of hard corals to settle, grow, calcify and persist, presents a unique set of challenges. In many reef areas, increasingly frequent environmental disturbances combined with anthropogenic stressors are challenging the natural resilience of reef systems. Adaptively managing coral reefs to support their resilience requires a dynamic understanding of their health and condition. The journey towards the goal of ensuring managers of the Great Barrier Reef (GBR) have a dynamic understanding of reef health and condition forms the focus of this thesis.\ud \ud Dynamic information on reef health will only become available to managers at the scale of the GBR by building capacity among regular reef visitors to assess and monitor reef condition and impacts. A key issue is that many impacts on coral reef health are cryptic, ephemeral and readily confused with other impacts. Chapter 2 describes the development and production of a field guide that enables observers to recognise characteristic signs of compromised coral health on Indo-Pacific Reefs. The guide's structure is based on a colour-coded decision tree that serves as a visual index to help users navigate the content. The decision tree aids the differential diagnosis of diseases and other reef health impacts using characteristic macroscopic signs. The layout of the content was developed in consultation with coral health experts, managers, rangers and tourism operators. The final guide, published in 2008, takes the form of a spiral bound book of underwater cards made to fit the pockets found in dive equipment.\ud \ud In the year following publication of the guide, it was used to enable managers, rangers and tourism staff working within the GBR Marine Park (GBRMP) to distinguish among coral diseases and other reef health impacts. Since 2009, this enhanced capacity among non-specialist observers has provided an early warning system for disease outbreaks. The value of this early warning system is described in the strategic framework for responding to disease presented in Chapter 3. The strategic framework enables managers to use remote sensing and field observations to produce a near real-time estimate of outbreak likelihood and impact severity. Automated coral disease outbreak alerts are now created at the Great Barrier Reef Marine Park Authority (GBRMPA) based upon outbreak thresholds developed while writing the response framework.\ud \ud The development and implementation of the framework helped to focus the views of my GBRMPA colleagues on the increasing need for holistic evaluation of coral reef health. Until 2009, GBRMP managers had limited access to detailed information on reef condition and impacts, primarily from only 48 sites surveyed once every two years by the AIMS Long Term Monitoring Program. In Chapter 4, I describe how from 2009-2014, I led the process of developing the revised 'Eye on the Reef' program, which integrates previous participatory monitoring programs and includes: a Reef Health and Impact Survey (RHIS) method tailored to the time constraints of rangers and tourism operators, an online and field-based training system, a web-enabled database and data entry interface, and automated reporting through Google Earth™. The integrated Eye on the Reef program has now become the primary mechanism by which the GBRMPA gathers up-to-date information on coral reef health and impacts in the Marine Park. Previously, the GBRMPA had access to less than 10% of the information on reef condition and impacts that is available now. Importantly, the scene is now set to use the information extensively to inform adaptive resilience-based management. \ud A severe tropical cyclone in 2011 provided an opportunity to test the RHIS protocol and evaluate the effectiveness of a management action. TC Yasi was a category 5 cyclone when it crossed the Park and was unique among the storms that have crossed the Park since 1985, in that it was both severe and had a large circulation size. In the weeks that followed TC Yasi crossing the Reef, dozens of managers, rangers and research scientists conducted 882 RHIS at 76 reef locations. In Chapter 5, I present the results of this study, which revealed cross-shelf variation in the severity of mechanical damage caused by the storm, as well as patterns in impact severity with respect to direction (north and south) and distance from the cyclone eye. A key conclusion from this work is that more coral was lost in the 24-hour period in which TC Yasi crossed the Park than in any other 24-hour period in at least the last 30 years.\ud Understanding spatial patterns in the severity of impacts following TC Yasi helped the GBRMPA to communicate key information about the event and to target local-scale actions to support recovery. After such actions are implemented, the integrated Eye on the Reef network can help managers evaluate the effectiveness of the actions. Chapter 6 reviews a recent example of such an evaluation from the southern Great Barrier Reef, where the RHIS protocol was used to assess the effectiveness of no-anchoring areas (NAAs) established in 2008. I led teams of managers from GBRMPA and rangers from Queensland Parks and Wildlife that completed RHIS protocols within the NAAs and at control sites from 2008-2012. Declines in anchor damage were immediately apparent in 2010 and virtually no anchor damage was seen within the NAAs by 2012. The Keppel Bay case study is an example of how the effectiveness of a management action can be evaluated by having non-specialist observers undertake RHIS. A significant outcome of the Keppel Bay study is a precedent for using the observer network and survey protocol to assess management effectiveness and that can guide the use of the network/protocol in this way in future years.\ud \ud The ability to target local-scale, short-term actions to support recovery of the GBR has been greatly enhanced as a result of the work presented in this thesis. The Keppel Bay study within Chapter 6 highlights that there are multiple benefits for managers (and management of the Reef) as a result of involving community members in monitoring coral reef condition and impacts. The Keppel Bay study encapsulates the primary message of my thesis and the story of how adaptive management is meant to work. Actions to support reef resilience and recovery (Chapter 6), can now be targeted, evaluated and refined as a consequence of building capacity among non-specialists to monitor reef condition and impacts (Chapters 2-5). The network of observers participating in Eye on the Reef monitoring is now providing information on reef condition and impacts from hundreds of reefs every year. The consequence is that we are starting to dynamically understand reef health, condition and environmental exposure. Importantly, this enables the GBR to be managed adaptively by responding to impacts and by increasingly targeting and trialling actions to support reef resilience

Data from: Impacts and recovery from Severe Tropical Cyclone Yasi on the Great Barrier Reef

Full recovery of coral reefs from tropical cyclone (TC) damage can take decades, making cyclones a major driver of habitat condition where they occur regularly. Since 1985, 44 TCs generated gale force winds (≥17 metres/second) within the Great Barrier Reef Marine Park (GBRMP). Of the hurricane strength TCs (≥H1—Saffir Simpson scale; ≥ category 3 Australian scale), TC Yasi (February, 2011) was the largest. In the weeks after TC Yasi crossed the GBRMP, participating researchers, managers and rangers assessed the extent and severity of reef damage via 841 Reef Health and Impact Surveys at 70 reefs. Records were scaled into five damage levels representing increasingly widespread colony-level damage (1, 2, 3) and reef structural damage (4, 5). Average damage severity was significantly affected by direction (north vs south of the cyclone track), reef shelf position (mid-shelf vs outer-shelf) and habitat type. More outer-shelf reefs suffered structural damage than mid-shelf reefs within 150 km of the track. Structural damage spanned a greater latitudinal range for mid-shelf reefs than outer-shelf reefs (400 vs 300 km). Structural damage was patchily distributed at all distances, but more so as distance from the track increased. Damage extended much further from the track than during other recent intense cyclones that had smaller circulation sizes. Just over 15% (3,834 km2) of the total reef area of the GBRMP is estimated to have sustained some level of coral damage, with ~4% (949 km2) sustaining a degree of structural damage. TC Yasi likely caused the greatest loss of coral cover on the GBR in a 24-hour period since 1985. Severely impacted reefs have started to recover; coral cover increased an average of 4% between 2011 and 2013 at re-surveyed reefs. The in situ assessment of impacts described here is the largest in scale ever conducted on the Great Barrier Reef following a reef health disturbance

The role of Great Barrier Reef tourism operators in addressing climate change through strategic communication and direct action

© 2017 Informa UK Limited, trading as Taylor & Francis Group. The projected decline in reef health worldwide will have huge repercussions on millions of stakeholders depending upon coral reefs. Urgent action is needed to sustain coral reefs into the future. Tourism operators are recognised as stewards of Australia's Great Barrier Reef (GBR), a World Heritage Site, and are taking action on climate change, through their business practices and by engaging guests with interpretation and targeted messages. Yet little is known about how tourism operators along the GBR perceive climate change, or what actions they believe are most effective to address climate change impacts on the GBR. We describe a set of semi-structured interviews with 19 tourism operators in the Whitsundays and Cairns, the most popular tourism destinations along the GBR. Using a thematic analysis to code and report patterns within the data, we show tourism operators recognise the threat of climate change and strongly support increased action to address it. Most respondents are hesitant to engage their guests about climate change despite acknowledging an interest, expertise, and responsibility to do so. Understanding the barriers preventing tourism operators from addressing climate change is an important step towards helping them, and the tourists visiting the region, take action to protect the GBR

A framework for responding to coral disease outbreaks that facilitates adaptive management

Predicted increases in coral disease outbreaks associated with climate change have implications for coral reef ecosystems and the people and industries that depend on them. It is critical that coral reef managers understand these implications and have the ability to assess and reduce risk, detect and contain outbreaks, and monitor and minimise impacts. Here, we present a coral disease response framework that has four core components: (1) an early warning system, (2) a tiered impact assessment program, (3) scaled management actions and (4) a communication plan. The early warning system combines predictive tools that monitor the risk of outbreaks of temperature-dependent coral diseases with in situ observations provided by a network of observers who regularly report on coral health and reef state. Verified reports of an increase in disease prevalence trigger a tiered response of more detailed impact assessment, targeted research and/or management actions. The response is scaled to the risk posed by the outbreak, which is a function of the severity and spatial extent of the impacts. We review potential management actions to mitigate coral disease impacts and facilitate recovery, considering emerging strategies unique to coral disease and more established strategies to support reef resilience. We also describe approaches to communicating about coral disease outbreaks that will address common misperceptions and raise awareness of the coral disease threat. By adopting this framework, managers and researchers can establish a community of practice and can develop response plans for the management of coral disease outbreaks based on local needs. The collaborations between managers and researchers we suggest will enable adaptive management of disease impacts following evaluating the cost-effectiveness of emerging response actions and incrementally improving our understanding of outbreak causation

Coral restoration: socio-ecological perspectives of benefits and limitations

Coral restoration is increasingly used globally as a management tool to minimize accelerating coral reef degradation resulting from climate change. Yet, the science of coral restoration is still very focused on ecological and technical considerations, impeding the understanding of how coral restoration can be used to improve reef resilience in the context of socio-ecological systems. Here, we visited four well-established coral restoration projects in different regions of the world (Thailand, Maldives, Florida Keys, and US Virgin Islands), and conducted key-informant interviews to characterize local stakeholder's perceptions of the key benefits and limitations associated with restoration efforts. Our results reveal that perceptions around coral reef restoration encompass far more than ecological considerations, and include all four dimensions of sustainability: ecological, social, economic, and governance, suggesting that effective coral restoration should be guided by the principles of sustainability science. Socio-cultural benefits were the most frequently mentioned (72.4% of all respondents), while technical problems were the most common theme for limitations of coral restoration efforts (58.3% of the respondents). Participants also revealed some key points likely to improve the outcomes of coral restoration efforts such as the need to better embrace socio-cultural dimensions in goal setting, evaluate ecological outcomes more broadly, secure long-term funding and improve management and logistics of day to day practices. While we identify several important limitations of coral reef restoration, particularly around amateur workforces and limited involvement of local communities, our results suggest that coral restoration can be used as a powerful conservation education tool to provide hope, enhance agency, promote stewardship and strengthen coral reef conservation strategies

Journal of biomaterials and tissue engineering : jbt

Full recovery of coral reefs from tropical cyclone (TC) damage can take decades, making cyclones a major driver of habitat condition where they occur regularly. Since 1985, 44 TCs generated gale force winds (≥17 metres/second) within the Great Barrier Reef Marine Park (GBRMP). Of the hurricane strength TCs (≥H1—Saffir Simpson scale; ≥ category 3 Australian scale), TC Yasi (February, 2011) was the largest. In the weeks after TC Yasi crossed the GBRMP, participating researchers, managers and rangers assessed the extent and severity of reef damage via 841 Reef Health and Impact Surveys at 70 reefs. Records were scaled into five damage levels representing increasingly widespread colony-level damage (1, 2, 3) and reef structural damage (4, 5). Average damage severity was significantly affected by direction (north vs south of the cyclone track), reef shelf position (mid-shelf vs outer-shelf) and habitat type. More outer-shelf reefs suffered structural damage than mid-shelf reefs within 150 km of the track. Structural damage spanned a greater latitudinal range for mid-shelf reefs than outer-shelf reefs (400 vs 300 km). Structural damage was patchily distributed at all distances, but more so as distance from the track increased. Damage extended much further from the track than during other recent intense cyclones that had smaller circulation sizes. Just over 15% (3,834 km2) of the total reef area of the GBRMP is estimated to have sustained some level of coral damage, with ~4% (949 km2) sustaining a degree of structural damage. TC Yasi likely caused the greatest loss of coral cover on the GBR in a 24-hour period since 1985. Severely impacted reefs have started to recover; coral cover increased an average of 4% between 2011 and 2013 at re-surveyed reefs. The in situ assessment of impacts described here is the largest in scale ever conducted on the Great Barrier Reef following a reef health disturbance