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Tropical cyclones can dramatically reduce coral cover, coral diversity and structural complexity, which can all cause flow-on effects to fish communities. In 2016, Fiji sustained extensive damage from one of the most severe cyclones recorded in the southern hemisphere (Category 5 cyclone Winston). We assessed the impacts of cyclone Winston on the coral reef habitat and fish assemblages in Kubulau and Levuka districts in Fiji. Wave modelling showed that cyclone-generated waves were substantially larger and persisted longer in Levuka than Kubulau. Damage to live corals was spatially variable and highest in Levuka, with the extent of damage highly correlated to the exposure, height and duration of waves at each site. We recorded increases in macroalgae directly after the cyclone and increases in encrusting coralline algae two years after the cyclone. We did not detect many changes in the fish assemblage caused by cyclone Winston. Obligate corallivores, and species within this group, Chaetodon baronessa and Labrichthys unilineatus, were the only fish to show a decline post-cyclone, most likely caused by declines in coral cover. We found that the modelling of cyclone wave dynamics (wave height, duration and exposure) explained the variation and damage to live corals better than proximity to the cyclone path, providing a useful tool to predict cyclone damage. Future climate models predict that more cyclones will reach the highest intensities. Understanding the impact this will have on vulnerable coastal communities that are dependent on marine resources and are protected from wave energy by reefs is essential for effective mitigation and adaptive management plans.

Despite increasing recognition of the need for more diverse and equitable representation in the sciences, it is unclear whether measurable progress has been made. Here, we examine trends in authorship in coral reef science from 1,677 articles published over the past 16 years (2003-2018) and find that while representation of authors that are women (from 18% to 33%) and from non-OECD nations (from 4% to 13%) have increased over time, progress is slow in achieving more equitable representation. For example, it would take over two decades at the current rate, for female representation to reach 50%, and even slower for non-OECD countries considering change is happening at a slower pace, and equitable representation would likely be higher given there are more coral reef non-OECD countries. . OECD nations also continue to dominate authorship contributions in coral reef science (89%), in research conducted in both OECD (63%) and non-OECD nations (68%). We identify systemic issues that remain prevalent in coral reef science (i.e. parachute science, gender bias) that likely contribute to observed trends. We provide recommendations to address systemic biases in research to foster a more inclusive global science community. Adoption of these recommendations will lead to more creative, innovative, and impactful scientific approaches urgently needed for coral reefs and contribute to environmental justice efforts.

Ocean warming is negatively impacting coral reef ecosystems and considerable effort is currently invested in projecting coral reef futures under 21st century climate change. A limiting factor in these projections is lack of quantitative data on the thermal thresholds of different reef communities, due in large part to spatial and temporal gaps in bleaching observations. Here we apply a coral bleaching proxy, skeletal stress bands, to reconstruct the history of bleaching on eight coral reefs in the central equatorial Pacific (CEP) and use this information to constrain the thermal thresholds of their coral communities. First, three genera of massive corals collected on both Pacific and Caribbean reefs are used to derive a calibration between the proportion of corals that form stress bands during a bleaching event, and the total observed bleaching incidence in the community of mixed coral taxa. The correlation is highly significant, indicating that stress bands in massive corals reflect community-level bleaching severity (R2 = 0.945, p

The Bird's Head Seascape (BHS), Papua, Indonesia is located within the epicenter of global marine biodiversity and has been the focus of recent conservation efforts to protect marine resources. Here, we provide an overview of Marine Protected Areas (MPAs) progress in the BHS over the past decade, including establishment history, changes in management effectiveness and ecosystem health, as well as examining trends in tourism growth. While generally viewed as a conservation success story, we reflect on both successes and challenges in the BHS, identifying where we need to continue to improve and adapt in response to rapid economic and environmental change. As of 2020, BHS MPAs cover 5.1 million ha across 23 MPAs. As expected, management effectiveness is steadily increasing in BHS MPAs—although newer MPAs face substantial capacity gaps. Tourism is rapidly growing—with an almost 3,000% increase in tourist visits between 2007 and 2018. Overall, hard coral cover in monitored BHS MPAs remained stable at 33% from 2010 to 2019, although trends in reef fish biomass were more variable. Given continued conservation challenges in the region, BHS MPAs are successfully preventing biodiversity loss while providing ecosystem services for local communities.

International audience; Coral reef fisheries depend on reef fish biomass to support ecosystem functioning and sustainable fisheries. Here, we evaluated coral reefs across 4,000 km of the Indonesian archipelago to reveal a large gradient of biomass, from 17,000 kg/ha.Trophic pyramids characterized by planktivore dominance emerged at high biomass, suggesting the importance of pelagic pathways for reef productivity. Total biomass and the biomass of most trophic groups were higher within gear restricted and no-take management, but the greatest biomass was found on unmanaged remote reefs. Within marine protected areas (MPAs), 41.6% and 43.6% of gear restricted and no-take zones,respectively, met a global biomass target of 500 kg/ha, compared with 71.8% of remote sites. To improve conservation outcomes for Indonesia’s biodiverse and economically important coral reef fisheries, our results suggest to: (1) strengthen management within Indonesia’s existing MPAs and (2) precautionarily manage remote reefs with high biomass.

Wailagilala is one of two ‘true’ atolls in Fiji. Our findings confirm the presence of nesting green turtle (Chelonia mydas); continued occurrence of breeding seabird populations, including documenting the fifth site in Fiji of nesting white tern (Gygis alba); and provides data on coral genera and benthic cover.

In the face of climate change, warming oceans, and repeated mass coral bleaching, coral reef conservation is at a timely crossroads. There is a new urgency to support and strengthen a rich history of conservation partnerships and actions, while also building toward new actions to meet unparalleled global threats. The goal of this white paper is to synthesize and summarize the diversity of tools, approaches and solutions for coral reef conservation implemented to date and to understand the enabling conditions that lead to successful coral reef conservation. Framed as a “solution-scape,” this white paper seeks to support ongoing decisions to strengthen existing assets and build new investments into portfolios of global coral reef conservation that are equitable and aligned with diverse cultures and worldviews. We conclude with 10 recommendations that focus on equitable conservation practices that will align successful interventions with diverse cultures and worldviews, help ensure that the right decisions are made, and strengthen investments into conservation portfolios that will lead to successful coral reef conservation.

The Republic of Kiribati is largely composed of infertile, low-lying atolls, and coral islands in the central Pacific. Kiribati’s geographical isolation and remoteness makes it difficult to access regional and global economic markets, and it is considered as one of the least developed countries in the Pacific. However, Kiribati has one of the largest exclusive economic zones with globally important tuna stocks. Many of the uninhabited atolls in the Line and Phoenix Island group boast excellent examples of healthy coral reefs without anthropogenic stresses, and are home to globally significant populations of seabirds. Recent deep-sea research suggests high biodiversity in benthic habitats below 200 ft., with many species new to science. The limited flora of Kiribati is ecologically critical to wildlife on the atolls, as well as for the culture and survival of the i-Kiribati people. Although there are few published scientific studies, a review of technical reports suggests localized pollution, destructive fishing practices, overfishing, and poorly planned coastal infrastructure have all contributed to the decline of coastal resources. Regionally, Kiribati has made significant commitments toward the protection of marine resources in the Pacific Ocean, the largest of which is the declaration of the 405,755 km2 Phoenix Islands Protected Area and World Heritage Area. There is growing interest to expanding their terrestrial protected areas to include complementary marine protected areas in the Line Islands.

Fiji is one of the most developed of the Pacific Island economies and its people are highly dependent on the country’s rich biodiversity and natural resources for food, agriculture, tourism, culture, coastal protection, shelter, recreational sports, and other vital human needs. The country has undergone rapid changes in growth and development and the coastal ecosystems are increasingly threatened by a number of anthropogenic activities (e.g., overharvesting and overexploitation of land and sea resources, mining, coastal development) and their associated impacts (e.g., sedimentation, eutrophication, and pollution). At the same time, Fiji is vulnerable to natural disasters such as tropical cyclones and the impacts of climate change. These threats are resulting in losses in coastal habitats with a loss of 5% of mangroves from 1991 to 2007, particularly around urban areas. Fiji’s coral reefs, which have demonstrated considerable resilience to coral bleaching, are vulnerable to crown-of-thorns starfish outbreaks, damage from cyclones, and coastal development. Seagrass habitats are critical nursery areas for fish and feeding areas for migratory turtles, but are poorly documented and threatened by coastal development. A Category 5 cyclone in 2016 caused loss and damage across all sectors including infrastructure, agricultural systems, and coastal ecosystems in the order of US$945 million. However, there are significant efforts to protect and restore habitats and fisheries through inshore locally managed marine areas connected to larger, deeper water marine managed areas, as well as an expansion in integrated coastal management efforts. Sustainable use and practical management of coastal resources are urged while there is still a chance of ecosystem repair and restoration.

Resilience underpins the sustainability of both ecological and social systems. Extensive loss of reef corals following recent mass bleaching events have challenged the notion that support of system resilience is a viable reef management strategy. While resilience-based management (RBM) cannot prevent the damaging effects of major disturbances, such as mass bleaching events, it can support natural processes that promote resistance and recovery. Here, we review the potential of RBM to help sustain coral reefs in the 21st century. We explore the scope for supporting resilience through existing management approaches and emerging technologies and discuss their opportunities and limitations in a changing climate. We argue that for RBM to be effective in a changing world, reef management strategies need to involve both existing and new interventions that together reduce stress, support the fitness of populations and species, and help people and economies to adapt to a highly altered ecosystem.

With increasing stressors to coral reefs, defining tools that evaluate their dynamics and resilience is important to interpret system trajectories and direct conservation efforts. In this context, surveys must go beyond conventional monitoring approaches that focus on abundance and biomass of key groups and quantify metrics that better assess ecological processes and ecosystem trajectories. By measuring a variety of conventional (e.g. proportional cover of broad benthic groups, biomass of herbivorous fish) and complementary resilience-based metrics (e.g. algal turf height, coral recruitment rates, juvenile coral densities, herbivorous fish grazing rates), this study evaluated the ecosystem responses to community-based management in Fiji. The study was conducted across three paired tabu areas (periodically closed to fishing) and adjacent fished sites. Conventional metrics reflected no management effect on benthic or herbivorous fish assemblages. In contrast, the complementary metrics generally indicated positive effects of management, particularly within the benthos. Significant differences were observed for turf height (33% lower), coral recruitment rate (159% higher) and juvenile coral density (42% higher) within areas closed to fishing compared to adjacent open reefs. In addition, turf height was inversely related to coral recruitment and juvenile coral density, and longer turfs (≥5 mm) were more competitive in interaction with corals. These results emphasise that conventional metrics may overlook benefits of local management to inshore reefs, and that incorporating complementary resilience-based metrics such as turf height into reef survey protocols will strengthen their capacity to predict the plausible future condition of reefs and their responses to disturbances., This work was supported by the (German) Federal Ministry of Education and Research (BMBF) through the ‘Nachwuchsgruppen Globaler Wandel 4 + 1’ (REPICORE, grant number 01LN1303A).

Figure 2 in the original article has been updated with this figure 2 due to discrepancies related to incorrect mapping with one of the islands.

Coastal ecosystems can be degraded by poor water quality. Tracing the causes of poor water quality back to land-use change is necessary to target catchment management for coastal zone management. However, existing models for tracing the sources of pollution require extensive data-sets which are not available for many of the world’s coral reef regions that may have severe water quality issues. Here we develop a hierarchical Bayesian model that uses freely available satellite data to infer the connection between land-uses in catchments and water clarity in coastal oceans. We apply the model to estimate the influence of land-use change on water clarity in Fiji. We tested the model’s predictions against underwater surveys, finding that predictions of poor water quality are consistent with observations of high siltation and low coverage of sediment-sensitive coral genera. The model thus provides a means to link land-use change to declines in coastal water quality.

Cumulative pressures from global climate and ocean change combined with multiple regional and local-scale stressors pose fundamental challenges to coral reef managers worldwide. Understanding how cumulative stressors affect coral reef vulnerability is critical for successful reef conservation now and in the future. In this review, we present the case that strategically managing for increased ecological resilience (capacity for stress resistance and recovery) can reduce coral reef vulnerability (risk of net decline) up to a point. Specifically, we propose an operational framework for identifying effective management levers to enhance resilience and support management decisions that reduce reef vulnerability. Building on a system understanding of biological and ecological processes that drive resilience of coral reefs in different environmental and socio-economic settings, we present an Adaptive Resilience-Based management (ARBM) framework and suggest a set of guidelines for how and where resilience can be enhanced via management interventions. We argue that press-type stressors (pollution, sedimentation, overfishing, ocean warming and acidification) are key threats to coral reef resilience by affecting processes underpinning resistance and recovery, while pulse-type (acute) stressors (e.g. storms, bleaching events, crown-of-thorns starfish outbreaks) increase the demand for resilience. We apply the framework to a set of example problems for Caribbean and Indo-Pacific reefs. A combined strategy of active risk reduction and resilience support is needed, informed by key management objectives, knowledge of reef ecosystem processes and consideration of environmental and social drivers. As climate change and ocean acidification erode the resilience and increase the vulnerability of coral reefs globally, successful adaptive management of coral reefs will become increasingly difficult. Given limited resources, on-the-ground solutions are likely to focus increasingly on actions that support resilience at finer spatial scales, and that are tightly linked to ecosystem goods and services.

Climate change-related disturbances are increasingly recognized as critical threats to biodiversity and species abundance. On coral reefs, climate disturbances have known consequences for reef fishes, but it is often difficult to isolate the effect of coral bleaching from preceding or simultaneous disturbances such as fishing, pollution, and habitat loss. In this study, pre-bleaching surveys of fish family assemblages in the remote Phoenix Islands in 2002 are compared to post-bleaching in 2005, following severe thermal stress. Post-bleaching, total coral cover decreased substantially, as did the combined abundance of all fish families. Yet, changes in abundance for specific fish families were not uniform, and varied greatly from site to site. Of the 13 fish families examined, 3 exhibited significant changes in abundance from 2002 to 2005, regardless of site (Carangidae, Chaetodontidae, and serranid subfamily Epinephelinae). For these families, we explored whether changes in abundance were related to island type (island vs atoll) and/or declining coral cover (percent change). Carangidae on islands experienced larger changes in abundance than those on atolls, though declines in abundance over time were not associated with changes in live coral cover. In contrast, for Chaetodontidae, declines in abundance over time were most dramatic on atolls, and were also associated with changes in live coral cover. The remoteness of the Phoenix Islands excludes many typical local anthropogenic stressors as drivers of short-term changes; observed changes are instead more likely attributed to natural variation in fish populations, or associated with coral loss following the 2002–2003 major thermal stress event.

The Bird's Head Seascape located in eastern Indonesia is the global epicenter of tropical shallow water marine biodiversity with over 600 species of corals and 1,638 species of coral reef fishes. The Seascape also includes critical habitats for globally threatened marine species, including sea turtles and cetaceans. Since 2001, the region has undergone rapid development in fisheries, oil and gas extraction, mining and logging. The expansion of these sectors, combined with illegal activities and poorly planned coastal development, is accelerating deterioration of coastal and marine environments. At the same time, regency governments have expanded their marine protected area networks to cover 3,594,702 ha of islands and coastal waters. Low population numbers, relatively healthy natural resources and a strong tenure system in eastern Indonesia provide an opportunity for government and local communities to collaboratively manage their resources sustainably to ensure long-term food security, while meeting their development aspirations.

The Phoenix Islands (Republic of Kiribati, 172–170°W and 2.5–5°S) experience intra- and inter-annual sea surface temperature variability of ≈2°C and have few local anthropogenic impacts. From July 2002, a thermal stress event occurred, which peaked at 21 Degree Heating Weeks (DHW) in January 2003 and persisted for 4 years. Such thermal stress was greater than any thermal event reported in the coral reef literature. Reef surveys were conducted in July 2000, June 2002, and May 2005, for six of the eight islands. Sampling was stratified by exposure (windward, leeward, and lagoon) and depth (5, 10, 15, and 25 m). The thermal stress event caused mass coral mortality, and coral cover declined by approximately 60% between 2002 and 2005. However, mortality varied among sites (12–100%) and among islands (42–79%) and varied in accordance with the presence of a lagoon, island size, and windward vs. leeward exposure. Leeward reefs experienced the highest and most consistent decline in coral cover. Island size and the presence of a lagoon showed positive correlations with coral mortality, most likely because of the longer water residence time enhancing heating. Windward reefs showed cooler conditions than leeward reefs. Recently dead corals were observed at depths >35 m on windward and >45 m on leeward reefs. Between-island variation in temperature had no effect on between-island variation in coral mortality. Mortality levels reported here were comparable to those reported for the most extreme thermal stress events of 9–10 DHW in other regions. These results highlight the high degree of acclimation and/or adaptation of the corals in the Phoenix Islands to their local temperature regime, and their consequent vulnerability to anomalous events. Moreover, the results suggest the need to adjust thermal stress calculations to reflect local temperature variation.

Blast fishing has destroyed many coral reefs in Southeast Asia by creating large fields of dead coral rubble where new coral recruits settle but cannot survive and grow. Possible management responses include reef rehabilitation of damaged areas, and/or increased enforcement to protect still-living ones. Here we show that in Komodo National Park, Indonesia, rehabilitation by installing locally-quarried rocks on blasted rubble fields can be relatively low cost (∼US$4.80 per m 2 ) and simple, but it is not economically viable at large scales. Although rehabilitation without enforcement is unlikely to be effective, we compared rehabilitation data (costs and coral growth over 8 years) and enforcement costs to conduct two economic analyses: cost-per-area calculations and a cost-effectiveness model over 7 years, and found that rehabilitation costs ∼70 and ∼5-times more, respectively, than marine patrols to enforce blast fishing bans. Hence, we recommend that marine protected area managers prioritize investment in achieving compliance with regulations above investment in rehabilitation to ensure that reefs continue to generate biodiversity and fisheries benefits and tourist revenues.

High intraspecific variability and lack of adequate field descriptions or distinguishing skeletal features has made identification of the scleractinian coral Platygyra daedalea challenging. This sp ...

The reproductive ecology of the hermaphroditic broadcast spawning scleractinian reef coral Platygyra daedalea was studied on lagoonal reefs in Kenya. While single annual gametogenic cycles occurred in 84% of colonies, biannual gametogenic cycles were recorded in 16% of colonies and these patterns occurred in two morphotypes. In colonies with a single annual cycle, oogenesis occurred for 6–7 months from September to March and spermatogenesis for 5 months from November to March. In biannually spawning colonies, oogenic cycles overlapped for at least 2 months prior to gamete release. The major spawning period occurred in February and March, with minor spawning also occurring in August–October in biannually spawning colonies. Reproductive effort was lower during the minor winter compared to the major summer spawning, with fewer colonies reproducing (12.5–19.2%), not all mesenteries producing oocytes (32.5%) and less than half of the mesenteries with mature oocytes had associated spermaries (48.1%).

The Republic of Kiribati's Phoenix Islands Protected Area (PIPA), located in the equatorial central Pacific, is the largest and deepest UNESCO World Heritage site on earth. Created in 2008, it was the first Marine Protected Area (MPA) of its kind (at the time of inception, the largest in the world) and includes eight low-lying islands, shallow coral reefs, submerged shallow and deep seamounts and extensive open-ocean and ocean floor habitat. Due to their isolation, the shallow reef habitats have been protected de facto from severe exploitation, though the surrounding waters have been continually fished for large pelagics and whales over many decades. PIPA was created under a partnership between the Government of Kiribati and the international non-governmental organizations-Conservation International and the New England Aquarium. PIPA has a unique conservation strategy as the first marine MPA to use a conservation contract mechanism with a corresponding Conservation Trust established to be both a sustainable financing mechanism and a check-and-balance to the oversight and maintenance of the MPA. As PIPA moves forward with its management objectives, it is well positioned to be a global model for large MPA design and implementation in similar contexts. The islands and shallow reefs have already shown benefits from protection, though the pending full closure of PIPA (and assessments thereof) will be critical for determining success of the MPA as a refuge for open-ocean pelagic and deep-sea marine life. As global ocean resources are continually being extracted to support a growing global population, PIPA's closure is both timely and of global significance.