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The coral reefs of the Pitcairn Islands are in one of the most remote areas of the Pacific Ocean, and yet they are exposed to the impacts of anthropogenic climate change. The Pitcairn Islands Marine Protected Area was designated in 2016 and is one of the largest in the world, but the marine environment around these highly isolated islands remains poorly documented. Evidence collated here indicates that while the Pitcairn Islands' reefs have thus far been relatively sheltered from the effect of warming sea temperatures, there is substantial risk of future coral decalcification due to ocean acidification. The projected acceleration in the rate of sea level rise, and the reefs' exposure to risks from distant ocean swells and cold-water intrusions, add further uncertainty as to whether these islands and their reefs will continue to adapt and persist into the future. Coordinated action within the context of the Pitcairn Islands Marine Protected Area can help enhance the resilience of the reefs in the Pitcairn Islands. Options include management of other human pressures, control of invasive species and active reef interventions. More research, however, is needed in order to better assess what are the most appropriate and feasible options to protect these reefs.

The ocean crisis is urgent and central to human wellbeing and life on Earth; past and current activities are damaging the planet's main life support system for future generations. We are witnessing an increase in ocean heat, disturbance, acidification, bio‐invasions and nutrients, and reducing oxygen levels. Several of these act like ratchets: once detrimental or negative changes have occurred, they may lock in place and may not be reversible, especially at gross ecological and ocean process scales. Each change may represent a loss to humanity of resources, ecosystem function, oxygen production and species. The longer we pursue unsuitable actions, the more we close the path to recovery and better ocean health and greater benefits for humanity in the future. We stand at a critical juncture and have identified eight priority issues that need to be addressed in unison to help avert a potential ecological disaster in the global ocean. They form a purposely ambitious agenda for global governance and are aimed at informing decision‐makers at a high level. They should also be of interest to the general public. Of all the themes, the highest priority is to rigorously address global warming and limit surface temperature rise to 1.5°C by 2100, as warming is the pre‐eminent factor driving change in the ocean. The other themes are establishing a robust and comprehensive High Seas Treaty, enforcing existing standards for Marine Protected Areas and expanding their coverage, especially in terms of high levels of protection, adopting a precautionary pause on deep‐sea mining, ending overfishing and destructive fishing practices, radically reducing marine pollution, putting in place a financing mechanism for ocean management and protection, and lastly, scaling up science/data gathering and facilitating data sharing. By implementing all eight measures in unison, as a coordinated strategy, we can build resilience to climate change, help sustain fisheries productivity, particularly for low‐income countries dependent on fisheries, protect coasts (e.g. via soft‐engineering/habitat‐based approaches), promote mitigation (e.g. carbon storage) and enable improved adaptation to rapid global change.

There are major concerns about the ecological impact of extreme weather events. In the oceans, marine heatwaves (MHWs) are an increasing threat causing, for example, recent devastation to coral reefs around the world. We show that these impacts extend to adjacent terrestrial systems and could negatively affect the breeding of endangered species. We demonstrate that during an MHW that resulted in major coral bleaching and mortality in a large, remote marine protected area, anomalously warm temperatures also occurred on sea turtle nesting beaches. Granger causality testing showed that variations in sea surface temperature strongly influenced sand temperatures on beaches. We estimate that the warm conditions on both coral reefs and sandy beaches during the MHW were unprecedented in the last 70 years. Model predictions suggest that the most extreme female-biased hatchling sex ratio and the lowest hatchling survival in nests in the last 70 years both occurred during the heatwave. Our work shows that predicted increases in the frequency and intensity of MHWs will likely have growing impacts on sea turtle nesting beaches as well as other terrestrial coastal environments.

Several political instruments are in place to tackle effects of climate change and help arrest the global decline of coral reefs. Unfortunately, most are inadequate and anyway are being ignored by many important nations. Rising ocean temperatures are not linear, but act in pulses, so that reefs degrade in steps rather than smoothly. Terminally degraded reefs are now common, and those in very good condition are rare. Several potential solutions have been proposed, none being adequate alone but all being needed to arrest the decline. Arresting the rise in CO2 is a key, long-term requirement, yet levels of this gas are still increasing, as are local requirements such as effective pollution and overfishing controls. Also important is limiting resource extraction, which essentially means limiting human populations. Most scientists consider saving coral reefs now to be a political and sociological problem, not a scientific one. We have lost nearly half the world’s coral reefs and if societies cannot act in what is becoming a diminishing window of opportunity, we will lose most of the rest within another human lifetime.

The symbiosis between corals and the dinoflagellates—zooxanthellae—is the key to a tight recycling of nutrients on reefs that generally thrive best in nutrient poor parts of the oceans. But several other mechanisms and species groups aid transmission of organic matter and energy along the numerous food chains of a reef. Viruses, bacteria, and archaea are key to the recycling of carbon and organic compounds, making the ‘microbial loop’, one key but invisible aspect to how the reef functions. Cyanobacteria, formerly blue-green algae, are a major part of the micro-benthos too, and are important primary producers. Protists are also hugely abundant—larger, single-celled organisms which are eukaryotes with cells with nuclei, and this group has species that exist in planktonic and benthic forms. Foraminifera are important protists, being abundant and having calcareous tests, so that they are significant sand producers in some areas. Finally, zooplankton provide food for numerous reef species, and indeed larvae from all species form part of the plankton temporarily too.

One consequence of the extremely high biodiversity found on reefs is the enormous number of interlocking connections between components. But connections can be destroyed by many kinds of stressors such as pollutants, as can the species themselves. Some species or processes have high redundancy—if destroyed others can fill their role on a reef—while other species or processes may be more or less irreplaceable, in which case when they are destroyed key processes maintaining a healthy reef can be destroyed too. Because so many countries and human communities are dependent on reefs, reef degradation, which is now occurring on a very worrying scale, is of increasing concern. Impacts fall into two main categories: those caused by numerous, usually localized, impacts, such as different forms of pollution and shoreline developments that create large quantities of sediment; and those caused by the more recently recognized, and probably more serious, long-term factors associated with climate change. All of these are ultimately interlinked and all are caused by human activities. Many occur concurrently, each exacerbating the harmful effects of others, and many are synergistic in their impacts. Sewage, nutrient run-off, landfill, dredging, and sedimentation are most important, as are chemicals, pesticides, and metals. Coral diseases are increasing also, commonly as a result. In many areas now too overfishing has become critical and may be the most ecosystem-distorting factor of all.

Coral reefs are tropical ecosystems but show global patterns. The Caribbean has about 60 reef-building coral species, while Southeast Asia has nearly 1,000, this number broadly diminishing with distance east and west from the Southeast Asian region. Diversity of corals also diminishes broadly with distance north and south of the equator. While basic patterns exist, there are several kinds of reef in the same sense that there are different kinds of forests, sometimes forming near-monocultures, sometimes with more diverse mixtures of species. Their key to success is that they house vast numbers of captive dinoflagellates that photosynthesize in a close symbiosis, which explains how these complex ecosystems persist in the absence of substantial fields of large, visible seaweeds. All deposit limestone in its aragonite form, in a way characteristic to each species, which has been used for distinguishing between species. The basic unit of a coral, the polyp, reproduces sexually, but more importantly by asexual budding, which allows for the growth of large colonies of polyps, all clones. Numerous other organisms have crucial associations with the coral polyp: bacteria and archaea especially, the whole forming what is now termed the coral holobiont. Aside from photosynthesis, corals have nematocysts in their tentacles to capture zooplankton food. Corals compete for space using these stinging cells also, amongst other methods. On any reef, soft corals are numerous, especially in the Caribbean, though these do not deposit limestone rock. Calcareous algae are crucial reef-building components too, particularly in the shallows.

Fish, like corals, have geographical patterns across regions and across individual reefs, being structured in the latter case by wave energy and depth. The thousands of species show a variety of feeding patterns. Detritus feeders are very abundant, feeding on the detritus on the seabed, especially in the fine, filamentous algal turf on apparently bare rock. Plankton feeders are common also, and herbivorous fishes show a large abundance, perhaps a quarter of the total species present, cropping algae that otherwise would grow unchecked and smother coral. Since turf algae also contain many micro-species and detritus, most herbivores also ingest much food other than simple plant material. Carnivores range from extreme specialists, such as polyp-picking butterflyfish, to generalists. Sharks and barracuda only consume other fish and generally are at the top of their food chains. The complicated ecological structure of the food webs can be clarified by analysing nitrogen isotope ratios in their tissues. Other important coral carnivores include the crown of thorns starfish, which can remove almost all living coral on a reef when it develops into plagues. Overfishing by humans greatly disturbs the equilibrium of a reef, and this is increasingly causing reef degradation.

Ocean temperatures are rising. This is critical for corals and other reef organisms because most live very close to their thermal limits already. The rise is caused by the greenhouse effect from increasing CO2 emissions. Superimposed on a general background rise caused by the general increase in heat content of the world are pulses—ocean heatwaves—caused by vagaries in ocean circulation. Globally, this is now the greatest threat to reefs. Warming pulses cause mass coral bleaching and mortality when the overstressed symbiotic algae are expelled from the corals, showing the white limestone beneath the now transparent coral tissue. All coral reef areas of the world now exhibit mass bleaching events. Recovery of a reef is possible, but only if given some decades of stable temperatures, and predictions are that warming events are occurring increasingly frequently and are of increasing severity. Coral cover on reefs in all reef areas is declining sharply. Seawater also becomes increasingly acidic, which impedes coral calcification. Added to this, there is a lag of 20–40 years for carbon dioxide in the air to equilibrate with the ocean, so even were there to be a cessation in the rise in the atmosphere today, these effects would continue to develop for a few decades more. 350 parts per million CO2 is considered to be a threshold concentration for calcification to be possible but already the atmosphere is at about 415 ppm. Sea levels are rising too as a result, and reefs are degrading and losing their ability to act as breakwaters.

Given the recent trend towards establishing very large marine protected areas (MPAs) and the high potential of these to contribute to global conservation targets, we review outcomes of the last decade of marine conservation research in the British Indian Ocean Territory (BIOT), one of the largest MPAs in the world. The BIOT MPA consists of the atolls of the Chagos Archipelago, interspersed with and surrounded by deep oceanic waters. Islands around the atoll rims serve as nesting grounds for sea birds. Extensive and diverse shallow and mesophotic reef habitats provide essential habitat and feeding grounds for all marine life, and the absence of local human impacts may improve recovery after coral bleaching events. Census data have shown recent increases in the abundance of sea turtles, high numbers of nesting seabirds and high fish abundance, at least some of which is linked to the lack of recent harvesting. For example, across the archipelago the annual number of green turtle clutches (Chelonia mydas) is ~ 20,500 and increasing and the number of seabirds is ~ 1 million. Animal tracking studies have shown that some taxa breed and/or forage consistently within the MPA (e.g. some reef fishes, elasmobranchs and seabirds), suggesting the MPA has the potential to provide long-term protection. In contrast, post-nesting green turtles travel up to 4000 km to distant foraging sites, so the protected beaches in the Chagos Archipelago provide a nesting sanctuary for individuals that forage across an ocean basin and several geopolitical borders. Surveys using divers and underwater video systems show high habitat diversity and abundant marine life on all trophic levels. For example, coral cover can be as high as 40–50%. Ecological studies are shedding light on how remote ecosystems function, connect to each other and respond to climate-driven stressors compared to other locations that are more locally impacted. However, important threats to this MPA have been identified, particularly global heating events, and Illegal, Unreported and Unregulated (IUU) fishing activity, which considerably impact both reef and pelagic fishes.

Aim: Large-scale variation in species richness results from multiple environmental controls. We proposed to identify the main factors that influence species richness of reef corals to provide insight into natural forces and their implications for future climate impacts. Location: Indian Ocean. Methods: We applied quantile regression (QR) to predict coral species richness and to evaluate the influence of reef area, biogeographical connection - represented by reef area up-current, geological provinces defined by plate tectonics, latitude, longitude and mainland-island separation, the physico-chemical factors of photosynthetically active radiation (PAR), salinity and primary productivity and seven properties of sea surface temperature (mean, minimum, maximum, standard deviation, range, kurtosis and skewness) on coral species richness. Predictions at three quantiles (0.50, 0.75 and 0.95) were compared against ordinary least squares regression (OLS) analysis. Results: All four models successfully predicted species richness, with the 95% QR model showing the best fit. According to this model, reef area, number of reefs up-current and mean-SST had positive effects while maximum and kurtosis-SST had negative effects on richness. The distribution of observed richness values in relation to the regression line suggested this model revealed the main limiting factors. High predicted richness sites were located in the region from Western Australia to Central Indian Ocean Islands and southern India, the Mozambique Channel and East Africa and Southern Red Sea and Gulf of Aden. Sites with low predicted richness were Arabian/Persian Gulf and Gulf of Oman, South Africa and south-west Madagascar, Gulf of Kutch, Bay of Bengal and the Mascarenes. Conclusions: Temperature properties played a prominent role in influencing species richness mainly as latent energy and stress rather than thermal stability. These thermal properties indicate the conditions needed to promote coral diversity and selecting climate refugia for conservation management.

The atolls and coral banks of the Chagos Archipelago (British Indian Ocean Territory) in the central Indian Ocean were badly affected by the warm water event that started in 2015 and lasted for nearly two years. On these reefs, coral mortality was very severe, reducing coral cover to

Layered double hydroxides (LDHs) with high and tailorable UV-Vis-NIR absorption were prepared through transitionmetal (TM) modification. The synthesis method used and amount of TM present were found to influence the UV-Vis-NIR absorption intensity, -range, and the optical bandgap.It was found that the incorporation of TMs in MgAl-LDH results in the existence of a "UV-Vis-NIR absorption fingerprint", the intensity of which can be tuned by the amount of TM present. There also exist differences in the UV-Vis-NIR absorption spectra and bandgaps obtained for MgAl-LDH synthesised using different synthesis conditions and methods, but these are not as visible when including transition metals. Further, the materials exhibit very complex spectra for which adequate explanation is lacking in literature. Finally, standard methods to determine the bandgap of materials, did not give conclusive results for all materials, only for some, and indicate that some of the materials might have multiple different transition types.

Author(s): Moore, Brian; Shah, Manish I; Owusu-Ansah, Sylvia; Gross, Toni; Brown, Kathleen; Gausche-Hill, Marianne; Remick, Katherine; Adelgais, Kathleen; Lyng, John; Rappaport, Lara; Snow, Sally; Wright-Johnson, Cynthia; Leonard, Julie C; AMERICAN ACADEMY OF PEDIATRICS, Committee on Pediatric Emergency Medicine and Section on Emergency Medicine EMS Subcommittee; AMERICAN COLLEGE OF EMERGENCY PHYSICIANS, Emergency Medical Services Committee; EMERGENCY NURSES ASSOCIATION, Pediatric Committee; NATIONAL ASSOCIATION OF EMERGENCY MEDICAL SERVICES PHYSICIANS, Standards and Clinical Practice Committee; NATIONAL ASSOCIATION OF EMERGENCY MEDICAL TECHNICIANS, Emergency Pediatric Care Committee; Pediatric Readiness in Emergency Medical Services Systems; POLICY STATEMENT; Organizational Principles to Guide and Define the Child Health Care System and/or Improve the Health of All Children

The Chagos Archipelago (British Indian Ocean Territory, or BIOT) has 55 islands totalling approximately 5,000 ha spread over approximately 50,000 km 2 of the central Indian Ocean. From the first human settlements, which occurred in the late 1700s, and for the following century, all of the larger islands were converted into coconut plantations. During this period the disturbance to and elimination of the native flora and fauna in Chagos atolls was especially profound because these islands were used solely for the production of coconut and its products. Regarding vegetation, many times more species were introduced than were native, and several introduced species subsequently became invasive. The bird colonies, turtles and the land crabs were hugely reduced due to human consumption, land disturbance and the introduction of rats and other inappropriate and often free-ranging animals, such as pigs. The condition of the reefs, however, remains excellent, such that the area was declared a no-take marine reserve in 2010. For some years, BIOT was the world’s largest marine no-take conservation area. This status was achieved mainly because of its reefs; the islands are still heavily dominated by increasingly derelict, rat-infested coconut plantations and lack birds on most previously planted islands. However, on the smallest islands, many no larger than a few ha in size, there are both native plant communities and huge numbers of breeding seabirds. These relatively undisturbed fragments are acting as the core of current conservation efforts to restore some of the larger islands to their pre-plantation condition. This paper documents, as far as is possible from the relatively sparse archival documents, the course of events and extent of the terrestrial changes that took place in this archipelago before modern concepts of conservation emerged and remarks on the present, planned and funded restoration efforts that can be based on such knowledge.

Being low and flat, atoll islands are often used as case studies against which to gauge the likely impacts of future sea-level rise on coastline stability. Furnished with lengthy temporal datasets, Pacific atolls form the majority of studies with scant information published for sites in the Indian Ocean. To address this imbalance, this study considers Diego Garcia, an atoll island situated in the remote equatorial Indian Ocean, which has undergone pronounced natural and anthropogenic change in the last fifty years. To explore the former, time separated remote sensing images spanning the years 1963–2013 are assembled to provide insight into the natural dynamics of the shoreline of this island and ocean climate data are compiled to investigate possible controls. Disregarding the precinct of the atoll on which a military complex has been constructed, overall land area of Diego Garcia decreased by a net value of only 0.92% between 1963 and 2013. While net island area is relatively unchanged, 12% of the shoreline that is not in the military precinct displayed discernible accretion and 15% has receded, with the lagoon-facing coastline having undergone the most pronounced changes and at rates higher than recorded for the island's exterior. Broad trends in the morphological adjustment of the island exist. The north-eastern limb of the atoll has generally receded while the south-eastern limb has extended. The south of the island has also extended, the south-western region has eroded and the north-western part has generally also eroded with the exception of notable shoreline extension at Simpson Point. The most common mechanism by which the lagoon-ward coastline has aggraded is through the in-filling of cuspate embayments with sediment which is later stabilized by the expansion of terrestrial vegetation. This evolution is most active in the complex network of embayments in the south of the atoll lagoon. The ocean-facing coastline, by contrast, typically aggrades and erodes through the linear shift of the vegetated coast along the strike of the beach line. While the areal extent of Diego Garcia has been almost static for the last half century, the annualized rate of flux of the coastline is considerable at 0.30 m yr − 1 ; a rate comparable to other atoll islands. The literature consistently reports two factors as relevant to increasing the rate of shoreline migration – human modification of it and sea-level rise. Both are foreseeably set to increase for Diego Garcia, the former due to its strategic importance, not least its use as a military base, and the latter due to global environmental change. The findings of this work serve to remind that the coastline of Diego Garcia, as for all atoll islands, is naturally dynamic and will likely become more so in the future.

The global decline of reef corals has been driven largely by several marine heatwaves. This has greatly reduced coral cover but has reduced coral diversity also. While there is a lack of data in most locations to detect coral species losses, reefs of the Chagos Archipelago, central Indian Ocean, have long term monitoring data extending back to the late 1970s. Severe declines in cover have occurred since the 1970s, with regional extinctions of some species and key species assemblages. There is a severe decline in coral settlement, along with a substantial loss of habitat quality which has reduced the habitat available for settlement. This is a clear precursor to positive feedback. Regional species extinctions here occur mainly when total coral cover is

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.