Lyndon DeVantier

One-third of reef-building corals face elevated extinction risk from climate change and local impacts

The conservation status of 845 zooxanthellate reef-building coral species was assessed by using International Union for Conservation of Nature Red List Criteria. Of the 704 species that could be assigned conservation status, 32.8% are in categories with elevated risk of extinction. Declines in abundance are associated with bleaching and diseases driven by elevated sea surface temperatures, with extinction risk further exacerbated by local-scale anthropogenic disturbances. The proportion of corals threatened with extinction has increased dramatically in recent decades and exceeds that of most terrestrial groups. The Caribbean has the largest proportion of corals in high extinction risk categories, whereas the Coral Triangle (western Pacific) has the highest proportion of species in all categories of elevated extinction risk. Our results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures.

Identifying the World's Most Climate Change Vulnerable Species: A Systematic Trait-Based Assessment of all Birds, Amphibians and Corals

Climate change will have far-reaching impacts on biodiversity, including increasing extinction rates. Current approaches to quantifying such impacts focus on measuring exposure to climatic change and largely ignore the biological differences between species that may significantly increase or reduce their vulnerability. To address this, we present a framework for assessing three dimensions of climate change vulnerability, namely sensitivity, exposure and adaptive capacity; this draws on species’ biological traits and their modeled exposure to projected climatic changes. In the largest such assessment to date, we applied this approach to each of the world’s birds, amphibians and corals (16,857 species). The resulting assessments identify the species with greatest relative vulnerability to climate change and the geographic areas in which they are concentrated, including the Amazon basin for amphibians and birds, and the central Indo-west Pacific (Coral Triangle) for corals. We found that high concentration areas for species with traits conferring highest sensitivity and lowest adaptive capacity differ from those of highly exposed species, and we identify areas where exposure-based assessments alone may over or under-estimate climate change impacts. We found that 608–851 bird (6–9%), 670–933 amphibian (11–15%), and 47–73 coral species (6–9%) are both highly climate change vulnerable and already threatened with extinction on the IUCN Red List. The remaining highly climate change vulnerable species represent new priorities for conservation. Fewer species are highly climate change vulnerable under lower IPCC SRES emissions scenarios, indicating that reducing greenhouse emissions will reduce climate change driven extinctions. Our study answers the growing call for a more biologically and ecologically inclusive approach to assessing climate change vulnerability. By facilitating independent assessment of the three dimensions of climate change vulnerability, our approach can be used to devise species and area-specific conservation interventions and indices. The priorities we identify will strengthen global strategies to mitigate climate change impacts.

Overview of distribution patterns of zooxanthellate Scleractinia

This publication is an overview of a detailed study of coral distribution, diversity and affinities worldwide. The species distribution maps in www.coralsoftheworld.com are based on comprehensive global assessments of the world’s 150 coral ecoregions. Original surveys by the authors cover 4941 sites in 85 ecoregions worldwide. These are combined with a thorough summation of all biogeographic, taxonomic and related literature as well as an extensive review of museum and photographic collections worldwide and extensive inter-personal communications. Species occurrences in ecoregions are recorded as confirmed, strongly predicted, uncertain or absent. These data are used to present global maps of diversity and affinity at species level. There are two templates of Indo-Pacific diversity and affinity: one dominated by the Coral Triangle and one created by poleward continental boundary currents. There is a high degree of uniformity within the main body of the Coral Triangle; diversity and affinities both decrease in all directions. The Sunda Shelf ecoregion now qualifies for inclusion in the Coral Triangle and the Java Sea ecoregion is borderline. There is very little Indo-Pacific provincialism. Two separate centres of diversity occur in the Indian Ocean: the subequatorial west, and the Red Sea. Most species of the far eastern Pacific occur in the central Pacific. The Caribbean dominates Atlantic distribution and affinities and also has high uniformity. Individual ecoregions have very varying data comprehensiveness. Distribution patterns that distinguish between geographic variation within a species and the geographic overlap of sister species support the concept of reticulate evolution

The Coral Triangle

Spatial analyses of coral distributions at species level delineate the Coral Triangle and provide new insights into patterns of diversity and endemism around the globe. This study shows that the Coral Triangle, an area extending from the Philippines to the Solomon Islands, has 605 zooxanthellate corals including 15 regional endemics. This amounts to 76% of the world’s total species complement, giving this province the world’s highest conservation priority. Within the Coral Triangle, highest richness resides in the Bird’s Head Peninsula of Indonesian Papua, which hosts 574 species, with individual reefs supporting up to 280 species ha−1. The Red Sea/Arabian region, with 364 species and 27 regional endemics, has the second highest conservation priority. Reasons for the exceptional richness of the Coral Triangle include the geological setting, physical environment, and an array of ecological and evolutionary processes. These findings, supported by parallel distributions of reef fishes and other taxa, provide a clear scientific justification for the Coral Triangle Initiative, arguably one of the world’s most significant reef conservation undertakings.

Geological evidence for recurring outbreaks of the crown-of-thorns starfish: a reassessment from an ecological perspective

The abundance and distribution of Acanthaster planci skeletal elements in reef sediments have been presented as evidence that population outbreaks of the crown-of-thorns starfish on the Great Barrier Reef are not a new occurrence, but have been an integral part of the ecosystem for at least 7000 years on some reefs (Walbran et al. 1989a). Reassessment of the evidence shows that these claims are not justified and challenges the validity of several assumptions that are crucial to their thesis that outbreaks have been a recurrent phenomenon on the Great Barrier Reef. These are: (i) that the majority of starfish from outbreak populations remain and die on the host reef and that their skeletal elements add to the reef sediment, (ii) that reefs which have had recent A. planci outbreaks can be discriminated from those which have not by the abundance of starfish skeletal remains in recent sediments, (iii) that outbreaks will significantly increase the number of skeletal elements in reef sediments above normal background levels and, (iv) that the age of individual skeletal elements can be predicted from the age of their surrounding sediment or their depth in the sediment pile. We conclude that Walbran et al. do not have sufficient data to infer the outbreak history of A. planci from the sediment recored and that there are alternative interpretations of their findings. The possibility cannot be discounted that destructive population outbreaks of A. planci witnessed on the Great Barrier Reef since 1960 are unprecedented. The question of whether A. planci outbreaks are a naturally recurring phenomena or a novel, more recent development remains unanswered.