Focus |

Coral reefs

Coral reefs are astoundingly diverse ecosystems, built through intricate biotic and abiotic relationships. Yet climate change, pollution and over-harvesting are jeopardising not only the beauty and ecology of these systems, but also the food security, livelihoods and wave protection of hundreds of millions of people. This Focus brings together recent research and opinion published in Nature Research journals on the fundamentals of reef systems and how our activities are affecting them.

Editorial

One of the most visible impacts of current climate change is the catastrophic bleaching and death of corals in reefs around the world. This issue of Nature Ecology & Evolution and an online Focus highlight recent research documenting the transformation of these systems.

Editorial | | Nature Ecology & Evolution

Reef biology

Huanle Liu et al. report draft genomes of two Symbiodinium species, one from the most dominant type of symbionts in reef-building corals. They find evidence of positive selection in genes related to stress response, meiosis and other traits required for forming successful symbiotic relationships.

Article | Open Access | | Communications Biology

Human impacts

Biological responses to ocean acidification will depend on variation in tolerance and phenotypic plasticity over different timescales. This study of the spiny damselfish demonstrates the importance of parental variation and transgenerational effects in the response of fish to ocean acidification.

Article | | Nature Ecology & Evolution

Analysis of 60 sites in three ocean basins suggests that overgrowth of fleshy algae on coral reefs supports higher microbial abundances dominated by copiotrophic, potentially pathogenic bacteria via the provision of dissolved inorganic carbon.

Article | | Nature Microbiology

Analyses of current coral reef growth rates in the tropical western Atlantic and Indian Ocean show that few reefs will have the capacity to track sea-level rise projections under Representative Concentration Pathway scenarios without sustained ecological recovery.

Article | | Nature

Fish and invertebrate communities transformed across the span of the Great Barrier Reef following the 2016 bleaching event due to a decline in coral-feeding fishes resulting from coral loss, and because of different regional responses of key trophic groups to the direct effect of temperature.

Letter | | Nature

Acute heat stress from the extended marine heatwave of 2016 is a potent driver of the transformation of coral assemblages, which affects even the most remote and well-protected reefs of the Great Barrier Reef.

Letter | | Nature

Overfishing and nutrient pollution can damage coral reefs in part by increasing coral-algal competition. Here the authors simulate these stressors in a three year field experiment, and show that they interact to enhance sensitivity to temperature, predation and bacterial opportunism.

Article | Open Access | | Nature Communications

It has been suggested that deep coral reefs offer a refuge against warming and mass bleaching. Here Frade et al. look at the 2016 bleaching event in the northern Great Barrier Reef and found that deep reefs initially acted as thermal refuges, though this effect lessened in the late summer months.

Article | Open Access | | Nature Communications

Hannah Barkley and Anne Cohen and colleagues used bleaching signatures in coral skeletons to examine the Jarvis Island coral community response to multiple El Niño heatwaves. They find the historically productive ecosystem experienced 10 bleaching events in the past 60 years and its recovery provides insights into coral reef resilience under ocean warming.

Article | Open Access | | Communications Biology

Opinion

An integration of 20 years of data on fisheries catch and reef habitat characteristics shows how bleaching-induced shifts in reefscapes change species abundances but may not impair total catch capacity.

News & Views | | Nature Ecology & Evolution

Rapid evolution of morphological variations is shown to be linked to positions of coral reef fishes at trophic-web extremes. This finding suggests that current fishing practices on coral reefs that target top predators and seaweed-grazing fishes may undermine the potential for future species diversification.

News & Views | | Nature Ecology & Evolution

The importance of biodiversity for productive community functioning is emerging as one of a very few general rules in ecology, but evidence has been sparse that it applies in tropical coral reefs—until now.

News & Views | | Nature Ecology & Evolution

An assessment of the capacity of coral reefs to grow fast enough to keep up with projected rises in sea level finds that most reefs will fall behind if nothing is done to restore them.

News & Views | | Nature

The introduction of non-native rats can devastate island ecosystems. It now emerges that these rats also harm a complex web of interactions linking seabirds with the algae and fishes of nearby coral reefs.

News & Views | | Nature

Caroline Palmer proposes the concept of coral holobiont damage thresholds to stimulate research into coral health and immunity as tropical reefs are increasingly threatened by climate change. This framework may be used to develop targeted approaches to coral reef restoration, management and conservation.

Comment | Open Access | | Communications Biology