In 2005, months of unprecedented higher-than-normal water temperatures started a cascade of bleaching, disease, and death among corals in the Eastern Caribbean. Such events are increasing in frequency around the world and threaten these fragile ecosystems, which shelter a wealth of biodiversity and provide sources of food and pharmaceuticals. Researchers must determine how rising temperatures produce coral bleaching, the pathogens that cause disease in corals, and the environmental factors that foster disease outbreaks.

Wildlife and environmental groups are opposing the construction of the world's largest tidal power scheme on grounds that it will damage a unique ecosystem and that it will cost too much.

It all seemed too easy by half: to beat global warming just sprinkle some iron in the ocean, then watch as algae bloom en masse, sucking up carbon dioxide by the tonne. Now the idea is looking increasingly unlikely to go ahead in a big way. In the wake of a UN moratorium on the practice, the latest research suggests that seeding will trigger the build-up of an acid that can be lethal to marine organisms and humans.

The coastal and marine nitrogen cycle occupies a complex, central role within the biogeochemical cycles. Human interventions in the earth system have risen to unprecedented levels, strongly influencing the global nitrogen cycle. The nitrogen cycle in the open ocean compared to coastal ecosystems appears to have remained unharmed, although recent observations have shown increasing anthropogenic influence.

An effort in southern India to raise coastal farmers out of poverty by paying them to cultivate red algae for a food additive has gone awry.

A dispute about non-native algae has broken out in India between beverage giant PepsiCo and the Central Salt & Marine Chemicals Research Institute (CSMCRI), which is based in Bhavnagar, Gujarat. Institute researchers originally imported the alga Kappaphycus alvarezii for research; in 2001 PepsiCo began cultivating it for the food thickener carrageenan in the Gulf of Mannar marine bioreserve, along India's southeastern coast.