Jeremy Jackson, director of the Scripps Center for Marine Biodiversity and Conservation, cites the synergistic effects of habitat destruction, overfishing, ocean warming, increased acidification and massive nutrient runoff as culprits in a grand transformation of once complex ocean ecosystems. Areas that had featured intricate marine food webs with large animals are being converted into simplistic ecosystems dominated by microbes, toxic algal blooms, jellyfish and disease.

The relationship between natural variations in coral species diversity, reef development and ecosystem function on coral reefs is poorly understood. Recent coral diversity varies 10-fold among geographic regions, but rates of poor growth are broadly similar, suggesting that diversity is unimportant for reef development.