Coral reefs are spectacularly important living structures. For example, they protect coastal communities from storm surge & erosion, provide habitat & refuge to animals, supply food to humans, offer valuable economic services (e.g., tourism), & supply numerous invaluable benefits, like carbon sequestration & nutrient cycling.
Coral reefs are fragile and gravely threatened. Many coral reefs have suffered more than 90% coral death in the last couple decades, with very high death rates in 2017.
Threats to corals include nutrient pollution (e.g., farms, human waste), temperature rise, ocean acidification, habitat degradation, aquaculture, sediment loading, invasive species, overfishing, bomb and cyanide fishing, aquarium trade, and African dust carrying disease causing bacteria.
The film, Chasing Coral, nicely documents the impact of climate change causing coral bleaching and death, and also highlights the need for ocean explorers to share their observations.
eOceans' researchers efforts have discovered that:
- nutrient pollution from human wastewater makes it to coral reefs, even if they are far offshore and water tests appear clean
- nutrient pollution causes coral-killing sponges to explode in size and number
- reef sharks are largely absent where they were once common
- traditional scientific methods of censusing reef fish communities have biases that overestimate the abundance, and biomass of mobile fishes. Correction estimates for underwater visual censuses can be found here.
- reef sharks in Thailand are abundant enough to be observed by divers, and that some populations may be threatened