Unsustainable fishing practices are particularly damaging to coral reef habitats. “Coral reef fisheries, though often relatively small in scale, may have disproportionately large impacts on the ecosystem if conducted unsustainably,” according to NOAA’s Coral Reef Conservation Program. The fish found near coral reefs are part of the coral ecosystem — the fish eat algae off the coral, which helps keep the algae levels down and the coral healthy.

The negative effect of depleted fish populations in coral reefs, because of extraction for the aquarium trade, for food or as a bycatch of other species, is exacerbated by other environmental stressors such as pollution and climate change.

The chemicals and increased amounts of sediment that ends up in ocean water because of land-based pollutants can sicken or even kill some fish and coral species. Runoff from land-based human development disrupts the fragile ecological cycles of coral reefs.

The US Commission on Ocean Policy reports that “pollution and runoff from coastal areas also deprive reefs of life-sustaining light and oxygen.”

Manmade climate change and the associated rising ocean temperatures are causing coral bleaching and additional infectious diseases among coral. High levels of carbon dioxide are altering the chemistry of ocean water by decreasing pH levels and creating ocean acidification.

In fact, many coral reef conservationists worry that if we fail to reduce our global carbon emissions, the resulting rise in ocean temperature and ocean acidification would render all other coral conservation efforts futile.