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