Answer:
Pollution from sewage, waste, and chemicals
Sewage or other wastes may be released into the local waters surrounding coral reefs from boats, hotels, or resorts etc
Such sewage pollution leads to nutrient enrichment in ocean water, which favours algal growth at the expense of coral organisms.
Inappropriate solid waste disposal can lead to the leaching of toxic chemicals into local waters, and litter and debris can blow and wash into coral reef waters.
Boats and Anchors
Boats grounding in coral reef habitat can damage corals, as can anchors. Anchors can cause a great deal of coral breakage and fragmentation, particularly from large boats like freighters and cruise ships. Heavy chains from large ships can break or dislodge corals. These damages to corals can last for many years.
Anchoring can also damage the habitats near reefs such as seagrasses that serve as nurseries and habitats for the juveniles of different coral reef organisms.
Marinas may inappropriately dispose of oils and paint residues, polluting local waters, and additional pollution may occur during fuelling
Scuba diving and snorkelling
While most diving and snorkelling activities have little physical impact on coral reefs, physical damages to corals can and do occur when people stand on, walk on, kick, touch, trample, and when their equipment contacts corals.
Coral colonies can be broken and coral tissues can be damaged when such activities occur. Divers and snorkelers can also kick up sediment that is damaging to coral reefs.
Step-by-step explanation: