Often, when people vacation in tropical locations surrounded by beautiful reefs they want to take coral souvenirs home. These shops receive their corals from commercial collectors who select well developed colonies which will make them the most money. This is very damaging because a large amount of the most healthy corals are selected. Coral reefs also receive much damage from both commercial and private vessels. The leakage of fuels into the water and the occurrences of spills by large tankers are extremely damaging to local corals.
Boat anchors are also very damaging to reefs by breaking and destroying entire colonies.
The grounding of large sea-going vessels also results in large sections of coral reefs being destroyed. Since most corals mass spawn and produce floating gametes, pollutants and toxins on the surface can effect coral reproduction and development for a large area. Therefore, much care must be taken to reduce or prevent the spillage and leakage of contaminants into the water as well as to improve cleanup procedures of such accidents. Although much of the coral reefs degradation is directly blamed on human impact, there are several natural disturbances which cause significant damage to coral reefs. The most recognized of these events are hurricanes, or typhoons, which bring large and powerful waves to the tropics.