Marine debris. Ghost net still posing a potential entanglement hazard for large marine animals.

Marine debris. Plastic and metallic debris on a reef.

Marine debris. A beach blanket wrapped around coral. To see effects of this, proceed to image reef3142.

Marine debris. Showing the effect of a beach blanket wrapped around coral. Note all of the dead area where the beach blanket in image reef3141 was wrapped around the coral.

Careless dispersal of garbage in coastal regions can lead directly to degradation of the marine environment.

Careless dispersal of garbage in coastal regions can lead directly to degradation of the marine environment.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Result of standing on staghorn coral. See image reef3149.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps. See image reef3148.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps. See image reef3148.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps. Note snorkeler in background.

Damage to coral in areas of concentrated dive tourism.

Diver remaining above reef.

Divers looking and enjoying without disturbing the reef.

Diver ready to photograph and looking and enjoying without disturbing the reef.

Divers looking and enjoying without disturbing the reef.

Make sure not to touch the bottom when snorkeling or scuba diving.

Make sure not to touch the bottom when snorkeling or scuba diving.

Make sure not to touch the bottom when snorkeling or scuba diving.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Make sure not to touch the bottom when snorkeling or scuba diving.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Make sure not to touch the bottom when snorkeling or scuba diving.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps.

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps. Note anchor line extending to bottom in upper right of image. Anchor could be damaging delicate reef

Dive tourism can place additional stress on reefs. Standing on or handling live corals can damage or even kill the coral polyps. Note anchor line extending to bottom. Anchor could be damaging delicate reef animals.

SCUBA divers approaching a sinkhole on a Guamanian reef.

SCUBA divers approaching a sinkhole on a Guamanian reef.

A dive tourist loving a coral reef structure to death as touching can damage or kill delicate coral polyps.

Dive tourists loving a coral reef structure to death as touching can damage or kill delicate coral polyps.

Dive tourists loving a coral reef structure to death as touching can damage or kill delicate coral polyps.

Tourists posing at a Guam reef attraction. See images reef3177 and reef3180.

Careless trailing of flippers on bottom can add to sedimentation problems affecting coral reefs.

Careless trailing of flippers on bottom can add to sedimentation problems affecting coral reefs.

Photographing tourists at a Guam reef attraction. See images reef3180 and reef3 174.

SCUBA diver refraining from touching reef animals. Unnecessarily touching and handling coral and coral reef animals places unnecessary stress on the reef and could kill many delicate creatures.

Divers unnecessarily touching and handling coral and coral reef animals place unnecessary stress on the reef and could kill many delicate creatures.

Photographer standing on coral to obtain photograph of tourists could be causing damage to delicate coral polyps. See image reef3177.

Scientist studying area affected by coral reef bleaching.

Scientist studying area affected by coral reef bleaching.

Scientist studying area affected by coral reef bleaching.

Scientist studying area affected by coral reef bleaching.

Scientist studying area affected by coral reef bleaching.

Scientist studying area affected by coral reef bleaching.

Disease ravaged coral.

Algae covering diseased and dying coral reef.