Page 352 - Hawaii: Diving, Surfing, Pearl Harbor, Volcanoes and More

owever, in the face of other human- of algae, which smothers reefs by cutting artificial prawn farms.
H induced pressures, corals have become off their sunlight. Trash also kills coral reef
vulnerable. In many cases, bleached coral animals. Floating trash can cover reefs, ining also destroys coral. Sometimes
colonies die. In the past few decades, the blocking off sunlight that polyps need to M coral pieces are removed for use as
amount of carbon dioxide in the air has in- survive. Turtles often mistake plastic bags bricks or road-fill. Or, sand and limestone
creased by one-third. This is harmful to cor- for jellyfish and eat them. Plastic blocks from coral reefs are made into cement
als because increased amounts of carbon the turtle’s digestive tract, causing them to for new buildings. But corals aren’t only
dioxide are dissolving into the water, which starve to death. Lost or discarded fishing removed from their habitat for construc-
appears to be dissolving the skeletons of nets - called “ghost nets” - can snag on reefs tion; they are also sold as souvenirs. Coral
corals. As a result, coral in waters with large and strangle thousands of fish, sea turtles curios and jewelry are often sold to tourists
amounts of carbon dioxide form weaker and marine mammals. and exporters in the markets of developing
skeletons, making them more vulnerable to countries.
damage from waves, careless tourists, and onstruction along coasts, inshore con-
destructive fishers. C struction, mining, logging and farming ourist resorts that empty their sewage
along coastal rivers can all lead to erosion. T directly into the water surrounding
cientists have identified pollution as As a result, particles end up in the ocean coral reefs contribute to coral reef degra-
S one of the leading causes of coral reef and cover coral reefs. This ‘smothers’ coral dation. Wastes kept in poorly maintained
degradation. This threat comes from a and deprives it of the light it needs to sur- septic tanks can also leak into surrounding
variety of sources. For example, oil, gas and vive. Mangrove trees and sea grasses, which ground water, eventually seeping out to the
pesticide contamination poisons coral and normally act as filters for sediment, are reefs. Careless boating, diving, snorkeling
marine life. Reefs are harmed when human, also being rapidly destroyed. This has led and fishing can also damage coral reefs.
animal waste and/or fertilizer is dumped to an increase in the amount of sediment Whenever people grab, kick, walk on, or stir
into the ocean or when river systems carry reaching coral reefs. Mangrove forests are up sediment in the reefs, they contribute
these pollutants to reef waters. These often cut for firewood or removed to create to coral reef destruction. Corals are also
pollutants increase the level of nitrogen open beaches. They are also destroyed by harmed or killed when people drop anchors
around coral reefs, causing an overgrowth prawn harvesters to open up areas to create on them or when people collect coral.