10 percent of the world's coral reefs are
(federal task force study)
2/3rds of the world's coral reef systems are being damaged,
by human activities.
(National Oceanic and Atmospheric Administration)
There are many stresses to coral reefs, both from natural causes and human
fishing methods (overfishing, trawling, dynamite, poison)
that muddy the water and smother coral with sediment
mining and ornamental fish and shell collectors (aquarium fish
and harmful human behavior (reef-hopping, manhandling, boat
warming, changing climates, storms and other natural events
and tourism development
Global warming is responsible for the destruction and severe degradation
of a quarter of the world's coral reefs.
Extreme climate changes are causing higher water temperatures. This causes
algae living within coral to be expelled, which brings about coral bleaching and
death to living polyps. Even a one-degree change can affect the
survival of a reef. Outbreaks of Crown-of-Thorns starfish have
damaged some coral reefs severely. Construction and logging can
cause soil erosion which washes sediment down rivers and waterways into
the ocean. This muddies the waters and prevents sunlight from
reaching the coral.
Dead coral and death of an ecosystem
Besides massive pollution, the harmful effects of global warming, Crown-of-Thorns starfish invasions, and other environmentally damaging human
activities; many harmful methods are being used by humans to capture tropical species and coral to sell worldwide, mostly for home aquariums. Camouflage cannot help, nor can all the nooks and crannies in the coral offer protection as hiding
spots, as you will see when you read the following:
DANGER IN THE REEF - NO PLACE
TRAWLING - Indiscriminate
and large-scale seabed devastation is brought about by trawling, where the
sea bottom is completely leveled by heavy steel, chains and nets dragged by
fishing trawlers. Coral, plants and animals are all scraped up into huge
nets, leaving the ocean habitat below destroyed. It is estimated that 25
billion animals caught in these nets each year are thrown back into the sea as
garbage because they can't be sold. It takes centuries for a coral
reef to develop and a few minutes to destroy it by trawling!
See pictures of the devastation caused by trawlers
Read more about trawling and other harmful
human behavior on our
Impacts on Oceans page.
For more information, see: Scraping the Seabed Raw (ABC
DYNAMITE - To stun the fish and bring them out
of hiding, dynamite is exploded near the reef. This temporarily paralyzes
hundreds of tropical fish and other species so the collectors can gather up huge
amounts quickly. The concussion from the explosion kills many
species. It takes centuries for a coral reef to develop and an instant
for an explosion to destroy it!
CYANIDE POISONING - Another damaging
and illegal hunting method is the use of cyanide
poisoning. The hunter squirts the cyanide in and around the coral to temporarily
immobilize sealife so they can be caught. But the poison floats around and
kills a great
amount of smaller fish and also the coral animals.
For more information, see: New Threat to Coral Reefs: Hobbyists (MSNBC
U.S. Port Authorities
inspectors are testing imported fish for cyanide poisoning. Most aquarium
fish come from the Philippines and Indonesia. There are very loose laws in
poorer countries for the protection of coral ecosystems. It is estimated
that of tropical fish harvested, only one out of every ten survive.