July 30,2013
The Great Barrier Reef is a unique and beautiful natural wonder. The
reef is 2,300 km (1,426 miles) long, encompassing a total area of over
300,000 square km (186,000 square miles), and is reportedly the only
living structure on Earth visible from space.
Coral reefs are
formed when coral animals, or polyps, attach to a hard surface and build
a cup-shaped exoskeleton, or calyx, by excreting calcium carbonate. The
polyps will occasionally detach from their calyx and secrete a new one
above it, causing the coral structure to grow slowly over time,
according to the National Oceanic and Atmospheric Administration. The
origin of the Great Barrier Reef can be traced back to an ice age that
occurred roughly 15,000 years ago, when much of the Earth's water was
locked in glaciers, and sea levels were 300-400 feet lower than they are
today. Coral polyps settled along Queensland's continental shelf, which
was exposed to air at that time, and as the glaciers melted and the sea
level rose, the coral structures were able to grow fast enough to keep
the coral polyps in the lighted surface waters where they were able to
survive,
marinebio.net reports.
The Great Barrier Reef contains close to 400 different types of corals,
the Australian Great Barrier Reef Marine Park Authority states,
which form structures in an amazing variety of shapes and colors,
making the reef a place of incredible beauty, resembling a rainforest in
an alien landscape.
In fact, coral reefs are often called
rainforests of the sea because of their biodiversity, and even though
they consist of less than .01% of the Earth's oceans, they provide a
home for 25% of all marine species,
the dailymail.co.uk reports.
The Great Barrier Reef, the largest reef structure in the world,
contains 500 seaweed species, 215 species of birds, 16 species of
snakes, 4,000 species of mollusks and 1,500 different species of fish,
according to the Sydney Sea Life Aquarium.
In
addition, the reef also provides a home for over 30 different species
of marine mammals for at least part of the year, including Indo-Pacific
humpback dolphins, Australian snubfin dolphins, spinner dolphins,
pan-tropical spotted dolphins, killer whales, short-finned pilot whales,
sperm whales, and humpback whales, which return to the reef from May to
September in order to have their calves and build up strength for their
return trip to the Antarctic,
states greatbarrierreef.org.
Six of the seven species of sea-turtles also dwell in the confines of
The Great Barrier Reef, and the reef provides a protected home for the
iconic dugongs, also known as sea cows, endangered marine mammals which
were at least partially responsible for the legends of mermaids when
they were first seen by early sailors,
according to the Australian Great Barrier Reef Marine Park Authority.
The
reef is extremely important to humans as well. Majestic marine mammals,
the riot of color from the many diverse species of fish, the unearthly
beauty of the coral "forest", and the warm gentle ocean currents all
contribute to making the Great Barrier Reef a popular tourist
destination, and other parts of the reef supports a large commercial
fishing industry that is vital to the Australian economy, as well as
fishing in the reef providing food for indigenous people,
the Great Barrier Reef Marine Park Authority reports.
The GBRMPA is responsible for insuring that the waters of the reef are
not overfished, as well addressing other threats to the reef such as
pollution from the millions of tourists who visit each year, in order to
make sure this delicate ecosystem is not harmed.
The most
powerful threat to the reef seems to come from the forces of nature.
Intense hurricanes can cause massive damage to the reef. The Great
Barrier Reef seems to have lost half of its coral cover in the past 27
years, with loss being attributed to the following causes: storm damage -
48%, crown of thorns starfish - 42%, and coral bleaching - 10%,
according to researchers from the Australian Institute of Marine Science.
The CEO of the AIMS goes on to say if the starfish proliferation could
be halted, the reef could start to recover, growing at a rate of 0.89%
per year. Coral bleaching is a phenomenon in which ocean conditions,
such as temperature or acidification, cause the corals to expel the
algae which give them their color, and while corals can survive
bleaching, they become more vulnerable when it occurs,
according to NOAA. According to another study that was
reported on weather.com
from Institut Pierre Simon Laplace and Stanford University, ocean
acidification, which the study states is a condition in which the ocean
becomes more acidic as a result of CO2 emissions, may result in the
death of all shallow-water coral reefs in the next 100 years.
