Coral Bleaching

Global Warming is the average increase of temperatures across the globe. Although it is difficult to say when the current global warming began, the effects are becoming more and more prevalent. Over the next century, the global temperature is projected to continue to rise, and the effects will increase as well. Here is an article from National Geographic that discusses the major Effects of Global Warming.

Global warming is also one of the leading threats to the Great Barrier Reef and coral reefs all over the world. The effect is called coral bleaching. I am still trying to understand all the details, but the Coral Reef Alliance gives a great description and describes the process of coral bleaching.

Coral bleaching "...occurs when coral polyps, stressed by heat or ultraviolet radiation, expel the algae that live within them. These algae, called zooxanthellae, normally provide the coral with up to 80% of its energy, making zooxanthellae essential for coral survival. The algae are also normally responsible for the color of coral, so when they are expelled, the color appears white or "bleached." There is a chance that bleached coral can recover if conditions return to normal quickly enough." Coral Reef Alliance Website.


Photo Credit: ABC News

If the ocean temperatures continue to rise, the algae will leave and the coral will die. There are simple things that everyone can do on a daily basis to prevent or slow down global warming, which could eventually stop coral bleaching.

-Be aware of the amount of electricity you use. When you leave a room, turn off the lights and any other appliances you are not using.

-Replace regular light bulbs with energy-efficient bulbs.

-Use only the amount of water you need. Make sure your washer is full before doing a load of laundry, and try to limit the amount of time you are in the shower.

-Walk, ride a bike or use public transportation when possible as an alternative to driving.

-Recycle in your home and buy recycled products.

-Use recyclable bags when going to the store as an alternative to plastic grocery bags.

-Only run your heater or air conditioner when it is necessary.

-Spread awareness! The more people who know, the better!

There are some great websites that give detailed lists of how to prevent global warming. Check them out! There are also some conservation groups in Australia and around the world who have started campaigns to decrease the effects of global warming, and ultimately the threats to the Great Barrier Reef. I will go into more detail about these groups in an upcoming post, but here is a video from one of these groups, the Great Barrier Reef Marine Park Authority, talking about Coral Bleaching.

GBRMPA Coral Bleaching Video


Photo Credit: Whitsunday Boat Show

Overfishing in the Reef

As may be expected, some of the main threats to any ecosystem come from humans. More specifically, one of the main threats to the Great Barrier Reef today is overfishing. According to a University of Michigan website on Human Impact on the Great Barrier Reef, “Overfishing of certain species near coral reefs can easily affect the reef's ecological balance and biodiversity.” When a species of fish is hunted, it can create an imbalance that has a negative effect on the reef. A decrease in a herbivore, or plant-eating species can cause an increase in algae on the coral. For example, the Surgeonfish feeds primarily on algae on coral in shallow waters.

Photo Credit: AustralianMuseum.net.au

The coral requires a certain amount of nutrients that only fish can provide in order to maintain the reef. “Since certain amounts of nutrients, oxygen and salt content the fishes in the coral reef ecosystem help maintain the balance needed by the corals, without these fishes the coral reef will collapse,” (Human Impact on the Great Barrier Reef.) However, an imbalance of marine life is not the only negative effect that overfishing has on the Great Barrier Reef.

The initial fishing can also cause damage to the reef as well. The fishing boats create pollution that is harmful to the reef. The equipment that the fishers use, like nets, can also be harmful to the reef, especially if they become unattached from the boat and get tangled in the coral.

Bycatch is another problem affecting the Great Barrier Reef. Bycatch is the unwanted marine life caught by the fishing gear, and it is either kept and killed or thrown back into the water. Many times, if the animal gets thrown back, it hurts or kills the animal and, according to The Rhode Island Sea Grant, the unwanted fish, or discard, “does not become a part of the reproducing population. As a result, discard not only affects the current population, but influences the species’ opportunity to replenish itself.” Bycatch can consist of dolphins and different species of whales.

Photo Credit: habadive.com.au

According to Buzzle.com, about "1/3rd of the Great Barrier Reef is protected by the Great Barrier Reef Marine Park, which prohibits fishing without proper documentation." The Australian government is trying to take action against overfishing in the Great Barrier Reef, but the reef covers such a large area, it is hard to monitor. People need to realize that the reef is unlike anything else in the world, and little things we do, like fishing, add up and cause tremendous damages.

Photo Credit: University of Michigan - Human Impact on the Great Barrier Reef

National Geographic Video

Here is a link to an informative video on the structure and life in the Great Barrier Reef by National Geographic. They also talk a little bit the dangers facing the reef.

National Geographic - Great Barrier Reef Video

A Natural Wonder

I spent the spring of 2009 studying abroad at the University of Sydney. During my five months abroad, I fell in love with Australia and the beauty and diversity of the land. I was fortunate enough to spend a couple days in Cairns, and was able to scuba dive in the Great Barrier Reef. One of the things the instructors kept telling us was that we were going to be the last generation to enjoy the reef because of the environmental factors that threaten it. Before I get into these threats, I would like to talk about the reef and why it is one of the seven natural wonders of the world.


The Great Barrier Reef from Space
Photo Credit: greatbarrierreef.org

As the only living structure that can be seen from space, the Great Barrier Reef spans roughly 1,250 miles down the east coast of Australia. The diversity of sea life is unlike any other. According to BarrierReefAustralia.com, the reef is home to 2,800 species of fish, 400 different types of coral, 500 species of seaweed, and 215 species of birds.

In 2007, an article, "Great Barrier Reef may harbour cures for hundreds of diseases," was published by an online news website called Thaindian News that discussed the medical benefits of the Great Barrier Reef. The author explains that a chemical produced by marine sponges is a key ingredient in the treatment used to treat patients with AIDS.

That article was published 3 years ago. Think of the advances in technology and research in the last three years. Can you imagine how many more natural chemicals and treatments for diseases could be discovered in the Great Barrier Reef in the years to come?

According to Mangobay.com, by 2050, 95% of the coral could be dead. There are so many resources and unknown benefits of the reef, not to mention that it is one of the most beautiful structures in the natural world. It's a shame that there are so many factors working against it, and generations to come will not have the pleasure of enjoying it.


Photo Credit: abc.net.au