4th+grade+Coral+Reefs

http://www.ecokids.ca/PUB/eco_info/topics/oceans/coral_reefs.cfm (printed 3-1)

http://news.nationalgeographic.com/news/pf/10063392.html (printed 3-1)

**Coral Reefs (printed 3-1)**

Treasures of the Sea
**The whimsical names of corals—bubble, staghorn, starburst and brain—hint at their spectacular appearance, but not necessarily at their true value. As the largest living structures on the planet, coral reefs are also among the greatest storehouses of biodiversity on Earth.**

**Coral reefs are also one of the most threatened marine systems. Scientists estimate that unless we take immediate action, we could lose up to 70 percent of coral reefs by 2050.**

**Causes:**

**Nutrients**

The health and diversity of coral reefs are threatened by excess nutrients carried into the ocean from the terrestrial and coastal zone. Discharged sewage (treated and untreated) and industrial pollutants as well as surface run off containing traces of agricultural fertilisers, animal waste and sediments from deforested areas alter the natural balance of nutrients in the ocean. This influences the survival, growth, reproduction and recruitment of corals as well interactions of corals with other marine organisms.

**Ocean acidification**

As carbon emissions from human activities cause atmospheric levels of CO2 to rise, the amount of CO2 absorbed and released by the ocean can become imbalanced. Atmospheric levels of CO2 have risen from pre-industrial levels of ~280 parts per million (ppm) to today’s level ~387 ppm with the ocean absorbing approximately 30% of CO2 from the atmosphere.

As CO2 is absorbed into the ocean from the atmosphere, it naturally dissolves in the seawater to form carbonic acid (H2CO3). As further hydrogen ions are loss, the dissolved CO2 can form bicarbonate (HCO3–) and carbonate (CO32–). As the ocean absorbs greater amounts of CO2, changes in the proportions of these three carbon forms which can increase ocean acidity and **low concentrations of carbonate ions**.

Corals and calcareous algae use carbonate and calcium ions to build their calcium carbonate (CaCO3) skeletons which form and strengthen the underlying structure of coral reef systems. As the availability of carbonate ions decreases, the production of coral skeletons will slow or form at a lower density than usual causing a weakness in the reef framework. If calcification rates in corals and coralline algae slow, erosion levels may exceed reef growth destabilising coral reef structures.

**Sea level rise**

Historically, the growth rate of corals has matched or exceeded the rate of rising sea surface levels. However, scientists fear that the predicted rates of sea level rise for the turn of the next century (~10 mm/yr) are greater than coral reef growth rates (~6 mm/yr). If the rate of sea level rise exceeds coral growth, coral reefs living at their lower depth limits could drown. The impact of sea level rise could become more serious if the calcification rates of coral slow as a result of ocean acidification. As well as the potential for drowning coral reefs, the rise in sea levels is expected to increase rates of coastal erosion and sedimentation. This in turn could pose a further threat to coral reefs.

**10 Easy Steps to Help Protect Coral Reefs**
Do you want to make a difference every day? Want to learn about simple, effective actions you can take to help save coral reefs and the fish, animals, and plants that depend on them? You've come to the right place!
 * 1) **Conserve water:** The less water you use, the less runoff and wastewater will pollute our oceans.
 * 2) <span style="font-family: Times New Roman,serif;">**Help reduce pollution:** Walk, bike or ride the bus. Fossil fuel emissions from cars and industry raise lead to ocean warming which causes mass-bleaching of corals and can lead to widespread destruction of reefs.
 * 3) <span style="font-family: Times New Roman,serif;">**Use only ecological or organic fertilizers:** Although you may live thousands of miles from a coral reef ecosystem, these products flow into the water system, pollute the ocean, and can harm coral reefs and marine life.
 * 4) <span style="font-family: Times New Roman,serif;">**Dispose of your trash properly:** Don't leave unwanted fishing lines or nets in the water or on the beach. Any kind of litter pollutes the water and can harm the reef and the fish.
 * 5) <span style="font-family: Times New Roman,serif;">**Support reef-friendly businesses:** Ask the fishing, boating, hotel, aquarium, dive or snorkeling operators how they protect the reef. Be sure they care for the living reef ecosystem and ask if the organization responsible is part of a coral reef ecosystem management effort.
 * 6) <span style="font-family: Times New Roman,serif;">**Plant a tree:** Trees reduce runoff into the oceans. You will also contribute to reversing the warming of our planet and the rising temperatures of our oceans. Help us Plant a Billion.
 * 7) <span style="font-family: Times New Roman,serif;">**Practice safe and responsible diving and snorkeling:** Do not touch the reef or anchor your boat on the reef. Contact with the coral will damage the delicate coral animals, and anchoring on the reef can kill it, so look for sandy bottom or use moorings if available.
 * 8) <span style="font-family: Times New Roman,serif;">**Volunteer for a coral reef cleanup:** You don't live near a coral reef? Then do what many people do with their vacation: visit a coral reef. Spend an afternoon enjoying the beauty of one of the most diverse ecosystems on the Earth.
 * 9) <span style="font-family: Times New Roman,serif;">**Contact your government representatives:** Demand they take action to protect coral reefs, stop sewage pollution of our oceans, expand marine protected areas and take steps to reverse global warming.
 * 10) <span style="font-family: Times New Roman,serif;">**Spread the word:** Remember your own excitement at learning how important the planet's coral reefs are to us and the intricate global ecosystem. Share this excitement and encourage others to get involved. Send a free coral reef e-card today!