Summary: Assess coral bleaching using water temperature data from the NOAA National Data Buoy Center.
Objectives
* Describe the relationship between corals and zooxanthellae.
* Identify stresses to corals.
* Explain coral bleaching and the processes that cause coral bleaching.
* Examine water temperature data and compare to levels known to induce coral bleaching.
* Predict the effects of prolonged, increased temperaturs on coral reefs.
Introduction
The magnificent beauty of a coral reef is a true masterpiece of Mother Nature. A reef is a sculpture of living organisms, varied in color, texture, shape, and size. The creation of these works of art takes many, many years (some reefs are thousands of years old), and they don't exist solely for show. Reefs are building blocks for rich communities, providing habitat for a myriad of organisms, and they are some of the most diverse ecosystems on the planet. In addition, they support fishing grounds, attract tourists, and protect shorelines from waves and storms. "
How does climate change affect coral reefs?
The warmer air and ocean surface temperatures brought on by climate change impact corals and alter coral reef communities by prompting coral bleaching events and altering ocean chemistry. These impacts affect corals and the many organisms that use coral reefs as habitat.
Keeping Coral Clean
Seaweed overgrowth is a major problem for coral reefs and also seems to be a consequence of excessive harvesting of herbivorous fish. Dixson and Hay (p. 804) examined this effect on Fijian reefs. Species of small herbivorous gobies and coral-associated damselfish were compared for their effect on the toxic Chlorodesmis seaweed in experiments that required caging colonies of the branching coral Acropora nasuta and the associated fish species. Only the gobies actively removed algal fronds attached to the cages and only one species (itself toxic to predators) ate them; the damselfish simply defected from the arena when toxic algae were present. The hydrophobic toxins exuded in the algal mucus lysed coral polyps releasing cell constituents that, together with the algal toxin, attract the gobies, which then eat the algal fronds. Interestingly, the toxic goby became more toxic to predators after consumption of the seaweed, which may help to drive symbiosis with a coral colony.
"Some of the planet's most beautiful and diverse ecosystems are at risk. With temperatures on the rise, coral reefs are at greater risk for coral bleaching. Using ocean observing system data from NOAA's National Data Buoy Center, this classroom activity examines ocean temperatures off Puerto Rico to see how coral reefs are being impacted and predict what's on the horizon. Brought to you by Sea Grant's Bridge website and COSEE-NOW.
This activity was developed in response to the 2005 massive coral bleaching event in the Caribbean caused by high sea surface temperatures. Using ocean observing system data, water temperatures can be monitored to evaluate the likeliness of other bleaching events.
Via the COSEE-NOW online community, we were able to receive valuable feedback on making the graph of water temperature more user-friendly and expanding the discussion questions to evoke some higher level thinking from students.
This activity has been demonstrated to teachers at the National Marine Educators Association conference and Virginia Sea Grant professional development institutes; and to graduate students in several different settings.
http://www2.vims.edu/bridge/DATA.cfm?Bridge_Location=archive0406.html"
The shallow water reefs of the Coral Triangle, which stretches across Indonesia and north through the Philippines, host the world's greatest diversity of corals, fish, crustaceans, mollusks, and marine plant species. Now preliminary results from a joint Indonesian-U.S. marine survey indicate that the biodiversity runs deep. A remotely operated vehicle has captured stunning images of massive corals, as well as unusual crustaceans and fish living at depths never before surveyed, thousands of meters below the surface. And mapping of that sea floor has turned up a huge, previously unknown volcano.
Science On a Sphere
Well-crafted visualizations provide unique and powerful teaching tools
Science On a Sphere® is a large visualization system that uses computers and video projectors to display animated data onto the outside of a sphere. Researchers at NOAA developed Science On a Sphere® as an educational tool to help illustrate Earth System science to people of all ages. Animated images of complex processes such as ocean currents, sea level rise, and ocean acidification are used to to enhance the public's understanding of our dynamic environment.
Ocean Acidification on Science On a Sphere®
The movies below were developed for use on Science On a Sphere® and show computer model simulations of surface ocean pH and carbonate mineral saturation state for the years 1895 to 2094.
The first movie shows a computer recreation of surface ocean pH from 1895 to the present, and it forecasts how ocean pH will drop even more between now and 2094. Dark gray dots show cold-water coral reefs. Medium gray dots show warm-water coral reefs. You can see that ocean acidification was slow at the beginning of the movie, but it speeds up as time goes on. This is because humans are releasing carbon dioxide faster than the atmosphere-ocean system can handle.
"Oil Exploration
Oil Exploration
Gulf Drilling Disaster Triggers Scrutiny of Mediterranean Oil Rush
1. Laura Margottini*
A rush to find and extract oil in the Mediterranean Sea is threatening one of the planet's marine biodiversity hot spots, scientists warn.
PANTELLERIA, ITALY-This tiny speck in the Mediterranean, home to a few thousand people, seems like one of the most tranquil places in the world. But looks are deceptive. Pantelleria, in the Strait of Sicily halfway between Palermo and Tunis, is close to one of the world's busiest shipping lanes, and of late, its waters have also become the center of a new oil rush. Attracted by Italy's easygoing drilling regulations and low tax on oil extraction, dozens of companies have new plans for exploration and drilling in this part of the Mediterranean Sea.
At a recent meeting here,* however, scientists, conservationists, and environmental activists warned that such efforts put several important biodiversity hot spots in danger. An oil disaster like the Deepwater Horizon explosion, which sent oil gushing into the Gulf of Mexico for months, could easily ruin the Mediterranean ecology for a century or longer, some said.
The Italian government has recently issued 66 permissions for drilling around its coasts and 25 concessions for exploration. Another 67 applications for exploration are under review. "Italy now represents the region that holds the most exciting and significant long-term opportunities," one company, Northern Petroleum, says on its Web site. The Strait of Sicily is the center of attention, but other biodiversity hot spots, such as the Tremiti Islands in the Adriatic Sea, could soon be explored as well.
Italy isn't alone. Tunisia, for example, has granted concessions for oil exploration for most of its Mediterranean waters, without much political opposition. But the areas coveted by oil companies are ecological treasures, researchers and groups such as Greenpeace Italy stress. Last year, the Uni
Isles of Abundance
Britain has taken another step toward designating the world's largest marine reserve around the Chagos Islands, a group of 55 coral protrusions in the Indian Ocean. The government announced the end of a 4-month public comment period on 5 March and is expected to reach a final decision by May.
The Chagos contain half of the Indian Ocean's remaining healthy reefs. The waters are said to be among the cleanest on Earth, allowing corals to grow in deep water less vulnerable to global warming. The islands are located in the equatorial "tuna belt," which hosts what a Royal Zoological Society of London report called one of the "most exploited, badly enforced fisheries in the world."
A total ban on fishing in the 544,000-square-kilometer zone, an area the size of France, would make it an even larger protected area than the current record-holder, the 360,000-km2 Papahanaumokuakea Marine National Monument in the northwestern Hawaiian Islands. The Pew Environment Group has spearheaded a 3-year campaign for creation of a Chagos reserve. It would be "literally an island of abundance in a sea of depletion," says Pew's Jay Nelson.
The islands are uninhabited except for the U.S. Navy base on Diego Garcia. Some 1500 Chagossians were deported to Mauritius in the 1970s for military security.