The beauty and diversity of coral reefs is undeniable: nestled among the strangely shaped coral are a myriad of fish and other marine animals that help support local economies by providing jobs and increasing tourism. In addition, coral reefs are considered to be the “medicine cabinet” of the future, harboring organisms that may lead the way in the development of new medicines.
However, despite their importance, coral reefs are being damaged at an alarming rate. In fact, some scientists estimate that 60% of coral reefs around the world will be lost by 2030 if present rates of decline continue. They are extremely vulnerable to climate change, overfishing, and coastal pollution.
On Thursday, May 18, at 7:00 p.m., at the University of Delaware’s College of Marine Studies in Lewes, Mark Warner, assistant professor of marine biology-biochemistry, will present “Coral Reefs: Trouble in Paradise?” The lecture is part of the Ocean Currents Lecture Series, which is held on the third Thursday of the month, from April through September, at the Hugh R. Sharp Campus.
Coral reefs, which can take thousands of years to form, are composed of living and growing marine organisms called “polyps.” The polyps produce calcium carbonate or limestone that is left behind as it grows, building the structure of the reef. The surface of the reef, however, is covered with a thin veneer of living polyps, which are essentially only two cell layers thick.
In his presentation, Warner will discuss some of the major threats facing coral reefs today. For example, coastal development has caused increased sedimentation and pollution in the water, which blocks the sunlight that reefs need to grow. In addition, thousands of pounds of live coral are mined for construction purposes every year.
“The increase in atmospheric carbon dioxide due to human activities also affects coral reefs,” says Warner. “The carbon dioxide dissolves in the ocean in increasing amounts, raising the acidity of the ocean, and it becomes harder for the coral to make the calcium carbonate crystals that make up its skeleton.
“We may be looking at corals that can’t grow as quickly,” adds Warner. “They may become more brittle and break more easily, which are two bad things for a reef that must face seasonal damage by hurricanes and typhoons as well as physical damage by humans.”
Warner also will discuss his current research on coral bleaching in which the algae that live inside the polyps, providing them with the nutrients they need to grow, are expelled or die. Some algae are extremely susceptible to even a slight rise in seawater temperature. Warner is now working to determine whether other algae can better withstand rises in seawater temperature.
“My own work has shown there is a good biochemical basis for thermal tolerance in some of these algae,” says Warner. “What we don’t yet know, however, is if previously bleached corals can actually acquire new algae that may be better adapted for future warming events.” Warner joined the College of Marine Studies in 2001. He earned his doctorate in ecology and a bachelor’s degree in zoology from the University of Georgia in Athens, where he also completed a postdoctoral fellowship. In addition to his work on coral reefs, he is investigating how light affects the biological processes of several species of microalgae found in Delaware waters.
The lecture will begin at 7:00 p.m. in Room 104, Cannon Laboratory, at the Hugh R. Sharp Campus, 700 Pilottown Road, Lewes. The hour-long talk will be followed by light refreshments.
While the lecture is free and open to the public, seating is limited and reservations are required. To reserve your seat, please contact the college at (302) 645-4279.