|
Coral reefs are the crown jewels of the oceans. Teeming with life, they are hotspots of biological diversity. Coral reefs provide bountiful fishing grounds, serve as nurseries for a host of economically important marine organisms, and buffer our shorelines from the pounding surf of coastal storms. Like tropical rain forests, coral reefs are promising grounds for "bio-prospectors" seeking the next generation of wonder drugs and natural chemicals. The colorful, busy spectacle of schooling fish, swaying plants and soft corals, and the occasional passing sea turtle make coral reefs a yearly destination for millions of snorkelers, SCUBA divers, and other eco-tourists.
But for all their beauty and value, coral reefs are in trouble.
Stresses such as rising seawater temperatures, destructive and unsustainable fishing practices, dredging, shipwrecks, and increases in the amount of sediment, nutrients, and contaminants running off land and into coastal waters are making life hard on stony corals. These are the living organisms that build the hard, rock-like infrastructure that provides habitat to the abundant and diverse reef community. Recent research has shown a 21% reduction in the surface area of living corals worldwide over the past few decades. Ten percent of corals are so degraded that scientists do not expect them to recover.
| What is coral? |
|
|
| Brain Coral (Diploria strigosa) |
The keystone to a coral reef community—one of the world's most complex and biologically diverse ecosystems—is the stony coral. While many look like odd rock formations, stony corals are actually animals living in a symbiotic relationship with unique algal cells.
The animal exists as tiny, anemone-like polyps that live colonially and deposit a calcium carbonate skeleton as they grow (hence the name "stony" coral). The living tissue of coral is a thin layer covering the outer surface of the skeleton. The algal cells live inside the polyps and capture the energy of the sun through photosynthesis, helping the coral grow and reproduce. The rocky skeleton structures built by coral provide habitat to the many other organisms that live in the coral reef ecosystem, so the more they grow and the bigger they get, the more habitat becomes available to the coral reef community.
EPA's coral reef Web site.
|
"At the core of the diverse and complex coral reef ecosystem is a living organism—the stony coral. Because human activities are creating stresses for them, entire reef communities are threatened," explains William Fisher, a marine biologist with the U.S. Environmental Protection Agency's (EPA) Office of Research and Development. "The plight of coral is a great example of the interconnections among ecosystems, and helps us remember that what we do on land affects life in the water."
Because coral reefs are often some distance offshore, field research usually requires a boat and crew to ferry marine biologists and other specialists to and from the reef. Fisher's team is housed on board EPA's 224-foot Ocean Survey Vessel BOLD, which provides a base for the team's research to develop methods for assessing the condition of coral reefs. The team recently introduced a "Stony Coral Rapid Bioassessement Protocol," a procedure to effectively measure stony coral condition using rapid underwater surveys. It is expected that using the Protocol will increase our understanding of coral reefs in the waters off U.S. states and territories, and hopefully help protect them.
The Protocol outlines a routine for taking a reef's vital signs, giving biologists and others a way to monitor the stony corals and the overall health of the ecosystem. "The objective is to provide an efficient, inexpensive, and nondestructive method that generates useful indicators for land and coastal managers to monitor conditions on the reef," says Fisher.
The research team identified three core measurements that provide indicators of coral health. Because researchers take these measurements under water using SCUBA diving gear, the team kept the procedures fairly simple so researchers could take measurements quickly. Divers identify the corals species, measure the size of the colonies, and estimate the proportion of living tissue covering the surface. Because a stony coral colony is comprised of many individual polyps (see side bar for details) some of the polyps can die without affecting the others, leaving the colony partially alive and partially dead. Calculations made from the three core measurements provide useful information to managers on coral and reef health.
States, Tribes, and Territories looking to conduct routine monitoring to help protect their coral reefs are often limited by budgets. The standardized and efficient Stony Coral Rapid Bioassessment Protocol is expected to help researchers obtain reliable information while minimizing the costs of coral reef monitoring.
Protecting Reefs
While saving costs is certainly welcome, saving coral is the ultimate goal. "By learning what conditions to look for, we can work with the jurisdictions to identify reefs at risk and assess the effectiveness of protection techniques," says Fisher. "For example, we think that setting water quality standards to specifically protect reefs could be particularly effective."
The Clean Water Act calls on the EPA to set such standards in large part to restore and maintain the biological integrity of the nation's waters, including "the protection and propagation of fish, shellfish, and wildlife, and recreation in and on the water." These are things coral reefs have in abundance.
EPA's coral reef research program is advancing the scientific understanding of coral reefs and providing tools aimed at stemming coral reef degradation. It's part of a broader, international effort that has led to the formation of the U.S. Coral Reef Task Force and to the naming of 2008 as the International Year of the Reef. Without such efforts, the crown jewels of the world's oceans will continue to fade.
|
Fossil Fuel
