Scientist shine light on global seagrass crisis

(December 1, 2006) After more than 30 years of studying Chesapeake Bay seagrasses, VIMS researcher Dr. Robert Orth is well aware that this vital resource is in serious trouble, beset by a host of ills including excess nutrients, turbid water, and a warming climate.

Now, a new study by Orth and an international group of colleagues reveals what may be the most troublesome finding of all: the seagrass problem is global, yet the public remains largely unaware of its scope and significance.

The study, which appears in the December issue of BioScience, was conducted by Orth and 12 other members of the Global Seagrass Trajectories Working Group, part of a national effort to promote the analysis and synthesis of ecological information.

The group includes scientists from the United States (Alabama, California, Florida, Maryland, Virginia, New Hampshire, and NOAA's National Ocean Service), Australia, and Spain. It is supported by the National Center for Ecological Analysis and Synthesis (NCEAS), a center funded by the National Science Foundation, the University of California at Santa Barbara, and the state of California.

Orth's team found that reported cases of seagrass loss have increased almost tenfold over the last 40 years, in both tropical and temperate regions. Says Orth, "We compiled reports of seagrass loss from as far north as Denmark, as far south as Australia, and from the Chesapeake Bay to the Mediterranean, the Indian Ocean, and Japan."

The scientists argue that these losses constitute a global crisis for seagrasses, and attribute the losses largely to human activities in the coastal zone, as well as the increased frequency and intensity of hurricanes and other catastrophic weather events.

Despite the magnitude and rapidity of these losses, the team found that seagrasses receive from 3- to 100-times less media attention than coral reefs, salt marshes, and mangroves—even though seagrasses deliver "ecosystem services" that are at least twice as high as these other imperiled habitats. Among other services, seagrasses provide a home for many important fish and shellfish species, limit erosion, soak up nutrients, and help improve water clarity.

Orth attributes the public's lack of knowledge concerning the issue largely to the "invisibility of seagrasses." "These plants grow underwater," he notes, "and in very shallow areas that most boaters avoid. Also, the animals that seagrasses harbor are often small and hidden, in contrast to the large and dazzling organisms that attract the general public to coral reefs."

"We're doing a lot of research," says Orth, "but we're making minimal impact with the public except in the most developed parts of the world. Based on media reports of scientific papers, we're pretty low on the totem pole. Without strong public support, seagrass conservation efforts will continue to lag behind those of other key coastal ecosystems."

To address the crisis effectively, Orth's team recommends a two-pronged effort that combines increased conservation efforts with education for the public and resource managers.

"One of our goals in the NCEAS project," says Orth, "is to educate people about the value that seagrasses provide and how important they are compared to coral reefs, mangroves, and other coastal ecosystems. Right now we're the 'ugly duckling' of these charismatic habitats, but hopefully we're going to change that."