A reprint from American Scientist the magazine of Sigma Xi, The Scientific Research Society

This reprint is provided for personal and noncommercial use. For any other use, please send a request to Permissions, American Scientist, P.O. Box 13975, Research Triangle Park, NC, 27709, U.S.A., or by electronic mail to [email protected]. ©Sigma Xi, The Scientific Research Society and other rightsholders 178 American Scientist, Volume 102 © 2014 Sigma Xi, The Scientific Research Society. Reproduction with permission only. Contact [email protected]. Sightings

Taking a Digital Dive

A new global survey gets the best look yet at the world’s imperiled reefs.

Catherine Clabby

or years, Richard Vevers was exasperated by how Vevers likes the attention that the beauty shots attract. few people were aware of the threats to coral reefs, But he recognizes that the most scientifically significant vital habitats built by tiny invertebrates and the sym- photos are the less picturesque ones made by the survey biotic algae that feed them. A full quarter of all ma- cameras that point straight down. Traditionally, marine Frine species globally depend on tropical reefs as nurseries, scientists have assessed much the way botanists food sources, or lifelong homes. That entire ecosystem is in a count plants on land, only in scuba gear: They lay down precarious situation. Nineteen percent of all cataloged reefs quadrants, or square frames, on portions of a reef and have already been destroyed, scientists estimate; 35 percent photograph what lives inside those borders. No more than of what survives could disappear by 2050 due to destructive 250 square meters of healthy, ailing, or dead corals could fishing practices, pollution, and rising ocean temperatures. be documented on each dive. From those relatively small Nature photography intended to celebrate the amazing samples, the researchers then extrapolate about a reef’s underwater diversity may have inadvertently contributed overall makeup and health. to the problem. “When people see images they see the nice The Catlin survey records 4,000 square meters of reef per reefs. There is a perception that is very, very different from dive, delivering a deluge of data that has created new chal- the reality,” says Vevers, himself an underwater photogra- lenges. Computer vision specialists at Scripps are adapting pher as well as a marine conservationist. facial-recognition software invented by the Central Intel- Vevers decided to update the picture. He recruited ligence Agency to count and classify corals in the huge friends from the advertising industry, where he used to inventory of photos. “Hopefully we’ll get to the point work, to create a more honest portfolio of both healthy and where we can get information from hundreds of thousands ailing reefs. His original plan was to compile photos only of images within six months to a year, rather than 10 years, and share them globally for free. Then an international in- which is probably what it would take if you did it manu- surance company, Catlin Group, agreed to fund the project ally,” says David Kline, a Scripps biologist affili- with more than $1 million, if Vevers expanded it to include ated with the survey. data with scientific significance. This spring, the survey began work in biodiversity-rich The result is the Catlin Seaview Survey, developed by waters off the Philippines. Marine scientists planned to look Underwater Earth (an Australian nonprofit group Vevers for signs of damage from crown-of-thorn starfish, coral founded) and by marine biologists at the University of predators that live on reefs. The starfish don’t normally Queensland, the Scripps Institution of Oceanography, and cause lasting harm, but their populations can swell to de- elsewhere. Since 2012 the project has been building up a structive levels in places where fertilizer and other nutrients visual catalog of the world’s shallow reefs (depths less than wash from land to sea. Catlin survey cameras may also 20 meters), at a scale and resolution never before attempted. document damage caused by trash, boat groundings, and Photographers, researchers, and students conducting the illegal fishing. Catlin survey use three bundled waterproof cameras that In keeping with Vevers’s original vision, the survey data fire at once and capture complete, 360-degree underwater are being made available for free online, posted at the Catlin scenes every three seconds. Along with dangers such as Global Reef Record (http://globalreefrecord.org). The im- and debris, the survey has documented age bank should help conservationists locate thriving reefs much underwater splendor at the , in the that are good candidates to safeguard in new marine pre- Coral and Caribbean Seas, and off Bermuda, the Galápagos serves, says Manuel González-Rivero, a Queensland post- Islands, and Monaco. In 2012, Google launched an under- doctoral researcher coordinating the shallow reef survey. water “street view” that can create custom, virtual dives The photos may also help identify which corals are most using imagery from the survey. resistant to habitat degradation. One welcome surprise from the Catlin project is that it A fisheye-lens view of the Wilson Reef, located at the northern reach- is stirring hope, despite its abundant evidence that people es of the Great Barrier Reef off Australia, was captured by the Catlin are harming reefs. “Yes, we are impacting the reefs,” says Seaview Survey. In 2012 the survey started out by collecting images of González-Rivero, “but there still are areas with great poten- this reef system, the largest in the world. tial to be protected.” www.americanscientist.org © 2014 Sigma Xi, The Scientific Research Society. Reproduction 2014 May–June 179 with permission only. Contact [email protected]. A biodiversity map (above), developed at the Scripps Institution of Oceanography, is created with com- puter software that selects random points on survey photographs for analysis. Survey panoramas give a more sweeping view of reefs, including a spot off Bermuda (right) where corals pierce the sea surface.

To capture 360-degree underwater views, the survey packs three cameras in waterproof cases (left). Fish-eye lenses pointing to both sides and downward generate globe-shaped images (top) that can be combined with others to make panoramas. Off the coast of Bermuda, survey photographs (above) document healthy and bleached fire corals.

180 American Scientist, Volume 102 © 2014 Sigma Xi, The Scientific Research Society. Reproduction with permission only. Contact [email protected]. Green-tipped anemone coral (left) thrive at the Great Barrier Reef. Off St. Vincent Island in the Caribbean, survey divers photographed fishing nets (right) dropped onto the coral reef. Fishing nets can harm reef ecosystems by removing fish and other organisms that contribute to the health of corals, ecologists say. www.americanscientist.org © 2014 Sigma Xi, The Scientific Research Society. Reproduction 2014 May–June 181 with permission only. Contact [email protected].