CORVALLIS, Ore. - Some long-term research on the vast coral reefs around American Samoa has revealed a success story in efforts to halt destruction of these threatened ecosystems and shown that sustained efforts to rebuild them can be effective.
A recent survey by geographers from Oregon State University, using submersibles to study the reefs at depths rarely seen before, showed that in general the reefs are not only doing well, but some species are thriving that weren't even known in the area before.
The scene is radically different than it was about 20 years ago, said Dawn Wright, a professor of geosciences at OSU who has mapped and observed submarine terrain all over the world.
"American Samoa historically had some outstanding coral reefs, and is the only real tropical setting of the 13 national marine sanctuaries in the U.S.," Wright said. "But they were almost wiped out in the 1990s by hurricanes, a starfish invasion, and even dynamite fishing. Tuna factories poured raw sewage into the harbor, and there has been additional pollution from trash dumped into the ocean at beaches, and estuaries fouled by polluted stream runoff."
Since then, she said, a grass-roots educational program has helped educate the local public about the fragile nature of their reefs, created informational sessions in schools and villages, cut back on the abuses and stopped much of the pollution. Wright has assisted with some of these research and public outreach efforts for years.
"The programs worked," Wright said. "This amazing marine sanctuary now has a nearly clean bill of health after almost being destroyed. These coral reefs are like the rainforests of the ocean, places that are rich in biodiversity but easily degraded and lost. So to be able to save a treasure trove like this, which has over 140 species of corals and fish, is pretty encouraging."
The advances have been sufficient, Wright said, that there are discussions about establishing other protected areas throughout American Samoa. That was the focus of some of the most recent work in Samoa, in which direct observations were made from the Pisces V submersible at depths up to 400 meters, far beyond where corals can exist.
"With a submersible we can reach the 'twilight zone' at around 120 meters depth, which is one of the least explored parts of our oceans," Wright said.
"Our dives revealed 32 species of invertebrates and 91 species of fish," she said. "And we also found nine new species of fish and corals that were unknown to this area, raising some questions about how they were transported there from other parts of the ocean."
The research, Wright said, also helped confirm the accuracy of a "benthic terrain modeler" developed at OSU, a software system that can help predict what types of life may be found in certain areas, based on what is known about the physical nature of the ocean terrain. This system may also find use off the Oregon coast, she said, especially with a movement being considered to map it in more detail than ever before.
The recent studies were supported by a $230,000 grant from the National Undersea Research Program, and used ships and facilities from the Hawaii Undersea Research Laboratory. More details on this work can be found on the web at http://dusk.geo.orst.edu/djl/samoa/hurl
Data and findings from the OSU research will be used to aid decisions about the development of additional marine protected areas in American Samoa, Wright said.
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