Seaweed, Injection Wells Suspects In Reef Decline

A recent study shows that the proportion of the seafloor covered with coral is declining rapidly in some parts of Maui. Invasive alien seaweeds are blamed in part, but there could be other factors, says Russell Sparks of the state Department of Land and Natural Resourcesu Division of Aquatic Resources. The proximity of sewage injection wells is suspected as well. Some areas are seeing increased coral growth because they are recovering from storms, which can grind a reef to bits. At two study sites in the Ahihi-Kinau Natural Area Reserve u" both relatively insulated from human influences u" the coral is expanding at one and retreating at the other. Ten Maui sites have been studied regularly for the state by Eric Brown, a coral reef researcher at the University of Hawaii at Manoa. Earlier this year, a study reported that in Maalaea Bay the coral reef ecosystem is near collapse. Coral coverage there had been at least 50 percent in 1993 (and may have been as much as 75 percent), but it was down to 8 percent by 2006. Molokini, a remote and protected area, serves as a benchmark. Its coverage has remained steady at around 75 percent, Sparks said. Areas with the biggest swings in favor of algae are close to four areas where sewage injection wells are suspected of providing nutrients for seaweed. They are Maalaea, where the injection wells are private, connected to condominiums and the shopping center; and Lahaina, Kihei and Kahului, where the county has wastewater treatment plants...