Study tracks 20 years of ecological change for Laolao Bay coral reefs

Extensive coral reef surveys were recently completed across Laolao Bay in conjunction with an American Recovery and Reinvestment Act grant awarded to the Division of Environmental Quality, and the results are now available online (http://www.pacmares.com/Laolao_Bay.html).

The ARRA-funded project activities include ongoing road construction and drainage improvement in the western portion of the bay that will decrease land-based pollution being washed into the bay during storm events. The project also includes multi-year, revegetation efforts that aim to replant barren savannah uplands with native trees and shrubs. In association with these activities, ecological and water quality monitoring are being conducted by the Pacific Marine Resources Institute, a Saipan-based non-governmental organization conducting coral reef conservation research across the Pacific, in collaboration with THE CNMI’s marine monitoring program (comprising members from DEQ and Coastal Resources Management offices).

According to PMRI’s Dr. Peter Houk and DEQ ecologist Dr. Ryan Okano, the main goal of coral monitoring efforts was to produce a set of baseline conditions upon which the hopeful success of this project can eventually be evaluated. The released findings provide a comprehensive, pre-construction assessment of the coral reef condition in Laolao. But more influentially, a similar set of extensive surveys were conducted in 1991, in conjunction with the development of the Laolao Bay Golf Course. Thus, the current effort offers unique insight regarding change over the past 20 years—information that is rarely available to scientists and resource managers.

While the CNMI’s coral monitoring and management program has been documenting negative trends in coral abundance and diversity over the past 10 years, the new findings offer deeper insight. For example, along with declining coral condition there have been increases in macroalgae (or seaweeds) that are now beyond levels that can be considered “normal” or “healthy,” especially on the shallow reef flats. Unfortunately, enhanced algal growth hampers the settlement of new corals, and the cycle of life and physical structure on coral reefs. Houk describes that one major problem besides the increase in land-based pollution over the years has been a significant reduction in fish density, especially herbivorous fish that are know to eat macroalgae. Together, pollution and reduced herbivory represent the greatest localized threats to coral reefs worldwide. The positive news is that both are very manageable, but action is needed immediately. Laolao Bay is one of Saipan’s most desirable coastal areas, with some coral reefs valued at over $10 million per square kilometer based upon a recent economic study.

If Laolao’s reefs are to remain healthy and improve their ability to recover from natural disturbances such as typhoons and coral-eating starfish outbreaks, strategic plans are necessary to prioritize actions and generate funding. Such a strategic plan is exactly what DEQ used to win major ARRA funding to begin improving conditions in Laolao; however, more efforts are underway and will be needed.

“I was excited to have the chance to work with the excellent local monitoring and management programs that are building institutional support, public knowledge, and appropriate science necessary to define and evaluate CNMI’s marine resources,” said Houk. “If tourism is a major part of the local economy, then it only seems logical that healthy coral and fish populations will help to maximize our visitors’ experiences, and thus, economic gain.”[I] (PR)[/I]