From warming and coral bleaching to diseased corals, Guam continues to face challenges with its reefs. Some, however, are still unsure whether these events are a direct result of climate change, considering other factors.
Presenting on climate change and reef resilience Tuesday during the 4th Guam Coral Reef Symposium at the Conference on Island Sustainability were Mark Lander, a meteorologist with the Water and Environmental Research Institute at the University of Guam; David Burdick, a research associate from the UOG Marine Laboratory; and Laurie Raymundo, a professor at the UOG Marine Lab.
Burdick gave a presentation on the resilience of Guam’s reefs to climate change impacts, noting Guam’s first widespread, severe coral bleaching event in 2013, followed by another in 2017.
Yearly bleaching anticipated by 2050
He predicted that by 2030, Guam’s surrounding waters will see bleaching events every one to two years and that, by 2050, Guam might see a bleaching event every year and can anticipate a mass bleaching event.
His studies showed that northern Guam, in some places, has a more resilient reef than that of southern Guam, with deep-water resilience patterns being driven by herbivorous fish biomass and shallow-water resilience being bleaching resistance.
To help control the events, Burdick suggests continuing the work being done to improve water quality, crown-of-thorns predation, herbivorous fish populations and other reef-restoration activities.
Raymundo spoke on whether bleaching increases corals’ susceptibility to the white syndrome disease among staghorn acropora, concluding that, though stressed corals are more susceptible to disease, Guam’s diseased corals are not linked to temperature change.
Warming and cooling trends
Though the region can expect to grow increasingly warm, Lander, who spoke briefly on the climate of Micronesia, concluded that the region is both warming and cooling.
Lander presented several charts depicting the coinciding warming and cooling trends throughout the Micronesian islands of Guam, Yap, and Palau through the years, from the 1950s through 2019.
The region’s warmest year was 1998.
Lander also explained that Guam’s sea level has risen 12 centimeters since 1998 and remains at that level. He attributed the level “almost entirely” to trade winds, and not to warming effects, such as melting icebergs. Whether the cause is due to climate change, Lander is still uncertain.
He added that Guam’s rainfall is highly variable and is heaviest during typhoon season. According to Lander, Guam can see between 50 and 160 inches of rain in a year.
The meteorologist noted the island has experienced a drop in the number of typhoons. Though fewer, Lander said the storms the island does experience may become more intense.
Source: Google News : https://www.postguam.com/news/local/guam-s-corals-still-threatened-despite-questions-on-warming/article_d7886b8c-3182-11e8-944e-abb8d2aca2f9.html