by Wendy Whitcombe
Originally published at ScientificAmerican.com
When I applied for this course – Integrated Ecosystem Management in Micronesia – I had no idea about the history that I would literally be diving into. Before my classmates and I left for Guam, Dr. Haw and Dr. Ginsburg instructed us on the history and culture of Guam. Little did I know the effect this would have on my experience there.
In Apra Harbor, specifically Western Shoals, my classmates and I laid several transect lines each measuring 100 meters to measure substrate and count invertebrates. The coral coverage was amazing. In 30 feet of water the transect had 100 percent coverage consisting of multiple species of coral. The mountains of coral formed tunnels, impressive sculptures and huge overheads. It was breathtaking with the consortium of fish species.
Later, we motored across the harbor to SeaBee Junkyard, a site near the break wall where discarded World War II equipment lies along 200 meters of harbor bottom. The difference in the two sites was drastic. Some coral had grown on the World War II–era trucks, bulldozers and landing craft, but nothing compared to the abundance at Western Shoals. It took 50 years for the meager coral coverage to form at SeaBee Junkyard.
Currently, the U.S. military is debating whether or not to dredge the area immediately next to the reef we saw on our first dive in Western Shoals. The military wants to be able to permit an aircraft carrier to turn in place in the harbor near an anchorage. In order to construct this proposed site for the carrier, it is necessary to eradicate 72 acres of the reef near Western Shoals. The Environmental Impact Statement (EIS) submitted by the military received the lowest grade given by the Environmental Protection Agency (EPA). The environmental damage that will be done by dredging these reefs will greatly impact fish species and more specifically surrounding reefs.
My classmates and I had the opportunity to talk with Dr. Jason Biggs, a professor at the University of Guam. He helped write the response to the Environmental Impact Statement. Dr. Biggs discussed the results of the military’s plan of action. Dredging on 72 acres impacts 200 acres of surrounding reef. Although the military claims silt nets will be used to restrict the sedimentation from dredging, research has shown these nets to be futile. Sediment particles can be suspended in the water for long periods of time. Therefore, while churning the bottom and emitting sediment into the water, there will be huge increases in turbidity.
One effect is that this will decrease the amount of sunlight for corals to perform photosynthesis and grow. The estimated four years of dredging will completely alter the environment critical for coral to reproduce and grow. Once changed, this vital habitat will be lost along with acres of mesmerizing natural construction. It has taken thousands of years for the Western Shoals reef to multiply and grow into the majestic, towering city for marine life it is today.
These dives have helped me realize that some history cannot repeat itself. Once destroyed, history for these reefs virtually stops. What took thousands of years to create will be undone in 4. It may be the last opportunity in my lifetime that I or anyone else can dive in this ancient reef.
Wendy Whitcombe is a sophomore working toward a bachelor’s degree in environmental studies at USC Dornsife.