Environmental Science Research Track

Master of Science Environmental Science

RESEARCH TRACK

Guam and the Western Pacific offer extraordinary and unique research opportunities

The Western Pacific is legendary for the spectacular natural beauty of its lush tropical islands scattered across its vast deep-blue ocean. In the Mariana Archipelago, the sheer limestone cliffs of Guam, Rota, Tinian, Aguijan, and Saipan soar up to hundreds of feet above coconut-lined coral sand beaches, while the white surf batters the rims of the surrounding reefs. In the Caroline Islands to the south and eastward, the verdant slopes of Yap, Chuuk, Pohnpei, and Kosrae rise from the sea, and scores of remote atolls surround shimmering pristine lagoons that abound with turtles, flying fish, and a fascinating assortment of other creatures. The region is also home to some extraordinary planetary-scale natural phenomena, including the Mariana Trench, and the northern fringe of the West Pacific Warm Pool. Powerful typhoons spawn in the equatorial waters to the southeast and sweep across the region. The western Pacific is also notable for its seismic and volcanic activity. El Nino events bring punishing droughts, and storm surges and tsunamis can depopulate the low-standing atoll islands of Micronesia.

The region’s strategic geographic position has given it a unique and turbulent human history, extending from the first prehistoric settlement by people from Southeast Asia, to discovery and colonization by the Europeans beginning in the 16^th Century, to the cataclysmic battles between the United States and Imperial Japan during Word War II. More recently, the effects of economic development and prosperity are increasingly placing at risk some of the very beauty and charm of the region that have made it so attractive to residents, immigrants, tourists, and investors. The combination of its natural setting and the consequences of development make the region a unique natural laboratory for environmental scientists. Local problems of scientific interest range from control strategies for invasive species, to the protection of drinking water and estuaries into which coastal groundwater discharges, to the management of coral reefs and fish populations. Opportunities for work on global and regional phenomena include the study of West Pacific Warm Pool climate history, the regional effects of ENSO events, and the cause and effects of global and regional sea-level change.

Landfills are a major source of surface and groundwater contamination worldwide. In Guam, all civilian solid waste is disposed of at a single landfill located outside the village of Ordot in central Guam. This particular landfill has been in continuous use for over 50 years and receives about 70.8 cubic meter of solid waste per day. The western border of the dump encroaches onto wetlands that drain into the Lonfit River. This rather picturesque stream converges with the Sigua River to form the Pago River. Local residents fish all three rivers for food and the adjacent lands support a variety of agricultural activities including subsistence farming.

Unlike modern sanitary landfills, the Ordot Dump is not lined with an impervious material and does not have a leachate retention system in place. As a consequence, seasonally

dependant streams of brown, foul smelling liquid emerge at a number of points along the western edge and southern toe of the dump. These flow down gradient into the Lonfit River permeating into the surrounding soil en route. The composition of this leachate has never been fully characterized despite the potential health hazard that it likely represents. Given the dump’s close proximity to surface water resources and arable lands, there is understandable concern among local residents over the environmental and human health effects of sustained and uncontrolled leachate discharges into the area waters. With this in mind, a pilot study was undertaken to determine levels of chemical and biological contaminants in leachate streams arising from the Ordot Dump to monitor their surface and subsurface movement down gradient into the adjacent waters of the Lonfit River and Pago River systems. Two researchers (Dr. Gary Denton and Dr. Mohammad Golabi) are taking surface water samples from sites along the Lonfit/Pago river systems between the dump and the ocean. Samples were withdrawn directly into pre-cleaned 50 ml polypropylene syringes and filtered (0.45 µm) into 100-ml plastic vials.

Surface and subsurface flows down gradient of the dump were periodically sampled and analyzed for nutrients and heavy metals. The subsurface samples were also collected by lysimeter at 0.7-2.0 meter depths. A time-series analysis of aqueous and soil samples with emphasis on solute transport through the soil was made in this part of the study. In a separate analysis, emphasis was made on the aqueous system with special attention to possible pathogenic contaminants from the study site. Lysimeters were used to extract interstitial waters from soil inundated by the leach ate streams down gradient from the dump, and downstream in the Lonfit-Pago River system. Soil samples from adjacent to lysimeters and water samples from the streams surrounding the dump and the ocean water at the Pago Bay were obtained for these purposes.

Recent and ongoing research spans topics of global, regional, and local interest, include the following:

Biology-Ecology	Geosciences-Engineering	Management
Invasive species on tropical islands	West Pacific climatic history	Watershed management, Pohnpei Island, FSM
Tropical island terrestrial & aquatic ecology	Atoll island hydrology and modeling	Land coverage strategies for soil erosion control in southern Guam
Assessment & preservation of biodiversity	Geologic map of Guam	Land cover accuracy assessment for southern Guam
Systematics of Micronesian insects	Carbonate island karst geology of Guam, Saipan, Tinian, Aguijan, Rota, and Fais	Remote sensing applications to soil erosion and sediment loading in southern Guam badlands
Developing composting technology as a waste management strategy for resource recovery and recycling of organic wastes	Modeling the Northern Guam Lens Aquifer	A training needs assessment for hazardous waste handlers at Camp Butler, Okinawa.
	Saltwater intrusion in the Northern Guam Lens Aquifer	An evaluation of public participation in the EIA process in Palau.
	Dye trace studies of Guam’s aquifer and coastal zones	An assessment of the Environmental Education curriculum in Chuuk State, FSM public schools.
	Groundwater resources on Fais Island, Yap State, FSM	Using vetiver technology for mitigating sedimentation to improve the water quality in order to protect coral reefs
	Modeling recharge for the Northern Guam Lens Aquifer	Using composted organic waste as an alternative to synthetic fertilizers to improve soils agricultural sustainability in Guam and Micronesia
	Water distribution system modeling for island water supplies
	Water distribution system modeling for island water supplies
	Slow sand filter technology for FSM drinking water
	Soil erosion modeling for southern Guam watersheds

Thesis Requirements

General requirements for the research thesis are contained in the Graduate Bulletin. Theses in Environmental Science (some online as WERI technical reports) are expected to make an original contribution to the selected sub-discipline and reflect mastery of the knowledge and skills required successfully pursue advanced study and research in environmental science. At the discretion of the Advisory Committee, a thesis deemed to be worthy of publication in a peer-reviewed professional journal may be awarded the grade of “Pass with Distinction.” The thesis grade (Pass with Distinction, Pass, or Fail) is assigned by the Advisory Committee, based on its evaluation of the written thesis and its oral defense.