Water Resources Research Act Program

Details for Project ID 2003GU22B

Persistent Pollutants in Biotic Components of Tanapag Lagoon, Saipan, with Emphasis on Areas Impacted by Streams, Storm Water Runoff and Sewer Outfalls

Institute: Guam
Year Established: 2003 Start Date: 2003-03-01 End Date: 2004-02-29
Total Federal Funds: $32,167 Total Non-Federal Funds: Not available

Principal Investigators: Gary Denton, Harold Wood

Project Summary: Tanapag Lagoon borders the western shore of central Saipan. It harbors a rich diversity of marine life and supports a variety of commercial and recreational activities. Over the last quarter century, Tanapag Lagoon has become heavily impacted by the activities of man. Primary sources of anthropogenic disturbance in these waters include a power station and commercial port (Saipan Harbor), two small boat marinas, a sewer outfall, several garment factories, auto and boat repair shops, wood shops, government vehicle maintenance yards, a commercial laundry, and an acetylene gas producer. There are also a number of old military dumps and disposal sites in the area as well as a municipal dump that has served as the islands only solid waste disposal site for the last 50 years. Several streams and storm drains empty into the lagoon during the rainy season and provide a mode of transport into the ocean for any land-based contaminants. Overflows from sewer lines are also commonplace at this time of the year and the whole area is inundated by storm water runoff during periods of prolonged wet weather. The effects of these perturbations on the indigenous biota within the lagoon are largely unknown. Likewise, fundamental data describing the abundance and distribution of persistent and potentially toxic pollutants within the system is also lacking. Mindful of these shortcomings, a contaminant assessment of surface sediments within Tanapag Lagoon was recently completed. The project described herein proposes to determine contaminants of potential concern (heavy metals, pesticides and PCBs) within biotic components of this lagoon and is seen as a logical extension of the work already completed. The study will essentially be divided into two discrete phases. Phase 1 will focus on dominant organisms inhabiting the shallow nearshore waters of the lagoon with emphasis given to those groups that have high bioindicator potential and are either sessile or are restricted in their movement. Sampling will be conducted largely on an opportunistic basis depending upon species abundance and availability at each site of interest and will be biased towards potential land-based contaminant sources. The area north of San Roque village, in the northern section of the lagoon, is relatively far removed from potential contaminant sources and will serve as a reference (control) site. It is anticipated that samples will be collected from 8-10 locations along the coastline between the reference site and Muchot Point at the southern end of the lagoon. Phase II of this investigation will explore contaminant levels in biotic resources from the lagoon that are popularly consumed by local people. Particular emphasis will be given to food fish commonly taken by conventional fishing methods. The objectives of the study are to establish a reliable database with which future findings may be compared and evaluated; identify hotspots and delineate areas of contaminant enrichment within the study area, and assess the degree of contamination in Tanapag Lagoon by reference to levels reported for clean and polluted environments in tropical regions from elsewhere in the world, including Guam. Potential health risks (if any) associated with the long-term consumption of edible resources surveyed will also be evaluated.