Saipan’s nearshore fisheries studied for heavy metals

A study this year looks at the adverse effects of stormwater runoff from wartime dumpsites on the near shore fisheries along the eastern side of Saipan.

Of soil from 32 sites examined, soil from seven exceeded Saipan’s currently adopted screening levels, according to the Water and Research Institute of the Western Pacific University of Guam.

But when weighed against the U.S. Environmental Protection Agency’s “more conservative” ecological screen levels, samples from all sites yielded heavy metal that exceeded levels for at least one element, according to WERI.

In an email, Dr. Gary Denton, lead investigator of the project, said the research will be presented at this year’s Asia Pacific Academy of Science, Science Education, and Environmental Management at the American Memorial Park next month on Nov. 18 to 19.

He said the primary objective of the research was to see if metals, especially mercury, were being transported from these wartime dumpsites into the coastal belt and being taken up by nearshore fish that are popularly harvested for food.

The great majority of wartime dumpsites are located in watersheds and on the eastern side of Saipan.

Looking at past data, WERI listed contaminants like heavy metals, chlorinated hydrocarbons, petroleum, and polycyclic aromatic hydrocarbons as the most encountered contaminants. However, no previous data on the movement of these chemicals into the coast exist.

WERI noted of “particular importance” the heavy metals, pesticides, and PCBs that may accumulate and concentrate in living organisms.

This stormwater-induced movement from the old dumpsites may have left “undesirable characteristics” on aquatic resources used for food, according to WERI.

Samples were taken from the soils of several of these dumpsites and from some surface water drainage pathways leading to the coast.

WERI stated that the project is currently looking to gauge the magnitude of metal contamination in nearshore waters by studying the algae and limpets there.

They noted that preliminary data from this survey showed that metal enrichment of biotic components has occurred at some of the locations.

The study to be presented at the November conference will be on extending the heavy metal monitoring program to fisheries, looking specifically at fish used for food, according to WERI. The study will identify the potential health risks of the consumption of these fish.

The study addresses the concerns voiced by CNMI stakeholders at WERI’s 2012 Advisory Council meeting regarding the impact of Formerly Used Defense Sites, or FUDS, on Saipan’s aquatic resources, according to WERI.

The study is titled “Heavy Metal Status of Nearshore Fisheries Impacted by Old Military Dumpsites on the Eastern side of Saipan, CNMI.”