Polychlorinated Biphenyls and Metals in Marine Species from French Frigate Shoals, North Pacific Ocean X.-S. Miao, 1 C. Swenson, 2 K. Yanagihara, 1 Q. X. Li 1 1 Department of Environmental Biochemistry, University of Hawaii, Honolulu, Hawaii 96822, USA 2 U.S. Fish and Wildlife Service, Pacific Islands Office, Honolulu, Hawaii 96850, USA Received: 19 April 1999/Accepted: 2 November 1999 Abstract. Polychlorinated biphenyls (PCBs) and metals were analyzed in coral (Porites lobata), fish (Stegastes fasciolatus), crab (Grapsus tenuicrustatus), and sediment samples collected from Tern Island, and the reference samples from Trig and La Perouse Islands. All three islands are part of French Frigate Shoals, a national wildlife refuge in the North Pacific Ocean. Average concentrations of total PCBs ranged from 154 to 274 ng/g in the sediments, from 120 to 267 ng/g in the corals, from 387 to 4,500 ng/g in the crabs, and 1,340 to 46,000 ng/g, dry weight, in the fishes. High concentrations in marine species indicate there is PCB source(s) in French Frigate Shoals, especially Tern Island. Tetra- and pentachlorobiphenyls were 64–66% of the total PCB levels in the sediments, and they accounted for 57–65% of total PCBs in the corals. Penta- and hexachlorobiphenyls were 76–84% of total PCBs in the fishes, and they accounted for 79–85% in the crab samples. The sediment and coral were predominated by lower chlorinated PCB congeners, whereas the fish and crab bioaccumulated mainly higher chlorinated congeners. Selenium concentrations (16–23 μg/g) in sediments were much higher than some reported baseline values (0.4–2.5 μg/g). The average concentra- tions of arsenic, cadmium, lead, and selenium in the coral and fish were about equal to or less than those in the sediments. Concentrations of arsenic and cadmium in the crabs (49–51 and 3–4 μg/g, respectively) were approximately twofold of those in the sediments. Tern Island is the largest island in the coral reef atoll known as French Frigate Shoals. The entire atoll, which includes La Perouse and Trig Islands, is part of the Hawaiian Island National Wildlife Refuges (NWR). French Frigate Shoals is home to thousands of nesting seabirds and migratory shore- birds, endangered monk seals, nesting sea turtles, and a complex community of coral reef fishes and invertebrates. The U.S. Navy operated an airfield and fueling station on Tern Island from 1942 to 1946. The U.S. Coast Guard (USCG) operated a long-range navigation station on the island from 1952 to 1979. Large quantities of uncharacterized debris were landfilled on the island, and some was pushed directly into the ocean. USCG field surveys conducted in 1997 revealed that most of the marine debris is scattered off the north shore of the island and consists of batteries, transformers, a fuel tank, and other potential contaminant sources. The survey also revealed massive quantities of unidentified metallic debris buried behind the seawall along most of the northern shore of Tern Island. Elevated levels of polychlorinated biphenyls (PCBs) have also been detected in the island soils (URS Greiner Woodward Clyde 1999). Various contaminants, including PCBs, petroleum hydrocarbons, dioxins, and metals, may be leaching into the marine environment. PCBs are among the most widely known class of contami- nants because of their ubiquity, potential for magnification in the food chain, and harmful effects (Mimmi 1994; Loomis et al., 1997; Hansen et al., 1998). Coral reefs are among the world’s richest ecosystems, second only to tropical rain forests in species diversity, and are vulnerable to the introduction of wide variety of toxic substances, such as metals and organic chemicals (Meehan and Ostrander 1997). However, to our knowledge the presence of PCBs in coral tissues has not been previously reported. This report is the first step of our study to elucidate the sources, magnitude, and distribution of PCBs in the remote Tern Island in French Frigate Shoals. The results will be useful for ecological risk assessment and understanding of the fate of PCBs in marine ecosystems. Materials and Methods Sample Site and Collection Marine samples were collected from the waters off of the northwest (NW) and northeast (NE) corners of the Tern Island seawall (Figure 1). Tern Island is located approximately 166°W longitude and 24°N latitude. The two sampling sites are about one-half mile apart and are located in shallow water from 0 to 10 yards out from the seawall. Total area of Tern Island is approximately 35 acres. Reference samples were collected from around Trig and La Perouse Islands, located in French Frigate Shoals and approximately 2.2 and 7.0 miles from Tern Island, respectively. Reference crab samples were collected from Kaena Point on Oahu Island. All samples were collected from March 28–31, 1998. Correspondence to: Q. X. Li Arch. Environ. Contam. Toxicol. 38, 464–471 (2000) DOI: 10.1007/s002449910061 ARCHIVESOF E nvironmental Contamination and T oxicology  2000 Springer-Verlag NewYork Inc.