PARENT SESSION

HA5 Bioaccumulation and Biomagnifications
203 Oregon Ballroom
8:00 AM - 12:00 PM, Thursday

() Predicted dietary exposure of POPs in southeastern U.S. bottlenose dolphins.

Pulster, E¹, Smalling, K¹, Maruya, K¹, ¹ Skidaway Institute of Oceanography, Savannah, GA, USA

ABSTRACT- Assessment of dietary exposure is a vital element in the risk assessment process for POPs that biomagnify. During the last half of the 20th century, hundreds to thousands of kg of a rare PCB mixture (Aroclor 1268) and the organochlorine pesticide toxaphene were discharged into Brunswick (GA) area estuaries. We determined PCB and toxaphene concentrations and profiles in several species of fish foraged upon by bottlenose dolphin (Tursiops truncatus) from estuaries near Savannah, GA (SAV), Brunswick, GA (BRN), and Jacksonville, FL, (JAX) using GC-ECD and GC-ECNI-MS. Grand mean total PCBs (PCBs) were 18.8±11.2, 93.8±19.1, 1510±437, 37.6±22.9 ng/g for SAV, Terry and Purvis Creeks (BRN) and JAX fish, respectively. Toxaphene levels (TOX) were 150±140, 1300±580, 16±6.7 and 23±10 ng/g for SAV, Terry and Purvis Creeks (BRN) and JAX fish, respectively. PCB congener profiles in Brunswick fish resembled Aroclor 1268 and were different than the other sites, suggesting their utility, if conserved in resident T. truncatus, as markers of inshore residence time. Using a simple biomagnification model, the predicted (PCB level in resident BRN dolphins was 23 g/g, a level that exceeds published thresholds associated with deleterious effects on marine mammals. Remaining work include predicting toxaphene levels in resident inshore T. tursiops, determining if seasonal differences in POP fish levels exist, and quantifying the risk to inshore dolphin populations in coastal Georgia associated with ingesting POP-contaminated prey fish.

Key words: biomagnification, T. truncatus, toxaphene, pcb