T4 PM Endangered Species and Environmental Contaminants: Status of the Science (Part 2)
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in Ballroom 4

(OST-1117-769573) Mom its all your fault! Maternal transfer of contaminants in San Francisco estuary striped bass.

Ostrach, D¹, Low, J¹, Whiteman, S¹, Zinkl, J¹, ¹ University of California at Davis, Davis, CA, USA

ABSTRACT- The Striped bass population in the San Francisco Estuary collapsed in the 1970s reaching the lowest 38mm index of abundance ever in 2004. Field and laboratory investigations indicate sublethal contaminant exposure of early life stages of striped bass occurs in this estuary but is poorly understood. Female striped bass were captured using standard electro-fishing techniques during the spring months of 1999-2001. River-captured and hatchery-reared F-3 generation (control) female striped bass were spawned, eggs hatched and larvae reared under identical conditions during all 3 years. Pre-spawn eggs were obtained and frozen for subsequent analysis. Organic chemical and pesticide analysis was performed by GC-ECD and trace element analysis by ICP-MS. Larvae from hatchery-reared and river-collected females were sampled at 1 - 16 days after hatching and fixed in 10% formalin. Whole larvae were embedded in glycol methacrylate, serial sectioned at 4 microns thickness and stained with hematoxylin and eosin for histopathological evaluation. Yolk, brain, liver and whole body data was obtained for each larvae using the Computer Assisted Stereology Toolbox and volumes calculated using the Cavalieri method. Biologically significant levels of PCBs, PBDEs and pesticides were found in all egg samples from river-collected striped bass. Significant differences in yolk utilization, brain development, liver development and overall growth was observed in larvae from the river-collected female striped bass as compared with controls. Chemical analysis and histopathological results suggest that contaminants found in the eggs are causing endocrine and CNS disruption during early stage larval development. This study provides clear evidence of maternal transfer of xenobiotics and their effects on larval striped bass in the San Francisco Estuary system. This investigation presents new information that can help to better understand the fate of contaminants and manage the problems associated with maternal transfer of xenobiotics in fish populations in this estuary system.

Key words: maternal transfer, bioaccumulation, xenobiotics, striped bass eggs