Biochemical response of marine mammals to external contaminants: metals and inflammatory agents

EPA Grant Number: R826103
Title: Biochemical response of marine mammals to external contaminants: metals and inflammatory agents
Investigators: Castellini, Michael A.
Institution: University of Alaska - Fairbanks
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1997 through September 30, 2000
Project Amount: $301,171
RFA: Exploratory Research - Environmental Biology (1997) RFA Text |  Recipients Lists
Research Category: Biology/Life Sciences , Ecosystems


Previous studies of metal contaminants in marine mammals have dealt strictly with absolute levels of metals in necropsied tissues, not with the impact of those metals on the living organism. That is, they have not assessed the biological response to those metals. The assay for blood metallothionein (MT) is a measure of the biological response of an animal to excessive metal and as such offers a potential biomarker for metal contamination. Recent data suggest that a significant zinc and resulting elevated MT event occurred in the Steller sea lion population in Southeast Alaska within the last 5 years. Results also indicate at least 10% of Prince William Sound harbor seals show elevated zinc and plasma nitric oxide (anti-oxidant) levels suggesting environmental contamination. Additionally, both species show significantly elevated chronic Acute Phase Reactions as monitored by plasma haptoglobin (Hp) levels indicating an increased inflammatory response. While these marine mammals are a significant food resource for Alaskan coastal Native peoples, several of these species are threatened and endangered.


The primary goal of this project is to characterize the response chemistry of metal, nitric oxide, and inflammatory blood indicators in populations of marine mammals in Alaska. To achieve this goal, the project defines three measurable objectives:
  • Examine archived blood samples from marine mammals for plasma metal, MT and Hp levels relative to potential past contamination events.
  • Collect current blood samples to test for ongoing response events particularly in relation to the interactions of metal, inflammatory and anti-oxidant biochemistry.
  • Begin controlled laboratory studies of the detailed biochemical pathways involved in the reactions of marine mammals to external contamination.

Expected Results:

This project will provide essential information on whether natural populations of Alaskan seals and sea lions exhibit biochemical responses that may be induced by external contaminants. It will also initiate controlled laboratory studies on the same indicators so that natural variations in those indicators can be better predicted. It is the first study of its kind to approach the question of potential biochemical responses to metals and inflammatory agent in these animals.

Supplemental Keywords:

Alaska, AK, marine mammals, fish, ecological effects, population, indicators, zoology, monitoring, heavy metals., RFA, Scientific Discipline, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, State, Zoology, Ecological Effects - Environmental Exposure & Risk, Environmental Monitoring, Ecology and Ecosystems, Ecological Risk Assessment, Biology, Ecological Indicators, marine ecosystem, ecological effects, limnology, ecological exposure, biomarkers, inflammatory agents, ecosystem indicators, ecosystem management, Alaska (AK), aquatic ecosystems, marine mammals, acute phase reactions

Progress and Final Reports:

  • 1998
  • 1999
  • Final