Physiological Effects of Pollutants in the Bottlenose Dolphin

EPA Grant Number: R823209
Title: Physiological Effects of Pollutants in the Bottlenose Dolphin
Investigators: Busbee, David L.
Institution: Texas A & M University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1996 through December 31, 1998
Project Amount: $416,564
RFA: Exploratory Research - Environmental Biology (1995) RFA Text |  Recipients Lists
Research Category: Biology/Life Sciences , Health , Ecosystems


The estuarine and near shore waters of industrialized and agricultural areas are contaminated with a mixture of pollutants, including halogenated aromatic hydrocarbons (HAH), aromatic hydrocarbons (AH), and polycyclic aromatic hydrocarbons (PAH). Among these are a number of toxic and/or carcinogenic chemicals that are known to stimulate a variety of adverse responses in man and laboratory animals, including weight loss, dermal lesions, thymic atrophy, immune system dysfunction, and cell transformation. This proposal plans to evaluate some of the physiological and biochemical responses to HAH, AH and PAH in tissues of bottlenose dolphins from heavily polluted areas of the Texas Gulf Coast. Control animals for this study will be resident dolphins maintained at the US Naval Command, Control and Ocean Surveillance Center (NCCOSC, RTD&E Div, NRAD), in San Diego. Test animals will include dolphins that strand on the Texas coast and are studied in an ongoing Marine Mammal Research Program at Texas A&M University. Control animals will provide blood samples and skin biopsies. From these we will obtain blood serum, peripheral blood lymphocytes, skin keratinocytes and subdermal blubber. In addition, stranded animals that die will provide a source of liver that will be taken when it can be obtained immediately after death, and large quantities of skin and blubber for extensive examinations and for methods development. Chemical residue levels and specific residue compositions will be determined on blubber samples. Mitogen-initiated blastogenesis in peripheral blood lymphocytes and immunoglobulin levels in serum of control animals will be determined as measures of normal immune system function. Hydrocarbon-DNA adduct levels will be assessed in epidermal keratinocytes, hepatocytes (when possible), and peripheral blood lymphocytes. Capacity to repair DNA damage will be evaluated in keratinocytes and peripheral blood lymphocytes. Cytochrome P450 induction capacity and the capacity to metabolize reference chemicals will be determined in fresh and cultured epithelial cells. The approach is to initiate development of a dolphin CYP1A1 cDNA which will be used for probe development and will be cloned into a baculovirus expression system to obtain pure protein for hybridoma and monoclonal anti-dolphin CYP1A1 IgG generation. Simultaneously, cytochrome P450s isolated from liver samples will be purified to isozyme levels and used to generate monoclonal or polyclonal IgG specific to dolphin CYP1A1. This investigation will provide data for the determination of how dolphins react to hydrocarbon pollutants. This could provide a basis for the development of regulatory guidelines and policies governing the tolerance levels for chronic chemical exposure in marine mammals.

Supplemental Keywords:

RFA, Scientific Discipline, Geographic Area, Waste, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Chemical Mixtures - Environmental Exposure & Risk, Environmental Chemistry, State, Chemistry, Ecological Effects - Environmental Exposure & Risk, chemical mixtures, Ecological Effects - Human Health, Biology, Ecological Indicators, cell transformation, Texas, cytochrome P450, amphibians, dermal lesions, chemical contaminants, PAH, Lymphocytes, hydrocarbons, aquatic ecosystems, bottlenose dolphin, immune systems, TX, California (CA), cancer risk

Progress and Final Reports:

  • 1996
  • 1997
  • Final