Bone Density of the Bottlenose Dolphin: Detecting and Monitoring Effects of Endocrine Disrupting Compound Exposure in a Long-Lived Mammalian Model Species for Human Health Research

EPA Grant Number: FP917822
Title: Bone Density of the Bottlenose Dolphin: Detecting and Monitoring Effects of Endocrine Disrupting Compound Exposure in a Long-Lived Mammalian Model Species for Human Health Research
Investigators: Powell, James Wright Burrus
Institution: Portland State University
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2015 through August 31, 2018
Project Amount: $132,000
RFA: STAR Graduate Fellowships (2015) RFA Text |  Recipients Lists
Research Category: Academic Fellowships

Objective:

I will study archived skeletal and soft tissue specimens, live bottlenose dolphins, and historic contaminant data to define the association between environmental contaminant exposure and bone density of bottlenose dolphins. My research will address the following specific aims:

  1. Establish normative distribution of bone density for bottlenose dolphins utilizing a comprehensive archive of skeletal specimens.
  2. Test for an association between bone density and endocrine disrupting compound contaminant levels using historically archived skeletal and soft tissue specimens.
  3. Clinically assess bone density in live bottlenose dolphins from a universally accepted reference population and areas of elevated endocrine disrupting compound contamination."

Approach:

Bone density analysis of live bottlenose dolphins required the development of a custom ultrasound device and unique protocols due to inherent issues and limitations of radiographic-based approaches in an open-water, field setting.

I have adapted existing technologies to meet the unique requirements of this novel study and have developed a prototype device that has been laboratory-tested on disarticulated pectoral flippers from dead, stranded bottlenose dolphins and field-tested on live bottlenose dolphins at the National Marine Mammal Foundation/US Navy Marine Mammal Program. This device will be used to assess bone density in live dolphins during capture-release health assessments at research sites and a control reference population over the course of this study.

Blubber specimens collected/archived during capture-release health assessments and during post-mortem investigations will be analyzed for PCBs, CHLs, DDT and its metabolites, HCB, and PBDEs following established protocols. Samples for contaminant analysis will be collected for each live animal assessed.

Expected Results:

  1. I hypothesize that bottlenose dolphin bone density will increase linearly with age and body mass following a pattern similar to accepted human model of bone deposition.
  2. I hypothesize that bottlenose dolphin bone density will be lower in individuals and from sites with elevated contaminant levels.
  3. I hypothesize that bone density will be higher in dolphins from the reference population than dolphins residing in sites characterized by elevated contamination.

Supplemental Keywords:

bone density, anthropogenic contaminants, persistent organic pollutants, marine mammals, bottlenose dolphins, osteodensitometry, quantitative ultrasound

Progress and Final Reports:

  • 2016
  • 2017
  • Final