Cardiotoxicity Assessment

Co-PIs: Cynthia Smith (NMMF, diagnostic technique development, and application), Katie Colegrove (U of Illinois, pathology) and Forrest Gomez (NMMF, veterinarian)

Key Collaborators: Sharon Huston (San Diego Veterinary Cardiology, Board-certified veterinary cardiologist)

Deepwater Horizon (DWH) oil causes cardiac abnormalities in fish and birds, including symptoms associated with cardiomyopathy, arrhythmia, abnormal heart development, and reduced cardiac output (e.g., Harr et al., 2017; Esbaugh et al., 2016). Preliminary findings in past common bottlenose dolphin (CBND) health assessments suggest there may be an increased number of animals with heart murmurs in Barataria Bay, LA (heavily oiled during the DWH oil spill) compared to Sarasota Bay, FL (no oiling during DWH). The CARMMHA Cardiac Assessment Project will address this question more directly.

Veterinarians at NMMF and San Diego Veterinary Cardiology will collaborate to develop techniques to assess cardiac health on wild CBNDs in the field. First, they will use animals in managed populations to establish the methodology in a controlled setting. Then the techniques will be used in the CARMMHA field health assessments. With those data in hand, the veterinarians will include the cardiac assessments in the overall health prognosis of each animal, then compare the prevalence of individuals with cardiac abnormalities between unoiled and oiled locations.

To supplement the work conducted with live, capture-released animals, the University of Illinois will analyze archived cardiac tissues from dead, stranded CBNDs in the Gulf of Mexico since the DWH oil spill, and compare the prevalence of cardiac lesions in these samples to those from animals outside of the DWH oil spill footprint. This will help our team identify if and what types of cardiac problems may have led to the increase in CBND (and other cetacean) mortality associated with DWH.

Progress Summary

September 5, 2019 – The CARMMHA Cardiac Team has developed and tested standardized cardiac health assessment techniques with both managed and wild bottlenose dolphins. 

Preliminary results were presented at a CARMMHA health assessment workshop in Chicago and publications are now in preparation. We are also working with collaborators at the University of Miami Acute Phase Proteins Lab to validate a panel of  dolphin cardiac biomarkers. In addition, our team finished data collection and analysis of heart lesions in stranded dolphins that were recovered within the oil spill footprint for comparison to reference populations.