Abstract:

Grading of histologic heart lesions was performed on 100 common bottlenose dolphins (Tursiops truncatus) that stranded in the northern Gulf of Mexico from 2010 - February 2019, following the Deepwater Horizon (DWH) oil spill. Heart lesions were graded in 42 reference dolphins stranding outside of the oil spill time frame and location for reference. Lesions able to be consistently scored across stranded dolphins included myocyte nuclear rowing, myocyte nuclear karyomegaly, myocardial fibrosis, myocardial fibrosis severity, myocarditis, myocardial degeneration and/or necrosis, vascular arteriosclerosis, myocardial lipofuscinosis, and the presence of heart failure.

Suggested Citation:

Kathleen Colegrove, Forrest Gomez, and Cynthia Smith. 2020. Grading of cardiac histologic lesions from dolphins stranding following the Deepwater Horizon oil spill compared to reference dolphins. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-jvr9-jh10

Purpose:

This dataset is a summary of the cardiac lesion scoring from 42 reference dolphins and 100 northern Gulf of Mexico dolphins that stranded following the DWH oil spill to evaluate the presence of cardiac lesions in stranded dolphins in the oil spill footprint.

Data Parameters and Units:

Category Reference or northern Gulf of Mexico (nGOM) case? Field.ID Unique identifier for stranded dolphin Exam.ID Identification number for each histopathology case Age.Class Age class of the stranded dolphin based on length: perinate, neonate, calf, subadult, or adult Tooth.Age.Years Age by tooth dentin growth ring analysis by year. Total.Length.cm Total body length measured in cm Strand.Year Year of carcass stranding (YYYY) Strand.State State of carcass stranding Heart.Nuclear.Rowing Indicates whether case has the lesion of cardiomyocyte nuclear rowing. Present or Absent. Heart.Nulear.Karyomegaly Indicates whether case has the lesion of cardiomyocyte nuclear megakaryosis. Present or Absent. Heart.Fibrosis Indicates whether case has the lesion of myocardial fibrosis. Present or Absent. Heart.Fibrosis.Severity Fibrosis severity. 0=absent; 1=Mild; 2=Moderate; 3=Severe Heart.Myocarditis Indicates whether case has the lesion of myocarditis. Present or Absent. Heart.Degeneration.Necrosis Indicates whether case has the lesion of myocardial degeneration or necrois. Present or Absent. Heart.Lipofuscin Indicates whether case has the lesion of myocardial lipofuscin accumulation. Present or Absent. Heart.Arteriosclerosis Indicates whether case has the lesion of myocardial arteriosclerosis. Present or Absent. Heart.Failure Indicates whether case has the lesion(s) of heart failure. Present or Absent.

Methods:

Heart tissue stranded dolphins were evaluated histologically for lesions including myocyte nuclear rowing, myocyte nuclear karyomegaly, myocardial fibrosis, myocardial fibrosis severity, myocarditis, myocardial degeneration and/or necrosis, vascular arteriosclerosis, myocardial lipofuscinosis. Lesions were compared between reference dolphins (N=42) and dolphins stranding in the oil spill footprint (N=100) between 2010 and February 2019. Age was evaluated using tooth dentin growth ring analysis and standard length as a proxy for age.

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