Assessing impacts of oil and ingested plastic in black skimmers from the Deepwater Horizon oil spill

Examinations of seabirds from oil spills provide resource managers demographic and trauma related data that inform damage assessments for affected species. We examined black skimmers (Rynchops niger; n = 49) from the Deepwater Horizon oil spill for demographics, ingested petroleum, and plastics. The majority were hatch-year males in poor body condition (57%), with atrophied, dehydrated, or pale organs possibly attributed to external oil exposure. Six (12%) black skimmers had evidence of external oiling, three (6%) were fouled by crude oil, one (2%) had biological fouling, and two (4%) were fouled in a synthetic substance, suspected to be chemical dispersant. Damage to organs suggested that internal examinations should be performed alongside external surveys to provide a thorough understanding of the total number of individuals impacted by a spill, and that timely internal examinations are essential. No evidence of ingested petroleum or plastics was found.