Mercury, cadmium, copper, arsenic, and selenium measurements in the feathers of adult eastern brown pelicans (Pelecanus occidentalis carolinensis) and chicks in multiple breeding grounds in the northern Gulf of Mexico.

Several trace metals and metalloids have been introduced into aquatic ecosystems due to anthropogenic activities. Some of these elements like mercury (in the form of methylmercury) are easily transferred from one trophic level to another and can accumulate to toxic quantities in organisms at the top of aquatic food webs. For this reason, seabirds like the eastern brown pelican (Pelecanus occidentalis carolinensis) are susceptible to heavy metal and metalloid toxicity and may warrant periodic monitoring.