Overview

• Researchers sampled 18 active river otter latrines along Maryland’s Rhode River over 11 months, recovering an average of 28 scats per site and analyzing them with microscopy and DNA metabarcoding.
• Metabarcoding and microscopic examination identified a broad diet dominated by teleost fish and crustaceans with occasional ducks, amphibians and invasive species like common carp.
• DNA sequences from six parasite classes were detected in the scat, with most parasites originating from fish prey and a smaller number likely infecting otters directly.
• Researchers also suggest that river otters could serve as disease sentinels, signaling zoonotic risks in coastal environments.
• Findings reflect population-level patterns and are constrained by gaps in taxonomic reference libraries and the inability to assign scats to individual otters.