River otters are at the top of the trophic food chain, with a varied diet that, for Illinois’ otters, usually includes multiple fish species, mollusks, crayfish, and amphibians—as found by Satterthwaite-Phillips and collaborators in their fatty acid analysis of otter’s adipose tissue conducted in 2014 (Satterthwaite-Phillips et al. 2014). Other reports also indicate that river otters may pray on reptiles (including snakes and turtles), insects and their larvae, and occasionally other mammals and birds.
The variation in the diet of river otters makes them excellent biomonitors—organisms that accumulate in their tissues environmental contaminants—, providing quantitative information about the environment’s quality in specific areas and over time. In Illinois, another study conducted by Carpenter et al. (2014) identified organochlorine pesticides such as dieldrin and DDE (a Continue reading “From their environment to their behavior”
The study published in the journal “Ecotoxicology and Environmental Safety” found high concentrations of chemical compounds in the livers of 23 otters in central Illinois.
“Thus otters serve as biomonitors — organisms that contain information on the quantitative and qualitative aspects of the environment — of wildlife exposure,” according to a new study. They also serve as biomonitors for human health because the same toxic chemicals found in otters have also been found in people who eat contaminated fish.
“there are specific watersheds that are areas of concern — not only for otters — for any of the wildlife species that are living in those places, especially those at the top of the food chain.”