Otters Play a Vital Role in Ecology of Rivers

Otters play a vital role in ecology of rivers Image 1. A river otter named Mary has been at the Maryland Zoo since 2001 when she arrived as an orphaned pup. Here, she enjoys some fish. An otter's strong jaws can bite through bones and even turtle shells. Photo: Ann Cameron Siegal/Washington Post Playful North American river otters often sound like squeaky toys as they wrestle each other, slide down riverbanks or frolic in water. Spotting these cute, furry animals is good fun. It is also good news for the environment. North American river otters are a species whose population can indicate how healthy (or not) the environment is. The otters experienced a steep drop in numbers in the 1900s. This was due to fur trapping and pollution. They are not considered endangered today, though. The nomadic animals often travel miles over land or through rivers and streams. They seek habitats with clean water and a healthy fish population. River otters are high on the food chain. They eat fish, clams, snakes, turtles, small mammals and birds. Researchers look for contaminants and parasites in otter spraint, or poop. This helps scientists learn about the health of the surrounding environment and its food sources. River otters don't need music to do a funny rhythmic two-step with their short hind legs, while raising their long tails and wiggling their butts as they defecate. This funny motion, known as "the poop dance," releases spraint that serves as an identification among otters. Spraint is one of the things scientists look for to track the presence of otters. Karen Sheffield is the manager of Huntley Meadows Park in Virginia. She notes that while otter sightings are unpredictable, recent tracks and spraints show there has been increased otter activity there. A wetlands restoration project finished six years ago at the park. It is minimizing invasive species, making way for healthy native ones. The Elizabeth River is a key Chesapeake Bay tributary flowing between Norfolk and Portsmouth, Virginia. It was long considered a "dead river" because of toxins. It's now flourishing after a decade of community efforts to keep out chemicals and waste. "In the past five years, we have seen a great many more otters," said Marjorie Mayfield Jackson. She is the director of the Elizabeth River Project. "It means we are doing our job in the community and for the otters." Nonprofit organizations are raising awareness of river otters' importance. The Elizabeth River Project helped develop an otter display at Nauticus science center in nearby Norfolk, Virginia. Wild otters are often seen hanging around the docks there. An "Otter Spotter" program encourages volunteers within the river's watershed to document any other sightings or signs of activity. A newly formed Smithsonian Institution project is looking for people, including kids, to help scientists learn more about the animals. "No one has ever done scientific research on otters in the Chesapeake Bay area," said Karen McDonald. She is part of of the Chesapeake Bay Otter Alliance. The alliance is the Smithsonian's citizen-science project. It is designed to help people understand otters and their important role in the food web. Anyone can email sightings of river otters or their spraints. And everyone can help provide a good home for the otters. "Otters need a clean watershed to live," McDonald said. "We are all watershed neighbors, and we need to be good neighbors."