The city Health Department has issued an advisory to warn residents and visitors that there have been multiple sightings of coyotes on Plum Island. Officials are urging people to avoid interaction with the animals, which typically weigh between 35 and 50 pounds and have an appearance similar to that of a German shepherd. The advisory asks residents to take precautions such as keeping pets indoors, and to avoid providing food for the animals by storing garbage in a secure container. If a coyote is seen, make sure pets are safe and secured and make loud noises to scare the animal off. If an immediate threat toward humans exists, people are directed to call the city’s animal control officer, the Newburyport Police Department, or the Massachusetts environmental police. For more information, contact Robert F. Bracey, the city’s director of public health, or Matthew J. Lipinski, animal control officer, at the city Health Department, 978-465-4410.