She advises boaters and picnickers to stay at least 300 yards away from pupping ledges until late June. Pups generally go off on their own after three to six weeks, she said. For the rest of the summer, Wood and Deacoff will study the seals feeding behavior and measure levels of contaminants, such as dioxins, chlorinated pesticides and PCBs, and heavy metals in the tissues of seals and their prey. These toxins reduce immunity and slow growth and development, Shaw said. Wood and Deacoff explained that they will check contaminant levels in seals by collecting seal scat from ledges and common seal prey.
Seals primarily feed on hake, cod, herring, squid and bottom fish.
They will also study the tissue of dead seals picked up by stranding stations, such as Allied Whale at College of the Atlantic in Bar Harbor. Allied Whale is a member of the Northeast Regional Stranding Network and is the only organization in Maine authorized by the National Marine Fisheries Service to respond to marine mammal strandings. Harbor seals are a good indicator of contaminants in Maine s coastal ecosystem, Shaw said, because they are one of the top predators in the ocean and are very similar to humans biologically and metabolically. Seals and humans also eat many of the same fish, making them a good indicator of human health risks. Harbor seals, like humans, are long-lived sometimes up to 40 years and contaminants accumulate in their tissue over time.