What to do if you find a baby seal alone. Seal mums leave their pups very early on in life, when they are weaned at three to four weeks old. It's not unusual to see a seal pup by itself. Three women are on the Beach Rd walkway are guarding the pup… The Marine Mammal Protection Act prohibits human interaction with seal pups and other marine mammals on the beach. If you suspect a seal pup is in distress or being harassed, contact a park ranger or call the NOAA West Coast Marine Mammal Stranding Network Hotline at 1-866-767-6114. People are being warned to keep their dogs on a lead on a popular Matua walkway to help protect an injured seal pup. If you find a seal pup that looks fit and healthy and shows no signs of distress, monitor it first from a safe distance for 24 hours.