Adorable harbor seal pups are starting to dot Marin’s beaches and wildlife officials are urging people to leave them alone.

The Point Reyes National Seashore and the Marine Mammal Center say harbor seal pups, born in late winter and early spring, could suffer permanent harm if they are moved or if their mothers are scared off.

“If you see mothers and pups, the first thing to do is remove yourself from the area,” said Dave Zahniser, rescue and rehabilitation manager at the mammal center. “If people get close, they can flush the mothers into the water.”

Visitors should never pick up a seal pup that may look abandoned as most often it is waiting for its mother to return.

“It can begin a cycle that leads to abandonment: people scare off the mother, then see a pup by itself and they want to help, someone tries to move the animal or pick it up and it becomes less likely the mother will return,” Zahniser said.

To ensure that harbor seals are not disturbed, visitors are asked to stay at least 100 yards away from resting seals. Pups are about 2 feet long and weigh about 24 pounds. Females generally give birth on sandy beaches or rocky reefs to a single pup, which nurses for three to four weeks.

If people see a marine mammal in distress they should call the mammal center at 415-289-SEAL and it will send a trained responder to assess the situation and perform a rescue if needed. Seven harbor seals are already being treated at the center.

Beginning Tuesday through June 30, the annual closure of Drakes Estero to the westernmost point of Limantour Spit will be implemented to protect the harbor seals.

“All recreational water access in Drakes Estero is closed during this season,” said John Dell’Osso, chief of interpretation at Point Reyes National Seashore.

The closure applies to kayak and canoe usage, surfers, wind surfers, abalone divers and other water sports participants around harbor seal colonies in the area.

Point Reyes National Seashore has the largest mainland breeding colony of harbor seals in California. Resting and pupping harbor seals come onshore in various parts of the park, particularly in Tomales Bay, Tomales Point, Double Point, Drakes Estero and Bolinas Lagoon. Seals are federally protected animals under the Marine Mammal Protection Act and it is illegal to disturb them while resting.

Last year, more than 3,700 harbor seals were counted, 1,050 of which were pups. The number of seals breeding at Point Reyes represents around 20 percent of the California mainland population estimate.