The closure of Drakes Estero begins Monday and will last until June 30 to protect the colony of harbor seals during their most sensitive time of the year, according to park officials.
The closure applies to kayak and canoe usage, and also applies to surfers, windsurfers, abalone divers, recreational fishermen, and other water sport users in the area.
Each year, thousands of seals congregate in the park, many of whom give birth on the sandbars and remote beaches. The seals generally congregate in Tomales Bay, Tomales Point, Double Point, Drakes Estero, and Bolinas Lagoon, according to park officials.
Last year about 3,500 harbor seals were counted in the area, including about 1,000 pups. That number makes up about 20 percent of the state's mainland population of the species.
Visitors in the area that come across the animals are asked to stay at least 100 yards away, and should never pick up a seal pup that may look abandoned. Pups may appear abandoned, but are likely waiting for their mother to return, according to park officials.
Harbor seals are protected under the Marine Mammal Protection Act of 1972.