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National Marine Sanctuary

Monterey Bay National Marine Sanctuary was established in September 1992. The sanctuary encompasses a shoreline length of 276 miles and 6,094 square miles of ocean from Marin to Cambria. It supports one of the world's most diverse ecosystems, home to numerous mammal, fish, bird, invertebrate and plant species.

Marine sanctuaries strive to preserve ocean environments that are still relatively pristine while promoting multiple use of the area for enjoyment by everyone. Ninety percent of the U.S. population lives within 200 miles of the nation's coastlines and competition for use of ocean resources is growing rapidly.

Monterey Bay Marine Life
  • Marine mammals - 36 species
  • Seabirds - more than 180 species
  • Fish - at least 525 species
  • Turtles - 4 species
  • Invertebrates 31 phyla
  • Marine algae (plants) - 450+ species
Approximately 21 endangered and threatened animals spend all or part of their lives in the sanctuary.

Grey whales are seasonal migrants, traveling close to shore during two annual migrations between Alaska and breeding grounds in Baja California. Blue whales are found in the sanctuary from late spring to late autumn. Other cetaceans include Minke whales, Fin whales, Humpback whales, Pacific Right whales, Sperm whales, and several porpoise and dolphin species.

The sea otter population within the sanctuary is estimated to be more than 1,200. Thirty-one percent of the population inhabits the coastal area from Point Sur to Año Nuevo/Pigeon Point. An official California Sea Otter Game Refuge extends from Carmel south to Santa Rosa Creek near Cambria, encompassing about half of the otter's established range.

Upwelling (the movement of deep, nutrient rich ocean water to the surface) is a critical element in the sanctuary. The cold, nutrient rich water from the ocean floor triggers a food web that feeds a remarkable mix of organisms from the smallest microscopic plants (phytoplankton) to Earth's largest creature, the endangered Blue whale. Upwelling occurs on the West Coast during the summer. When the cold water rises to the surface and meets the warmer air temperatures, marine fog is produced.

Giant kelp is the fastest growing plant on earth; it grows up to 14 inches a day in water as deep as 100 feet. The kelp supports biological communities among their protective canopies, and is a favorite resting spot of the sea otter, which naps in the protective bed of floating strands. When the kelp is washed ashore, it continues to support communities of invertebrates, crustaceans and birds.

You can view many of these marine species at the Monterey Bay Aquarium, while scuba diving or along the Monterey Bay Coastal Recreation Trail.

Federally Regulated Activities

Federal regulations prohibit the following activities within Monterey Bay National Marine Sanctuary:

  • Exploring for, developing or producing oil, gas or minerals
  • Discharge or deposit of any materials (some specific exceptions)
  • Moving, removing or injuring a Sanctuary historic resource
  • Altering the seabed (some specific exceptions)
  • Disturbing marine mammals, sea turtles or marine birds
  • Flying motorized aircraft below 1,000 feet in certain areas
  • Possessing any historical resource, marine mammal, sea turtle or marine bird
  • Interfering with enforcement of Sanctuary laws or regulations
  • Operating "personal watercraft" (Jet Skis) outside of the four designated zone

The sanctuary has many diverse uses, including the following:

  • Board sports, SCUBA diving, free diving and snorkeling
  • Boating, sailing and harbors
  • Coastal development
  • Commercial and recreational fishing
  • Kelp harvesting
  • Military activities
  • Tourism and recreation
  • Scientific research
  • Shipping


The Monterey Bay submarine canyon is larger than the Grand Canyon! The deepest point in the sanctuary is 10,663 feet (3,250 meters). It is also the second largest marine sanctuary in the United States (second to American Samoa), the largest marine sanctuary in the world by volume, and the second largest in the world by area. The average surface area is a cold 55 F (13 C).


Monterey Bay National Marine Sanctuary