Portuguese Ledge State Marine Conservation Area

Pteropod in Portuguese Ledge SMCA

Overview

Portuguese Ledge State Marine Conservation Area (SMCA) covers almost 11 square miles of ocean habitat roughly four miles offshore in Monterey Bay. This SMCA has the greatest depth range of any marine protected area (MPA) in California, from just more than 300 to around 4,800 feet. The SMCA's seafloor is mostly composed of soft sand and sediments, but does include a limited amount of hard, rocky seafloor habitat. 

A portion of the SMCA dips into the deep Monterey Submarine Canyon. This offshore region is important for many deep-sea fishes, particularly deepwater rockfish like greenspotted and chilipepper rockfishes; this area was designated an MPA in 2007 to protect deepwater species such as these.

Each year, Monterey Bay hosts an unparalleled wildlife viewing display. Humpback, gray, and blue whales feast on plankton, krill, and schooling fish. Dolphins, seals, and sea lions join the feast by hunting schools of baitfish, while seabirds add to the chaotic scene by diving into the water from great heights. While these charismatic species put on quite a show, this area also supports thriving populations of other, less visible marine life.

Within Portuguese Ledge SMCA, the take of all living marine resources is prohibited with the exception of fishing for pelagic finfish (a list of the allowed species that are included can be found in the "Regulations" section below).

Regulations

It is unlawful to injure, damage, take, or possess any living, geological, or cultural marine resource, EXCEPT:

Recreational and commercial take of pelagic finfish (northern anchovy, barracudas, billfishes, dorado (dolphinfish), Pacific herring, jack mackerel, Pacific mackerel, salmon, Pacific sardine, blue shark, salmon shark, shortfin mako shark, thresher shark, swordfish, tunas, Pacific bonito, and yellowtail) is allowed. No commercial take of marlin is allowed. Not more than five percent by weight of any commercial pelagic finfish catch landed or possessed shall be other incidentally taken species.

California Code of Regulations Title 14, Section 632(b)(74)(opens in new tab)

Quick Facts

MPA size: 10.64 square miles

Depth range: 302 to 4,793 feet

Habitat composition:

  • Sand/mud: 10.44 square miles
  • Rock: 0.20 square miles

Video Gallery

Portuguese Ledge State Marine Conservation Area

Dive Deep with a Remotely Operated Vehicle: Portuguese Ledge State Marine Conservation Area


California's MPA Network

About Portuguese Ledge State Marine Conservation Area

Natural History

Strawberry anemones, red gorgonians, and fish near ocean floor in Portuguese Ledge SMCA
Strawberry anemones, red gorgonians, and rockfish are among the species that can be found near the seafloor in Portuguese Ledge SMCA. CDFW/MARE photo

Portuguese Ledge SMCA encompasses a wide variety of habitats, from sandy seafloor to deep crevices of the Monterey Submarine Canyon. The Monterey Canyon has been shaped by tectonic movement, erosion, and fast-flowing deep water, making it a complex and dynamic environment home to hundreds of species, including bizarre deep-dwelling creatures like the longhorn fangtooth fish and the bloody-belly comb jelly. The Monterey Canyon, of which Portuguese Ledge is a part of, is more than 13,000 feet at its deepest point, almost twice as deep as the Grand Canyon. 

Coastal upwelling drives the deep canyon’s high productivity and species diversity. Upwelling occurs when warmer, nutrient-poor surface water is blown offshore by coastal winds, and cold, nutrient-rich water rises to the surface from the depths of the canyon. This makes it one of the most productive marine ecosystems in the world, creating a thriving habitat for a diversity of marine plants and animals, including more than 500 species of fish alone. Portuguese Ledge SMCA was designed to protect some of the deepwater habitats utilized by overfished, deepwater rockfish species to promote their recovery.

Cultural History

Pacific hake in Portuguese Ledge SMCA
Pacific hake is one of the commercially important fish species that can be found in Portuguese Ledge SMCA. CDFW/MARE photo

For centuries, Native American Tribes in California have relied on marine and coastal resources. Many Native American Tribes in California continue to regularly harvest marine resources within their ancestral territories and maintain relationships with the coast for ongoing customary uses. Before the Spanish arrived, much of the territory from San Francisco to Monterey was inhabited by the Ohlone people. The Ohlone traditionally subsisted on the abundant marine and terrestrial resources in Monterey, collecting abalone, urchins, limpets, and seaweeds in rocky intertidal areas and steelhead trout and salmon from the rivers and the coast. During the 18th century, tribal communities were displaced by the Spanish, who established missions. In Monterey, the first presidio was built in 1770.  

Portuguese Ledge and the greater Monterey Canyon were used during the rapid expansion of the whaling and fishing industries of Monterey Bay in the middle to late 19th century. Chinese immigrants launched the fishing industry and turned Monterey into a thriving fishing port, with commercial fisheries that harvested abalone, rockfish, flatfish, sardines, and squid. Between 1915 and 1950, estimates suggest that 235,000 tons of sardine were fished from the bay every year, until the fishery collapsed in the 1950s. Similar collapses of other fish stocks from overfishing resulted in more stringent regulations and the implementation of MPAs. 

Today, Monterey Bay supports a thriving fishing industry and is a model of balanced management between conservation, recreation, and commercial uses. Portuguese Ledge SMCA is one important part of a greater conservation network in Monterey Bay including many state MPAs as well as the Monterey Bay National Marine Sanctuary. The MPAs and Sanctuary not only provide protection for marine ecosystems, but also draw tourists, support fisheries, and help to conserve California’s marine resources for future generations.

Recreation

Longnose skate, eel pout, fragile pink urchins, sunflower stars, and feather stars on the ocean floor in Portuguese Ledge SMCA
Longnose skate and eelpout in Portuguese Ledge SMCA. CDFW/MARE photo

Portuguese Ledge SMCA is located offshore, within Monterey Bay, and is only accessible by boat. For those with access to a boat, Portuguese Ledge SMCA provides excellent fishing for pelagic finfishes, such as swordfish, tuna, and bonito, but take of non-pelagic finfish is prohibited.

Monterey Bay and the canyon areas also offer some of the best whale watching in the world. Humpback, gray, and blue whales are commonly seen, and orcas are occasionally observed. The closest harbor to the Portuguese Ledge SMCA is Monterey Harbor, where people can launch their boats and enjoy the wildlife viewing located offshore. 

 

 

Coordinates

This area is bounded by straight lines connecting the following points in the order listed:

36° 43.000' N. lat. 121° 56.000' W. long.;
36° 43.000' N. lat. 122° 01.294' W. long.;
36° 41.000' N. lat. 122° 00.706' W. long.;
36° 41.000' N. lat. 121° 56.000' W. long.; and
36° 43.000' N. lat. 121° 56.000' W. long.

California Code of Regulations Title 14, Section 632(b)(74)

Map

Map of Portuguese Ledge State Marine Conservation Area - link opens in new window

Facts, Map & Regulations

MPA fact sheet