Southern California Bight

From Wikipedia, the free encyclopedia
Jump to: navigation, search

The Southern California Bight is the curved coastline of Southern California from Point Conception to San Diego. The area includes the Channel Islands and part of the Pacific Ocean.[1] Native Americans occupied the Southern California Bight before the arrival of Spanish explorers in the 16th century. This region is known for having a climate similar to that of the Mediterranean with similar weather patterns consisting of rainy winters and dry summers. The Southern California Bight has a thriving ecosystem that is home to many species of plant life, fish, birds, and mammals.

History[edit]

In 1513, there were an estimated 700,000 Native Americans living in the region making it the most populated area of North America. In 1542, Juan Rodríguez Cabrillo of Spain and his crew were the first European explorers to land on this coastal region in the present day San Diego Bay. The first permanent European settlers of the Southern California Bight led by Juan Pérez arrived in 1769 on the San Antonio. The Spanish government had planned a three-part occupation plan to check the Russian’s settlement in Alta California.[2][3] The Chumash Indian tribe occupied the coastal region of Southern California for thousands of years prior to the arrival of international explorers.[4]

In 2013 to 2014, scientists witnessed the largest die-off of sea stars ever recorded along the Pacific Coast. The outbreak of sea star wasting disease caused significant changes to the ecosystem as sea stars are a keystone species that plays an important role in controlling the numbers of other creatures.[5]

Climate[edit]

The climate of the region that constitutes the Southern California Bight is consistent throughout the area. There is a difference in monthly mean temperature of 10°C between the cities of Los Angeles and San Diego. Most precipitation in this coastal area takes place in the months of December, January, and February with a monthly mean rate of 2.0-3.3in.[6]

Biology[edit]

The Southern California Bight acts as a transition between many different water masses, including the Pacific subarctic, Pacific equatorial, and the North Pacific central water masses. Due its central location, the fish fauna includes species native to these other water masses. A total of 481 species of California marine fish, 195 species of birds, and 7 species of pinnipeds inhabit the Southern California Bight. [2]

Phytoplankton[edit]

Phytoplankton serve an important role in the Southern Californian coastal ecosystem. These single-celled organisms are the main food source for zooplankton and help support the fish population. In doing so, they help establish a stable food chain for all the animals in the coastal region. Since the population of fish is directly related to the production of phytoplankton, the growth in phytoplankton numbers increases the yield of local fisheries.[2]

Fish[edit]

Common fish found in the epipelagic zone include:

Common fish found in the neritic zone include:

Common fish found in the rocky intertidal zone include:

Many different species of fish rely on the kelp forests as a source of life. Populations of fish are larger in areas with a higher concentration of kelp. Fish that live in and rely on kelp forests include kelp surfperch (Brachyistius frenatus), kelp bass (Paralabrax clathratus), giant kelpfish (Heterostichus rostratus), and kelp rockfish (Sebastes atrovirens). A study conducted near San Luis Obispo, California showed that when kelp was removed from a nearby reef, fish biomass declined by 63%. Juvenile fish rely on kelp beds a nursery grounds. Southern California Edison built a 174-acre kelp reef (70 ha) off San Clemente in 2008.[7]

Birds[edit]

The Southern California Bight is home to over 195 species of birds, including endangered species such as the light-footed clapper rail (Rallus longirostris levipes). Some birds nest and hunt near bodies of waters, such as bays, harbors, and oceans, including areas where kelp grows. Some species, such as the brown pelican and some species of cormorants commonly dive head first into the water, attempting to catch fish. Other species of birds, such as grebes and loons migrate from Baja California over the nearshore waters, and will stop to fish and feed. Birds that live in the rocky shore have adapted to finding food, and specialize in prying grabbing prey that clings to the rocky shore. Common birds of the rocky seashore include black oystercatchers (Haemotopus bachmani), wandering tattlers (Heteroscelus incanus), and wandering surfbirds (Aphorize virgata). Other birds, such as sandpipers, egrets, and herons utilize tidal patterns, venturing out to rocks during low tide in hopes of catching prey. Non-seabirds also nest on rocky seashore surfaces. Peregrine falcons and ravens and known to nest on remote sea cliffs. Sandy beaches are inhabited by plovers, terns, marbled godwits (Limosa fedoa), and several species of gulls.[2][3]

Marine Mammals[edit]

Due to its central location of warm and cool ocean currents, the Southern California Bight sees a wide variety of marine mammals. Some reside here regularly, some pass through on migratory routes, and others only show up to utilize a certain food source. The Marine Mammal Protection Act and Endangered Species Act helped to prevent any marine mammal "take", which entails hunting, harassing, exploring marine mammals for their pelt, meat, oil, etc.[2]

Pinnipeds[edit]

The most abundant pinnipeds in the Southern California Bight are the California sea lions. Northern elephant seals are known to have breeding grounds in the Southern California Bight, mostly on San Miguel and San Nicolas Island. Sea otters were once common in the Southern California Bight, but due to hunting, they have since mostly retreated to northern waters. Otter sighting in the Southern California Bight happen rarely.

Cetaceans[edit]

Blue whales use the Southern California Bight as a part of their migratory routes. They leave Baja California by early summer, and are usually present in the Southern California Bight in June. Gray whales also pass through the Southern California Bight on their migration routes, typically migrating very close to land. They pass through the Southern California Bight on their southbound route from December through February towards Baja California, and return northbound towards southern Alaska, passing the Southern California Bight from February to May. Their migration patterns are among the longest of any mammal, spanning over 10,000 miles. The common dolphin is the most abundant cetacean in the Southern California Bight. Common dolphins typically appear in the Southern California Bight during years with warmer water, and are more abundant in the summer and winter.

Natural Resources[edit]

The Southern California Bight is characterized by coastal and offshore oil reserves. For the past century, the offshore areas of coastal cities such as Goleta, Santa Monica, and Huntington Beach have been home to oil extraction sites. With the presence of these oil reserves comes the construction of relative infrastructure including pipelines. Other primary resources that come from the Southern California Bight region include anchovies, sardines, mackerel, and bass. The thriving marine life and accessible seafood source has led to the development of harbors and marinas all across the Southern California coast.[6]

External links[edit]

References[edit]

  1. ^ Dailey, M. D., Reish, D. J., Anderson, J. W. (editors), 1993. Ecology of the Southern California Bight: A Synthesis and Interpretation. University of California Press, Berkeley / Los Angeles / London, 926 pp.
  2. ^ a b c d e f Dailey, Murray. "Ecology of the Southern California Bight". 
  3. ^ a b Lentz, Joan. Introduction to Birds of the Southern California Coast. 
  4. ^ Ward, Michael K. "Timoloqinash: Incorporating Chumash Cultural Self-History into the History of California" (PDF). Wishtoyo. 
  5. ^ Netburn, Deborah (November 26, 2014) "Scientists find likely culprit behind mysterious sea star deaths" Los Angeles Times
  6. ^ a b Panel on Southern California Bight of the Committee on a Systems Assessment of Marine Environmental Monitoring. "Monitoring Southern California's Coastal Waters". 
  7. ^ Swegles, Fred (April 17, 2015). "Artificial reef: plenty of kelp, not enough fish". The Orange County Register.