Pinnipeds of the Central Coast
California sea lion Zalophus californianus
California sea lion
California sea lions, classified as "eared seals," are indigenous to the West Coast of North America. They inhabit coastal waters and frequent areas such as beaches, docks, buoys, and jetties. California sea lions primarily forage in the offshore regions of coastal areas, where they consume a diverse array of prey including squid, anchovies, mackerel, rockfish, and sardines, which are abundant in upwelling zones.
Northern elephant seal Mirounga angustirostris
Northern elephant seal
The northern elephant seal, the largest "true" seal in the Northern Hemisphere, features adult males employing their sizable, inflatable noses for vocal threats during the winter breeding season. Predominantly found in colonies off southern California, particularly in the Channel Islands, they undertake one of the lengthiest mammalian migrations, with some individuals journeying over 13,000 miles roundtrip.
Harbor seal Phoca vitulina
Harbor seal
Harbor seals, prevalent marine mammals along both the U.S. West and East Coasts, are frequently observed lounging on rocky shores and sandy beaches, as well as on drifting ice formations within glacial fjords. Often adopting a distinctive "banana-like" posture with their head and rear flippers elevated, these seals showcase their characteristic behavior of sunbathing and resting.
California Sea Lion
California sea lion Zalophus californianus
Length: Males, on average, grow up to 3.4 m to 4.0 m (11 to 13 ft); females can be up 4.6 to 4.9 m (15 to 16 ft) long
Weight: Up to 4,500 lbs
Life expectancy: 40 to 70 years old
Habitat: Coastal and off-shore temperate and sub-tropical waters (50 - 80 °F)
Diet: Marine mammals (seals and sea lions), fishes, and sometimes smaller sharks. Juveniles typically eat invertebrates and bottom fishes.
Conservation Status: Vulnerable or near threatened according to the International Union for Conservation of Nature (IUCN).
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California sea lions, classified as "eared seals," are indigenous to the West Coast of North America. They inhabit coastal waters and frequent areas such as beaches, docks, buoys, and jetties. California sea lions primarily forage in the offshore regions of coastal areas, where they consume a diverse array of prey including squid, anchovies, mackerel, rockfish, and sardines, which are abundant in upwelling zones.
Why do pinnipeds need protection?
Incidental Capture (Bycatch)
Harbor seals are vulnerable to entanglement in various fishing gear like gillnets, trawls, and purse seines, as well as marine debris. Such entanglements can lead to exhaustion, impaired feeding, or severe injury, ultimately impacting their reproductive success and survival.
How are pinnipeds currently protected?
National Legislation
Marine Mammal Protection Act
The Marine Mammal Protection Act (MMPA) of 1972 prohibits the harassment, hunting, capture, and killing of pinnipeds in U.S. waters. The MMPA establishes regulations to ensure the conservation and management of pinniped populations, including the designation of marine mammal protection zones and the implementation of measures to mitigate human impacts. Additionally, the MMPA mandates the development of recovery plans for depleted or threatened pinniped species, along with research programs to monitor population trends and assess threats to their well-being.
California Sea Lion
Zalophus californianus
Length: Males, on average, grow up to 3.4 m to 4.0 m (11 to 13 ft); females can be up 4.6 to 4.9 m (15 to 16 ft) long
Weight: Up to 4,500 lbs
Life expectancy: 40 to 70 years old
Habitat: Coastal and off-shore temperate and sub-tropical waters (50 - 80 °F)
Diet: Marine mammals (seals and sea lions), fishes, and sometimes smaller sharks. Juveniles typically eat invertebrates and bottom fishes.
Conservation Status: Vulnerable or near threatened according to the International Union for Conservation of Nature (IUCN).
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The Costa Lab
During the 1990s, Costa and fellow researchers from UCSC initiated the deployment of satellite tracking tags on elephant seals at the Año Nuevo rookery, situated north of Santa Cruz. The initial findings were nothing short of remarkable. Costa recalled, "Before we tagged elephant seals, prevailing knowledge suggested their range was confined to the California Current. We were astonished to discover their extensive travels across the entire North Pacific Ocean. It was a paradigm shift from observing them directly to allowing the animals to reveal their migratory routes."
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TOPP Program
In 2000, Costa collaborated with Barbara Block from Stanford University and others to establish the Tagging of Pacific Predators (TOPP) program. This decade-long endeavor aimed to monitor the movements of prominent marine predators in the Pacific Ocean. Costa oversaw the tracking of various marine mammals, birds, and turtles as part of TOPP, which encompassed the tracking of sharks and tunas as well.
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Global Pinniped Studies
Costa's research laboratory has conducted pioneering tracking studies on a global scale, encompassing diverse species such as albatrosses, sooty shearwaters, California sea lions, Galapagos sea lions, crabeater seals, Weddell seals, and southern elephant seals. Concurrently, ongoing investigations into the biology of northern elephant seals at UC's Año Nuevo Natural Reserve have continued to yield valuable insights under his team's guidance.
Northern elephant seal Mirounga angustirostris
The northern elephant seal, the largest "true" seal in the Northern Hemisphere, features adult males employing their sizable, inflatable noses for vocal threats during the winter breeding season. Predominantly found in colonies off southern California, particularly in the Channel Islands, they undertake one of the lengthiest mammalian migrations, with some individuals journeying over 13,000 miles roundtrip.
Harbor seal
Phoca vitulina
Harbor seals, prevalent marine mammals along both the U.S. West and East Coasts, are frequently observed lounging on rocky shores and sandy beaches, as well as on drifting ice formations within glacial fjords. Often adopting a distinctive "banana-like" posture with their head and rear flippers elevated, these seals showcase their characteristic behavior of sunbathing and resting. Their ubiquitous presence in coastal habitats makes them a familiar sight to coastal residents and visitors alike, contributing to the rich tapestry of marine life along the California shoreline.
California sea lion
Zalophus californianus
California sea lions, classified as "eared seals," are indigenous to the West Coast of North America. They inhabit coastal waters and frequent areas such as beaches, docks, buoys, and jetties. California sea lions primarily forage in the offshore regions of coastal areas, where they consume a diverse array of prey including squid, anchovies, mackerel, rockfish, and sardines, which are abundant in upwelling zones.
