OTS Coastal Bottlenose Dolphin Project

© 2024 Eric Martin Aquarist and Creative Arts Director, Oceanographic Teaching Stations, Inc.

Welcome to the OTS Coastal Bottlenose Dolphin Project

Every day, bottlenose dolphins swim along the coast of the Santa Monica Bay, to the delight of beachgoers, swimmers, surfers and visitors. Bottlenose dolphins are among the most recognizable cetaceans (whales and dolphins) since they live in close proximity to humans in nearshore coastal waters, bays, and estuaries. They are often involved in captive dolphin performances and “swim with the dolphins” programs. Captive bottlenose dolphins have contributed significantly to research in echolocation, thermoregulation, diving physiology, communication and behavior. Despite the wealth of information from captive dolphins, less is known about dolphin behavior in the wild, even though knowledge of this behavior can contribute to dolphin conservation programs.

Your tax-deductible donation will help us continue our observations of the coastal bottlenose dolphins


Since 2018, Oceanographic Teaching Stations, Inc. (OTS) aquarist, Eric Martin, has been observing, photographing and video recording the behavior of three pods of coastal bottlenose dolphins that are frequent visitors to the Manhattan Beach Pier/Roundhouse Aquarium. These observations will be used to prepare educational material and will be shared with the public to promote dolphin awareness and conservation. All photography was conducted following the NOAA guidelines for responsible observation of dolphins and other marine mammals.


Eric Martin

Eric Martin

John Roberts

John Roberts

Val Hill

Val Hill

Lynne Gross

Lynne Gross

Charles “Chuck” Milam

Charles “Chuck” Milam


Bottlenose dolphins (Tursiops truncatus), also called common bottlenose dolphins, are found in tropical and temperate oceanic waters throughout the world. They are generalists, able to occupy a number of different habitats and utilize a varied diet, including small fish, squid, and crustaceans. Depending on the prey and the local environment, they use a variety of feeding behaviors.

The anatomy of the bottlenose dolphin

Bottlenose dolphins are mammals that need to surface to breathe every few minutes.  They have a streamlined body and lack many external structures of terrestrial mammals, including hind-limbs and ears. This allows them to swim at speeds greater than 20 miles per hour. They range in length from 6 to 13 feet and weigh between 500 and 1400 pounds.  Adult males are larger than females.  Their lifespan can be 40 years or greater, and females tend to live longer than males.

Bottlenose dolphins do not have a strictly defined mating season and newborn calves are seen throughout the year.  Their reproductive anatomy and behavior are complex.  Dolphins have no obvious secondary sexual characteristics, making it difficult to differentiate males from females.  Gestation is approximately 12 months.  Calves will nurse for 2 years or more and remain associated with their mothers for 3-6 years.

In addition to the coastal bottlenose dolphins we observe, there are local offshore bottlenose dolphins.  The two represent different ecotypes (separate populations adapted to different local conditions).  The coastal and offshore bottlenose dolphins differ somewhat in morphology and genetic makeup.


How can we understand dolphin behavior? Anthropomorphizing, or attributing human emotions or intentions to animals, is discouraged by some scientists. Other scientists argue that ignoring animal cognition and emotions, especially in highly intelligent and social animals like dolphins, may result in our missing something fundamental.

One way to understand behavior is to ask how it is adaptive. Adaptive behavior is defined as any behavior that contributes directly or indirectly to an individual’s reproductive success. Darwin’s theory of natural selection is often stated as “survival of the fittest,” but “reproduction of the fittest” is a better description. A more complete understanding of bottlenose dolphin behavior, including family structure, migration patterns, resource utilization and interaction with other species, including humans, could improve efforts to conserve these charismatic animals.


1. Family associations
2. Feeding
3. Mating
4. Interactions between different groups/families/species
5. Cooperative behavior
6. Interactions with humans


www.oceanconservation.org/be -whale-aware/


  • Keep your distance (100 yards for whales, 50 yards for dolphins, porpoises, seals, sea lions, and turtles).
  • Stop or slow down and avoid sudden changes in speed or direction
  • Never follow behind, approach head on, encircle, or trap animals between your vessel and shore
  • Never go between a mother and calf
  • Limit your observation time to 30 minutes
  • Never interact with (touch, feed, or ride) the animals


See a dolphin or other marine mammal stranded on the beach and in distress?

  • Do not touch, pick up or feed the animal.
  • Do not try to return the animal to the water.
  • Note the location as accurately as possible.
  • Call Marine Animal Rescue in El Segundo 310-455-2729 or Marine Mammal Care Center 1-800-39-WHALE.


For More Information about Bottlenose Dolphins, See the Following:

For a Narrative Description of Dolphin Research, see:

Bearzi, Maddalena. Dolphin Confidential: Confessions of a Field Biologist. Chicago: University of Chicago Press, 2012.

Your tax-deductible donation will help us continue our observations of the coastal bottlenose dolphins

Save the Date for our next dolphin event: July 24, 6:30PM at the Roundhouse Aquarium.

The Dolphin Triad – 3 short dolphin discussions: Drones and Dolphins, Plankton and Dolphins, and Humans and Dolphins.

Click here for more information

Please subscribe to our YouTube channel and get notified when we go LIVE with dolphins off the pier


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