San Diego offers unique opportunities to observe diverse marine wildlife in its natural environment. The city’s coastal position and rich ocean ecosystem attract a variety of marine life throughout the year. Visitors can encounter migrating whales and playful dolphins.
The Majestic Gray Whales
Gray whales undertake one of the longest migrations of any mammal. Their journey spans up to 14,000 miles round-trip, moving from their Arctic feeding grounds to the warmer breeding lagoons of Baja California, Mexico. This impressive migration makes them the most reliably sighted whale species in San Diego during the winter and early spring months.
The peak season for observing gray whales in San Diego occurs from December through April, with sightings most frequent in January and February. These whales can grow to about 49 feet long and weigh around 90,000 pounds. They are characterized by a mottled gray body and a lack of a dorsal fin, possessing a dorsal hump followed by a series of knuckles. They are often seen traveling alone or in small groups, swimming at an average speed of 5 mph during their migration.
During their passage, gray whales exhibit behaviors such as spouting, where they exhale a heart-shaped blow. They are bottom feeders, consuming invertebrates like amphipods by rolling on their side and filtering food from the seafloor. Mothers with new calves are among the last to depart the Baja lagoons, staying closer to shore during their northward migration.
Summer’s Blue and Fin Whales
As seasons shift, San Diego’s waters welcome other large whale species, including blue whales and fin whales. Blue whales, the largest animals on Earth, are seen from mid-June through September. They can reach lengths of up to 100 feet and weigh up to 200 tons.
Blue whales migrate to the San Diego area in search of abundant krill, their primary food source, often found in the nutrient-rich offshore waters. While cruising at about 5 mph, blue whales can reach speeds of up to 31 mph in short bursts. Their distinctive, towering spout can reach heights of up to 30 feet.
Fin whales, known as the “greyhounds of the sea,” are also present from June to October. These whales are the second-largest species, growing up to 85 feet long and weighing around 80 tons. They can achieve burst speeds of up to 29 mph, making them the fastest baleen whales. Fin whales feed on krill and small schooling fish, using their long throat grooves to gulp large quantities of food.
Other Notable Marine Mammals and Occasional Visitors
Beyond gray, blue, and fin whales, San Diego’s marine environment hosts a variety of other mammals and occasional whale visitors. Humpback whales are sighted from mid-October to November, and again in March and April, known for their acrobatic displays like breaching and tail slaps. These whales travel between their feeding grounds in Alaska and breeding areas in Mexico and Central America.
Minke whales are also occasionally observed, though less frequently than the major migratory species. The waters off San Diego are also home to a diverse population of dolphins, with common, bottlenose, Risso’s, and Pacific white-sided dolphins frequently sighted. Common dolphins are known for their playful behavior, often riding boat wakes in large pods.
California sea lions and harbor seals are commonly encountered, often seen lounging on buoys or near the coastline. While less common, orcas, which are the largest members of the dolphin family, are rare but possible sightings, particularly in October. These varied marine mammals contribute to San Diego’s rich biodiversity.