California has logged 167 Dall’s porpoise records, enough to place it among the more frequently recorded marine mammals in this batch, concentrated well offshore along the state’s northern and central coast.
Cold water from the California Current, not the whole coastline
This is the largest porpoise species and the only member of its genus, built for cold water rather than the warmer stretches of the southern coast. Records concentrate off the northern and central California coast, generally farther offshore than the smaller harbor porpoise, tracking the cold, nutrient-rich water the California Current pushes south along that stretch. Its sharp black-and-white pattern and stocky build get it mistaken for a baby orca at a glance, and it’s fast enough to throw up a distinctive spray, sometimes called a rooster tail, when it swims hard alongside a boat.
A summer surge tied to what the cold water brings
Records climb through spring and peak hard in July and August, more than double the winter count. That timing lines up with the California Current’s seasonal upwelling, when cold water rising from depth carries the squid and small schooling fish, like hake and sand lance, that make up most of this porpoise’s diet. More food offshore means more porpoises for boats and researchers to find.
Status in California
Dall’s porpoise isn’t currently ranked by NatureServe in California. It’s classified as native to state waters, matching a cold-water species that’s recorded here in every month but shows up far more often once the summer upwelling gets underway.
Full species profile
