Javier Mendoza  /  The Animals  /  Ocean
The bait ball · Ocean

Pacific Sardine

Sardinops sagax

A sardine is a few inches of silver. A school of them is a single animal that wheels and splits as marlin, sea lions and dolphins come through, and it feeds the whole coast.

A huge swirling bait ball of sardines beneath the ocean surface, with two striped marlin circling below in deep blue water.
The Sardine Run · Baja California · © Javier MendozaOrder this print
~12 in
Maximum length; most are 6 to 10 in
NOAA Fisheries
Millions
Fish in a single school; bait balls form when predators press them
NOAA Fisheries
Closed
US directed sardine fishery, every year since 2015
Pacific Fishery Management Council
Cannery Row
The 1940s collapse that emptied Monterey's canneries
NOAA Fisheries

The bait ball

Sardines school for safety, and when predators press a school from below and the sides it tightens into a spinning sphere, a bait ball. Then the feeding begins in turns: striped marlin slashing through with their bills, sea lions, dolphins, tuna, diving birds, sometimes a whale from below to finish it. Off Baja California in autumn, this is the greatest open-ocean spectacle in the eastern Pacific.

Boom and bust

The Pacific sardine population swings with ocean temperature cycles and with fishing. The crash of the late 1940s emptied Monterey's Cannery Row. The stock fell again in the 2010s, and the Pacific Fishery Management Council closed the US directed fishery in 2015; it has stayed closed since, with only small incidental allowances.

A longer guide to this species, with what it means for Southern California, is on My Clean Ocean →

In the collection

1 frame · prints from 12″ to 40″+
A huge swirling bait ball of sardines beneath the ocean surface, with two striped marlin circling below in deep blue water.
The Sardine RunBaja California

Thousands of sardines wheel as a single silver organism while striped marlin circle below — the open ocean's oldest chase, seconds before the ball breaks.

View & order this print →
Own the photograph
Museum-quality prints from 16-bit masters — metal, canvas or archival fine-art paper, printed in the USA.
Order a print

Questions people ask

What is a bait ball?

A tight, spinning sphere of small fish, often sardines, formed when predators press a school from below and the sides. Dolphins, sea lions, tuna and diving birds then feed on it in turns.

What eats sardines?

Almost everything: sea lions, dolphins, humpback whales, tuna, marlin, sharks, brown pelicans and cormorants. Sardines are a forage fish at the base of the coastal food web.

Why is the sardine fishery closed?

The Pacific sardine stock fell below the minimum set in US fishery rules, so the Pacific Fishery Management Council closed the directed commercial fishery in 2015. It has remained closed since.

Sources
  1. NOAA Fisheries species profile: Pacific sardine
  2. Pacific Fishery Management Council: Coastal Pelagic Species, annual sardine harvest specifications (2015 onward)
  3. NOAA Southwest Fisheries Science Center sardine assessments
More animals
Great White SharkThe ocean's most storied predator Shortfin Mako SharkThe fastest shark in the world Blue SharkThe most fished shark on Earth Bull SharkThe shark that swims up rivers All 17 animalsLand & ocean