We're used to seeing them tightly packed in tins on our supermarket shelves, but even in nature it seems that sardines stick close together.
These amazing pictures show shoals of the fish packed so dense off the coast of the Philippines they block out the light of the tropical sun.
While the annual gathering of vast shoals of thousands of sardines is a well-documented event in South African waters, the Philippine sardine run was unheard of three years ago.
According to world-renowned underwater photographer Dr Alexey Stoyda, the fish were first spotted gathering in large numbers around the island of Pescador, near Cebu, in the Philippines, in March 2009.
For three months, large swells of sardine were spotted circling the island before their number dwindled and they disappeared.
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Divers capture pictures of fish shoals so dense they block out the sun in Philippines | Mail Online
