Shearwaters eat small crustaceans, plankton, squid, fish, and in some cases, floating scraps.
Oodles more information at the related link listed below:
Most probably a Yelkouan Shearwater. Also known as a Mediterranean Shearwater
Shearwater Aircraft was created in 2009.
Buller's Shearwater was created in 1888.
Streaked Shearwater was created in 1835.
Cory's Shearwater was created in 1769.
Sooty Shearwater was created in 1789.
Hutton's Shearwater was created in 1912.
Shearwater - album - was created in 1972.
Bryan's Shearwater was created in 2011.
Heinroth's Shearwater was created in 1919.
Townsend's Shearwater was created in 1890.
Little Shearwater was created in 1838.