This video is called Snowy Egret fishing – Garceta.
From National Wildlife Magazine in the USA:
FACE-TO-FACE WITH SEABIRDS
Mention the name Alcatraz and most people think of a penal colony, not a bird colony. And in fact, the former maximum-security prison that once held the country’s most notorious criminals on a 19-acre island in San Francisco Bay is among the National Park Service’s most popular sites, attracting nearly 1.4 million visitors a year. Few of them realize that it also is one of the nation’s premier locations for getting a close look at the breeding behavior of seven species of seabirds—species that elsewhere along the Pacific Coast often appear as distant dots on inaccessible rocks during the nesting season. …
For birders, the star attraction is probably Brandt’s cormorant, a species that ranges only along the West Coast, primarily in remote places where people can’t see them. Three mated pairs of the birds first appeared on Alcatraz in 1991; by last summer, nearly 2,000 pairs were nesting on the cliffs there. “There is just one other colony of Brandt’s that breeds in this kind of estuarine environment—along the Columbia River in Oregon,” notes biologist Julie Thayer, who manages the PRBO project. But only Alcatraz provides people with a front-row-center view of these tall birds, as well as great opportunities to see pigeon guillemots [see also here], black-crowned night-herons, pelagic cormorants, snowy egrets, and western and California gulls.
When Spanish explorers sailed past the island in the late 1700s, they named it La Isla de los Alcatraces (“Island of the Pelicans”) for the large numbers of seabirds roosting there. By the time the U.S. government opened the prison in 1934, however, human activity had driven away almost all of the colonies from the site. Even the jail’s most renowned bird-watcher, Robert Stroud—the so-called Birdman of Alcatraz who spent 17 years on The Rock—saw few of the creatures there. The convicted murderer’s research, which resulted in two books on avian diseases, occurred during his earlier incarceration in Kansas. Only after the penitentiary was closed in 1963 did the birds begin to return.
See also here.