Pier 39 sea lion colony

A resident population of California sea lions began regularly hauling out on floating docks at Pier 39 in the late 1980s and has since become a well-documented, year-round phenomenon. The animals use the engineered marina floats for resting and breeding, creating an urban marine colony immediately adjacent to downtown San Francisco. The colony's establishment and seasonal population fluctuations have been monitored by marine biologists and local agencies as an example of wildlife adapting to altered waterfront structures.