Description of Conditions Preceding the 2011 Redondo Beach, California, Fish Kill

Abstract

Miller, E.F., 2014. Description of conditions preceding the 2011 Redondo Beach, California, fish kill. On 8 March 2011, hypoxic conditions resulted in the loss of ca. 1.5 million Sardinops sagax in King Harbor, Redondo Beach, California. Uncertainty remains regarding the school's entrance into the harbor and the hydrographic conditions leading up to the event. Unusually depressed dissolved oxygen concentrations and acidic pH at 4–7 m depth in the main channel of the harbor were recorded on February 22 during permit-required power plant discharge monitoring. Similarly minimal tidal amplitude occurred on 22 February and 8 March, resulting in minimal seawater exchange within the harbor. Power plant impingement surveys at the nearby generating station began observing S. sagax in January, with an order of magnitude more individuals impinged on 3 February than any prior 24-hour survey and continued impingement occurring at above average levels through February. The data suggested the school entered in late January and might have remained through February at depth. When the 8 March neap tide occurred, hypoxic conditions developed in Basin 1, the most secluded basin, leading to the fish kill.