Oxford Basin, Wetland and conservation area in Marina del Rey, Los Angeles County, US

Oxford Basin is a 10.7-acre constructed wetland and wildlife conservation area in the northwest corner of Marina del Rey, between Washington Boulevard and Admiralty Way. It is a remnant of the Ballona Valley ecosystem and one of the last intertidal mud flats in Los Angeles County, with a circulation berm, bioswales and native coastal sage scrub, salt marsh and willow scrub plantings.

The site came about when the Marina del Rey harbor was developed in the 1950s and a former landfill was converted into a water management system. This transformation later protected surrounding neighborhoods from flooding.

The basin was named the Marina Del Rey County Bird Conservation Area in 1963, partly through Audubon Society advocacy. Until the 1980s, abandoned livestock such as rabbits, chickens and domestic ducks lived at a spot called Duck Pond; they were removed to other county parks in 1989 after complaints about noise and odor.

The area is easy to walk around with designated pathways and has parking available at nearby park and beach lots. It is best visited during daylight hours when the viewing areas are fully accessible.

Before the 2016 renewal, a 2010 invertebrate survey of the muddy basin recorded 85 terrestrial and marine taxa: two mollusks, eight spiders, 67 insects and eight other arthropods. The $14.7 million project removed about 3,000 cubic yards of polluted sediment and planted 200 milkweeds.