Expansion of Oxygen Deficiency in Santa Monica Basin

We propose to look at changes in sedimentation in Santa Monica Basin and use this well documented repository to extract information about recent changes in water column oxygen content. The proposed sediment work provides both a longer view on changes to the Urban Ocean, but we also have the opportunity to measure changes that have occurred over the last 35 years, which is the period when the basin sediments were last surveyed. 

Changing oceanic conditions will leave a signature on the sea floor; hence our collection of cores will act as a repository for measuring the impact of hypoxia as it encroaches upon benthic communities. Our goal is to provide geological, geochemical, and biological evidence of change to the benthic environment. This has an impact on local ocean stakeholders.

OBJECTIVES:

• Determine the extent and depth of lamination in sediment cores collected from transects across Santa Monica Basin

• Measure bomb-produced Cs-137 in sediment cores in order to establish the sedimentation history since 1970

• Archive and/or process cores in a way compatible with future study of live-dead faunal assemblages which help in identifying benthic ecosystem changes. 

• Determine concentrations of reduced iron, phosphate, and other chemical species in the porewater and supernatant water of sediment cores to estimate their production rates and benthic fluxes into the water column.