Student-led marine sediment coring adventures!

May 28

To explore the influence of a giant metropolis on microbial activity in marine sediments, my awesome and adventurous Applied and Environmental Microbiology students and I embarked on the California State University’s Research Vessel Yellowfin to gravity core the San Pedro Channel!

The San Pedro Channel has been in the news lately and not for good reasons. Recent expeditions have recorded the unreported dumping of DDT decades ago in still leaking barrels. Unfortunately, this environment’s proximity to mankind (16 million + population in the Greater Los Angeles area) has facilitated this and many other environmental insults over the years.

To catalogue the state of microbial metabolisms in marine sediments as a metric for benthic biogeochemical “health”, we collected sediment samples from three locations at increasing distance away from the port of Los Angeles. From each core we generated various subsamples at different depths and collected geochemical and DNA data. In 2023, we will similarly collect sediment samples from the Santa Catalina Island slope down into the basin.

Soon, we will sequence the collected DNA and plan to develop a comprehensive catalogue of predicted microbial metabolism as a function of anthropogenic influence, or distance from humans, on the sediment collection site. Specifically, we will have ecologically comparable sediment samples in terms of distance from land, water depth, and depth beneath the sediment, allowing rigorous statistical modeling of the specific parameters (for example: LA vs Catalina = 16 million vs 3 thousand humans) that influence the sediment microbial ecology of the San Pedro Channel. This unique survey will reveal currently unknown impacts of a large metropolis on important marine biogeochemical processes occurring at and below the seafloor.

Stay tuned!

Special thanks to the SCMI R/V Yellowfin crew.

Extra special thanks to Engineer Denis Mahafee for putting together and testing our gravity corer with just a few weeks notice!