Identifying Benthic Invertebrates at Southern California DDT Dumpsites

Our role in the DDT research is to archive and identify representative benthic invertebrates from Dumpsites 1 and 2. These preserved specimens and their DNA sequences will serve as important reference materials for other research topics, such as the potential spread of DDT+ contamination through the food web.During research expeditions in 2021-2024, SIO-BIC Curator Greg Rouse, SIO-BIC Collection Manager Charlotte Seid, and collaborators collected benthic invertebrates from sediment cores and barrels at the Santa Monica Basin, San Pedro Basin, and neighboring control sites. They preserved specimens for examination and archival; photographed live animals to capture color, texture, and size; and, critically, collected samples suitable for DNA sequencing. Many benthic invertebrate species reported from southern California in historic publications do not yet have DNA sequences available, so establishing a baseline DNA library for species at the DDT dumpsites will facilitate future identification of these species anywhere in the world.Using a combination of DNA data and morphological examination by taxonomic specialists, the benthic invertebrates will be identified to the highest possible degree of accuracy and the DNA sequences will be made publicly available. Some specimens have already been determined to represent new species, previously unknown to science!