HOLOCENE OYSTER ASSEMBLAGE OF NEWPORT BAY, CALIFORNIA: UNDERSTANDING THE PAST TO HELP RESTORE THE FUTURE

Oysters have played a large role in the ecology throughout Orange County’s geologic history, but there has been a vast decline in the diversity and abundance within the region. Current restoration projects at CSU Fullerton aim to reestablish the only native oyster, the Olympia oyster, Ostrea lurida back into its southern California habitat. Fished to near-extinction in the 1930s, then further damaged by sulfite pollution from paper mills, Ostrea lurida's species habitat once stretched beyond the southern California coast to Baja, Mexico. The modern history of oysters has been well documented by biologists, however the paleontological history of oysters is less well known and many questions remain unanswered such as: Was Ostrea lurida always the only native oyster or did multiple oyster species live here? What other organisms thrived as a result of the oysters' reefal hard ground? How did the thickness of oyster beds vary through geological time? Did ocean environments play a role in community structure through time and if so, how? We examined the paleoecology of Holocene oyster communities within Newport Bay to help answer these questions. Results reveal highly diverse and abundant oyster communities were present in Newport Bay approximately 10,000 years ago. Our results here will be compared to future studies examining oyster history over the last 70 million years of geological history within Orange County. The authors are presently analyzing specimens housed at the John D. Cooper Center. This research will aid the ongoing restoration projects throughout southern California by providing a long-term perspective of community change through time.