Eastern Oysters (Crassostrea virginica) Health Assessment in the Rehoboth Bay

Abstract

Investigating Oyster Health Status by Studying Oyster Condition Index and Natural Oyster Sets in Rehoboth Bay, Delaware Sara Berzinji1, Aaron Bland2, Memory Nakazwe2, Mohana Gadde2, and Gulnihal Ozbay2, Ph.D. 1Ransom Everglades High School, Miami, FL 2Department of Agriculture and Natural Resources, Delaware State University, Dover, DE Over the past few decades, oyster (Crassostrea virginica) populations have been in decline. One of the many bodies of water affected by this is the Rehoboth Bay. This research focuses on assessing the health of oysters placed in seven different sites along the Bay. Assessing which locations are thriving will help in creating more successful artificial reefs and therefore lead to healthier aquatic ecosystems. While there is a large issue with oyster populations, this research focused on those in the Rehoboth Bay. Bags with oysters were deployed at each of the seven sites in the early summer of 2020 and were collected 5-6 weeks later. This process was repeated two more times, in late summer and then in the fall of 2020. Spats were counted and the condition index was calculated by measuring the height, width, and depth of the oysters along with the weight of their shells and tissue dry and wet. Calculating the condition index and counting the number of spats help determine if the oysters were healthy. The condition index remained generally constant throughout the 3 testing periods and the recruitment rates at each site were also constant with the exception of the BBR site which had a higher average number of spat along with the S Cove site. These results can be used to create healthy and successful oyster reefs in the Rehoboth Bay and better the health of the ecosystem. Keywords: oyster restoration, oyster recruitment, condition index, Rehoboth Bay, Crassostrea virginica Acknowledgments: We acknowledge USDA NIFA Capacity Building Grant Award# 2016-06642 for funding my internship and the project as part of the student experiential learning goal and the Project Director, Dr. Gulnihal Ozbay for providing this internship opportunity.