Aquaculture America 2023

February 23 - 26, 2023

New Orleans, Louisiana USA

ASSESSING OYSTER GROWTH AND THE HABITAT VALUE OF OYSTER AQUACULTURE GEAR FOR ESTUARINE FISHES AND INVERTEBRATES

Authors: Edward Hale*, Timothy Smoot, Lenna Wood, Maddy Windsor

*School of Marine Science & Policy; Delaware Sea Grant College Program; College of Earth, Ocean, and Environment; University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA; ehale@udel.edu

 



The harvest of Hard Clam (Mercenaria mercenaria) and Eastern Oyster (Crassostrea virginica) from Delaware’s Inland Bays (Rehoboth Bay, Indian River Bay, and Little Assawoman Bay) has been an important resource for the people of southern Delaware for centuries. From the post-war period to 1979, bottom ground in Rehoboth and Indian River bays was used for the cultivation of Eastern Oyster. Unfortunately, natural oyster populations within Delaware Bay and the Inland Bays have been greatly reduced due to historical overharvest, and disease vectors among other factors. In order to augment natural harvest and support the demand for Eastern Oyster, commercial oyster aquaculture was reinstated in the Inland Bays in 2017. In multiple studies along the US east coast and within the Inland Bays, fishes and invertebrates have been observed around oyster cages and other types of gear used to grow oysters. Oyster farms may therefore be supporting fisheries through ephemeral habitat provisioning for juvenile fishes. Research on oyster aquaculture gear as habitat for fishes within Delaware’s Inland Bays has thus far focused on oyster gardening programs and the relative value of artificial oyster reef habitat. Our project aims to further our scientific understanding of the ecological services rendered by shellfish farming by examining the habitat value of 1) traditional on-bottom commercial aquaculture gear and 2) an experimental gear type actively used by a commercial oyster farmer through a single growing season. Preliminary results suggest variability in diversity and evenness are present between two different gear types assessed with higher species richness and diversity observed in bottom gear compared to an experimental floating cage.