Survival Data of Strengthened and Non-Strengthened Oysters on Two Restored Reefs in Georgia, USA

The eastern oyster, Crassostrea virginica, is known to respond to chemical cues from their predators by strengthening their shell in defense. The chemical cues homarine and trigonelline, found in the urine of blue crabs, Callinectes sapidus, are two metabolic waste products known to cause this inducible defense in juvenile oysters. We tested whether this shell strengthening defense is beneficial for juvenile oysters in a restored reef setting by inducing oyster spat with chemical cues, placing them onto a restored reef and measuring their survival for 50-100 days. The first reef location is a previously restored reef (approximately 10 years old) with limited physical exposure to wind waves and boat wake. Juvenile oysters were placed at this site in September of 2021 and survival was measured for 49 days. The second reef location is a newly restored oyster reef (less than 1 year old) that acts as a living shoreline, with significant exposure to boat wake and wind waves. Juvenile oysters were protected from predation using mesh wrapping with an opening of 1 square cm and placed at the reef site in April 2023, where survival was monitored for 103 days. Site locations: Reef 1 (dock site) - 31.988948°, -81.024001° Reef 2 (living shoreline reef) - 32.067957°,-80.985005°

美洲东部牡蛎（Crassostrea virginica）可通过强化贝壳的防御策略，对捕食者释放的化学信号作出响应。研究人员在蓝蟹（Callinectes sapidus）的尿液中检出高肌肽（homarine）与胡卢巴碱（trigonelline）这两种代谢废物，二者已被证实可诱导幼牡蛎产生该诱导型防御反应。本研究通过化学信号诱导牡蛎稚贝（oyster spat）产生贝壳强化防御，将其投放至修复后的牡蛎礁生境中，并连续监测50至100天的存活率，以验证该防御策略对幼牡蛎的生存益处。
首个礁体点位为一处修复时长约10年的已修复牡蛎礁，受风浪与船舶尾流的物理扰动较为有限。研究团队于2021年9月将幼牡蛎投放于此，持续监测其存活率共49天。
第二个礁体点位为一处建成不足1年的新建修复牡蛎礁，作为活海岸（living shoreline）存在，易受到船舶尾流与风浪的显著物理扰动。2023年4月，研究人员使用孔径为1平方厘米的网罩对幼牡蛎进行捕食防护，将其投放至该礁体点位后，持续监测存活率达103天。
礁体点位信息：
礁1（码头点位）——31.988948°，-81.024001°
礁2（活海岸礁体）——32.067957°，-80.985005°