Ocean Acidification Affects Larval Swimming in Ostrea lurida but not Crassostrea gigas

• Main Author: Buckham, Shannon
• Format: Text
• Language: English
• Published: Western CEDAR 2015
• Subjects: Environmental Sciences; Pacific; Crassostrea gigas; Ocean acidification; Pacific oyster
• Online Access: https://cedar.wwu.edu/wwuet/451; https://doi.org/10.25710/35x0-2c06; https://cedar.wwu.edu/context/wwuet/article/1459/viewcontent/Buckham_MS_Thesis.pdf

The effects of ocean acidification (OA), which results from increased CO2 emissions, are of particular concern for calcifying marine organisms. In marine invertebrates, the larval stages are generally considered the most vulnerable to the effects of OA and many recent studies show negative impacts of OA on early developmental stages of calcifying marine invertebrates. I studied the impact of OA on larval swimming performance and behavior in the Pacific oyster, Crassostrea gigas, and the Olympia oyster, Ostrea lurida. Swimming studies can be used to understand how short-term performance and behavior changes may affect the long-term success of populations. In this study, digital larval tracking was used to test for changes in swimming performance and behavior in larvae reared at pCO2 levels of 400, 800, and 1200 ppm. Experiments were run on hatchery-bred larvae from the beginning of the larval period to the pediveliger stage. Morphological and energetic changes were analyzed to determine if they corresponded to swimming performance and behavior differences between pCO2 treatments. Results showed few swimming performance changes in C. gigas larvae and no changes in swimming behavior, suggesting that transport will not be affected by OA in this species. However, C. gigas was affected morphologically and energetically by OA. O. lurida increased swimming speeds in response to increased pCO2 levels, but vertical displacement velocity did not change. O. lurida also increased helical pitch and energy allocated to swimming in response to OA, but did not show any morphological changes. Swimming performance and behavior changes observed in O. lurida suggest that OA could affect larval transport and connectivity in this species, ultimately affecting the success of later developmental stages.