Combined effects of acidification and hypoxia on the estuarine ctenophore, Mnemiopsis leidyi
Citation:
Moso, E., L. Enzor, C. Hankins, AND M. Barron. Combined effects of acidification and hypoxia on the estuarine ctenophore, Mnemiopsis leidyi. Society for Integrative and Comparative Biology, San Francisco, CA, January 03 - 07, 2018.
Impact/Purpose:
The Nutrient Enhance Coastal Acidification and Hypoxia (NECAH) team is studying the singular effects of acidification and hypoxia in conjunction with the combined effect of both stressors. Multiple studies are being conducted by this team on a range of estuarine species to determine the coastal impact of lowered dissolved oxygen (DO) and pH. This study was conducted on the estuarine ctenophore, Mnemiopsis leidyi, because there is a lack of study focused on the impact of acidification and the combined stress of acidification to the ctenophore. The results of this study highlight the impact of lower pH and DO on the overall health and survival of the estuarine ctenophore, Mnemiopsis leidyi, and indicate the variability of sensitivity between younger and older life stages. The Mnemiopsis leidyi consumes copious amounts plankton and its sensitivity to environmental fluctuations could significantly impact planktonic availability within the coastal environment. This is an important link in most trophic pathways and could significantly impact other estuary species who rely on plankton to service their diet. It also contributes to a FY18 deliverable under SSWR 4.02B.
Description:
Estuaries are transitive zones which experience large fluctuations in environmental parameters (temperature, dissolved oxygen, pH, etc.). The interactive effects of reduced dissolved oxygen (DO) and elevated pCO2 on estuarine organisms is not currently well understood. Ctenophores are an important factor in estuarine planktonic trophic pathways because they are voracious consumers of planktonic organisms. Ctenophores have shown a resistance to the negative effects of hypoxia, however, there is little information about their resistance to acidification and combined effects of hypoxia and acidification. This study determined acute sensitivity by measuring the survivability at two life stages of the ctenophore Mnemiopsis leidyi, larval (early cydippid) and adult (reproductive lobate). Over a 5-day test period ctenophores were exposed to four treatments: ambient, elevated pCO2 (~1300µatm, IPCC RCP 8.5 scenario), hypoxic (low dissolved oxygen, ~2 mg/L), combined (elevated pCO2 and hypoxic). Preliminary research suggests a sensitivity to elevated pCO2 and combined treatments and no effect in the hypoxic treatment.