title: Ocean Warming and CO₂-Induced Acidification Impact the Lipid Content of a Marine Predatory Gastropod.
abstract: Ocean warming and acidification are current global environmental challenges impacting aquatic organisms. A shift in conditions outside the optimal environmental range for marine species is likely to generate stress that could impact metabolic activity, with consequences for the biosynthesis of marine lipids. The aim of this study was to investigate differences in the lipid content of Dicathais orbita exposed to current and predicted future climate change scenarios. The whelks were exposed to a combination of temperature and CO₂-induced acidification treatments in controlled flowthrough seawater mesocosms for 35 days. Under current conditions, D. orbita foot tissue has an average of 6 mg lipid/g tissue, but at predicted future ocean temperatures, the total lipid content dropped significantly, to almost half. The fatty acid composition is dominated by polyunsaturated fatty acids (PUFA 52%) with an n-3:6 fatty acid ratio of almost 2, which remains unchanged under future ocean conditions. However, we detected an interactive effect of temperature and pCO₂ on the % PUFAs and n-3 and n-6 fatty acids were significantly reduced by elevated water temperature, while both the saturated and monounsaturated fatty acids were significantly reduced under increased pCO₂ acidifying conditions. The present study indicates the potential for relatively small predicted changes in ocean conditions to reduce lipid reserves and alter the fatty acid composition of a predatory marine mollusc. This has potential implications for the growth and survivorship of whelks under future conditions, but only minimal implications for human consumption of D. orbita as nutritional seafood are predicted.
authors.affiliation: Marine Ecology Research Center, School of Environment, Science and Engineering, Southern Cross University, P.O. Box 157, Lismore, NSW 2480, Australia. r.regino.10@student.scu.edu.au.
authors.forename: Roselyn
authors.initials: R
authors.lastname: Valles-Regino
authors.affiliation: National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia. ricky.tate22@gmail.com.
authors.forename: Rick
authors.initials: R
authors.lastname: Tate
authors.affiliation: National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia. brendan.kelaher@scu.edu.au.
authors.forename: Brendan
authors.initials: B
authors.lastname: Kelaher
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia. dale.savins@scu.edu.au.
authors.forename: Dale
authors.initials: D
authors.lastname: Savins
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, NSW 2480, Australia. ashley.dowell@scu.edu.au.
authors.forename: Ashley
authors.initials: A
authors.lastname: Dowell
authors.affiliation: Marine Ecology Research Center, School of Environment, Science and Engineering, Southern Cross University, P.O. Box 157, Lismore, NSW 2480, Australia. kirsten.benkendorff@scu.edu.au.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Benkendorff
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry*; D057231:Climate Change; D005227:Fatty Acids / Q000737:chemistry; D049851:Gastropoda / Q000737:chemistry*; D057232:Global Warming; D008055:Lipids / Q000737:chemistry*; D009792:Oceans and Seas; D012623:Seawater; D013696:Temperature
chemical_list: D005227:Fatty Acids; D008055:Lipids; D002245:Carbon Dioxide
keywords: Dicathais orbita; marine lipids; n-3; n-6; ocean climate change; plasmalogens; polyunsaturated fatty acids