title: Eutrophication and warming-driven green tides (Ulva rigida) are predicted to increase under future climate change scenarios.
abstract: The incidence and severity of extraordinary macroalgae blooms (green tides) are increasing. Here, climate change (ocean warming and acidification) impacts on life history and biochemical responses of a causative green tide species, Ulva rigida, were investigated under combinations of pH (7.95, 7.55, corresponding to lower and higher pCO2), temperature (14, 18°C) and nitrate availability (6 and 150μmolL-1). The higher temperature accelerated the onset and magnitude of gamete settlement. Any two factor combination promoted germination and accelerated growth in young plants. The higher temperature increased reproduction, which increased further in combination with elevated pCO2or nitrate. Reproductive success was highest (64.4±5.1%) when the upper limits of all three variables were combined. Biochemically, more protein and lipid but less carbohydrate were synthesized under higher temperature and nitrate conditions. These results suggest that climate change may cause more severe green tides, particularly when eutrophication cannot be effectively controlled.
authors.affiliation: School of Marine Science and Technology, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, England, UK.
authors.forename: Guang
authors.initials: G
authors.lastname: Gao
authors.affiliation: School of Marine Science and Technology, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, England, UK.
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Clare
authors.affiliation: Seaweed & Co. Ltd., Office 2.3 North Tyneside Business Centre, 54a Saville Street, North Tyneside NE30 1NT, England, UK.
authors.forename: Craig
authors.initials: C
authors.lastname: Rose
authors.affiliation: School of Marine Science and Technology, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, England, UK. Electronic address: gary.caldwell@ncl.ac.uk.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Caldwell
mesh_terms: D057231:Climate Change; D005068:Eutrophication; D018525:Germination; D006863:Hydrogen-Ion Concentration; D050356:Lipid Metabolism; D009566:Nitrates / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D012098:Reproduction; D012624:Seaweed / Q000254:growth & development; D013696:Temperature; D044445:Ulva / Q000254:growth & development / Q000502:physiology*; D006113:United Kingdom
chemical_list: D009566:Nitrates; D011506:Proteins
keywords: Eutrophication; Germination; Ocean acidification; Ocean warming; Reproduction; Settlement