title: Seagrass ecophysiological performance under ocean warming and acidification.
abstract: Seagrasses play an essential ecological role within coastal habitats and their worldwide population decline has been linked to different types of anthropogenic forces. We investigated, for the first time, the combined effects of future ocean warming and acidification on fundamental biological processes of Zostera noltii, including shoot density, leaf coloration, photophysiology (electron transport rate, ETR; maximum PSII quantum yield, Fv/Fm) and photosynthetic pigments. Shoot density was severely affected under warming conditions, with a concomitant increase in the frequency of brownish colored leaves (seagrass die-off). Warming was responsible for a significant decrease in ETR and Fv/Fm(particularly under control pH conditions), while promoting the highest ETR variability (among experimental treatments). Warming also elicited a significant increase in pheophytin and carotenoid levels, alongside an increase in carotenoid/chlorophyll ratio and De-Epoxidation State (DES). Acidification significantly affected photosynthetic pigments content (antheraxanthin, β-carotene, violaxanthin and zeaxanthin), with a significant decrease being recorded under the warming scenario. No significant interaction between ocean acidification and warming was observed. Our findings suggest that future ocean warming will be a foremost determinant stressor influencing Z. noltii survival and physiological performance. Additionally, acidification conditions to occur in the future will be unable to counteract deleterious effects posed by ocean warming.
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Repolho
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Duarte
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.|Departamento de Biologia &CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Gisela
authors.initials: G
authors.lastname: Dionísio
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: Paula
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
authors.forename: Ana R
authors.initials: AR
authors.lastname: Lopes
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
authors.forename: Inês C
authors.initials: IC
authors.lastname: Rosa
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
authors.forename: Tiago F
authors.initials: TF
authors.lastname: Grilo
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Caçador
authors.affiliation: Departamento de Biologia &CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Calado
authors.affiliation: MARE - Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Avenida Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Rosa
mesh_terms: D000143:Acids / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D018462:Photobiology; D010858:Pigmentation; D018515:Plant Leaves / Q000502:physiology; D018520:Plant Shoots / Q000502:physiology; D035962:Zosteraceae / Q000502:physiology*
chemical_list: D000143:Acids