2026-05-29T23:07:29Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/403952026-02-03T11:15:48Zcom_10630_2254col_10630_37953

A warmer Arctic compromises winter survival of habitat-forming seaweeds López-Gordillo, Francisco Javier Carmona-Fernández, Raquel Jiménez-Gámez, Carlos Algas marinas Cambios climáticos Continuous winter darkness at a latitude of 79_N was simulated in cultures of four species of Arctic seaweeds at 3 and 8°C. The laminarians Saccharina latissima and Alaria esculenta, and the rhodophytes Phycodrys rubens and Ptilota gunneri were monitored for 4 months in total darkness and after 1 week following light return in early spring, under controlled laboratory conditions. Biomass loss during darkness was enhanced by the high temperature in all species. At 8°C, the two laminarians were unable to resume growth upon re-illumination. Alaria esculenta showed new blade production by the end of the dark period, but only at 3°C. In all species, the photosynthetic ability was sustained, not suspended, during the whole dark period. P. rubens exhibited lower photosynthetic potential at 8°C than at 3°C during the darkness period, but it was able to recover its O2 evolving potential upon reillumination, as P. gunneri and S. latissima did, but the latter only at 3°C. The reactivation of photosynthesis seemed to involve photosystem II over photosystem I, as 7 d of photoperiod after the prolonged darkness was not enough to fully recover the PAM-related photosynthetic parameters. Only small changes were recorded in the internal chemical composition (total C, total N, carbohydrates, proteins, and lipids), but species-specific differences were observed. Unlike subarctic areas with an operating photoperiod along the year, a warmer polar night might pose a limit to the ability of multi-year seaweeds to occupy the new ice-free illuminated areas of the Arctic coasts, so that newcomers will potentially be restricted to the spring-summer season. 2025-10-22T10:52:15Z 2025-10-22T10:52:15Z 2025-10-22T10:52:15Z 2022 journal article Gordillo FJL, Carmona R and Jiménez C (2022) A Warmer Arctic Compromises Winter Survival of Habitat-Forming Seaweeds. Front. Mar. Sci. 8:750209. doi: 10.3389/fmars.2021.750209 https://hdl.handle.net/10630/40395 10.3389/fmars.2021.750209 eng open access Frontiers in Marine Science