Fabio Méndez 1, 3, 4, Francisco Bahamonde 1, 2, 3, Zambra López 1, 5, Juan Pablo Rodríguez 1, 3, 4, Andrés Mansilla 1, 3, 5.
1 Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Punta Arenas, Chile.
2 Programa de Magíster en Ciencias mención Manejo y Conservación de Recursos Naturales en Ambientes Subantárticos, Universidad de Magallanes, Casilla 113-D, Punta Arenas, Chile.
3 Cape Horn International Center (CHIC), Universidad de Magallanes, Punta Arenas, Chile.
4 Programa de Doctorado en Ciencias Antárticas y Subantárticas, Universidad de Magallanes, Punta Arenas Chile.
5 Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE)
West Antarctic Peninsula has been affected by the increase in temperature in terrestrial and marine ecosystems. Consequently, changes have been observed in environmental variables such as light intensity, temperature, salinity and turbidity, those changes force macroalgae to adapt ecophysiologically to survive. The present study evaluates the effect of environmental variables and the ecophysiology of Adenocystis utricularis along a latitudinal gradient on the Antarctic Peninsula. Adult individuals (n=7) were collected in 8 sites along a north-south latitudinal gradient (62° to 67°S) on the Antarctic Peninsula, during the summer of 2022. Photosynthetic (ETRmax, α and Ek) and pigment parameters (Chl a, Chl c and Fucox) were obtained. Results showed significant differences among sites. In addition, a negative correlation was observed between the ETRmax and Ek variables and the latitudinal gradient, these variables decreased from sites of lower to higher latitude. The variable α had a positive correlation with the latitudinal gradient, increasing significantly from lower to higher latitude sites. Photosynthetic pigment concentration showed significant differences only for Chl a and Chl c among sites. Finally, Fucox showed a negative correlation with latitudinal gradient, decreasing significantly from lower to higher latitude sites. These ecophysiological variations are influenced by local environmental factors, which are increased by climate change. Therefore, the species A. utricularis must be strategic in its spatial distribution and efficient in light uptake, and in this way to adapt and survive these extreme conditions.