TY - JOUR AU - Figueroa, Félix L AU - Hermoso-Bentrán, Maibe AU - Celis-Plá, Paula SM AU - Bonomi-Barufi, José AU - Álvarez-Gómez, Félix AU - Korbee, Nathalie AU - López-Calderón, Jorge AU - Cota-Lucero, Tania AU - Riosmena-Rodríguez, Rafael PY - 2016/06/15 Y2 - 2024/03/29 TI - Photosynthetic activity estimated as in vivo chlorophyll a fluorescence in calcareous red macroalgae JF - Ciencias Marinas JA - Cienc. Mar. VL - 42 IS - 2 SE - Research Article DO - 10.7773/cm.v42i2.2587 UR - https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/2587 SP - 139-155 AB - <p>Photosynthetic activity was estimated, in 2 different sets of experiments, as <em>in vivo</em> chlorophyll <em>a</em> fluorescence in 2 calcareous red macroalgae: <em>Neogoniolithon brassica-florida</em>, which forms vermetid reefs with <em>Dendropoma petraeum</em>, and the rhodolith-forming <em>Lithophyllum margaritae</em>. In the first set of experiments, vermetid reefs collected from the Cabo de Gata-Níjar Natural Park (Almería, Spain) were incubated for 6 months in outdoor mesocosms at 2 different temperatures: ambient temperature (T) and ambient temperature plus 2 ºC (T+). Daily variations in effective quantum yields were related to the increase in solar radiation. Electron transport rate (ETR) was higher at T+ than at T. Oxygen production, estimated from ETR, was higher in <em>N. brassica-florida</em> growing in vermetid reefs in the coastal area than in those incubated in mesocosms or under laboratory conditions. In the second set of experiments, <em>L. margaritae</em> specimens with or without attached epifauna (mainly sponges) were collected at 2 sites (Pedregoso and CFE) on the Baja California Peninsula, Mexico, and at 2 depths (1 and 2 m). ETR values for rhodoliths collected at 1 m depth and with attached epifauna were higher than those for rhodoliths collected at 2 m depth, indicating the importance of greater incident radiation on photosynthetic activity. Photosynthetic activity was higher in <em>L. margaritae</em> collected from Pedregoso, the site with better water quality (high transparency and low pollution) and rocky substrate availability. In the CFE samples, the photosynthetic efficiency (alpha<sub>ETR</sub>) was highest in rhodoliths with attached epifauna. The highest ETR values for <em>N. brassica</em>-florida at T+ and the highest alpha<sub>ETR</sub> or ETR values for <em>L. margaritae</em> with attached sponges may be explained by the increase in CO<sub>2</sub> available for photosynthesis due to the respiration of the associated fauna. The usefulness of in vivo chlorophyll <em>a</em> fluorescence for estimating photosynthetic production in calcareous macroalgae under multifactorial experiments is discussed.&nbsp;</p> ER -