Depth distribution of canopy‐forming algae of the order Fucales is related to their photosynthetic features. (21st March 2021)

• Record Type: Journal Article
• Authors: Sant, Natàlia; Ballesteros, Enric
• Is Part Of: Marine ecology. Volume 42:Number 3(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-21
• Subjects: Cystoseira -- depth -- Fucales -- light -- macroalgae -- photosynthesis; Marine ecology -- Periodicals; 577.705
• DOI: 10.1111/maec.12651
• Languages: English
• ISSNs: 0173-9565

Abstract

Abstract: Photosynthetic features and dark respiration of different species of dominant canopy‐forming algae of the Order Fucales (Phaeophyceae) consistently change with depth. Photosynthetic efficiency (α) and light at compensation ( I c ) change according to the amount of light available at each depth, α increasing and Ic decreasing with depth. However, the values of light at saturation ( I k ) do not show any depth pattern. Deep‐water species show higher photosynthesis at saturation ( P max ) and lower dark respiration ( R d ) than shallow water ones. This result contrasts with the expected reduction of P max in low light environments shown by terrestrial plants but is consistent with other studies performed in macroalgae, suggesting that P max and α show the same trend of variation in the marine environment. The positive correlation between P max and α cannot be explained by differences in thickness as all tested species show an extremely high morphological similarity. The increase in P max with depth is also coupled to an increase of N and P content in branches, which points to nutrient‐limited photosynthesis in shallow water species.