Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity. (August 2019)

• Record Type: Journal Article
• Authors: Tala, Fadia; López, Boris A.; Velásquez, Marcel; Jeldres, Ricardo; Macaya, Erasmo C.; Mansilla, Andrés; Ojeda, Jaime; Thiel, Martin
• Is Part Of: Marine environmental research. Volume 149(2019)
• Page Start: 67
• Page End: 79
• Publication Date: 2019-08
• Subjects: Chile -- Durvillaea antarctica -- Floating persistence -- Rafting -- Dispersal -- Floating seaweeds -- Temperature; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2019.05.013
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: Current knowledge about the performance of floating seaweeds as dispersal vectors comes mostly from mid latitudes (30°–40°), but phylogeographic studies suggest that long-distance dispersal (LDD) is more common at high latitudes (50°–60°). To test this hypothesis, long-term field experiments with floating southern bull kelp Durvillaea antarctica were conducted along a latitudinal gradient (30°S, 37°S and 54°S) in austral winter and summer. Floating time exceeded 200d in winter at the high latitudes but in summer it dropped to 90d, being still higher than at low latitudes (<45d). Biomass variations were due to loss of buoyant fronds. Reproductive activity diminished during long floating times. Physiological changes included mainly a reduction in photosynthetic (Fv /Fm and pigments) rather than in defence variables (phlorotannins and antioxidant activity). The observed long floating persistence and long-term acclimation responses at 54°S support the hypothesis of LDD by kelp rafts at high latitudes. Highlights: MERE 2019_145 Tala et al. Long-distance rafting of seaweeds is more prevalent at high latitudes. Floating persistence and physiological acclimation of Durvillaea antarctica depended on latitude and season. The proportion of thalli with mature conceptacles were reduced during long floating times. Morphological changes were more important for sinking of floating D. antarctica than physiological changes. The results confirm that kelp rafting is favored at high latitudes.