Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity
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 fl...
Published in: | Marine Environmental Research |
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Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier Ltd
2019
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Subjects: | |
Online Access: | https://doi.org/10.1016/j.marenvres.2019.05.013 https://repositorio.uchile.cl/handle/2250/172596 |
Summary: | 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. |
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