Population biology of Durvillaea antarctica and Lessonia nigrescens (Phaeophyta) on the rocky shores of southern Chile

Abstract

The Lessonia nigrescens-Durvdlaea antarctica belt is a characteristic feature of the lower intertidal zone along the Chilean coast. This study describes the dynamics of the Lessonja-Durvillaea assemblage in an exposed locality of southern Chile. Abundance, spatial and ten~poral distribution, reproductive penods and response to experimental pruning were quantified. The results revealed differences in population dynamics between species. L. nigrescens had low recruitment, but a longer life expectancy. In contrast, D. antarctica had great temporal fluctuations in abundance, which were associated to massive recruitment during the warmer seasons. It occupied zones where old L. nigrescens individuals were dislodged by wave action. Replacement of D. antarctica by L. nigrescens was not seen. Regeneration from pruned plants of the 2 species was evident during the first months, but subsequently, deterioration of the regenerated parts was seen, leading to the degeneration and detachment of the whole plant. Thus, for management plans, the total removal of old individuals would be preferable.

Occurrence of arsenic species in the seagrass Posidonia oceanica and in the marine algae Lessonia nigrescens and Durvillaea antarctica

“…It is reported that L. nigrescens has high sorption capacity of arsenic from the surrounding aquatic media, as is shown in samples collected in the Valparaiso Bay, Chile ). In the present paper, we observed this absorption capacity in samples collected in the same zone, and at the same time, we can compare this capacity with the lower sorption capacity observed in D. antarctica since both species share their habitat in some zones in the Chilean coast and show competitive interactions (Westermeier et al 1994).…”

Holdfast fragmentation of Macrocystis pyrifera (integrifolia morph) and Lessonia berteroana in Atacama (Chile): a novel approach for kelp bed restoration

“…The ecological significance of Macrocystis and Lessonia beds along the coast of Chile has been discussed repeatedly by various authors, stressing their role as natural microhabitats, nurseries, protection structures, substrata, and food (Santelices et al 1980;Santelices & Ojeda 1984a;Ojeda & Santelices 1984;Westermeier & Möller 1990;Westermeier et al 1994;Graham et al 2007). Various studies not only evaluated the effects of harvesting techniques, including their immediate impact, but also tried to forecast long-time consequences.…”

“…In Bahia Chasco, commercial Macrocystis integrifolia harvesting is based on the thinning of weak adult specimens and the pruning of younger individuals (Westermeier et al 2014a). In contrast, Lessonia berteroana (northern lineage of L. nigrescens; sensu Gonzalez et al 2012) biomass is totally removed from high-energy rocky intertidal areas in the Atacama coast, since pruning schemes have not been successful (Westermeier et al 1994). The age of kelp individuals is frequently ignored, and juvenile specimens are harvested before sexual maturity, with negative consequences.…”

Seasonal variation in floating persistence of detached Durvillaea antarctica (Chamisso) Hariot thalli

“…It is also very abundant along the Chilean coast on exposed rocky shores (Westermeier et al 1994, Fraser et al 2010a. Furthermore, D. antarctica possesses a unique gas-filled honeycomb structure within the blades, which gives strength and extreme buoyancy, and offers protection against potential damage by the strong waves in its natural habitat (Skottsberg 1941, Santelices et al 1980, Hay 1994, Koehl 1999.…”