Research Center y Desarrollo Tecnologico en Algas

Coquimbo, Chile

Research Center y Desarrollo Tecnologico en Algas

Coquimbo, Chile

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Rothausler E.,Católica del Norte University | Rothausler E.,University of Rostock | Rothausler E.,University of Tokyo | Gomez I.,Austral University of Chile | And 6 more authors.
Limnology and Oceanography | Year: 2011

During summer 2009, we conducted a field experiment and a field survey at 30°S in the coastal Humboldt Current to determine how floating time affects the physiological performance of kelp rafts. For the field experiment kelp rafts were tethered in coastal waters and the field survey was specifically designed to collect freefloating Macrocystis pyrifera across a latitudinal temperature gradient that reflects natural floating time. Experimental kelps were kept under photosynthetic active radiation (PAR) and PAR + ultraviolet (UV; PAR + UV) using filter foils, and tethered at the sea surface in their natural habitat. Ultraviolet radiation (UVR) did not affect kelp physiology, but caused a decrease in kelp biomass. The field survey confirmed that sea-surface temperature increased with distance from upstream source populations of M. pyrifera. Rafts sampled at increasing distance from sources showed high epibiont cover and reduced blade lengths. Physiological performance declined with increasing size of algal epibionts, which are indicators of floating time. Rafts that were farthest from the southern source populations had lost their sporophylls, suggesting that dispersal potential decreases with increasing floating time. The combined effects of abiotic (UVR and temperature) and biotic factors accelerate degradation of M. pyrifera and, thus, can impede successful dispersal in the Humboldt Current at 30°S. This suggests that floating macroalgae can be important dispersal vectors in areas with moderate environmental stress (i.e., in temperate oceans). © 2011, by the American Society of Limnology and Oceanography, Inc.


Rothausler E.,Católica del Norte University | Rothausler E.,University of Rostock | Gomez I.,Austral University of Chile | Karsten U.,University of Rostock | And 3 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2011

Large numbers of giant kelp rafts are floating along temperate coasts of the southern hemisphere, carrying a wide diversity of associated organisms with them. During voyages, floating kelps are exposed to strong variations in environmental conditions such as UV-radiation (UVR) and temperature that affect algal physiology, growth, and reproductive output. Consequently, it was predicted that the interactive effects of high temperature and UVR suppress algal persistence and reproductive output at the sea surface. This hypothesis was tested by exposing Macrocystis pyrifera (Linnaeus) C. Agardh sporophytes to two irradiance (PAR, PAR+UV) and three temperature (cool, ambient, warm) conditions. An outdoor-tank experiment with two consecutive runs (1st and 2nd) was conducted in northern-central Chile (30°S) to assess growth and physiological responses (pigment contents and photosynthesis) of floating M. pyrifera. Results showed that after being afloat for 15days, algae physiologically acclimated efficiently to changing abiotic conditions by a decrease in pigment contents and dynamic photoinhibition. However, in kelps exposed to 20°C these acclimation processes operated at the expense of growth, resulting in reduced biomass gains, lower blade elongation rates, and diminished reproduction. Overall, floating M. pyrifera responded with high physiological plasticity to the tested UV regimes (UVB 30-100kJm-2; UVA 300-2000kJm-2), but under stressful temperature conditions (~20°C) photoacclimation processes are costly and an important fraction of the energy gained via photosynthesis becomes unavailable for algal growth. We suggest that at mid latitudes (25°S-40°S) detached sporophytes of M. pyrifera have the capacity to float for long time periods and over large distances at water temperatures <20°C. © 2011 Elsevier B.V.


Graiff A.,Católica del Norte University | Graiff A.,University of Rostock | Pantoja J.F.,Católica del Norte University | Tala F.,Católica del Norte University | And 2 more authors.
Marine Biology | Year: 2016

Floating seaweeds serve as dispersal agents for various organisms, but their survival at the sea surface may be compromised by physiological stress and epibiont overgrowth. Most previous experiments have been conducted in laboratory mesocosms where epibiont colonization is limited, but in their natural environment floating seaweeds are frequently overgrown by epibionts, which might negatively affect seaweeds or even cause their sinking. To test this hypothesis, we conducted field experiments in northern-central Chile (30°S) with floating giant kelps Macrocystis pyrifera to determine the time until sinking, epibiotic bryozoan load, and their physiological status across different seasons. Floating sporophytes persisted for at least 4 weeks at the sea surface and sank in all seasons after bryozoan loads exceeded 40 % of the raft biomass. At the time of sinking, the kelp rafts were physiologically viable and biomass losses were relatively minor. In autumn, kelp rafts stayed afloat for an average of 41 days (maximum: 52 days) during moderate environmental conditions (cool water temperature and moderate solar radiation) and slow growth of epibionts. However, higher water temperatures in summer seemed to enhance the growth of epibiotic bryozoans but not the growth of M. pyrifera, causing earlier sinking. The results indicate that the high growth rates of encrusting bryozoans provoke sinking of the kelp rafts, representing the first demonstrated case of epibiont-induced sinking of otherwise healthy floating seaweeds. Increasing global temperatures may enhance epibiont growth and thereby suppress the dispersal potential of floating seaweeds, even of species known for their high acclimation potential to the conditions at the sea surface. © 2016, Springer-Verlag Berlin Heidelberg.


Graiff A.,Católica del Norte University | Graiff A.,University of Rostock | Karsten U.,University of Rostock | Meyer S.,Católica del Norte University | And 5 more authors.
Botanica Marina | Year: 2013

Several large kelp species are capable of long-distance dispersal via rafting. However, seasonal changes in environmental conditions at the sea surface may variably affect the physiological status of the floating thalli; challenging conditions during summer may accelerate disintegration and cause rapid sinking. We used the bull kelp Durvillaea antarctica from northern-central Chile (30 S) to test seasonal variation in floating persistence. Experiments with tethered specimens were conducted in all seasons to assess how variable environmental conditions influence the morphology and photosynthetic characteristics of floating D. antarctica. Floating specimens stayed afloat at the surface for more than 1 month during moderate environmental conditions that prevailed in winter, spring, and fall. However, higher water temperatures and intense solar radiation in summer resulted in significant biomass losses and rapid disintegration of the floating kelps; consequently, they sank within <1 month. These strong seasonal effects were reflected in decreasing maximal quantum yield as well as in maximum relative electron transport rates of photosynthesis. Understanding physiological responses of floating algae is important because increasing global temperatures and shifts in solar radiation may strongly affect the survival of floating algae, potentially reducing the distances and frequencies of rafting dispersal. © 2013 by Walter de Gruyter Berlin Boston 2013.


Bulboa C.,Católica del Norte University | Bulboa C.,Research Center y Desarrollo Tecnologico en Algas | Macchiavello J.,Católica del Norte University | Macchiavello J.,Research Center y Desarrollo Tecnologico en Algas | And 2 more authors.
Aquatic Botany | Year: 2010

Chondracanthus chamissoi (C. Agardh) Kützing is an economically important red seaweed with an extended latitudinal distribution along the south-east Pacific. Here we report on the seasonal in vitro germination of carpospores and tetraspores from four populations distributed from 27 to 41° S on the Chilean coast. Our results show that both types of spores exhibited a different physiological behavior related to the geographic origin of the specimens. Germination occurred throughout the year for both spore types in the four populations. However, for the northern locations (Calderilla, La Herradura and Puerto Aldea) germination was higher in spring, while for the southern location (Lechagua), germination was higher in summer. The growth rate of carposporelings and tetrasporelings varied seasonally in all locations studied, with higher growth in spring. Among all, carposporelings from Lechagua specimens reached the highest growth rates (9.3 ± 0.2% d-1). However, spores from Herradura and P. Aldea had a good germination and SGR in all seasons and would be good candidates to start spores-based cultivation of this valuable resource in Chile. © 2009 Elsevier B.V. All rights reserved.


Macchiavello J.,Católica del Norte University | Macchiavello J.,Research Center y Desarrollo Tecnologico en Algas | Araya E.,Católica del Norte University | Bulboa C.,Católica del Norte University | Bulboa C.,Research Center y Desarrollo Tecnologico en Algas
Journal of Applied Phycology | Year: 2010

Since the establishment of abalone farming, there has been an increase in the demand for Macrocystis as a food source. Therefore, the pressure on natural stock has also augmented and the sustainability of the actual harvesting practices has been questioned. In this article, an attempt to farm Macrocystis pyrifera by zoospores in northern Chile is described; initially under laboratory conditions and subsequently by cultivation in the sea. The experiments were executed during 1 year and two different cultivation methodologies were used: a direct and an indirect method. A maximum frond length of 175cm was reached and 22 kg m-1of rope was produced after 120 to 150 days of cultivation in the sea. The algae grew under both methodologies, and no differences in algal length and biomass were detected between the two cultivation systems. However, the direct culture method can be recommended for productive and practical reasons. © 2010 Springer Science+Business Media B.V.

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