UCN-CEAZA
Mass die-off of the cold-water coral Desmophyllum dianthus in the Chilean Patagonian fjord region.
Försterra, G., Häussermann, V., Laudien, J., Jantzen, C., Sellanes, J., & Muñoz, P.
In fjords and channels of the Chilean Patagonia, the solitary cold-water coral Desmophyllum dianthus (Esper, 1794) can be found in depths as shallow as 7 m as part of a deep-water emerging benthic community. In the Comau Fjord, one of three Chilean fjords where this species is forming large banks with multiple branched pseudo colonies on the steep rock walls, shallow water coral communities have been monitored for more than a decade. In 2012, a mass die-off was observed along 8.4 km of coast line and at least down to 70 m depth. Only specimens of D. dianthus were affected while other organisms, including two more scleractinian species, were not visibly damaged. The event coincides with exceptionally high efflux of methane and sulfide enriched water from cold vents in the rock walls at this site. Due to strongly increased salmon farming activity in the last decade, algae blooms have increased in frequency and intensity as a result of elevated primary production. We hypothesize and provide evidence that either harmful substances from the cold vents or hypoxia following an exceptionally strong algae bloom—or the synergistic effects of both—might have caused the mass mortality.
Año: 2014
Palabras claves:
Referencia APA: Försterra, G., Häussermann, V., Laudien, J., Jantzen, C., Sellanes, J., & Muñoz, P. (2014). Mass die-off of the cold-water coral Desmophyllum dianthus in the Chilean Patagonian fjord region. BMS, 90(3), 895-899.
Economic valuation of kelp forests in northern Chile: values of goods and services of the ecosystem.
Vásquez, J., Zuñiga, S., Tala, F., Piaget, N., Rodríguez, D., & Vega, J.
Kelp beds, besides being one of the most important benthic resources in northern Chile, provide a variety of environmental goods and services. In order to evaluate economically the wild kelp populations in northern Chile (26° to 32° S) more than simply their commercial value as a source of raw materials for alginate extraction, we used several economic indicators to holistically assess the value of a group of brown seaweeds of economic importance, Lessonia spp. and Macrocystis pyrifera: (1) market value of biomass as a source of raw material for extraction of alginic acid, (2) market value of associated species of economic importance, (3) value as a source of scientific information, (4) value as a climate buffer (CO2 capture and release of O2), (5) value of associated biodiversity (non-commercial species), (6) value as cultural heritage and (7) value as a reservoir of biodiversity. Existence values of kelp beds which estimate the willingness of citizens to pay and work without payment to preserve the ecosystem were calculated using the contingent valuation technique. The results indicate that kelp beds in northern Chile have a total value of US $540 million. Of this total, kelp fishery accounts for 75 % and associated-species fisheries account for 15 %. In this context, the economic value of Chilean kelp beds is mainly associated with the industry of alginate extraction. By contrast, existence value as a source of scientific information or environmental buffer for CO2 capture or O2 production represents only 9 % of the total value, representing a very low relative importance to society. The economic valuation of coastal resources and marine ecosystems is a complementary tool for decision making and implementation of public policies related to the conservation and sustainable exploitation of renewable resources and their ecosystems.
Año: 2014
Palabras claves: Kelp fishery, Phaeophyta, Administrative policies, Ecosystem goods and services, Conservation, Economic value.
Referencia APA: Vásquez, J., Zuñiga, S., Tala, F., Piaget, N., Rodríguez, D., & Vega, J. (2014). Economic valuation of kelp forests in northern Chile: values of goods and services of the ecosystem. J Appl Phycol, 26(2), 1081-1088.
Geochemistry of reduced fluids from shallow cold vents hosting chemosynthetic communities (Comau Fjord, Chilean Patagonia, ∼42°S).
Muñoz, P., Sellanes, J., Villalobos, K., Zapata-Hernández, G., Mayr, C., & Araya, K.
Reduced fluids from shallow-marine vents sustain chemosynthetic bacterial mats located at the base of the volcano Barranco Colorado in Comau Fjord (X-Huinay; 42°23.279′S, 72°27.635′W). We characterized the chemical environment in which these bacteria thrive. To this end, we analyzed CH4, ∑H2S, O2, DIC, and stable isotopes (δ13C, δ2H and δ18O) and compared them with readings taken at a control station (which lacks evidence of fluid venting and mat-forming bacteria). In addition, CTD measurements, chlorophyll-a, and nutrient analyses were performed. At depths of approximately 5–7 m, the water column exhibited a pycnocline that formed under the influence of fresh water discharges, especially during the summer season, which also affected the surface temperature. Bacterial mats and elemental sulfur flocs were observed in the vicinity of the vents (X-Huinay station), and higher concentrations of reduced compounds (CH4 and ∑H2S) were found in the vent fluids, in particular at a depth of 36 m. No significant differences in the temperatures of vent and ambient waters were detected. The bottom water close to the vents possessed notably low concentrations of reduced compounds, indicating a rapid and large-quantity dilution of the chemicals from vents. The surface water featured light isotopic values of δ2H and 18O due to the freshwater input from melting ice and precipitation. A linear mixing trend was observed between the freshwater (negative isotopic values) and the fjord bottom water (positive values) that was not influenced by vent fluid. This trend suggests that the venting water corresponds to the mixing among local meteoric water, spring water, and seawater. This result is relevant to understanding how freshwater and meteoric water influence the chemical composition of seawater and how this mixing could impact the marine biota in the vicinities of the vents.
Año: 2014
Palabras claves:
Referencia APA: Muñoz, P., Sellanes, J., Villalobos, K., Zapata-Hernández, G., Mayr, C., & Araya, K. (2014). Geochemistry of reduced fluids from shallow cold vents hosting chemosynthetic communities (Comau Fjord, Chilean Patagonia, ∼42°S). Progress In Oceanography, 129, 159-169.
Molecular phylogeny of hinge-beak shrimps (Decapoda: Caridea: Rhynchocinetes and Cinetorhynchus ) and allies: a formal test of familiar and generic monophyly using a multilocus phylogeny.
Baeza, J., Bauer, R., Okuno, J., & Thiel, M.
The Rhynchocinetidae (‘hinge-beak’ shrimps) is a family of marine caridean decapods with considerable variation in sexual dimorphism, male weaponry, mating tactics, and sexual systems. Thus, this group is an excellent model with which to analyse the evolution of these important characteristics, which are of interest not only in shrimps specifically but also in animal taxa in general. Yet, there exists no phylogenetic hypothesis, either molecular or morphological, for this taxon against which to test either the evolution of behavioural traits within the Rhynchocinetidae or its genealogical relationships with other caridean taxa. In this study, we tested (1) hypotheses on the phylogenetic relationships of rhynchocinetid shrimps, and (2) the efficacy of different (one-, two-, and three-phase) methods to generate a reliable phylogeny. Total genomic DNA was extracted from tissue samples taken from 17 species of Rhynchocinetidae and five other species currently or previously assigned to the same superfamily (Nematocarcinoidea); six species from other superfamilies were used as outgroups. Sequences from two nuclear genes (H3 and Enolase) and one mitochondrial gene (12S) were used to construct phylogenies. One-phase phylogenetic analyses (SATé-II) and classical two- and three-phase phylogenetic analyses were employed, using both maximum likelihood and Bayesian inference methods. Both a two-gene data set (H3 and Enolase) and a three-gene data set (H3, Enolase, 12S) were utilized to explore the relationships amongst the targeted species. These analyses showed that the superfamily Nematocarcinoidea, as currently accepted, is polyphyletic. Furthermore, the two major clades recognized by the SATé-II analysis are clearly concordant with the genera Rhynchocinetes and Cinetorhynchus, which are currently recognized in the morphological-based classification (implicit phylogeny) as composing the family Rhynchocinetidae. The SATé-II method is considered superior to the other phylogenetic analyses employed, which failed to recognize these two major clades. Studies using more genes and a more complete species data set are needed to test yet unresolved inter- and intrafamilial systematic and evolutionary questions about this remarkable clade of caridean shrimps. © 2014 The Linnean Society of London
Año: 2014
Palabras claves: Bayesian hypothesis testing; Crustacea; SATé-II.
Referencia APA: Baeza, J., Bauer, R., Okuno, J., & Thiel, M. (2014). Molecular phylogeny of hinge-beak shrimps (Decapoda: Caridea: Rhynchocinetes and Cinetorhynchus) and allies: a formal test of familiar and generic monophyly using a multilocus phylogeny. Zool J Linn Soc, 172(2), 426-450.
Major consequences of minor damage: impacts of small grazers on fast-growing kelps.
Poore, A., Gutow, L., F. Pantoja, J., Tala, F., Jofré Madariaga, D., & Thiel, M.
Damage by small herbivores can have disproportionately large effects on the fitness of individual plants if damage is concentrated on valuable tissues or on select individuals within a population. In marine systems, the impact of tissue loss on the growth rates of habitat-forming algae is poorly understood. We quantified the grazing damage by an isopod Amphoroidea typa on two species of large kelps, Lessonia spicata and Macrocystis pyrifera, in temperate Chile to test whether non-lethal grazing damage could reduce kelp growth rates and photosynthetic efficiency. For L. spicata, grazing damage was widespread in the field, unevenly distributed on several spatial scales (among individuals and among tissue types) and negatively correlated with blade growth rates. In field experiments, feeding by A. typa reduced the concentration of photosynthetic pigments and led to large reductions (~80 %) in blade growth rates despite limited loss of kelp biomass (0.5 % per day). For M. pyrifera, rates of damage in the field were lower and high densities of grazers were unable to reduce growth rates in field experiments. These results demonstrate that even low per capita grazing rates can result in large reductions in the growth of a kelp, due the spatial clustering of herbivores in the field and the selective removal of photosynthetically active tissues. The impacts of small herbivores on plant performance are thus not easily predicted from consumption rates or abundance in the field, and vary with plant species due to variation in their ability to compensate for damage.
Año: 2014
Palabras claves: Grazing, Herbivory, Isopods, Lessonia, Mesograzers, Macroalgae, Macrocystis, Plant–herbivore interactions.
Referencia APA: Poore, A., Gutow, L., F. Pantoja, J., Tala, F., Jofré Madariaga, D., & Thiel, M. (2014). Major consequences of minor damage: impacts of small grazers on fast-growing kelps. Oecologia, 174(3), 789-801.
Plastic Pollution in the World’s Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea.
Eriksen, M., Lebreton, L., Carson, H., Thiel, M., Moore, C., & Borerro, J. et al.
Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007–2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N = 680) and visual survey transects of large plastic debris (N = 891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic <4.75 mm and meso- and macroplastic >4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove <4.75 mm plastic particles from the ocean surface.
Año: 2014
Palabras claves: Oceans, Density, Particle size, Pollution, Southern Hemisphere, Indian Ocean, Marine conservation, Mediterranean Sea.
Referencia APA: Eriksen, M., Lebreton, L., Carson, H., Thiel, M., Moore, C., & Borerro, J. et al. (2014). Plastic Pollution in the World's Oceans: More than 5 Trillion Plastic Pieces Weighing over 250,000 Tons Afloat at Sea. Plos ONE, 9(12), e111913.
Succession in intertidal mussel bed assemblages on different shores: species mobility matters.
Valdivia, N., Buschbaum, C., & Thiel, M.
Biogenic substrata such as epibenthic mussel aggregations are common in coastal regions worldwide and harbour diverse assemblages of sessile and mobile species. However, colonisation patterns on biogenic substrata are still not well understood. We tested whether succession develops as a linear sequence of temporal changes in the species richness and community structure of sessile and mobile assemblages associated with intertidal mussel beds of sedimentary and rocky shores in Germany and Chile, respectively. Because of their broad differences, these study sites were analysed separately to examine whether similar successional patterns occur under differing environmental conditions and species pools. At each study site, we conducted an experiment that separates the effects of successional age (deployment duration) and the time when settlement substrata are deployed (deployment timing). Colonisation dynamics differed between timings and between sessile and mobile species. In addition, timing effects were stronger at the sedimentary than at the rocky study site. For sessile organisms, for example, species richness increased steadily with successional age at both study sites, but at the sedimentary site, the magnitude of this increase varied between the different months of deployment. For mobile organisms, a high proportion of the total species pool colonised the settlement substrata within the first month of deployment at both sites. After this initial colonization peak, mobile species richness showed a minor but significant increase with successional age at both sites. We suggest that species dispersal ability at the local scale (mobility) mediates the response of species-rich assemblages to natural and anthropogenic disturbances.
Año: 2014
Palabras claves: Context-dependency, Determinism, Facilitation, Hard-bottom, Soft-bottom, Stochastic, Succession.
Referencia APA: Valdivia, N., Buschbaum, C., & Thiel, M. (2014). Succession in intertidal mussel bed assemblages on different shores: species mobility matters. Marine Ecology Progress Series, 497, 131-142
Phylogeographic Structure in Benthic Marine Invertebrates of the Southeast Pacific Coast of Chile with Differing Dispersal Potential.
Haye, P., Segovia, N., Muñoz-Herrera, N., Gálvez, F., Martínez, A., & Meynard, A. et al.
The role of dispersal potential on phylogeographic structure, evidenced by the degree of genetic structure and the presence of coincident genetic and biogeographic breaks, was evaluated in a macrogeographic comparative approach along the north-central coast of Chile, across the biogeographic transition zone at 30°S. Using 2,217 partial sequences of the mitochondrial Cytochrome Oxidase I gene of eight benthic invertebrate species along ca. 2,600 km of coast, we contrasted dispersal potential with genetic structure and determined the concordance between genetic divergence between biogeographic regions and the biogeographic transition zone at 30°S. Genetic diversity and differentiation highly differed between species with high and low dispersal potential. Dispersal potential, sometimes together with biogeographic region, was the factor that best explained the genetic structure of the eight species. The three low dispersal species, and one species assigned to the high dispersal category, had a phylogeographic discontinuity coincident with the biogeographic transition zone at 30°S. Furthermore, coalescent analyses based on the isolation-with-migration model validate that the split between biogeographic regions north and south of 30°S has a historic origin. The signatures of the historic break in high dispersers is parsimoniously explained by the homogenizing effects of gene flow that have erased the genetic signatures, if ever existed, in high dispersers. Of the four species with structure across the break, only two had significant albeit very low levels of asymmetric migration across the transition zone. Historic processes have led to the current biogeographic and phylogeographic structure of marine species with limited dispersal along the north-central coast of Chile, with a strong lasting impact in their genetic structure.
Año: 2014
Palabras claves: Phylogeography, Biogeography, Haplotypes, Population genetics, Chile (country), Gene flow, Larvae, Marine biology.
Referencia APA: Haye, P., Segovia, N., Muñoz-Herrera, N., Gálvez, F., Martínez, A., & Meynard, A. et al. (2014). Phylogeographic Structure in Benthic Marine Invertebrates of the Southeast Pacific Coast of Chile with Differing Dispersal Potential. Plos ONE, 9(2), e88613.
Impact of grazing by the sea urchin Tetrapygus niger on the kelp Lessonia trabeculata in Northern Chile.
Perreault, M., Borgeaud, I., & Gaymer, C.
The ability of sea urchins to destroy kelp forests, leaving large areas stripped of vegetation and covered by sparse calcareous algae is well known. The reduction in active predators of sea urchins combined with their broad diet makes them an important factor in the structuring of subtidal benthic marine systems. In central and northern Chile, the sea urchin Tetrapygus niger is known to reduce the spread of the subtidal kelp Lessonia trabeculata. However, its impact on the different development stages of L. trabeculata has never been quantified or compared to other possible causes of the loss of material. The objective of this study was to quantify the grazing impact of T. niger on L. trabeculata at different stages of development (recruits, juveniles and adults). An exclusion experiment was conducted to evaluate the grazing effect of T. niger on kelp recruitment within a kelp bed, and kelp transplant experiments were conducted to quantify T. niger's impact on the stipes and fronds of juvenile and adult L. trabeculata. Our results showed that under natural sea urchin densities (10 ind. m− 2), T. niger prevented the recruitment of L. trabeculata. Tetrapygus niger completely consumed juvenile plants but only attacked the stipes of adult plants. Tetrapygus niger seems to use different feeding strategies depending on the ontogeny of the plant. Lessonia trabeculata seems unable to defend itself against the impact of intensive grazing by sea urchins, which may be the primary source of mortality of recruits and juveniles of L. trabeculata. However, T. niger's impact on adult plants is limited and shared with other herbivores that graze the fronds, such as fishes and spider crabs.
Año: 2014
Palabras claves: Chile; Herbivory; Lessonia trabeculata; Rocky subtidal; Sea urchin–kelp interaction; Tetrapygus niger.
Referencia APA: Perreault, M., Borgeaud, I., & Gaymer, C. (2014). Impact of grazing by the sea urchin Tetrapygus niger on the kelp Lessonia trabeculata in Northern Chile. Journal Of Experimental Marine Biology And Ecology, 453, 22-27.
Morphological, physiological and reproductive conditions of rafting bull kelp (Durvillaea antarctica) in northern-central Chile (30°S).
Tala, F., Gómez, I., Luna-Jorquera, G. et al.
The bull kelp Durvillaea antarctica is a common floating alga in the southern hemisphere, but despite the ecological and biogeographic importance of kelp rafts, little is known about the responses of detached kelps to the conditions at the sea surface. The morphological, physiological and reproductive performances of D. antarctica rafts in the Coastal System of Coquimbo, Chile (CSC, ~30°S), were examined during winter and summer of two successive years (2010/11 and 2011/12). Epibionts (Lepas spp.) that only attach to floating objects were used as indicator for the floating time of kelp rafts. Photosynthetic efficiency and reproductive maturity of both benthic and floating algae varied seasonally, with a stronger decrease in summer than in winter. Blade size (measured as weight proportion of kelp individuals), phlorotannin concentrations and antioxidant activities were lower in floating than in benthic algae. Environmental conditions and floating time affected the blade tissues, with stronger negative effects during summer. These results confirm that floating persistence of D. antarctica in the CSC is suppressed during the summer months, which indicates that the dispersal potential of this (and other) floating algae varies seasonally.
Año: 2013
Palabras claves:
Referencia APA: Tala, F., Gómez, I., Luna-Jorquera, G. et al. (2013). Morphological, physiological and reproductive conditions of rafting bull kelp (Durvillaea antarctica) in northern-central Chile (30°S). Marine Biology, 160(6), 1339–1351.
Interactions Between Spatially Explicit Conservation and Management Measures: Implications for the Governance of Marine Protected Areas.
Cárcamo, P. & Gaymer, C.
Marine protected areas are not established in an institutional and governance vacuum and managers should pay attention to the wider social–ecological system in which they are immersed. This article examines Islas Choros-Damas Marine Reserve, a small marine protected area located in a highly productive and biologically diverse coastal marine ecosystem in northern Chile, and the interactions between human, institutional, and ecological dimensions beyond those existing within its boundaries. Through documents analysis, surveys, and interviews, we described marine reserve implementation (governing system) and the social and natural ecosystem-to-be-governed. We analyzed the interactions and the connections between the marine reserve and other spatially explicit conservation and/or management measures existing in the area and influencing management outcomes and governance. A top-down approach with poor stakeholder involvement characterized the implementation process. The marine reserve is highly connected with other spatially explicit measures and with a wider social–ecological system through various ecological processes and socio-economic interactions. Current institutional interactions with positive effects on the management and governance are scarce, although several potential interactions may be developed. For the study area, any management action must recognize interferences from outside conditions and consider some of them (e.g., ecotourism management) as cross-cutting actions for the entire social–ecological system. We consider that institutional interactions and the development of social networks are opportunities to any collective effort aiming to improve governance of Islas Choros-Damas marine reserve. Communication of connections and interactions between marine protected areas and the wider social–ecological system (as described in this study) is proposed as a strategy to improve stakeholder participation in Chilean marine protected areas.
Año: 2013
Palabras claves: Marine protected areas, Institutional interactions, Chile, Governance, Ecosystem-based management, Social–ecological system.
Referencia APA: Cárcamo, P. & Gaymer, C. (2013). Interactions Between Spatially Explicit Conservation and Management Measures: Implications for the Governance of Marine Protected Areas. Environmental Management, 52(6), 1355-1368.
Coalescence in wild organisms of the intertidal population of Lessonia berteroana in northern Chile: management and sustainability effects.
Rodríguez, D., Oróstica, M., & Vásquez, J.
Lessonia berteroana is the subject of 85 % of the total harvest of Chilean brown seaweeds, representing close to 10 % of total kelp biomass worldwide harvested for alginic acid extraction. Frequent incidence of coalescent holdfasts was detected in natural populations, and this process gives rise to fused sporophytes. This study presents the coalescence events in natural populations in northern Chile. During 2011, in natural intertidal populations, 435 target sporophytes of different sizes were observed weekly and 63.90 % (278) showed physical signs of coalescent disks. We were able to distinguish five fusion modes depending on the number and size of each of the participant sporophytes and their spatial distribution. There was a progressive decrease of density and an increase in the number of stipes of each sporophyte over time. Two processes were recognized: active fusion of juvenile sporophytes and passive fusion of adult and senescent sporophytes. However, most of the coalescence processes were detected in juvenile sporophytes with a holdfast diameter of 0.5 to 2 cm. The minimum distance between pairs of coalescing sporophytes was 0.5 cm, and the maximum distance was 13 cm. For good harvesting practices, it is recommended that plants with over 20 cm holdfast diameter are harvested from natural populations because over this size, all of the plants have reproduced. Coalescence events would produce plants with legal size requirement; however, these plant units would not be reproductive, affecting the sustainability of this important coastal resource.
Año: 2013
Palabras claves: Lessonia berteroana population, Coalescence process, Management and sustainability.
Referencia APA: Rodríguez, D., Oróstica, M., & Vásquez, J. (2013). Coalescence in wild organisms of the intertidal population of Lessonia berteroana in northern Chile: management and sustainability effects. J Appl Phycol, 26(2), 1115-1122.