UCN-CEAZA
The Status of Kelp Exploitation and Marine Agronomy, with Emphasis on Macrocystis pyrifera, in Chile.
Buschmann, A., Prescott, S., Potin, P., Faugeron, S., Vásquez, J., & Camus, C. et al.
Kelp cultivation started in Japan, China and Korea, mainly for human consumption; new applications are still expanding. In Chile, three ‘wild’ Lessonia species and Macrocystis pyrifera are under a strong and increasing pressure of exploitation mainly for alginate production and as a source of feed for abalone. Regulatory restrictions for kelp exploitation and the increased demand for biomass provided a positive environment for the installation of a kelp farming industry. Pilot-production studies demonstrated that 200 tonnes (fresh)/ha/year can be achieved and genetic diversity and breeding studies suggested that this volume could be increased. Kelp disease research is a necessary condition for securing the future development of this industry, as are environmental studies on the impacts of large-scale aquaculture. Beyond the positive bioremediation, ecosystem service effects that kelp farming can provide, especially in a region such as in southern Chile, where intensive salmon and mussel cultivation occurs. Life Cycle Assessment suggests that the energy returns on investment in kelp farming are positive, but more detailed data are still required.
Año: 2014
Palabras claves: Kelp exploitation and farming; Life cycle assessment; Macrocystis pyrifera; Seaweed diseases; Seaweed farming environmental impacts.
Referencia APA: Buschmann, A., Prescott, S., Potin, P., Faugeron, S., Vásquez, J., & Camus, C. et al. (2014). The Status of Kelp Exploitation and Marine Agronomy, with Emphasis on Macrocystis pyrifera, in Chile. Advances In Botanical Research, 161-188
Effects of predation on diel activity and habitat use of the coral-reef shrimp Cinetorhynchus hendersoni (Rhynchocinetidae).
Ory, N., Dudgeon, D., Duprey, N., & Thiel, M.
Nonlethal effects of predators on prey behaviour are still poorly understood, although they may have cascading effects through food webs. Underwater observations and experiments were conducted on a shallow fringing coral reef in Malaysia to examine whether predation risks affect diel activity, habitat use, and survival of the rhynchocinetid shrimp Cinetorhynchus hendersoni. The study site was within a protected area where predatory fish were abundant. Visual surveys and tethering experiments were conducted in April–May 2010 to compare the abundance of shrimps and predatory fishes and the relative predation intensity on shrimps during day and night. Shrimps were not seen during the day but came out of refuges at night, when the risk of being eaten was reduced. Shrimp preferences for substrata of different complexities and types were examined at night when they could be seen on the reef; complex substrata were preferred, while simple substrata were avoided. Shrimps were abundant on high-complexity columnar–foliate Porites rus, but tended to make little use of branching Acropora spp. Subsequent tethering experiments, conducted during daytime in June 2013, compared the relative mortality of shrimps on simple (sand–rubble, massive Porites spp.) and complex (P. rus, branching Acropora spp.) substrata under different predation risk scenarios (i.e., different tether lengths and exposure durations). The mortality of shrimps with short tethers (high risk) was high on all substrata while, under low and intermediate predation risks (long tethers), shrimp mortality was reduced on complex corals relative to that on sand–rubble or massive Porites spp. Overall, mortality was lowest on P. rus. Our study indicates that predation risks constrain shrimp activity and habitat choice, forcing them to hide deep inside complex substrata during the day. Such behavioural responses to predation risks and their consequences for the trophic role of invertebrate mesoconsumers warrant further investigation, especially in areas where predatory fishes have been overexploited.
Año: 2014
Palabras claves: Rhynchocinetid shrimps, Habitat complexity, Substratum structure, Predator–prey interactions, Risk effects,Tethering.
Referencia APA: Ory, N., Dudgeon, D., Duprey, N., & Thiel, M. (2014). Effects of predation on diel activity and habitat use of the coral-reef shrimp Cinetorhynchus hendersoni (Rhynchocinetidae). Coral Reefs, 33(3), 639-650.
Formulated diets for giant chilean frog Calyptocephalella gayi tadpoles
Toledo, P., Suazo, R., & Viana, M.
In this study, we conducted an experiment to evaluate the overall effect of novel diets on the growth, metamorphosis and survival of tadpoles of the endangered giant Chilean frog Calyptocephalella gayi (previously known as Caudiverbera caudiverbera) to evaluate the potential of this species for culture and repopulation purposes. Using fishmeal as the main protein source with a substitution of either scallop viscera or Spirulina meal, three treatments were formulated to contain similar amounts of protein and energy. The experiment was run for 75 days, after which the tadpoles showed no significant differences among treatments in terms of their growth or survival. This is the first study to report positive effects of different diets on the growth and survival of tadpoles of the giant Chilean frog. Therefore, it might be possible to extend the farming of Calyptocephalella gayi for human consumption and repopulation. Nevertheless, more efforts are needed to understand their nutritional requirements to formulate appropriate diets for this endangered frog.
Año: 2014
Palabras claves: Artificial diet, nutrition, protein sources, Spirulina meal, survival.
Referencia APA: Toledo, P., Suazo, R., & Viana, M. (2014). Formulated diets for giant chilean frog Calyptocephalella gayi tadpoles. Ciencia E Investigación Agraria, 41(1), 3-4.
Genetic assessment of parentage in the caridean rock shrimp Rhynchocinetes typus based on microsatellite markers.
Bailie, D., Thiel, M., Fitzpatrick, S., Connolly, M., Prodöhl, P., & Hynes, R.
Over the past decade, the common rock shrimp, Rhynchocinetes typus H. Milne Edwards, 1837, has been the focus of extensive investigations on mating behaviour. The species is now perceived as a model system for the study of reproductive strategies and sexual conflict in crustaceans displaying external fertilization. Using molecular markers, the current study assesses whether social mating behaviour in common rock shrimp translates into true genetic parentage. In a large mesocosm tank with >200 individuals of both sexes, the analysis of 15 families (22 eggs per female) for three informative microsatellites unambiguously confirmed multiple paternity in 11 instances (73%) involving, in each case, two to four males. Where more than one male was identified siring a particular brood, reproductive skew was apparent towards a single individual. Results suggest that multiple paternity in this species results from subordinate male coercive behaviour, female solicitation of multiple male matings or a combination of both.
Over the past decade, the common rock shrimp, Rhynchocinetes typus H. Milne Edwards, 1837, has been the focus of extensive investigations on mating behaviour. The species is now perceived as a model system for the study of reproductive strategies and sexual conflict in crustaceans displaying external fertilization. Using molecular markers, the current study assesses whether social mating behaviour in common rock shrimp translates into true genetic parentage. In a large mesocosm tank with >200 individuals of both sexes, the analysis of 15 families (22 eggs per female) for three informative microsatellites unambiguously confirmed multiple paternity in 11 instances (73%) involving, in each case, two to four males. Where more than one male was identified siring a particular brood, reproductive skew was apparent towards a single individual. Results suggest that multiple paternity in this species results from subordinate male coercive behaviour, female solicitation of multiple male matings or a combination of both.
Año: 2014
Palabras claves: Cryptic female choice; multiple paternity; convenience polyandry.
Referencia APA: Bailie, D., Thiel, M., Fitzpatrick, S., Connolly, M., Prodöhl, P., & Hynes, R. (2014). Genetic assessment of parentage in the caridean rock shrimp Rhynchocinetes typus based on microsatellite markers. Journal Of Crustacean Biology, 34(5), 658-662.
Efectos economicos de la estrategia de cosechas multiples en el cultivo del ostion del norte Argopecten purpuratus:una oportunidad para mejorar la competitividad.
Perez, E.
Una situación recurrente en el mercado de muchas especies bajo cultivo acuícola es la tendencia en la disminución del precio internacional en oposición al aumento en los costos de los insumos, lo que obliga a la industria a ser innovadora al momento de rentabilizar la inversión. Una opción poco explorada es el aumento del valor de la producción a través de una cuidadosa selección de tamaños y tiempos de cosechas. Las cosechas parciales permiten que calibres subóptimos puedan tener el tiempo necesario de crecimiento hasta alcanzar mejores atributos, al mismo tiempo que la fracción de mejor crecimiento es cosechada y puesta disponible en el mercado. Difiere significativamente de la estrategia alternativa de cosechas totales, donde la totalidad de la producción es cosechada al mismo tiempo. Así, el óptimo económico será resultado del tiempo de primera cosecha (DPC), de la longitud de cosecha (LC), número de cosechas (NC) e intervalo de tiempo (∆t) entre cosechas sucesivas. Mediante un modelo de simulación, alimentado con valores reales de una empresa de cultivo de ostión del norte (Argopecten purpuratus) se analizó el resultado económico de la estrategia de cosechas múltiples. Los resultados indican que las combinaciones alternativas de DPC, LC, ∆t y NC generan distintos niveles de rendimientos económicos, aspecto que debiera ser considerado por los productores. En los escenarios simulados de cosechas, una decisión incorrecta en este sentido podría generar una diferencia del orden de US$ 510.000.
Año: 2014
Palabras claves: Argopecten purpuratus, ostión del norte, cosechas múltiples, rendimiento económico,acuicultura.
Referencia APA: Perez, E. (2014). Efectos economicos de la estrategia de cosechas multiples en el cultivo del ostion del norte Argopecten purpuratus: una oportunidad para mejorar la competitividad. Latin American Journal Of Aquatic Research, 42(1), 180-191
Monitoring the sustainability of Lessonia nigrescens (Laminariales, Phaeophyceae) in northern Chile under strong harvest pressure.
Vega, J., Broitman, B., & Vásquez, J.
In the last decade, exploitation of Lessonia nigrescens in northern Chile has been carried out using the best practices agreed upon by consensus between fishermen, industry, government, and scientists. These practices focus on the selective harvest of sporophytes to allow the maintenance of a reproductive stock, facilitating recruitment and minimizing grazing of benthic herbivores. To improve coverage and accessibility, enforcement of administration measures along the northern coast of Chile requires ecological indicators to monitor the sustainability of Lessonia kelps. Over 2 years, density, biomass, recruitment, and size structure of Lessonia were sampled seasonally in coastal areas with different regimens of harvesting administration as follows: (1) Management Areas for Exploitation of Benthic Resources (MAEBR), (2) Open Access Areas (OAA), and (3) Marine Protected Areas without human intervention. The use of demographic parameters as ecological indicators allows discrimination between kelp beds where good harvesting practices have been applied by users (MAEBR), and areas where management recommendations have not been put in practice (OAA). The ecological indicators reinforced the concept of co-management in MAEBR as a viable harvesting administration system along the Chilean coast, and indicated a high-harvesting pressure in OAA. Moreover, together with other harvesting parameters, they could be useful to justify the application of other administration strategies, such as quotas or bans.
Año: 2014
Palabras claves: Kelp harvesting, Natural populations, Intertidal beds, Management, Conservation, Administration policies.
Referencia APA: Vega, J., Broitman, B., & Vásquez, J. (2014). Monitoring the sustainability of Lessonia nigrescens (Laminariales, Phaeophyceae) in northern Chile under strong harvest pressure. J Appl Phycol, 26(2), 791-801.
A test of large-scale reproductive migration in females of the amphidromous shrimp Macrobrachium acanthurus (Caridea : Palaemonidae) from south-eastern Brazil.
Bertini, G., Baeza, J., & Perez, E.
Macrobrachium acanthurus inhabits estuaries and rivers in the western Atlantic. It is not clear whether females migrate towards estuaries to hatch larvae, as reported for other congeneric shrimps. We tested whether females of M. acanthurus exhibit reproductive migrations. The population dynamics of this shrimp was studied in the Ribeira de Iguape River, Brazil. Four sites that differ in position with respect to the coast were sampled monthly during 2007. In M. acanthurus, reproduction was seasonal and reproductive intensity did not vary among study sites. Females brooding early and late embryos were found at all study sites during the reproductive season. No disappearance of reproductive females was observed at the study site located furthest away (~150 km) from the coast. Thus, reproductive females of M. acanthurus do not exhibit reproductive migrations towards estuaries to hatch larvae. Maturity in females was reached at smaller body sizes during the austral summer and spring compared with winter and autumn. Growth rate and body size was sex-specific; males grew slower but attained larger average and final body sizes than females. This information needs to be considered in assessing stocks and establishing sustainable management plans for M. acanthurus in Brazil.
Año: 2014
Palabras claves: Freshwater prawn, growth, maturity, reproduction, sex ratio.
Referencia APA: Bertini, G., Baeza, J., & Perez, E. (2014). A test of large-scale reproductive migration in females of the amphidromous shrimp Macrobrachium acanthurus (Caridea: Palaemonidae) from south-eastern Brazil. Mar. Freshwater Res.
Morphological, ultrastructural, and genetic characterization of coalescence in the intertidal and shallow subtidal kelps Lessonia spicata and L. berteroana (Laminariales, Heterokontophyta).
González, A., Borras-Chavez, R., Beltrán, J., Flores, V., Vásquez, J., & Santelices, B.
Coalescing macroalgae may fuse with conspecifics, forming genetically heterogeneous entities known as chimera. This process has been shown in taxa from roughly half the red algal orders and in the Codium species, a green alga. Field observations indicate that common and dominant kelps along central Chile exhibit a fused holdfast. We evaluated whether such fusions are true coalescence processes in Lessonia spicata and Lessonia berteroana. To this end, we characterized the ultrastructural event involved in holdfast fusion in the laboratory. Additionally, coalescence in natural populations was quantified by measuring the frequency of individuals with genetically heterogenic stipes within the same holdfast. Results indicate that coalescence appears as a frequent process in laboratory, mostly restricted to intraspecific fusions. During fusion, the meristodermatic cells located in the contact area modify their morphology and reduce the number of plastids, mitochondria, and cell inclusions. The cell wall becomes much thinner and develops plasmodesmata, enhancing communication with equivalent cells of the other coalescencing individual. Stipe genotyping indicates that there is a widespread occurrence of chimerism in both species and genetic heterogeneity is increasing directly with the increasing number of stipes. The combination of results suggests that kelp frequently coalesce in the field, and the histological response observed approaches that of red algae. Since kelps are part of the dominant vegetation in low intertidal and shallow subtidal beds, the adaptive values of coalescence in these species should be evaluated. It is concluded that coalescence and chimerism are evolutionary convergent processes, occurring in all three major groups of seaweeds.
Año: 2014
Palabras claves: Coalescence, Chimerism, Kelps, Lessonia, Microsatellites, Heterokontophyta.
Referencia APA: González, A., Borras-Chavez, R., Beltrán, J., Flores, V., Vásquez, J., & Santelices, B. (2014). Morphological, ultrastructural, and genetic characterization of coalescence in the intertidal and shallow subtidal kelps Lessonia spicata and L. berteroana (Laminariales, Heterokontophyta). J Appl Phycol, 26(2), 1107-1113.
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.
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.
Distribution and abundance of small plastic debris on beaches in the SE Pacific (Chile): A study supported by a citizen science project.
Hidalgo-Ruz, V. & Thiel, M.
The accumulation of large and small plastic debris is a problem throughout the world's oceans and coastlines. Abundances and types of small plastic debris have only been reported for some isolated beaches in the SE Pacific, but these data are insufficient to evaluate the situation in this region. The citizen science project "National Sampling of Small Plastic Debris” was supported by schoolchildren from all over Chile who documented the distribution and abundance of small plastic debris on Chilean beaches. Thirty-nine schools and nearly 1000 students from continental Chile and Easter Island participated in the activity. To validate the data obtained by the students, all samples were recounted in the laboratory. The results of the present study showed that the students were able to follow the instructions and generate reliable data. The average abundance obtained was 27 small plastic pieces per m2 for the continental coast of Chile, but the samples from Easter Island had extraordinarily higher abundances (>800 items per m2). The abundance of small plastic debris on the continental coast could be associated with coastal urban centers and their economic activities. The high abundance found on Easter Island can be explained mainly by the transport of plastic debris via the surface currents in the South Pacific Subtropical Gyre, resulting in the accumulation of small plastic debris on the beaches of the island. This first report of the widespread distribution and abundance of small plastic debris on Chilean beaches underscores the need to extend plastic debris research to ecological aspects of the problem and to improve waste management.
Año: 2013
Palabras claves: Small plastic debris; Anthropogenic litter; Plastics; Citizen Science; SE Pacific; Chile; Easter Island; Marine debris.
Referencia APA: Hidalgo-Ruz, V. & Thiel, M. (2013). Distribution and abundance of small plastic debris on beaches in the SE Pacific (Chile): A study supported by a citizen science project. Marine Environmental Research, 87-88, 12-18.
Effect of florfenicol and oxytetracycline treatments on the intensive larval culture of the Chilean scallop Argopecten purpuratus (Lamarck, 1819).
Miranda, C., Rojas, R., Abarca, A., & Hurtado, L.
The administration of antimicrobials to control bacterial pathologies in Chilean scallop hatcheries is a frequent practice, but their effects on these cultures remained unknown. This study was undertaken to obtain information on the effect of the administration of florfenicol and oxytetracycline on the growth, survival and bacterial content of scallop larvae under farming conditions. Florfenicol-treated cultures exhibited high survival rates (44% after 17 days of culture), whereas cultures not treated or treated with oxytetracycline collapsed after 11 days of culture. Surprisingly, no significant differences in the heterotrophic (Tukey test; P = 0.226) and Vibrio (Tukey test; P = 0.666) concentrations between the oxytetracycline-treated and untreated larval cultures were observed. Otherwise, florfenicol administered directly into rearing tanks produced significantly higher larval growth (Tukey test; P = 0.0001) and survival (Tukey test; P = 0.011) than bath treatment. When 2 and 4 mg L−1 of florfenicol were compared, no significant differences in growth (t-test; P = 0.4596) and survival (Tukey test; P = 0.057) were observed, suggesting that a concentration of 2 mg L−1 is sufficient to ensure larval production. The present results demonstrate the efficacy of florfenicol-based therapy to increase larval survival and growth at commercial scale and prompt the necessity to standardize its use in Chilean scallop hatcheries.
Año: 2013
Palabras claves: Bacteria; florfenicol; Chilean scallop; shellfish bacteriology; Argopecten purpuratus ; Chile.
Referencia APA: Miranda, C., Rojas, R., Abarca, A., & Hurtado, L. (2013). Effect of florfenicol and oxytetracycline treatments on the intensive larval culture of the Chilean scallop Argopecten purpuratus (Lamarck, 1819). Aquaculture Research, 45(1), 16-30.