UCN-CEAZA
Role of shellfish hatchery as a reservoir of antimicrobial resistant bacteria.
Miranda, C., Rojas, R., Garrido, M., Geisse, J., & González, G.
The main aim of this study was to determine the occurrence of resistant bacteria in florfenicol-treated and untreated scallop larval cultures from a commercial hatchery and to characterize some selected florfenicol-resistant strains. Larval cultures from untreated and treated rearing tanks exhibited percentages of copiotrophic bacteria resistant to florfenicol ranging from 0.03% to 10.67% and 0.49–18.34%, respectively, whereas florfenicol resistance among oligotrophic bacteria varied from 1.44% to 35.50% and 3.62–95.71%, from untreated and treated larvae, respectively. Florfenicol resistant microbiota from reared scallop larvae mainly belonged to the Pseudomonas and Pseudoalteromonas genus and were mainly resistant to florfenicol, chloramphenicol, streptomycin and co-trimoxazole. This is the first study reporting antimicrobial resistant bacteria associated to a shellfish hatchery and the results suggest that a continuous surveillance of antimicrobial resistance even in absence of antibacterial therapy is urgently required to evaluate potential undesirable consequences on the surrounding environments.
Año: 2013
Palabras claves: Florfenicol; Heterotrophic bacteria; Antimicrobial resistance; Scallop culture; Chile; Hatchery.
Referencia APA: Miranda, C., Rojas, R., Garrido, M., Geisse, J., & González, G. (2013). Role of shellfish hatchery as a reservoir of antimicrobial resistant bacteria. Marine Pollution Bulletin, 74(1), 334-343.
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.
Effects of isolation and fishing on the marine ecosystems of Easter Island and Salas y Gómez, Chile.
Friedlander, A., Ballesteros, E., Beets, J., Berkenpas, E., Gaymer, C., Gorny, M., & Sala, E.
An expedition to Salas y Gómez and Easter islands was conducted to develop a comprehensive baseline of the nearshore marine ecosystem, to survey seamounts of the recently created Motu Motiro Hiva Marine Park (MMHMP) – a no-take marine reserve of 150 000 km2 – and to compare these results with Easter Island where the marine ecosystem is similar but has no marine protection.
Live coral cover was surprisingly high at both Easter Island (53%) and Salas y Gómez (44%), especially considering their sub-tropical location, high wave energy environments, and geographic isolation.
Endemic and regionally-endemic species comprised 77% of the fish abundance at Easter Island and 73% at Salas y Gómez. Fish biomass at Salas y Gómez was relatively high (1.2 t ha-1) and included a large proportion of apex predators (43%), whereas at Easter Island it was almost three times lower (0.45 t ha-1) with large predators accounting for less than 2% of the biomass, despite good habitat quality.
The large cohort of small sharks and the absence of larger sharks at Salas y Gómez suggest mesopredator release consistent with recent shark fishing. The fish fauna at the seamounts between Easter Island and Salas y Gómez, outside of MMHMP, harboured 46% endemic species, including a new species of damselfish (Chromis sp. nov.) and probably a new species of Chimaera (Hydrolagus). Numerous seamounts adjacent to Salas y Gómez are currently not included in the MMHMP.
This expedition highlights the high biodiversity value of this remote part of the Pacific owing to the uniqueness (endemicity) of the fauna, large apex predator biomass, and geographic isolation.
Año: 2013
Palabras claves: Coral; biodiversity; no-take marine reserve; algae; fish; fishing.
Referencia APA: Friedlander, A., Ballesteros, E., Beets, J., Berkenpas, E., Gaymer, C., Gorny, M., & Sala, E. (2013). Effects of isolation and fishing on the marine ecosystems of Easter Island and Salas y Gómez, Chile. Aquatic Conserv: Mar. Freshw. Ecosyst., 23(4), 515-531.
Demography and feeding behavior of the kelp crab Taliepus marginatus in subtidal habitats dominated by the kelps Macrocystis pyrifera or Lessonia trabeculata.
Jofré Madariaga, D., Ortiz, M., & Thiel, M.
We studied the population and feeding ecology of the kelp crab Taliepus marginatus in subtidal kelp forests dominated by either of two morphologically different kelp species (Macrocystis pyrifera or Lessonia trabeculata) in northern Chile. The sizes and abundances of T. marginatus differed between the two kelp habitats. Kelp crabs were more abundant in the M. pyrifera forest than in the L. trabeculata forest. Size-frequency distributions showed that juvenile and immature crabs were more common in the M. pyrifera forest than in the L. trabeculata forest, where reproductive adults predominated. The smaller crabs in the M. pyrifera habitat also consumed a higher proportion of kelp tissues than the larger crabs in the L. trabeculata habitat, which had a higher proportion of animal food in their diet. In both kelp forests, individuals of T. marginatus showed a similar pattern of nocturnal feeding over a 24-h period, consuming more food at night than during the day. The more complex and dense forests of M. pyrifera appear to present better nursery habitats for juvenile kelp crabs than the more open and less dense forests dominated by L. trabeculata. These results suggest that the role of the two kelp habitats for T. marginatus varies during the life cycle of the kelp crabs, with M. pyrifera tending to have nursery function and L. trabeculata being more suitable as a reproductive habitat.
Año: 2013
Palabras claves: Habitat use; nursery habitat; reproductive habitat; diet.
Referencia APA: Jofré Madariaga, D., Ortiz, M., & Thiel, M. (2013). Demography and feeding behavior of the kelp crab Taliepus marginatus in subtidal habitats dominated by the kelps Macrocystis pyrifera or Lessonia trabeculata. Invertebrate Biology, 132(2), 133-144.
Opportunities and constraints of the institutional framework for the implementation of ecosystem-based management: The case of the Chilean coast.
Cárcamo, P., Garay-Flühmann, R., & Gaymer, C.
The implementation of ecosystem-based management usually develops from existing institutional and governance arrangements in a given area. Therefore, it is necessary to analyze the institutional framework of a region or country to assess whether this framework is compatible and whether it will promote or potentially hinder the implementation of new management strategies. This paper explores the possibilities and constraints of institutional frameworks (represented by legislation) concerning the possible implementation of ecosystem-based management of the Chilean coast. We evaluated the functional fit between a conceptual ecosystem defined by stakeholders (and based on ecosystem services, threats and uses/activities) and Chilean legislation related to coastal and marine resource planning and management. First, we measured the functional fit between the defined ecosystem and legislation through a quantitative analysis based on text revision and network analysis. Second, we evaluated different management, conservation and planning instruments existing in Chilean legislation, with respect to their suitability for the implementation of ecosystem-based management. We found that Chilean legislation rarely accounts for relationships defined between the different components of the ecosystem model. We observed low functional fit potential and many gaps in legislation. However, we found that certain existing instruments in the current legislation can be used as a foundation for implementing management based on the principles and criteria of ecosystem-based management (e.g., Multiple-Use Coastal Marine Protected Areas).
Año: 2013
Palabras claves:
Referencia APA: Cárcamo, P., Garay-Flühmann, R., & Gaymer, C. (2013). Opportunities and constraints of the institutional framework for the implementation of ecosystem-based management: The case of the Chilean coast. Ocean & Coastal Management, 84, 193-203.
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.
Host-use patterns and factors influencing the choice between anemone and urchin hosts by a caridean shrimp.
Ory, N., Dudgeon, & Thiel, M.
Small marine decapods often associate with other invertebrates in order to gain protection from predators. However, the factors that influence host choice by symbionts, such as shrimps, are poorly understood but may have important implications for the distribution and abundance of these mesoconsumers. In Hong Kong, the rhynchocinetid shrimp Rhynchocinetes brucei uses two alternative hosts: an urchin (Diadema setosum) and an anemone (Entacmaea quadricolor). We examined the association between R. brucei and its anemone and urchin hosts in the field and laboratory, investigating host choice and host fidelity. Underwater surveys on shallow rocky reefs in Hong Kong revealed that shrimps were rarely found outside refuges, such as crevices and holes, unless they were associated with anemones and urchins. Shrimps were more frequently associated with urchins than with anemones, although anemones were more abundant within the survey area. Host-choice experiments in the laboratory confirmed that, when given a choice, shrimps avoided open areas and associated with anemones, urchins or artificial refuges. Shrimps overwhelmingly chose urchins over artificial refuges, but did not show any clear preference for anemones over refuges. When offered a choice, shrimps displayed fidelity for their original host species (i.e. the host with which they were associated when collected from the field), suggesting that they imprinted upon the host. Host-imprinting may allow symbionts to efficiently relocate their original host species after separation (e.g. following nocturnal foraging trips) thereby, perhaps, reducing the risk of predation. However, host preference by R. brucei was facultative because shrimps would associate with an unfamiliar host when their original host was unavailable. This flexibility may allow shrimps to respond to local variability in host abundance.
Año: 2013
Palabras claves: Host-imprinting; Host selection; Refuge; Rocky reefs; Shrimp.
Referencia APA: Ory, N., Dudgeon, & Thiel, M. (2013). Host-use patterns and factors influencing the choice between anemone and urchin hosts by a caridean shrimp. Journal Of Experimental Marine Biology And Ecology, 449, 85-92.
Seasonal variation in floating persistence of detached Durvillaea antarctica (Chamisso) Hariot thalli.
Graiff, A., Karsten, U., Meyer, S., Pfender, D., Tala, F., & Thiel, M.
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.
Año: 2013
Palabras claves: Durvillaea antarctica; floating persistence; rafting; temperature; UV radiation.
Referencia APA: Graiff, A., Karsten, U., Meyer, S., Pfender, D., Tala, F., & Thiel, M. (2013). Seasonal variation in floating persistence of detached Durvillaea antarctica (Chamisso) Hariot thalli. Botanica Marina, 56(1).
Raymond T. Bauer, Recipient of the Crustacean Society excellence in research award.
Thiel, M.
Año: 2013
Palabras claves:
Referencia APA: Toonen, R., Wilhelm, T., Maxwell, S., Wagner, D., Bowen, B., & Sheppard, C., Terorokog, T., Moffittc, R., Gaymer, C.F., et al. (2013). One size does not fit all: The emerging frontier in large-scale marine conservation. Marine Pollution Bulletin, 77(1-2), 7-10.
Dispersal of post-larval macrobenthos in subtidal sedimentary habitats: Roles of vertical diel migration, water column, bedload transport and biological traits’ expression.
Pacheco, A., Uribe, R., Thiel, M., Oliva, M., & Riascos, J.
Post-larval dispersal along the sediment–water interface is an important process in the dynamics of macrobenthic populations and communities in marine sublittoral sediments. However, the modes of post-larval dispersal in low energy sublittoral habitats have been poorly documented. Herein we examined the specific dispersal mechanisms (diel vertical migration, water column, and bedload transport) and corresponding biological traits of the dispersing assemblage. At two sublittoral sites (sheltered and exposed) along the northern coast of Chile, we installed different trap types that capture benthic organisms with specific modes of dispersal (active emergence and passive water column drifting) and also by a combination of mechanisms (bedload transport, passive suspension and settlement from the water column). Our results show that even though there were common species in all types of traps, the post-larval macrobenthic assemblage depended on specific mechanisms of dispersal. At the sheltered site, abundant emerging taxa colonized sediments that were placed 0.5 m above the bottom and bedload-transported invertebrates appeared to be associated to the passive drifting of macroalgae. At the exposed site, assemblage dispersal was driven by specific mechanisms e.g. bedload transport and active emergence. At both sites the biological traits “small size, swimming, hard exoskeleton, free living and surface position” were associated to water column and bedload dispersal. This study highlights the importance of (i) the water–sediment interface for dispersal of post-larvae in sublittoral soft-bottom habitat, and (ii) a specific set of biological traits when dispersing either along the bottom or through the water column.
Año: 2013
Palabras claves: Emerging Benthos; Bottom Currents; Soft-bottom Communities; Humboldt Current Ecosystem.
Referencia APA: Pacheco, A., Uribe, R., Thiel, M., Oliva, M., & Riascos, J. (2013). Dispersal of post-larval macrobenthos in subtidal sedimentary habitats: Roles of vertical diel migration, water column, bedload transport and biological traits' expression. Journal Of Sea Research, 77, 79-92.