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The Lessonia nigrescens fishery in northern Chile: “how you harvest is more important than how much you harvest”

Autores:

Vásquez, J., Piaget, N., & Vega, J.

Resumen:

In Chile, management of natural resources usually starts right before its imminent collapse or after evident declination. In the northern area of the country, the fishery of brown seaweeds has an enormous social, ecological, and economical importance. More than 11,000 people depend directly or indirectly on the collection and harvesting of this resource. Ecologically, kelps constitute areas for food, reproduction, and refuge for hundreds of invertebrates and fish species. Economically, landings up to 300,000 dry tons per year represent close to US $60 million for the industry. Until 2002, the Chilean brown seaweed fishery was mainly sustained by natural mortality, where plants cast ashore were collected by artisanal fishermen. Since then, three brown seaweed species of economic importance (Lessonia nigrescens, Lessonia trabeculata, and Macrocystis pyrifera) have been intensively harvested in coastal areas between 18° and 32° S. To manage kelp populations along the northern Chilean coast, regulations have been based on the principle “how you harvest is more important than how much you harvest”. This exploitation strategy has been adopted in consensus between fishermen, industries, governmental entities, and scientists. Since L. nigrescens represents more than 70% of total brown seaweed landings, this study tests the effects of L. nigrescens harvesting on the following population variables: (1) abundance, (2) distribution, (3) juvenile recruitment, (4) plant morphology, (5) frequency of reproductive plants, and (6) biodiversity of the macroinvertebrate community associated to kelp holdfasts. Our results show that, despite the enormous harvesting pressure on Lessonia density and biomass, the associated macroinvertebrate richness has been maintained, due to normal plant growth and high recruitment all year round.

Año: 2012

Palabras claves: Kelp fishery, Natural populations, Intertidal, Management, Harvesting, Conservation, Administrative policies.

Referencia APA: Vásquez, J., Piaget, N., & Vega, J. (2012). The Lessonia nigrescens fishery in northern Chile: “how you harvest is more important than how much you harvest". J Appl Phycol, 24(3), 417-426.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 August 2011-30 September 2011.

Autores:

A’hara, S. W., Amouroux, P., Argo, E. E., Avand-Faghih, A., Barat, A., Barbieri, L., Bert, T. M., Blatrix, R., Blin, A., Bouktila, D., Broome, A., Burban, C., Capdevielle-Dulac, C., Casse, N., Chandra, S., Cho, K. J., Cottrell, J. E., Crawford, C. R., Davis, M. C., Delatte, H., Desneux, N., Djieto-lordon, C., Dubois, M. P., El-Mergawy, R. A. A. M., Gallardo-Escárate, C., Garcia, M., Gardiner, M.M., Guillemaud, T., Haye, P. A., Hellemans, B., Hinrichsen, P., Jeon, J. H., Kerdelhué, C., Kharrat, I., Kim, K. H., Kim, Y. Y., Kwan, Y.-S., Labbe, E. M., Lahood, E., Lee, K. M., Lee, W.-O., Lee, Y.-H., Legoff, I., Li, H., Lin, C.-P., Liu, S. S., Liu, Y. G., Long, D., Maes, G. E., Magnoux, E., Mahanta, P. C., Makni, H., Makni, M., Malausa, T., Matura, R., Mckey, D., Mcmillen Jackson, A. L., Méndez, M. A., Mezghani-Khemakhem, M., Michel, A. P., Paul, M., Murielcunha, J., Nibouche, S., Normand, F., Palkovacs, E. P., Pande, V., Parmentier, K., Peccoud, J., Piatscheck, F., Puchulutegui, C., Ramos, R., Ravest, G., Richner, H., Robbens, J., Rochat, D., Rousselet, J., Saladin, V., Sauve, M., Schlei, O., Schultz, T. F., Scobie, A. R., Segovia, N. I., Seyoum, S., Silvain, J.-f., Tabone, E., Van Houdt, J. K. J., Vandamme, S. G., Volckaert, F. A. M., Wenburg, J., Willis, T. V., Won, Y.-J., Ye, N. H., Zhang, W. and Zhang, Y. X.

Resumen:

This article documents the addition of 299 microsatellite marker loci and nine pairs of single-nucleotide polymorphism (SNP) EPIC primers to the Molecular Ecology Resources (MER) Database. Loci were developed for the following species: Alosa pseudoharengus, Alosa aestivalis, Aphis spiraecola, Argopecten purpuratus, Coreoleuciscus splendidus, Garra gotyla, Hippodamia convergens, Linnaea borealis, Menippe mercenaria, Menippe adina, Parus major, Pinus densiflora, Portunus trituberculatus, Procontarinia mangiferae, Rhynchophorus ferrugineus, Schizothorax richardsonii, Scophthalmus rhombus, Tetraponera aethiops, Thaumetopoea pityocampa, Tuta absoluta and Ugni molinae. These loci were cross-tested on the following species: Barilius bendelisis, Chiromantes haematocheir, Eriocheir sinensis, Eucalyptus camaldulensis, Eucalyptus cladocalix, Eucalyptus globulus, Garra litaninsis vishwanath, Garra para lissorhynchus, Guindilla trinervis, Hemigrapsus sanguineus, Luma chequen. Guayaba, Myrceugenia colchagüensis, Myrceugenia correifolia, Myrceugenia exsucca, Parasesarma plicatum, Parus major, Portunus pelagicus, Psidium guayaba, Schizothorax richardsonii, Scophthalmus maximus, Tetraponera latifrons, Thaumetopoea bonjeani, Thaumetopoea ispartensis, Thaumetopoea libanotica, Thaumetopoea pinivora, Thaumetopoea pityocampa ena clade, Thaumetopoea solitaria, Thaumetopoea wilkinsoni and Tor putitora. This article also documents the addition of nine EPIC primer pairs for Euphaea decorata, Euphaea formosa, Euphaea ornata and Euphaea yayeyamana.

Año: 2012

Palabras claves:

Referencia APA: Molecular Ecology Resources Primer Development Consortium, A’hara, S. W., Amouroux, P., Argo, E. E., Avand-Faghih, A., Barat, A., Barbieri, L., Bert, T. M., Blatrix, R., Blin, A., Bouktila, D., Broome, A., Burban, C., Capdevielle-Dulac, C., Casse, N., Chandra, S., Cho, K. J., Cottrell, J. E., Crawford, C. R., Davis, M. C., Delatte, H., Desneux, N., Djieto-lordon, C., Dubois, M. P., El-Mergawy, R. A. A. M., Gallardo-Escárate, C., Garcia, M., Gardiner, M.M., Guillemaud, T., Haye, P. A., Hellemans, B., Hinrichsen, P., Jeon, J. H., Kerdelhué, C., Kharrat, I., Kim, K. H., Kim, Y. Y., Kwan, Y.-S., Labbe, E. M., Lahood, E., Lee, K. M., Lee, W.-O., Lee, Y.-H., Legoff, I., Li, H., Lin, C.-P., Liu, S. S., Liu, Y. G., Long, D., Maes, G. E., Magnoux, E., Mahanta, P. C., Makni, H., Makni, M., Malausa, T., Matura, R., Mckey, D., Mcmillen Jackson, A. L., Méndez, M. A., Mezghani-Khemakhem, M., Michel, A. P., Paul, M., Murielcunha, J., Nibouche, S., Normand, F., Palkovacs, E. P., Pande, V., Parmentier, K., Peccoud, J., Piatscheck, F., Puchulutegui, C., Ramos, R., Ravest, G., Richner, H., Robbens, J., Rochat, D., Rousselet, J., Saladin, V., Sauve, M., Schlei, O., Schultz, T. F., Scobie, A. R., Segovia, N. I., Seyoum, S., Silvain, J.-f., Tabone, E., Van Houdt, J. K. J., Vandamme, S. G., Volckaert, F. A. M., Wenburg, J., Willis, T. V., Won, Y.-J., Ye, N. H., Zhang, W. and Zhang, Y. X. (2012). Permanent Genetic Resources added to Molecular Ecology Resources Database 1 August 2011–30 September 2011. Molecular Ecology Resources, 12: 185–189.

Plasticity in feeding selectivity and trophic structure of kelp forest associated fishes from northern Chile.

Autores:

Pérez-Matus, A., Pledger, S., Díaz, F., Ferry, L., & Vásquez, J.

Resumen:

One of the primary ways in which species interact with their environment is through foraging; thereby directly consuming some fraction of their surrounding habitat. The habitat itself, in turn, may dictate the types of foraging opportunities that are available to the inhabitants. To investigate the relationship between habitat availability and diet composition of habitat-associated fishes, we estimated the relative abundance of the potential sessile and mobile prey items and the diet of the fish species assemblage associated to kelp forest. Specifically, diet and feeding selectivity of the kelp-forest associated fish assemblage were determined by calculating Manly's alpha selectivity index. We determined the diet of kelp forest associated fishes and their foraging behavior by comparing prey availability with those items present in the stomachs of fishes captured by gill net and spear gun. We calculated the degree of dietary overlap among fishes from four locations along the northern coast of Chile. Results indicate that utilization of prey by predators is predominantly affected by potential prey availability. With the exception of the two carnivorous species such as Pinguipes chilensis (Valenciennes, 1883) and Paralabrax humeralis (Cuvier & Valenciennes, 1828), whose diet did not change among sites, all other kelp-associated fishes changed their dietary habitats to consistent with the availability of local resources. Benthic resources changed among the different study sites, which led to differing diets even in the same species from different locations. Eleven of the 12 kelp forest fishes also showed some selectively for benthic prey. We conclude that the ability of fishes to be plastic in their feeding preference and, therefore, partition the benthic resources may set adaptations to co-exist in a dynamic environment such as kelp forest.

Año: 2012

Palabras claves: Chile, Manly α, predation, trophic guilds, understory.

Referencia APA: Pérez-Matus, A., Pledger, S., Díaz, F., Ferry, L., & Vásquez, J. (2012). Plasticity in feeding selectivity and trophic structure of kelp forest associated fishes from northern Chile. Rev. Chil. Hist. Nat., 85(1), 29-48.

Bioeconomic effect from the size selection in red abalone intensive culture Haliotis rufescens as a production strategy.

Autores:

Pérez, E., Araya, A., Araneda, M., & Zúñiga, C.

Resumen:

The variability in growth is a common characteristic in mollusks breeding. Effects rising from the variability in the individual growth rate and the consequent dispersion of sizes in cultivation are important in financial terms. To manage this heterogeneity many firms use size selection, which can happen in two stages: toward the end of the stage of growing, or in the phase of growing of seeds. A bioeconomic model simulating the operation of a firm producing red abalone was implemented in spreadsheets. The firm produces 70 tons yearly. The model was structured in three sub-models. A biological sub-model detailed a batch’s dynamics, in terms of survival and growth, considering individual variation of size around a central value for each age. A technological sub-model described raw materials, the quantity of food and the energy required. Finally, the simulation model is completed with an economic integrated sub-model, where net present value is calculated considering income and costs over the time. Results of the alternative production strategies (with or without selection) are assessed according to: quantity of larvae and necessary spawners to reach the desired level of production; net present value (NPV) and necessary time to recover the investment. The number of larvae was approximately 17 millions larger for the case of the strategy of production with sizes selection and 73% more of available spawners is required for this larger amount of larvae. In the short term, the size-selection strategy increases the production costs at the initial time, compared with the strategy without selection. However, in the long term, this strategy generates greater NPV. The span for investment recovery was shorter for the case of the strategy with size selection and living product (nearly 2,140 days) than frozen (nearly 2,232 days); while without sizes selection a 15-year simulation showed the investment is not recovered. Finally, could be verified that size selection can be an interesting strategy to explore, since it improves the financial result, the same way other more expensive technological changes would.

Año: 2012

Palabras claves: Bioeconomic effect, Red abalone, Size selection, Strategy.

Referencia APA: Pérez, E., Araya, A., Araneda, M., & Zúñiga, C. (2012). Bioeconomic effect from the size selection in red abalone intensive culture Haliotis rufescens as a production strategy. Aquaculture International, 20(2), 333-345.

Estimating rat predation on Humboldt Penguin colonies in north-central Chile.

Autores:

Simeone, A. & Luna-Jorquera, G.

Resumen:

Rats (Rattus spp.) are among the most successful alien predators brought to islands by humans and have had devastating impacts on numerous seabird populations, but studies demonstrating rates of consumption and ecological impacts on penguins are scarce and mostly based on anecdotal evidence. We investigated the effects of rat predation on Humboldt Penguins (Spheniscus humboldti) by simulating unattended clutches with domestic Chicken eggs. Experiments were independently set at two Humboldt Penguin colonies in north (Pájaros Island, 29°S) and central Chile (Algarrobo Island, 33°S). At both colonies, eggs were primarily predated by rats (Rattus rattus = 70.8 % at Pájaros and Rattus norvegicus = 52.6 % at Algarrobo), and secondarily by Kelp Gulls (Larus dominicanus = 9.7 % at Pájaros and 15.8 % at Algarrobo). Significantly more eggs were predated at night. At both colonies, rates of rat and gull predation were highest within the first 12 h. Our study constitutes the first quantification of rats as important alien predators at Humboldt Penguin colonies. We suggest that rat presence at Humboldt Penguin colonies coupled with events that can cause temporary nest abandonment, such as human perturbation and El Niño events, may impact on the species’ breeding success. Eradication of rats is suggested to improve the nesting habitat of this and other threatened and endemic seabird species in the region.

Año: 2012

Palabras claves: Introduced species, Island conservation, Nest attendance, Alien predation, RattusPenguins

Referencia APA: Simeone, A. & Luna-Jorquera, G. (2012). Estimating rat predation on Humboldt Penguin colonies in north-central Chile. J Ornithol, 153(4), 1079-1085.

Estimaciones de crecimiento de Haliotis rufescens en cautiverio en el norte de Chile.

Autores:

Pérez E., Eduardo P. AU - Araya, AndreaTI.

Resumen:

El crecimiento en acuicultura es indicador directo de productividad,permite predecir el desarrollo del cultivo y la cosecha, afecta indirectamente el desempeño de variables tecnológicas y determina el tiempo necesario para obtener individuos de un tamaño específico, lo cual condiciona el beneficio económico de un cultivo. Estas condiciones requieren la toma de datos y descripción adecuada del crecimiento de la especie cultivada. En este trabajo se evalúan tres alternativas de ajuste de parámetros de crecimiento a partir de información recopilada en un centro de cultivo de abalón rojo Haliotis rufescens en Coquimbo, Chile, donde se midieron durante un año individuos de 1,4-4,3 años, por intervalos de tamaño de 15-25, 26-35, 36-45, 46-55 y 56-65mm de longitud. Para analizar la consistencia en la estimación de crecimiento, se utilizaron tres modelos: la ecuación de von Bertalanffy (ECVB), la versión con crecimiento estacionalizado de ECVB y el modelo generalizado de crecimiento de Schnute y Richards. Los tres modelos resultaron ser confiables para longitudes en edades de 1,4-4,3 años, y las curvas de ajuste pasan a través del centro de la nube de puntos. Coincide esta etapa con la fase de crecimiento exponencial de los organismos. Con un criterio estrictamente estadístico la ECVB en su versión estacionalizada es la más ajustada, por una menor suma de cuadrados. Dado que las extrapolaciones hacia edades mayores y menores resultan más exactas con el modelo generalizado de crecimiento, se concluye que éste representó mejor el crecimiento de H. rufescens en las condiciones locales de cultivo.

Año: 2012

Palabras claves:

Referencia APA: Pérez E., Eduardo P. AU - Araya, AndreaTI. (2012). Estimaciones de crecimiento de Haliotis rufescens en cautiverio en el norte de Chile. Interciencia, VL - 37IS - 2AB.

Anthropogenic structures as a spatial refuge from predation for the invasive bryozoan Bugula neritina.

Autores:

Dumont, C., Harris, L., & Gaymer, C.

Resumen:

Anthropogenic structures may play an important role in the marine invasion process by providing novel artificial habitats, often out of the reach of common benthic predators. A survey of piers in northern-central Chile revealed a change in the epibenthic assemblage on pilings at different distances from a rocky shore with abundant grazers and predators. Pilings on soft sediment, away from the rocky shore, were heavily colonized by the invasive bryozoan Bugula neritina. We therefore hypothesized that benthic predators may forage on pilings located on rocky bottom whereas pilings on soft sediment benefit from the absence of generalist benthic predators which do not occur on soft sediment. We examined piling communities using cages directly attached to pilings, where we included or excluded the sea urchin Tetrapygus niger and the rock shrimp Rhyncocinetes typus. Resultant communities differed substantially; a high percentage of bare space occurred in the presence of sea urchins, while turf algae dominated in the presence of shrimp. Both sea urchins and shrimp suppressed the colonization of the invasive B. neritina and, when acting together, totally prevented its recruitment. In contrast, invasive bryozoans colonized 95% of the available substratum in cages where predators were excluded. Our results show the important role of benthic generalist predators in limiting the establishment and spread of non-native species on anthropogenic structures. Further, this study highlights the unprecedented role of shrimp grazing in structuring hard-bottom communities.

Año: 2012

Palabras claves: Predation • Rock shrimp • Sea urchin • Invasive species • Fouling • Artificial hábitat.

Referencia APA: Dumont, C., Harris, L., & Gaymer, C. (2012). Anthropogenic structures as a spatial refuge from predation for the invasive bryozoan Bugula neritina. Marine Ecology Progress Series, 427, 95-103.