Assuntos
Bovinos/genética , Alimentos Geneticamente Modificados/economia , Edição de Genes , Cabras/genética , Gado/genética , Salmão/genética , Tilápia/genética , Animais , Argentina , Brasil , Aprovação de Drogas , Feminino , Rotulagem de Alimentos/legislação & jurisprudência , Rotulagem de Alimentos/normas , Cabras/metabolismo , Masculino , Muramidase/genética , Muramidase/metabolismo , Salmão/crescimento & desenvolvimento , Tilápia/crescimento & desenvolvimento , Estados Unidos , United States Food and Drug Administration/legislação & jurisprudênciaRESUMO
The impacts of any activity on marine ecosystems will depend on the characteristics of the receptor medium and its resilience to external pressures. Salmon farming industry develops along a constant gradient of hydrodynamic conditions in the south of Chile. However, the influence of the hydrodynamic characteristics (weak or strong) on the impacts of intensive salmon farming is still poorly understood. This one year study evaluates the impacts of salmon farming on the marine sediments of both protected and exposed marine zones differing in their hydrodynamic characteristics. Six physico-chemical, five biological variables and seven indexes of marine sediments status were evaluated under the salmon farming cages and control sites. Our results identified a few key variables and indexes necessary to accurately evaluate the salmon farming impacts on both protected and exposed zones. Interestingly, the ranking of importance of the variables and the temporality of the observed changes, varied depending on the hydrodynamic characteristics. Biological variables (nematodes abundance) and environmental indexes (Simpson's dominance, Shannon's diversity and Pielou evenness) are the first to reflect detrimental impacts under the salmon farming cages. Then the physico-chemical variables such as redox, sulphurs and phosphorus in both zones also show detrimental impacts. Based on the present results we propose that the hydrodynamic regime is an important driver of the magnitude and temporality of the effects of salmon farming on marine sediments. The variables and indexes that best reflect the effects of salmon farming, in both protected and exposed zones, are also described.
Assuntos
Aquicultura , Sedimentos Geológicos/análise , Salmão , Poluentes Químicos da Água/análise , Animais , Chile , Monitoramento Ambiental , Oceanos e Mares , Salmão/crescimento & desenvolvimentoRESUMO
Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microscopy and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.
Assuntos
Antibacterianos/análise , Monitoramento Ambiental/métodos , Fungos/crescimento & desenvolvimento , Sedimentos Geológicos/microbiologia , Oxitetraciclina/análise , Poluentes Químicos da Água/análise , Animais , Aquicultura , Biodegradação Ambiental , Chile , Estuários , Fungos/isolamento & purificação , Salmão/crescimento & desenvolvimento , Microbiologia da ÁguaRESUMO
Apex marine predators alter their foraging behavior in response to spatial and/or seasonal changes in natural prey distribution and abundance. However, few studies have identified the impacts of aquaculture that represents a spatially and temporally predictable and abundant resource on their foraging behavior. Using satellite telemetry and stable isotope analysis we examined the degree of spatial overlap between the South American sea lion (SASL) and salmon farms, and quantify the amount of native prey versus farmed salmonids in SASL diets. We instrumented eight SASL individuals with SRDL-GPS tags. Vibrissae, hair and skin samples were collected for δ13C and δ15N analyses from five of the tagged individuals and from four males captured in a haul-out located adjacent to salmon farms. Tracking results showed that almost all the foraging areas of SASL are within close proximity to salmon farms. The most important prey for the individuals analyzed was farmed salmonids, with an estimated median (±SD) contribution of 19.7 ± 13.5 and 15.3 ± 9.6 for hair and skin, respectively. Using vibrissae as a temporal record of diet for each individual, we observed a remarkable switch in diet composition in two SASL, from farmed salmonids to pelagic fishes, which coincided with the decrease of salmon production due to the infectious salmon anemia virus that affected salmon farms in Chile at the end of 2008. Our study demonstrates the usefulness of integrating stable isotope derived dietary data with movement patterns to characterize the impacts of a non-native prey on the foraging ecology of an apex marine predator, providing important applied implications in situations where interactions between aquaculture and wildlife are common.
Assuntos
Aquicultura , Salmão/crescimento & desenvolvimento , Leões-Marinhos/crescimento & desenvolvimento , Astronave , Animais , Isótopos de Carbono/análise , Chile , Dieta , Ecossistema , Feminino , Masculino , Isótopos de Nitrogênio/análise , Especificidade de Órgãos , Comportamento Predatório , Análise EspacialRESUMO
This article introduces a management tool for salmon farming, with a scope in the local sustainability of salmon aquaculture of the Aysen Fjord, Chilean Patagonia. Based on Integrated Coastal Zone Management (ICZM) principles, the tool combines a large 3-level nested hydrodynamic model, a particle tracking module and a GIS application into an assessment tool for particulate waste dispersal of salmon farming activities. The model offers an open source alternative to particulate waste modeling and evaluation, contributing with valuable information for local decision makers in the process of locating new facilities and monitoring stations.
Assuntos
Conservação de Recursos Energéticos/métodos , Pesqueiros/métodos , Modelos Teóricos , Gerenciamento de Resíduos , Poluição da Água/prevenção & controle , Animais , Chile , Conservação de Recursos Energéticos/economia , Conservação de Recursos Energéticos/estatística & dados numéricos , Técnicas de Apoio para a Decisão , Ecossistema , Pesqueiros/economia , Pesqueiros/normas , Salmão/crescimento & desenvolvimento , Fatores Socioeconômicos , Poluição da Água/estatística & dados numéricosRESUMO
First report of camallanus corderoi Torres, Teuber and Miranda, 1990 (Nematoda: Camallanidae) in cultured salmonids from Puyehue lake, Chile
Assuntos
Animais , Doenças dos Peixes/parasitologia , Nematoides/patogenicidade , Salmonidae/parasitologia , Salmão/crescimento & desenvolvimento , Chile , Ecossistema , Peixes/parasitologia , Microscopia , Contagem de Ovos de Parasitas/métodosRESUMO
1. Two pepsins, designated Pepsin I and Pepsin II, were isolated and partially characterized from the stomach of the adult stage salmon Oncorhynchus keta. This stage is developed in a marine environment. 2. One pepsin, designated Pepsin II, was isolated from the stomach of the juvenile stage salmon Oncorhynchus keta. This stage is developed in an estuarine environment. 3. The enzymes were partially purified by ammonium sulfate precipitation, ion exchange chromatography and gel filtration. 4. Pepsins I and II from adults and Pepsin II from juvenile showed proteolytic activity on acid-denatured hemoglobin with a pH optimum of 3. 5. The mol. wt determined by gel filtration on Sephadex G-100 of Pepsin I from juvenile species was found to be 32,000 whereas a value of 27,000 was determined for Pepsin II from juvenile and adult fish. 6. In contrast with Pepsin II, Pepsin I was activated by NaCl. It is suggested that the appearance of NaCl-activated pepsin would represent and adaptive response of the organism to the change from a low to a high salinity environment.