Niveles de cadmio y plomo en el exoesqueleto del cangrejo rojo (Ucides Occidentalis) del Golfo de Guayaquil (Las Loras – Puerto el Morro – Chupadores) y Machala (Puerto Bolívar)
Fecha
2013
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Universidad de Guayaquil. Facultad de Ciencias Naturales. Escuela de Ciencias Geológicas y Ambientales
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En Ecuador para doce especies de peces, camarón marino y de agua dulce,moluscos y calamar,las concentraciones de Cobre, Cadmio,Cromo,Zinc y Plomo se encuentran en los límites permisibles referidos en la 7 Normas Mexicanas (NOM-029-SSA1-1993),este hallazgo denota la acumulación ciertos metales en los organismos acuáticos muestreados en la Península de Santa Elena y Puerto Bolívar,no existen estudios que refieran las concentraciones de Cadmio y Plomo en el exoesqueleto del cangrejo rojo.Para efecto del estudio se eligieron 4 estaciones ubicadas en los esteros Chupadores, Las Loras, El Morro y Machala y se determinaron los niveles de Cadmio y Plomo en 36 exoesqueletos de cangrejo rojo Ucides Occidentalis capturados vivos. Una vez que los organismos llegaron al laboratorio se procedió a lavarlos con agua potable y luego con agua destilada,se separaron los tejidos, branquias, hepatopáncreas, patas y pinzas, quedando solo el exoesqueleto.El contenido de Cadmio y Plomo en el exoesqueleto fue determinado mediante el método de espectrofotometría de absorción atómica de flama,empleando el espectrofotómetro Perkin Elmer modelo AAnalyst 100. La concentración de Pb en las muestras llegan al orden promedio de 37, 26 mg/kg en la localidad de Chupadores, mientas que Las Loras, El Morro y Machala las concentraciones promedio encontradas es 43,10mg/kg.Por otro lado,al observar las tablas de resultados las concentraciones máximas encontradas para el contenido de Cd llegan al orden promedio de 3,67mg/kg en las localidades de Las Loras, El Morro y Machala en comparación con las concentraciones encontradas en Chupadores que alcanzan concentraciones promedio de 2,97 mg/kg. Los datos obtenidos demuestran que las concentraciones de Cadmio y Plomo del primer muestreo (inicio de veda-muda) mostraron una marcada diferencia en relación a las del segundo muestreo (30 días después de veda-muda) pudiendo deberse a un mecanismo de detoxificación por el cual los cangrejos se liberan de estos elementos tóxicos durante el proceso de muda (Marcovecchio et al,2006) y del análisis de tendencia no muestran relación entre el contenido de los metales estudiados con la talla del cefalotórax del cangrejo rojo,concluyendo que absorción y acumulación de metales pesados Cadmio y Plomo en el exoesqueleto del cangrejo rojo depende de las fases del proceso de muda.
In Ecuador for twelve species of fish, marine and freshwater shrimp, shellfish and squid, the concentrations of copper, cadmium, chromium, zinc and lead are found in the aforementioned permissible limits in 7 Mexican Standards (NOM-029-SSA1- 1993), this finding indicates certain metals accumulation in aquatic organisms sampled in the Peninsula of Santa Elena and Puerto Bolivar, no studies relating the concentrations of cadmium and lead in the exoskeleton of crab rojo.Para effect of the study were chosen in April stations located in sucking, Las Loras, El Morro and Machala estuaries and levels of cadmium and lead in 36 red crab exoskeletons Ucides occidentalis captured alive were determined. Once the bodies arrived at the laboratory proceeded to wash them with water and then with distilled water, tissue, gills, hepatopancreas, legs and claws were removed, leaving only the exoesqueleto.El content of cadmium and lead in the exoskeleton it was determined by the method of atomic absorption spectrophotometry flame, using the Perkin Elmer model AAnalyst 100. The concentration of Pb in the samples arrive at the average order of 37, 26 mg / kg in the town of sucking, lie Las Loras, The Morro and the average concentrations found Machala is 43,10mg / kg.Por other hand, observing the results tables maximum concentrations found for the Cd content reach the average order of 3,67mg / kg in the towns of Las Loras, Machala El Morro and compared with concentrations found in Chupadores reaching average concentrations of 2.97 mg / kg. The data show that concentrations of cadmium and lead in the first sampling (start closed-mute) showed a marked difference in relation to the second sampling (30 days after closed-mute) may be due to a detoxification mechanism for the crabs which are released from these toxic elements during the molting process (Marcovecchio et al, 2006) and trend analysis show no link between the content of the metals studied with the likes of the red crab carapace, concluding that uptake and accumulation Heavy cadmium and lead in the exoskeleton of the red crab metals depends on the stages of molting
In Ecuador for twelve species of fish, marine and freshwater shrimp, shellfish and squid, the concentrations of copper, cadmium, chromium, zinc and lead are found in the aforementioned permissible limits in 7 Mexican Standards (NOM-029-SSA1- 1993), this finding indicates certain metals accumulation in aquatic organisms sampled in the Peninsula of Santa Elena and Puerto Bolivar, no studies relating the concentrations of cadmium and lead in the exoskeleton of crab rojo.Para effect of the study were chosen in April stations located in sucking, Las Loras, El Morro and Machala estuaries and levels of cadmium and lead in 36 red crab exoskeletons Ucides occidentalis captured alive were determined. Once the bodies arrived at the laboratory proceeded to wash them with water and then with distilled water, tissue, gills, hepatopancreas, legs and claws were removed, leaving only the exoesqueleto.El content of cadmium and lead in the exoskeleton it was determined by the method of atomic absorption spectrophotometry flame, using the Perkin Elmer model AAnalyst 100. The concentration of Pb in the samples arrive at the average order of 37, 26 mg / kg in the town of sucking, lie Las Loras, The Morro and the average concentrations found Machala is 43,10mg / kg.Por other hand, observing the results tables maximum concentrations found for the Cd content reach the average order of 3,67mg / kg in the towns of Las Loras, Machala El Morro and compared with concentrations found in Chupadores reaching average concentrations of 2.97 mg / kg. The data show that concentrations of cadmium and lead in the first sampling (start closed-mute) showed a marked difference in relation to the second sampling (30 days after closed-mute) may be due to a detoxification mechanism for the crabs which are released from these toxic elements during the molting process (Marcovecchio et al, 2006) and trend analysis show no link between the content of the metals studied with the likes of the red crab carapace, concluding that uptake and accumulation Heavy cadmium and lead in the exoskeleton of the red crab metals depends on the stages of molting
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Cadmio, Biología marina, Métodos experimentales