Water bacteriological qualities of 22 recreational beaches in Ensenada Bay, Baja California, Mexico were analyzed during the summer and winter of 2008. Total and fecal coliforms as well as enterococci bacteria were us...Water bacteriological qualities of 22 recreational beaches in Ensenada Bay, Baja California, Mexico were analyzed during the summer and winter of 2008. Total and fecal coliforms as well as enterococci bacteria were used as pollution indicators. Results showed that bacteria concentrations were higher in winter than summer, associated with Southern California rainy season. Bacteria loads in winter exceeded both the daily and monthly standards showing a clear effect of storm water runoff in the quality of Todos Santos Bay recreational beaches. Statistical analysis showed significant differences between bacteria concentration during summer and winter. The general behavior of the indicators based on daily and monthly standards from high to low was enterococci > FC > TC> total/fecal ratio. Water discharged from 3 sewage treatment plants were responsible for the pollution observed at stations, when the uptake capacity of plants exceeded the storage. During summer pollution was due to non-programmed discharges from sewage treatment plants.展开更多
The species composition and infection levels were determined for helminth parasites in the mole crab, Emerita rathbunae, collected from seven sandy beaches from Guerrero and Michoacán, México. A total of 494...The species composition and infection levels were determined for helminth parasites in the mole crab, Emerita rathbunae, collected from seven sandy beaches from Guerrero and Michoacán, México. A total of 494 crabs were collected between August and December of 2009. The number of crabs that were examined from each beach varied from 40 in Lázaro Cárdenas to 114 in El Revolcadero. The cephalothorax length varied significantly between the sampled beaches, from 32.9 ± 5.5 mm (Ixtapa) to 40.5 ±1.7 mm(Las Trancas). Four species of larval parasites were identified: 1 metacercaria (Microphallus nicolli), 1 cystacanth (Profilicollis sp.), 1 cestode (Trypanorhyncha) and 1 nematode (Proleptus sp.). Infection levels (prevalence and mean abundance) varied significantly between beaches, due to possible differences in the availability of final or intermediate hosts in beaches visited by tourist and those beaches not visited by tourists, as well as the size of individual hosts. Helminth communities, at levels of component and infracommunity, were characterized by a low number of species (3 to 4) and a high dominance by the metacercaria of M. nicolli. The body size of the hosts was positively correlated with the number of parasites and species richness of helminths, indicating that larger crabs accumulate a higher number of parasites during the lifetime, and that they harbor a higher number of species of helminth than smaller crabs.展开更多
文摘Water bacteriological qualities of 22 recreational beaches in Ensenada Bay, Baja California, Mexico were analyzed during the summer and winter of 2008. Total and fecal coliforms as well as enterococci bacteria were used as pollution indicators. Results showed that bacteria concentrations were higher in winter than summer, associated with Southern California rainy season. Bacteria loads in winter exceeded both the daily and monthly standards showing a clear effect of storm water runoff in the quality of Todos Santos Bay recreational beaches. Statistical analysis showed significant differences between bacteria concentration during summer and winter. The general behavior of the indicators based on daily and monthly standards from high to low was enterococci > FC > TC> total/fecal ratio. Water discharged from 3 sewage treatment plants were responsible for the pollution observed at stations, when the uptake capacity of plants exceeded the storage. During summer pollution was due to non-programmed discharges from sewage treatment plants.
基金provided by the Programa de Mejoramiento del Profesorado(PROMEP)as part of the collaborative project“Red temática de colaboración:Calidad ambiental y desarrollo sustentableprovided to JV-G through the project“Parásitos del chiquilique Emerita rathbunae y su posible repercusión en la salud pública”,financed by the Universidad Autónoma de Guerrero,and Fomix Conacyt-Guerrero 2015The Consejo Nacional de Ciencia y Tecnología(CONACyT)provided a scholarship(No.247514)to GQ-R.
文摘The species composition and infection levels were determined for helminth parasites in the mole crab, Emerita rathbunae, collected from seven sandy beaches from Guerrero and Michoacán, México. A total of 494 crabs were collected between August and December of 2009. The number of crabs that were examined from each beach varied from 40 in Lázaro Cárdenas to 114 in El Revolcadero. The cephalothorax length varied significantly between the sampled beaches, from 32.9 ± 5.5 mm (Ixtapa) to 40.5 ±1.7 mm(Las Trancas). Four species of larval parasites were identified: 1 metacercaria (Microphallus nicolli), 1 cystacanth (Profilicollis sp.), 1 cestode (Trypanorhyncha) and 1 nematode (Proleptus sp.). Infection levels (prevalence and mean abundance) varied significantly between beaches, due to possible differences in the availability of final or intermediate hosts in beaches visited by tourist and those beaches not visited by tourists, as well as the size of individual hosts. Helminth communities, at levels of component and infracommunity, were characterized by a low number of species (3 to 4) and a high dominance by the metacercaria of M. nicolli. The body size of the hosts was positively correlated with the number of parasites and species richness of helminths, indicating that larger crabs accumulate a higher number of parasites during the lifetime, and that they harbor a higher number of species of helminth than smaller crabs.
