RESIDUOS DE COMPUESTOS ORGÁNICOS PERSISTENTES EN CAMARONES Y SEDIMENTOS DE LA COSTA Y SONDA DE CAMPECHE, MÉXICO

The capture of shrimp, resource that generates important currency, has been in frank descent. One of the possible causes is the presence of pollutants. Persistent organic pollutants (POPs) such as DDT insecticide, and the aroclors or polychlorinated biphenyls (PCBs) have long-term effects on the reproduction of many organisms. In this contribution, the results from studies regarding the presence of POPs in three types of shrimp from Campeche are exposed. The results indicate that white shrimp (L. setiferus) from the Lagoon of Términos presents average concentrations of 0.0042 ng g-1 of E-DDT, pink shrimp (F. duorarum) from the Bay of Campeche have average concentrations of 33.6 ng g-1 of E-DDT, and in the seabobshrimp (X. kroyeri) from the western zone of the Lagoon of Términos there were average concentrations of 2.74 ng g-1 of E-DDT. With relation to other studies, the concentrations of EDDT in shrimps have not decreased substantially; however, the highest ones correspond to degradation products DDE and DDD, indicating that the use of DDT has decreased and, due to the characteristics of these pollutants, it is quite likely that the residues of these compounds come from different sources, including atmospheric ones.La captura de camarón, recurso que genera divisas importantes, ha estado en franco descenso. Una de las posibles causas es la presencia de contaminantes. Los contaminantes orgánicos persistentes (COPs) como el insecticida DDT y los aroclores o policlorobidenilos (PCBs) tienen efectos a largo plazo sobre la reproducción de muchos organismos. En la presente contribución se expone los resultados de estudios acerca de la presencia de COPs en tres tipos de camarón provenientes de Campeche. Los resultados indican que el camarón blanco (L. setiferus) de la Laguna de Términos presenta concentraciones promedio de 0.0042 ng g-1 de E-DDT, los camarones rosados (F. duorarum) de la Sonda de Campeche tienen concentraciones promedio de 33.6 ng g-1 de E-DDT, y el camarón siete barbas (X. kroyeri) procedentes de la zona occidental de la LT se tuvieron concentraciones promedio de 2.74 ng g-1 de E-DDT. Con relación a otros estudios, las concentraciones de EDDT en camarones no han disminuido sustancialmente, sin embargo, las más altas corresponden a productos de degradación DDE y DDD, lo que indica que el uso del DDT ha disminuido y, debido a las características de estos contaminantes, es muy probable que los residuos de estos compuestos provengan de diferentes fuentes, incluyendo las atmosféricas

Contribution of commercial fish species to human mercury exposure: an evaluation near the Mid-Atlantic Ridge

Fish consumption is frequently associated with the prevention of some human diseases, being simultaneously a major pathway of mercury (Hg) exposure. Therefore, the aim of the study was to evaluate the contribution of 28 commercial fish species to the human Hg exposure in the Azores archipelago (Portuguese region with highest fish consumption per capita). These species potentially contributed on average to 7.47 mg of Hg per capita, although low Hg levels had been detected in fish. Mora moro and Zeus faber exceeded the maximum permitted for fish consumption (> 0.5 μg g−1 ww) even though they were not the species contributing the most to human Hg exposure. On the other hand, Katsuwonus pelamis was the main contributor due to increased fish landings. Furthermore, an increase in Hg content with trophic level has been suggested, as carnivore fish exhibited higher Hg levels than omnivores. In addition, demersal fish generally presented higher Hg concentration (although non-significant) than pelagic ones, possibly related with increased Hg values of their prey at this depth. Notwithstanding, THQ (Target Hazard Quotient) being < 1 for all species indicates that the daily human exposure to Hg via fish consumption is not likely to cause any negative health risks.publishe

A 16th century shipwreck mercury legacy and present mercury bioaccumulation in intertidal species

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Expression of estrogenic response genes to different concentration of 17ß-estradiol in male mosquitofish (Gambusia yucatana)

The proximate composition, amino acids and fatty acids composition in the muscle of wild, inshore and offshore cage-cultured large yellow croaker, Pseudosciaena crocea (Richardson, 1846), were determined to identify nutritional differences. Wild fish groups showed highest content of moisture and crude protein, but the lowest lipid content. Offshore cage-cultured fish showed significantly higher content of moisture and crude protein content, but lower crude lipid content than inshore cage-cultured fish. The content of aspartic acid, glutamic acid, and alanine was higher in wild large yellow croaker than inshore cage-cultured groups, but similar to offshore cage-cultured fish. Significant lower contents of total amino acids, essential amino acids, non-essential amino acids and flavor-enhancing amino acids content were recorded in two cultured fish groups than those in wild group. While no major differences in fatty acids composition were found between wild and cage-cultured groups except for linoleic acid. The fish from offshore cages has much better nutrient profile than inshore cage cultured fish, but was still inferior compared to wild fish

Ras gene in marine mussels: A molecular level response to petrochemical exposure.

Mussels are susceptible to numerous toxicants and are often employed as bioindicators. This study investigated the status of the ras proto-oncogene in Mytilus galloprovincialis following petrochemical exposure. A M. galloprovincialis homologue of the vertebrate ras gene was isolated, showing conserved sequence in regions of functional importance and a high incidence of polymorphic variation. Mutational damage was investigated in mussels chronically exposed to the water-accommodated fraction of #4 fuel-oil (WAF), and in mussels collected along the NW coast of Portugal in sites with different levels of petrochemical contamination. A ras gene point mutation was identified in the codon 35 of one individual exposed to 12.5% WAF. No mutations were detected in mussels from the WAF control or environmental samples. This represents the first report of a ras gene mutation, experimentally-induced by petrochemical exposure, in an invertebrate species

Ecotoxicology and Environmental Safety

Acesso restrito: Texto completo. p. 893-899.This study proposes short-term sublethal assays for the tropics using the fish Poecilia reticulata. Assays were evaluated under realistic exposure scenarios by simulating a runoff over an agricultural area sprayed with deltamethrin (Decis). In situ assays were performed inside microcosms set up to simulate runoff water entrance in lentic systems. Laboratory assays were conducted with water samples from the microcosms. In both assays the biochemical parameters were similarly responsive to Decis, with a significant inhibition of acetylcholinesterase (30–46%) and induction of lactate dehydrogenase (33–67%) and glutathione S-transferases (48–176%) activities, observed as of the lowest Decis dose. Postexposure feeding was more sensitive in the laboratory assay than in situ. Among the additional potential stressors, only acetylcholinesterase was significantly influenced by the runoff per se. The proposed methodologies were well adapted for assays with P. reticulata, as organisms were easily deployed and retrieved and enzymatic activities and postexposure feeding were sensitive endpoints