Evaluación espacio temporal de la influencia de hidrocarburos totales de petróleo en comunidades bentónicas de sedimentos de la cuenca baja del río Napo

Abstract

The purpose of the research was to evaluate the total petroleum hydrocarbons toxicity (TPH) present in sediment and its influence in benthic communities of Napo river tributaries, for this it was necessary to determine the (TPH) concentration of lead, cadmium and nickel in swamps sediment which are close to 25 sampling points including oil stations an mini-stations. In addition, some macroinvertebrates present in sediment were collected and identified. To determine the TPH concentration, it was necessary to use a gas chromatograph and the macroinvertebrates were identified by using GADPO macroinvertebrates guide, which helped determine the quality of the water by means of BMWP/Col index; additionally, (QBR), (IHF), geo-accumulation index and enrichment factor were also determined. QBR index reveals a high and important alteration in the places that were analyzed, IHF reflects that the habitat diversity is medium and low. According to TPH, during the first sampling month Sacha Central and Yuca Central points presented a very high toxicity level while Yulebra point a high toxicity level. In the second month, Yuca Central point presented a high toxicity. In the third month, Sacha Norte 1, Anaconda 1 and Culebra 1 presented a high toxicity level, Sacha Central, Sacha 192, and Yuca Central point presented a very high toxicity level regarding to TPH. The geo-accumulation index determined that there is no accumulation of metals analyzed, BMWP/col index reveals that water is critical and doubtful in most points. It is concluded that 76% of results obtained show that there is no any TPH significant toxicity, while 24% reflect a low, high and very high TPH toxicity where Yuca Central point has the highest concentration.