Toxicity, uptake, and depuration of crude oil-water mixtures by shrimps from Shatt Al-Arab River

Abstract EN

The intent of present study was to examine the toxicity, uptake, and depuration of oil–water mixtures from Nahran–Umar crude oil of two types, water soluble fractions (WSF) and oil-in-water dispersions (OWD).

The test organisms used in these experiments were the shrimps, Caridina babaulti basrensis and Atyaephyra desmaresti mesopotamica, presence in Shatt Al– Arab river.

In the toxicity test experiments, the two species of shrimps were subjected in river water to different concentrations of WSF and OWD using renewal toxicity system for 24 and 48 hours under laboratory conditions.

In the median lethal concentration (LC50) parameter, The shrimp C.

babaulti basrensis was more sensitive to oil-water mixtures than the shrimp A.

desmaresti mesopotamica.

The WSF was slightly more toxic to shrimps than the OWD.

In the uptake and depuration experiments, we exposed the shrimp, C.

babaulti basrensis to 2 ml of WSF/l of river water for 24 hours.

Exposure water and organisms were sampled periodically for the total hydrocarbons concentration.

Hydrocarbons levels in the exposure solution decreased rapidly while concentration in the shrimp tissue increased dramatically.

After 6 hours, tissue levels of hydrocarbons were 150 times grater than water levels.

Depuration of hydrocarbons was rapid and began during the exposure period, complete depuration did not occur.