Comparative toxicity of effluent to Tilapia guineensis and Clibanarius africanus

The continuous discharge of effluent into the adjoining environment is a major source of aquatic pollution which can trigger critical problems in the aquatic environment including terminating life forms directly or indirectly. This study aimed to comparatively investigate the toxicity of effluent to Tilapia guineensis (fish) and Clibanarius africanus (hermit crab). Treated effluent sample was sourced from a petroleum producing industry that discharges its effluent into Bonny estuary, Bonny while the test organisms were obtained from National Institute for Oceanography and Marine Research (NIOMR), Buguma both in Rivers State, Nigeria. The range of pH (7.24 – 7.59), salinity (17.46 – 27.31psu), temperature (22.00 – 23.42℃), dissolved oxygen (2.93 – 3.79mg/l) total dissolved solid (1479 – 19980 mg/l) and electrical conductivity (2957 – 29840uscm-1) of the test medium for the different concentrations of effluent were within the limits that permits survival of aquatic organisms. Clibanarius africanus displayed more tolerance than Tilapia guineensis. The median lethal concentration (LC50) of the treated effluent at 96hours for both Tilapia guineensis and Clibanarius africanus were very high (409,824mg/l and 299,008mg/l respectively) which implies that the treated effluent was not toxic to both organisms hence would not cause fatal effect on the test organisms. Thus, effluent treatment compliance and management is essential for protection of sensitive aquatic areas.