Radioactivity is related to energy that is released from radionuclides in the form of radiation. Ionizing radiation is produced as electromagnetic rays. These radiations are the cause of genetic, reproductive and cancerous effects in the living organisms.Because of the potential for radiation contamination in the food web to badly influence human and ecological well-being, and also the interest to understand the comparative influences of local and worldwide sources to present and upcoming radionuclide concentrations, many scientific efforts have been started to characterize radionuclides in the marine environment that includes biota, seawater and sediments. Radiological risk assessment is an estimation of the possibility of a lethal cancer over the lifetime of an exposed individual.The present study estimates the radiation dose rate of marine biota using point source distribution and Erica Tool with the measured seawater and sediment activity concentrations at Karachi Coast-Pakistan. The estimated dose rates are compared with the benchmark values for environmental protection from ionizing radiation. ukryj opis