A survey on bioconcentration capacities of some marine parasitic and free-living organisms in the Gulf of Oman

During the course of the present study 21 rays including Himantura cf. gerrardi and Glaucostegus granulatus infected with the four cestode species Tetragonocephalum sp., Polypocephalus sp., Rhinebothrium sp1., and Rhinebothrium sp2. as well as three species of free living animals including the barnacle Amphibalanus amphitrite, and the two bivalve species Saccostrea cucullata and Barbatia obliquata were studied from the Gulf of Oman in respect to their cadmium and lead concentrations. All specimens were analyzed using graphite furnace atomic absorption spectrometry (GFAAS) for metal concentrations. In all cases, Cd and Pb concentrations in cestodes were higher than those in the tissues of the respective fish. The cosmopolitan barnacle species A. amphitrite showed the highest bioconcentration for all metals. However, the cestode species and especially Polypocephalus sp. could be an additional reliable metal indicator. The combination of “mobile” parasites together with sedentary species (i.e. barnacles) might be the most effective way to indicate local pollution levels and to relate this to an estimation of the average pollution level in larger geographical zones.