Victor Chukwuebuka NWAFEE

Heavy metals are ubiquitous contaminants in the aquatic ecosystems, posing significant threats to fishes and other aquatic fauna which tend to bioaccumulate this toxicant in their muscle. This study was therefore carried out to investigate the bioconcentration of heavy metals in the muscles tissues of fish fauna within Ikpoba River, Benin city. A total number of 26 (13 Clarias garipienus and Tilapia zilli) fishes were collected from Ikpoba River between June to August 2023. Heavy metals (Cd, Ni, Pb, Cr and Co) in the muscles of the fish were estimated using atomic absorption spectrometer (AAS), while the ratio of heavy metals in the muscles of the fish
relative to water, was estimated using the bioconcentration index. The result showed that Nickel in the muscles of the benthic fish had the highest concentration in the month of June (21.21mg/kg) and lowest in the month of July (14.92mg/kg), while Nickel in the pelagic fish had the highest concentration in August (21.82mg/kg) and lowest in July (12.89mg/kg). Lead and Cadmium were found to be below detectible limit in benthic and pelagic fish muscle tissue across the sampling period. Chromium in the muscle tissue of the benthic fish has the highest in June (10.89mg/kg) and lowest in July (4.85mg/kg), while in pelagic fish, it was found to be highest in August (12.91mg/kg) and lowest in June (6.11mg/kg). The concentration of cobalt in benthic and pelagic fish was found to be highest in the month of August (3.44mg/kg and 12.91mg/kg) and lowest in the month of June (1.93mg/kg and 6.11mg/kg) respectively. These variations therefore signify the level of heavy metal accumulation in their tissues which have impacts on the aquatic ecosystem and human health.

Heavy metals are ubiquitous contaminants in the aquatic ecosystems, posing significant threats to fishes and other aquatic fauna which tend to bioaccumulate this toxicant in their muscle. This study was therefore carried out to investigate the bioconcentration of heavy metals in the muscles tissues of fish fauna within Ikpoba River, Benin city. A total number of 26 (13 Clarias garipienus and Tilapia zilli) fishes were collected from Ikpoba River between June to August 2023. Heavy metals (Cd, Ni, Pb, Cr and Co) in the muscles of the fish were estimated using atomic absorption spectrometer (AAS), while the ratio of heavy metals in the muscles of the fish relative to water, was estimated using the bioconcentration index. The result showed that Nickel in the muscles of the benthic fish had the highest concentration in the month of June (21.21mg/kg) and lowest in the month of July (14.92mg/kg), while Nickel in the pelagic fish had the highest concentration in August (21.82mg/kg) and lowest in July (12.89mg/kg). Lead and Cadmium were found to be below detectible limit in benthic and pelagic fish muscle tissue across the sampling period. Chromium in the muscle tissue of the benthic fish has the highest in June (10.89mg/kg) and lowest in July (4.85mg/kg), while in pelagic fish, it was found to be highest in August (12.91mg/kg) and lowest in June (6.11mg/kg). The concentration of cobalt in benthic and pelagic fish was found to be highest in the month of August (3.44mg/kg and 12.91mg/kg) and lowest in the month of June (1.93mg/kg and 6.11mg/kg) respectively. These variations therefore signify the level of heavy metal accumulation in their tissues which have impacts on the aquatic ecosystem and human health.