Enhanced microbial degradation of PET and PS microplastics under natural conditions in mangrove environment

In-situ bioremediation of mangrove soil contaminated with polyethylene terephthalate (PET) and polystyrene (PS) microplastics was investigated using indigenous microbial consortium with adequate capacity to degrade the plastics. Eight (8) bacteria were isolated from plastic/microplastic-inundated mangrove soil and screened for the ability to degrade PET and PS microplastics. Optical density at 600 nm and colony forming unit counts were measured to evaluate the growth response of the microbes in the presence of PS and PET microplastics at different times of exposure. Structural and surface changes that occurred post biodegradation on the microplastics were determined through EDS and SEM analysis. The obtained results demonstrated the elongation and disappearance of peaks, suggesting that the microbial consortium could modify both types of microplastics. The overall results of the microplastic degradation showed varied degrees of weight loss after 90 experimental days, with the treated plot recorded 18% weight loss. The augmented soil was increased in the concentrations of Si S, and Fe and decreased in the concentrations of C, O, Na, Mg, Al, Cl, and K after bioremediation.

A study of the fish fauna of Tagwai Lake Minna, Nigeria, in relation to gear selectivity

The fish fauna of Tagwai Lake Minna, Nigeria, was studied from July to September, 2010. Sampling was carried out during the day using different gears. A total of 1,669 specimens were sampled made up of 8 species in 7 genera and 6 families. Variation in the mesh size used greatly influenced catch in the lake. Cash net recorded the highest amount of catch (1,435) and gill net recorded the highest amount of fish species (6). Two Cichlids species, Tilapia zilli and Sarotherodon galilaeus were the most abundant in the catch, amounting to 33.01 and 26.06%, respectively. The families of Cichlidae and Mormyridae were the most abundant constituting 59.18 and 29.95% of the total catch respectively. Fish abundance showed low catches during the raining season (33.01%) and daytime.