The importance of phytoplankton in fresh water environment cannot be over emphasized. This study was designed to determine the phytoplankton diversity and abundance in water bodies exposed to different anthropogenic pressures. Water samples were collected from 19 water sources in four categories: Car wash, Municipal wastes, Car wash + Municipal wastes and Drinking water. Phytoplankton species were determined following standard procedures. Palmer's pollution index was used to evaluate the status of organic pollution. A total of 66 phytoplankton were identified belonging to 44 genera, 34 families and six phyla. There were 52, 32, 11 and 38 species recorded for Car Wash, Municipal Waste, Car wash + Municipal wastes and Drinking water sources, respectively. Nine species cut across the four categories while 22, three and two species were unique to car wash, municipal wastes and drinking water sources, respectively. Nitzschia and Chlorella were the most abundant genera in the different water sources. While phytoplankton abundance correlated positively with nutrients, diversity correlated negatively. The highest and lowest organic pollution indices (24 and 8 respectively), were recorded in the drinking water category. Car wash activity did not only encourage the growth and diversity of algae but also influenced the establishment of unique species, some which are harmful. Human activities in and around water sources in Buea are thus degrading water quality, putting the population at risk. There is therefore need to protect the water resources of Buea.

Macrophytes can occur as submerged, floating or emergent. They provide not only important structural supports in streams and river habitats, but also absorb and sequester pollutants, provide primary food production, nutrients and habitats to a wide range of macro and micro-organisms living in and around lotic sites. Their existence is however threatened by both anthropogenic and natural stresses. This study aimed to document macrophyte diversity and abundance in streams under different anthropogenic influences in Buea, southwestern Cameroon. Floristic surveys were carried out using 500 m long transects laid along the different streams. Plants encountered were identified and confirmed at the Limbe Botanic Garden Herbarium. One hundred and ten species belonging to 38 families and 83 genera were recorded. There were no floating species and only one stream had submerged species (Vallisneria spiralis L and Crinum calamistratum Bogner & Heine). The highest number of families (26), genera (58) and species (70) were obtained in Ndongo while the least of these taxa were obtained in Bulu (16, 35 and 39, respectively). Overall, Asteraceae and Poaceae were the most abundant, suggesting anemophilic dispersals. However, individual species abundances varied with streams. The highest diversity index (0.945) was in Wongangjio while the least (0.760) was in Nange, suggesting that waste discharge from car wash might influence species diversity negatively. The macrophyte composition was made up of obligate and non-obligate species as a consequence of anthropogenic influences. These results constitute baseline data for the area that can be exploited for further research and monitoring.

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