Abstract:
Estuarine ecosystems are classified as among the most productive systems on the planet earth
supporting an array of biodiversity. However, due to the ever increasing human population, they
experience environmental degradation originating from intensive anthropogenic activities hence the
need for regular assessment and monitoring to inform its management. The purpose of this study,
Original Research Article
Nyakeya et al.; Int. J. Environ. Clim. Change, vol. 14, no. 10, pp. 46-57, 2024; Article no.IJECC.121848
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therefore, was to analyze the spatio-temporal variation in water quality parameters in South Coast
estuarine ecosystem, Kenya. Twelve sampling stations were identified based on different
hydrological regimes, anthropogenic activities, and accessibility factors. Sampling was done for 12
months taking into account different seasons of the year. Such parameters as temperature,
dissolved oxygen, pH, conductivity, salinity and TDS were collected in situ using YSI Multiparameter
meter (Professional plus) whereas nutrients (nitrates, phosphates and ammonia) were analyzed in
the laboratory using established methods. Two-way analysis of variance (ANOVA) was applied to
discriminate any significant differences among stations and between seasons, and where there was
a difference, Tukey post hoc test was applied to show which site differed from each other. Principal
Component Analysis (PCA) was performed to correlate the environmental factors with sampling
sites, and months. There was significant difference in water quality parameters among the sampling
stations (P = .05) that was attributed mainly to anthropogenic activities, and both the point and non-
point sources of pollution. Conversely, there was no significant difference in most of the water
quality attributes in terms of seasons due to unpredictable weather patterns associated with climate
change. There is need for long term monitoring strategies in order to generate sufficient data for
sound management of South Coast estuary in Kenya. The study further recommends for community
sensitization and implementation of relevant policies on the protection and management of riparian
land.
