Data collection
Lake water levels (WLs) data were obtained from the Kenya Water Resources Authority (WARA) for the period from 1956-2018. The water level is monitored by a graduated wooden scale of 5 m height with the nearest 1-cm accuracy. The scale was installed at the lowest elevation in the southern part of the lake (Figure 1) to enable monitoring even during low lake levels. Additional WL data were obtained by the project from January 2020 to April 2021 using a similar scale and the same location. For each year of record, both for the two periods (1956-2018) and ( 2020-2021), both monthly and yearly mean lake levels were calculated and used to derive the lake water level fluctuation (WLF) indices as described below. Both the water quality parameters and fish landings were measured from three ecological zones (northern, central, and southern) in the lake extending from the northern to the southern parts of the lake (Figure 1) in order to cover the entire lake area. The characteristics of the three ecological zones of Lake Baringo are described in Walumona et al . (2021). A total of 9 stations (N1, N2, N3, C1, C2, C3, S1, S2, and S3), three from each zone, were then selected in the three ecological zones of the lake for water quality sampling. Station replicates are numbered according to the three zones and are shown in Figure 1.