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.