Temporal variation in lake properties
The results of PCA ordination showed a clear separation between the years based on the lake water quality properties and fisheries yields for a 13-year time frame (Figure 2). Of the five axes extracted in the PCA, only axes 1 and 2 are presented as they explain the majority of the extracted variance, 93.84% in total, 81.25 %, and 12.59 %, respectively.
The years 2013 and 2014 ordinated in the upper left of the biplot and are characterized as having high TN concentrations and total fish yields while, the years from 2008 to 2012 are ordinated to the lower right and characterized by having higher turbidity concentrations ranging between 73.69-185 NTU, higher WQI values fluctuating between 860.19 and 1443.47, higher TP levels varying from 146.66 to 240.35 µg. L-1indicating periods of poor water quality and high yearly water level fluctuations measured as yearly amplitude (1.56-9.36 m). Besides, the years 2015 to 2020 that were ordinated in the upper and lower left of the biplot are characterized by having higher DLTM, indicating an increase in the annual lake water levels relative to the long-term average. The other water quality parameters such as DO and temperature, known to affect assemblages and lake function, were not strong descriptors in the grouping of years using the first two components (Figure 2).