Data from: Effects of Nile tilapia (Oreochromis niloticus) cage aquaculture on water quality in the world’s largest tropical lake

Cage aquaculture in tropical lakes is an efficient means of generating
fish protein to ensure food security and support livelihoods. However, it
has been repeatedly criticized as injurious to lake ecosystems due to
eutrophication and other problems, and therefore ill-advised. This study
examined the impacts of Nile tilapia (Oreochromis niloticus) cage farming
on water quality across spatial scales in the world’s largest tropical
lake, Lake Victoria. The primary objectives were to determine if water
quality patterns differed between cage and control stations along a
background limnological gradient, and to identify the water quality
variables that contributed most to these differences. We postulated that
the spatial arrangement of sites in the lake would drive overarching
patterns of water quality variation, while cage aquaculture would have
additional impacts on these parameters across the spatial gradient. Water
column samples were collected from both cage and control stations at four
locations along a known gradient in limnology, across 2 years. The results
revealed significant differences in water quality between cage and control
stations at all four sites, with dissolved oxygen, pH, and silica
contributing the most to these differences. These findings highlight the
need for site-specific management strategies to both mitigate the
environmental impacts of cage aquaculture in tropical lakes and ensure
continuity of aquaculture production. Our study provides an approach that
can be applied to tropical lakes and reservoirs around the world.
Effective nutrient management and continuous monitoring are recommended to
support sustainable aquaculture in ecosystems under stress from growing
lakeside populations.