Government has explained circumstances under which large numbers of fish, especially Nile Perch were found dead on shores of Lake Victoria over the weekend.
There have been concerns by members of the public, especially those living near lakes over the large numbers of dead fish on lakeshores that many attributed to poisoning but the Ministry of Agriculture ruled it out.
Another statement by the National Environment Management Authority (NEMA) further explained the circumstances under which the fish died.
In a statement released on Sunday evening, NEMA noted that their preliminary investigations indicated that the deaths were due to a drop in oxygen levels in the lake which affected mainly Nile Perch, a species of fish known to be sensitive to low oxygen levels.
“As a result of the recent flooding and rising water levels, large masses of weeds were submerged and sunk into the lake bed. These weeds use up oxygen as they rot from within the lake hence a drop in the oxygen levels,” a statement by NEMA said.
“Also, the recent strong winds around the Lake Victoria basin have heightened lake overturn; a phenomenon that causes water from the bottom of the lake that is low in oxygen, to come up and mix with upper layers, where fish live; leading to a reduction in oxygen, hence the death of fish.”
Lake Victoria for the past one year recorded the highest water levels in many years with water consistently going up from 12metres to 13.32 metres.
The lake in a period of only six months recorded a rise of 1.32 metres which was 0.08 metres away from the highest level recorded, a phenomenon which has been attributed to the heavy rains which increase waters in the 23 rivers that pour into Lake Victoria.
The quick rise in water was also attributed to accelerated human activities especially environmental degradation, loss of forest cover, wetland encroachment and other practices affecting the, further reducing water storage capacities of water bodies.
According to NEMA, the ever-rising water levels, especially in Lake Victoria have come with a number of weeds that have seen the oxygen levels reduced in the lake and consequently the death of fish, especially Nile Perch that cannot adapt to low oxygen.
The environment body noted this is not the first time large scale fish deaths are occurring on Lake Victoria, noting that fishing communities have always referred to the situation as Kaliro and that it occurs periodically.
“Communities living around the lake are advised to bury the dead fish to contain the pungent smell; as further research and studies are undertaken by all stakeholders including, NEMA, Ministry of Agriculture, communities and developers among others.”