In general, the lowest β-D-glucosidase activities
in both seasons might be attributed to reduced
availability of polymeric carbohydrates (cellulose and
cellobiose) as a source of energy in these lake
ecosystems. In early summer (June), a significantly
higher level of β-D-glucosidase activity (p < 0.001) in
Ludas Lake (localities Ludas 1 and 2) in relation to
Palic and Provala was detected. According to Chróst
and Overbeck (Chróst and Overbeck, 1990) it could
indicate on phytoplankton bloom breakdown and water
blooms in the lakes examined in the present study are
documented during early summer (Simeunovic, 2010).
A significant decrease in alkaline phosphatase activity
recorded in localites Palic and Ludas 2 and increase in
localities Provala and Zobnatica recorded in October
is in accordance with the content of organic