11 locations in three water courses (Isabellawatering, the Zwarte Sluisbeek and the Nieuwe Kale) situated in the basin of the Gentse Kanalen were surveyed (Table 1 and Figure 1). The survey was performed on 28, 29 and 30 March in collaboration with the Provincial Fisheries Comity, the Provincial Centre for Environment Research and the ANB, all from Oost-Vlaanderen. Fish assemblage data were obtained by electric fishing from a boat or while wading using a 5 kW generator (DEKA 7000) with an adjustable output voltage ranging from 300 to 500 V. The pulse frequency is 480 Hz. In addition we placed some fyke nets along the banks of some sites for a period of two days. The locations and methodology used are given in table 2.
Abiotic parameters were recorded, they are pH, oxygen concentration, conductivity, current velocity and temperature (Table 3). Fish data include species, individual total length and weight (Tables 4 till 9). The Index of Biotic Integrity (IBI) was calculated (Table 10).
Nine species were collected in the Isabellawatering: three-spined stickleback, roach, bream, Prussian carp, carp, eel, rudd, pike and ide. This waters scores on average a moderate water quality.
In the Zwarte Sluisbeek eleven species were collected: three-spined stickleback, perch, roach, bream, Prussian carp, white bream, eel, ruffe, rudd, pike and pike perch. IBI scores are lower than for the Isabellawatering and on average the water quality is poor.
In the Nieuwe Kale ten species were collected: three-spined stickleback, roach, bream, Prussian carp, carp, white bream, eel, rudd and ide. The water quality is also poor.