Visbestandopnames op de Damse vaart

We surveyed 5 locations of the Damse Vaart on 13, 14 and 15 June 2006 (Table 1 and Map). This was done in collaboration with the Provincial Fishery Commission and the Agency for Nature and Forestry. The Damse Vaart is a channel between Brugge and Sluis a town in the Netherlands. To catch the fish we applied on each location two methodologies (Table 2). From the boat we fished with the electric gear (DEKA 7000) both banks over a distance of 250 m and we placed on both banks fyke nets. In one site we used also seine netting. Abiotic parameters were recorded, they are pH, oxygen concentration (DO), conductivity and temperature (Table 3). Fish data include species, individual total length and weight (Tables 4 till 7). The Index of Biotic Integrity (IBI) was calculated (Table 8).

In total we caught ten different species: perch, bitterling, roach, bream, white bream, eel, ruffe, rudd, pike and tench. Roach was caught most frequently followed by perch and eel. Species diversity ranged between 5 and 9 with per site an average of 6.8.
In the stretch between Brugge and Hoeke the lowest density and diversity was found. The next stretch, from Hoeke till the Dutch border contained the highest diversity. This was also the case in 2000. The IBI scores overall poor in the first stretch and moderate in the other one. In 2000 we had 16 different species including all those caught in 2006 (minus bitterling) and Crusian carp, stone moroko, Prusian carp, carp, pike perch and grass carp. The densities and diversities in 2006 obtained by electric fishing are much lower than those obtained in 2000.