Een hydrobiologische inventarisatie van sloten in het Oude Land van Strijen en de St. Anthonie-polder (Hoekse Waard)
[A hydrobiological inventory of ditches in the ‘Oude Land van Strijen’ and the St. Anthoniepolder (Hoekse Waard’]
De levende natuur , Volume 76 - Issue 12 p. 273- 279
A hydrobiological description of eight ditches in the Dutch inland polders "Oude Land van Strijen" and "St.-Anthoniepolder" (province of South-Holland) is given. The flora and macrofauna (table 2 and 3) have been studied in July and October 1971. A few chemical data (chloride-content and conductivity) of the water are presented. In the northern part of the area the percolating water is fresh due to the influence of the "Binnenbedijkte Maas", one of the few real freshwater lakes of the Deltaic region. In the southern part it is brackish due to the influence of the „Hollands Diep". The bottomprofile of the polders shows heavy river-clay poor in chalk (upper 40-100 cm) on peat. The examined ditches are hardly polluted and the water is clear. On the bottom of the ditches there is little sapropelium present and a pioneer character is conserved by cleaning the ditches yearly in late autumn. Chemical cleaning methods by herbicids are not used in these polders. The flora and fauna of the ditches are very rich as shown in table 2 and 3.