The third inventory of the demersal fish fauna by NIOZ took place in 1974. Main goal of these cruises in the Marsdiep basin was the habitat selection and depth distribution of juvenile plaice. The programme was supervised by dr. Jenne J. Zijlstra and beam trawl sampling took place with rubber dinghies in the intertidal and in deeper waters with RV Ephyra. All the fish were identified and measured on board. In total 8 cruises each of about 20 hauls were carried out.