The quality of IMARES' acoustic surveys proved quite unstable in recent years despite extra effort in this field to bring this instability down. The amount of involved scientists in acoustics has been small compared to demersal survey work. Therefore scientific standards of acoustic surveys are relatively low compared resulting in poor standardisation and minimal transparency. Highly specialised technical work made it even more difficult to exchange scientists within IMARES and the quality of acoustic surveys proved to be very sensitive to loss or change in personnel. This situation improved drastically in 2008 when more scientists got involved in acoustic projects and more effort was put in standardisation.