MOM : konsept og revidert utgave av overvåkingsprogrammet 1997

This report describes a management system (MOM) which can be used to regulate the environmental effects of marine fish farming, ensure good rearing conditions for the fish and avoid pollution. The latter part of the report contains a manual for the monitoring programme. MOM is based on a general concept for regulating environmental impact and its main elements are: simulation of impact (model), control of the impact (monitoring programme), and permissible limits for environmental impact (environmental quality standards (EQS)). Two terms link the three elements: the degree of exploitation and the leve1 of monitoring. Through the two terms the monitoring effort is adjusted according to the environmental impact on the site. MOM is based on agreement that fish farm sites should not deteriorate over time and that the impact must not lead to the extinction of the benthic infauna beneath the farm. The system recognizes three degrees of exploitation of a site, each of which is linked to a leve1 of monitoring. If the third degree of exploitation is exceeded the site is being overexploited. The monitoring programme consists of three types of investigation: A, B and C. The A-investigation is a simple sedimentation measurement beneath the net pens. The B-investigation is a characterization of the sediment conditions beneath the fish farm, and a set of EQS has been set in MOM. The C-investigation is a sediment fauna study and general EQS for infauna investigations are used. MOM distinguishes between three zones of impact around a fish farm: the local, the intermediate and the regional impact zones. The environmental impact is largest in the local impact zone where the larger particles settle. Here both the A-, the B- and the C-investigations are used. In the intermediate impact zone the impact is less and primarily due to the sedimentation of smaller particles. This zone is monitored by the B- and C-investigations. In the regional impact zone the more sensitive areas are monitored by the C-investigation. The latter part of this report is a manual for the monitoring programme including EQS. It is essential that the persons who perform the B-investigation should have experience of sediment investigations. The C-investigation can only be performed by specialists. MOM may be part of the scheme for regulating marine fish farming. The system is intended to keep the environmental impact from fish farming within agreed limits and avoid detrimental effects. Improved environment