Special protection needs
In Denmark, blue mussel fishery is conducted in the following Natura 2000 areas: Lovns Broad and Løgstør Broad in the Limfjord as well as in the Little Belt. Currently, the Natura 2000 area Nissum Broad in the Limfjord is open for a small-scale fishery for the European oyster.
In Natura 2000 areas, eelgrass and reefs are fully protected from blue mussels and oysters fishery. Furthermore, the fishery has to be sustainable for both the blue mussel and oyster populations.
The Danish Ministry for Environment and Food is the responsible authority for fishery management and regulation of all Natura 2000 areas at sea, and thereby for ensuring the right balance between development of the industry and environmental concerns. In Denmark, fishery for blue mussels and European oysters can only be conducted if the fisherman has a specific permit. The permit is issued yearly by the Danish Agricultural Agency/ Ministry for Environment and Food.
Before fishing activity can commence within a Natura 2000 area, an environmental impact assessment has to be conducted. An impact assessment means that the effect of the applied fishery is examined. Specifically, it is examined what impact the requested fishing activity will have on the designated species and habitats present in the current Natura 2000 area, as well as how the activity is compatible with the environmental goals given in water and nature management plans.
Thus, fishing for blue mussels and oysters should not be an obstacle for reaching and/ or maintaining a ‘favorable conservation status’ of the designated species and habitats in the Natura 2000 areas such as sea birds, marine mammals, reefs (H1170/ H1180), sandbanks (H1110), large shallow inlets and bays (H1160).
The National Institute for Aquatic Resources, Danish Technical University (DTU Aqua) conducts the environmental impact assessments, while the Ministry for Environment and Food makes the final decision whether a fishing permit can be issued. It is also assessed under which conditions the applied fishery must be conducted. In the current permits it is e.g. required that GPS and sensor equipment is used (Black-box system), that reefs and eelgrass are fully protected and larger stones are relayed.
In the Danish Mussel Policy, the acceptable level for cumulative effect has been set at 15 percent. Thus, fishing activity in Natura 2000 can only be allowed if the total effected area is less than 15 percent. Cumulative effect is calculated according to the regeneration time for a range of key ecosystem components such as blue mussel stock, eelgrass (no effect on eel grass is allowed), macro algae and bentic fauna. The area affected by blue mussel fishing is based on collected GPS data from the electronic monitoring devices (Black-box system). All fishing activities, including fishing for star fish and other fishing activities which imply the use of bottom contacting gear must be included in the calculation of the cumulative area effects. The Danish model for cumulative effects contains calculation of fishery effects for a period of five years. The cumulative effect is used in assessing ‘Integrity’ and is part of the environmental impact assessment, which DTU Aqua carries out.
Here you can read more about the Danish Mussel Policy (in Danish)
The calculation of the cumulative effects is essential for the assessment of the impact of fishery for blue mussels of the Natura 2000 areas. The cumulative effects are, however, supplemented by a range of criteria to be assessed regarding the impact on habitat integrity before a fishery license is issued. These criteria comprise of: cumulative effects of past seasons (area affected), rocks/stones brought ashore, number of vessels per area, other fishing activities in the area and oxygen depletion.