Abstract

This work evaluated the potential effect of wild seed collection systems used for the provision of seeds for mussel farming on wild populations of the mussel Mytilus chilensis in Reloncavi fjord, one of the most relevant seed provider ecosystems in southern Chile. For this purpose, a long line effort index (LEI) was defined as the ratio between the length of deployed seed collection longlines (unit of effort) and the length of the fjord coastline exhibiting suitable substrate for mussels within a radius of 250 to 500 m across 46 sampling sites. The effect of LEI was subsequently evaluated on local mussel populations, showing that, despite a high degree of variability, results suggest a negative effect of the increase in the index within a radius of 500 m (LEI500) on density, recruitment, proportion of occupied area and maximum depth of the wild mussel populations studied. LEI500 value >2 seems to represent a threshold for seed collection negative effects on wild populations of M. chilensis in the fjord. We suggest that this index should be evaluated as a management measure of wild seed collection, which may be further refined through feedback from permanent monitoring of mussel beds and mussel seed collection. Considering the importance of mussel aquaculture and its high dependence on ecosystem services, the implementation and maintenance of monitoring, together with the implementation of management measures is essential to balance the needs of the mussel farming farmers with those of conserving and protecting marine ecosystems.