Testing habitat suitability for shellfish restoration with small-scale pilot experiments

The global loss in ecosystem engineers has initiated calls for restoration, which includes the UN declaration of 2021-2030 as the decade of ecosystem restoration. As researchers dive into this decade it is important to consider the current state of an ecosystem to ensure restoration success. Pilot-scale restoration has been recommended by global guidelines and standards as an effective starting point for restoration to provide valuable initial information to increase efficiency and success of subsequent larger-scale restoration. To test habitat suitability, 4 t of green-lipped mussels were placed onto three 2.25 m(2) plots at five locations with differing benthic environments and assessed over 2 years. This study had a mean of 85% mussel survival at four of the five locations, while the restored shellfish in one location were completely extirpated, most likely by sea star predation. This pilot-scale restoration revealed location-specific differences that have implications for ensuring larger-scale restoration success, including mussel survival, density, and health, and recommends a timeframe of at least 18 months to properly assess habitat suitability. Overall, the results validated the efficacy of using small-scale pilot experiments to test habitat suitability and optimize location selection to maximize success and efficiency of larger-scale restoration efforts.