Cold-water corals (CWC) habitats dwell on continental shelves, slopes, seamounts, and ridge systems around the world’s oceans from 50 to 4000 m depth, providing heterogeneous habitats which support a myriad of associated fauna. These highly diverse ecosystems are threatened by human stressors such as fishing activities, gas and oil exploitation, and climate change.

This review, by means of a systematic literature search, aims to identify CWC restoration challenges, assess the most suitable techniques to restore them, and discuss future perspectives. Outcomes from the few restoration actions performed to date on CWCs, which have lasted between 1 to 4 years, provide evidence of the feasibility of coral transplantation and artificial reef deployments.

The authors state that there is still a lack of knowledge about the biological, ecological and habitat characteristics of CWC species, highly needed to aid the development of effective restoration measures. It is also stressed that scientific efforts should focus on testing novel and creative restoration techniques, especially to scale up to the spatial and temporal scales of impacts.

It is concluded that to ensure the long-term viability and success of any restoration action it is essential to include holistic and long-term monitoring programs, and to ideally combine active restoration with natural spontaneous regeneration strategies such as the implementation of deep-sea marine protected areas (MPAs). According to the review, such a combination of passive and active restoration approaches with involvement of local society would be the best optimal option to achieve and ensure CWC restoration success.

Montseny et al (2021) Active ecological restoration of cold-water corals: techniques, challenges, costs and future directions 8:621151.