In the Mediterranean Sea, brown algae belonging to the Cystoseira genus play a valuable role as foundation species. Due to evidences of regression/loss of the habitats of these species caused by the interplay of human and climatic disturbances, active restoration measures have been encouraged by EU regulations. In particular, non-destructive restoration techniques, which avoid the depletion of threatened species in donor populations, are strongly recommended.

This study reports the results of the first ex situ outplanting experience of Cystoseira amentacea var. stricta, implemented in the Cinque Terre Marine Protected Area (NW Mediterranean). A total of 400 clay tiles, hosting approximately three mm-long germlings of C. amentacea, were fixed to the rocky shore with screws. The tiles were monitored for the next 2 months by photographic sampling, assessing survival, cover and growth. Additional sampling was performed 6 months after tile deployment, after an unprecedented storm surge.

The obtained results show that after 2 months, over 40% of the tiles were covered with Cystoseira juveniles, which reached approximately eight mm in total length. The tiles that survived the storm hosted three to six cm-long juveniles.

The authors state that their findings show that outplanting of midlittoral canopy-forming species is a feasible approach for restoration efforts. It is concluded that the results of the study are strongly encouraging for the implementation of restoration actions for C. amentacea on a large scale, in light of EU guidelines.

De La Fuente et al. (2019) First ex situ outplanting of the habitat-forming seaweed Cystoseira amentacea var. stricta from a restoration perspective. PeerJ 7:e7290.