Rehabilitation of Mediterranean animal forests using gorgonians from fisheries by‐catch

Abstract

The assessment of effective and affordable restoration interventions is pivotal to developing new tools to mitigate habitat loss and enhance natural recovery. Gorgonians create important three-dimensional habitats in the Mediterranean Sea providing several ecosystem services associated with coralligenous reefs. Transplantations of the octocorals Eunicella cavolini, Eunicella singularis, and Paramuricea clavata were carried out at the site impacted by the wreck of the Costa Concordia in 2012. A total of 135 by-caught gorgonians, caught in the gears of local artisanal fishermen or found lying on the seabed by SCUBA divers, were transplanted on impacted coralligenous reefs between 20 and 35 m depth and monitored for 2.5 years. A high survival rate (82.1%) was recorded, with main losses attributable to the detachment of the organisms from the substrate rather than death of the colonies. Eunicella cavolini transplanted colonies and natural colonies used as controls were monitored and showed similar, and seasonally influenced, growth and healing rates. Epibiosis and necrosis events were reported in both transplanted and natural colonies during summer, highlighting the sensitivity of the species to thermal stress. The present study emphasizes the importance of a management framework as a stepping-stone to achieve effective restoration outcomes, including the removal of pressures that caused changes in natural communities and the participation of local stakeholders. The effectiveness of the methods and procedures proposed in this work allowed the restoration activities to continue at a larger scale during summer and autumn 2020.

Testing Transplantation Techniques for the Red Coral Corallium rubrum

“…The survival rates of the presented techniques are similar to the ones from transplantation experiments carried out with Mediterranean gorgonian species (30-98% of survival) [40][41][42][43]56,57]. However, they are lower than the average reported for previous C. rubrum experiments (71.5%), all conducted in an erected position, suggesting the inclination of the substrate can strongly affect the survival of transplants.…”

“…In addition, Corallium rubrum health can be negatively affected by rapidly growing stressors such as ocean acidification [23] and microplastic pollution [38], but its resilience seems to be enhanced when colonies grow in a high-biodiversity environment [39]. Research efforts on Mediterranean octocoral restoration techniques increased during the past decade including the investigation of transplantation methods [40][41][42][43] to define the best techniques to restore damaged coralligenous outcrops, one of the most vulnerable and fragile marine habitats in the Mediterranean Sea.…”

Feasibility of the Sabellarid Reef Habitat Restoration

“…A crucial issue for the success of this transplant experiment is the effective anchoring of the translocation units able to persist to local hydrodynamic conditions and avoid detachment. The underwater fixation of transplants using epoxy putty is a critical phase in transplantation experiments since transplants may be lost due to non-effective hardening of the bicomponent mixture and the relatively long time needed for its complete hardening (Casoli et al, 2021). This is particularly critical in shallow waters as in the present case study.…”

“…3 So far, some efforts have been made to restore degraded and threatened marine habitats (e.g., Boström-Einarsson et al, 2020;Cebrian et al, 2021;Montseny et al, 2021). In the Mediterranean Sea, several studies focused on the restoration of coralligenous formations (Fava et al, 2010;Forcioli et al, 2011;Montero-Serra et al, 2017;Topçu et al, 2018;Montseny et al, 2019;Pagès Escolà et al, 2020;Casoli et al, 2021), seagrass meadows (Pirrotta et al, 2015;Alagna et al, 2019;Da Ros et al, 2021;Mancini et al, 2021;Piazzi et al, 2021;Ventura et al, 2021), macroalgal forests (De La Fuente et al, 2019;Tamburello et al, 2019), and other vulnerable habitat-forming species (Baldacconi et al, 2010;Musco et al, 2017). Despite their ecological role and fragility, sabellarid reef habitats have been neglected in restoration studies so far.…”

When Scientists and Industry Technologies Mitigate Habitat Loss: The First Bioconstruction Relocation in the Mediterranean Sea

“…iii) March 2020 -April 2020. After the pipeline laying occurred between February 2020 and March 2020, the nuclei were relocated on the top of the pipeline using epoxy resin Milliput Standard Yellow-Grey type, which has been recently reported as effective and biocompatible epoxy putty to attach benthic colonial organisms (Casoli et al, 2022). The nuclei were relocated on 17 pipeline segments measuring 10 m in length close to the interfered bioconstruction from which they were removed.…”