First Restoration Experiment for Gongolaria barbata in Slovenian Coastal Waters. What Can Go Wrong?

Abstract

The global decline of brown algal forests along rocky coasts is causing an exceptional biodiversity loss. Regardless of conservation efforts, different techniques have been developed for large-scale restoration strategies in the Mediterranean Sea. In this study we tested ex situ pilot restoration of Gongolaria barbata (=Treptacantha barbata) for the first time in Slovenian coastal waters. Healthy apical fronds of the species were collected and the development of recruits on clay tiles was followed under laboratory conditions for 20 days. Despite the experimental difficulties experienced, especially due to the lack of antibiotics to prevent the growth of the biofilm, G. barbata recruits were outplanted in the sea on two concrete plates with 48 tiles each, protected by purpose-built cages to avoid grazing by herbivorous fish. The high survival rate of juveniles after four months in the field (89% of the tiles on the plate that was constantly protected) suggests that outplanting G. barbata is an operable approach for restoration efforts in the northern Adriatic Sea. Our first experiment in Slovenian coastal waters provides new information for the optimization of the best practices during the laboratory cultivation and addresses the early steps of restoration and introduction of young thalli in the natural environment.

A Roadmap for the Restoration of Mediterranean Macroalgal Forests

“…As demonstrated by Marion and Orth (2010), seagrass seed production in donor forests can vary dramatically from year to year, also due to climate change (Bevilacqua et al, 2019). Likewise, abnormal winter temperatures and exceptional wind periods (Bevilacqua et al, 2019;Orlando-Bonaca et al, 2021;Savonitto et al, 2021) lead to serious biological anomalies and the loss of the reproductive potential of Gongolaria barbata. Therefore, it is crucial to act as fast as possible during the reproductive season of the selected species to collect an appropriate number of mature apexes.…”

Mediterranean rocky reefs in the Anthropocene: Present status and future concerns

“…Yet, significant research is emerging, aiming at identifying both the feasibility and self-sustainability of restoration efforts as well as adequate techniques and spatial layouts (Claudet and Fraschetti, 2010). Concerning rocky habitats, most of these research efforts have focused on the recovery of macroalgal stands (Verdura et al, 2018;Guarnieri et al, 2020;Orlando-Bonaca et al, 2021;Savonitto et al, 2021). Recent efforts have also focused on the restoration of populations of invertebrate species, such as the scleractinian coral Astroides calycularis (Musco et al, 2017), the bryozoan Pentapora fascialis (Pagès-Escolà et al, 2020), and the limpet Patella ferruginea (Ferranti et al, 2021), with many novel technologies and approaches emerging, such as or the use of electro-mineral accretion for enhancing the settlement of the red coral Corallium rubrum (Benedetti et al, 2011).…”

Thermal vulnerability of the Levantine endemic and endangered habitat-forming macroalga, Gongolaria rayssiae: implications for reef carbon

“…Since the beginning of the 20 th century, a large number of studies have been conducted on macrophyte communities that focused mostly on the Western Mediterranean basin (Serio et al, 2006;Mangialajo et al, 2008a;Ballesteros et al, 2009;Cormaci et al, 2012;Tasķin et al, 2012;Vergeś et al, 2014;Thibaut et al, 2015;Mineur et al, 2015;Ivesǎ et al, 2016;Mancuso et al, 2018;Valdazo et al, 2020;Medrano et al, 2020;Orlando-bonaca et al, 2021). In contrast, information on distribution, dynamics, and ecology of these forests in the Eastern basin and specifically in the Levantine Sea, is scarce.…”