Conservation and restoration of marine forests in the Mediterranean Sea and the potential role of Marine Protected Areas

Abstract

Cystoseira species are some of the most important marine ecosystem-engineers, forming extended canopies comparable to land forests. Such forests are sensitive to human disturbances, like the decrease in water quality, the coastal development and the outbreak of herbivores. Conspicuous historical declines have been reported in many regions and several Cystoseira species are presently protected by European Union (EU) environmental policies. The aim of this work was to synthesize the conservation perspectives of Cystoseira forests in the Mediterranean Sea, focusing on the opportunities offered by artificial restoration and highlighting the potential role of Marine Protected Areas (MPAs). MPAs give a better protection to healthy forests than non-managed sites and may be a source of propagules for natural recovery and/or for non-destructive artificial restoration of nearby damaged forests. MPAs lacking Cystoseira forests may also represent preferential sites for reforestation. We proposed a flow-chart for the conservation and a reasoned restoration of Cystoseira in the Mediterranean Sea. The successful conservation of Cystoseira forests is still possible, via raising public awareness on the role of Cystoseira and reducing human impacts on coastal ecosystems. Such actions have to be coupled with more specific large-scale management plans, encompassing restoration actions and enforcement of protection within MPAs.

Tropicalization may invert trophic state and carbon budget of shallow temperate rocky reefs

“…In light of this present and looming threat, we urge to conserve reef functioning by reducing grazing through protection of predators and targeted fishing on spreading herbivores (Giakoumi et al, ). Marine protected areas (MPAs) were shown to increase the resilience of algal forests (Bates et al, ; Gianni et al, ). While our study was conducted in an MPA, it has not been well enforced, and surfcasting is still allowed, rendering the MPA mostly ineffective.…”

European seaweeds under pressure: Consequences for communities and ecosystem functioning

“…Trials in implementing dedicated artificial reefs, especially designed for seaweed key species (e.g. Choi et al, 2006;Seaman, 2007), as well as transplantation efforts (Susini et al, 2007;Gianni et al, 2013), are usually encouraging and should be part of restoration policies. Such efforts, however, may not have the same effect in mitigating impacts of global stressors such as global warming and biotic homogenization (with biological invasions as resilient biological pollution).…”

Thermal tolerance of Mediterranean marine macrophytes: Vulnerability to global warming

“…Thermal tolerance experiments were conducted using six Mediterranean macrophyte species, consisting of two seagrasses Canary and Cape Verde Islands (Short et al, 2010). Cystoseira compressa is a common brown seaweed inhabiting rocky shores of the Mediterranean coasts at 0-1 m depth and plays a central role as an engineering species on rocky shores (Gianni et al, 2013;Thibaut, Pinedo, Torras, & Ballesteros, 2005). Caulerpa prolifera is distributed across subtropical and tropical regions (Varela-Álvarez et al, 2015).…”