Pedro Beca-Carretero

Spanish National Research Council | CSIC · Institute of Marine Sciences

Dear Colleagues, The conservation of healthy populations of canopy forming seaweeds and seagrasses is key to the functioning of coastal and estuarine ecosystems in addition to the goods and services that these systems provide. During the last century, canopy forming seaweeds and seagrasses have suffered significant declines in their populations, which have been attributed to local and global stressors within a context of global change (e.g., metal contamination, eutrophication, seaweed harvesting, physical damage by trawling, invasions by alien species, introduction of diseases, acidification, climate change). In recent decades, numerous actions have been developed and undertaken to reduce the anthropogenic pressures in coastal and estuarine areas, leading to an enhancement in water quality and a reduction in local anthropogenic pressures. However, despite the enhancement in environmental conditions in many cases, limited or even no recovery of canopy forming seaweed and seagrass populations has been observed. Canopy forming macrophytes are considered ecosystem engineers, as their presence alter environmental conditions, increasing habitat complexity and reducing physicochemical stresses which, on many occasions, facilitates the settlement of new recruits and other species. When populations of these species decline, negative feedbacks can occur, leading to nonlinear responses and community shifts. Once seagrass meadows or seaweed forests disappear, natural recovery can be a slow process, especially in species with limited dispersion growth or recolonization abilities, as in the case for numerous Fucales, Tilopteridales, and Laminariales species or seagrasses. In these cases, restocking, restoration, or reforestation actions can boost the recolonization process if the pressures that produced the decline of the former populations disappear or have been sufficiently reduced. In the case of marine macrophytes, considerable progress has been made over the last few decades; however, the knowledge, methodologies, and techniques to develop large-scale restoration actions are limited in comparison with terrestrial macrophytes. Considering the critical role of this knowledge for the success of the current rallying call for the protection and revival of ecosystems by the United Nations (i.e., the UN Decade on Ecosystem Restoration), which will be crucial to achieving the sustainable development goals, we are looking for contributions focused on: 1. New methodologies for the restoration of canopy forming seagrasses and seaweeds 2. Optimization of culture conditions in the laboratory 3. Selection of more resistant strains 4. Production of seeds or propagules 5. Translocation experiments 6. Restoration and/or rehabilitation experiences 7. Protocols for the monitoring of the success of restorations actions 8. Modelling approaches used to identify suitable areas for restoration and to monitor changes over long time scales 9. Regional and local studies focused on genetic connectivity of marine macrophytes with interest for restoration actions 10. Historical distribution of macrophytes with interest for restoration at scales larger than 500 km 11. Other studies that can help to increase the success of restoration actions

A multi perspective approach to Irish seagrasses ecology and habitat mapping in the light of climate change. The methods include productivity, ecophysiology, ecological niche models, and field survey.