Modeling Macroalgal Forest Distribution at Mediterranean Scale: Present Status, Drivers of Changes and Insights for Conservation and Management

Abstract

Macroalgal forests are one of the most productive and valuable marine ecosystems, but yet strongly exposed to fragmentation and loss. Detailed large-scale information on their distribution is largely lacking, hindering conservation initiatives. In this study, a systematic effort to combine spatial data on Cystoseira C. Agardh canopies (Fucales, Phaeophyta) was carried out to develop a Habitat Suitability Model (HSM) at Mediterranean scale, providing critical tools to improve site prioritization for their management, restoration and protection. A georeferenced database on the occurrence of 20 Cystoseira species was produced collecting all the available information from published and grey literature, web data portals and co-authors personal data. Data were associated to 55 predictor variable layers in the (ASCII) raster format and were used in order to develop the HSM by means of a Random Forest, a very effective Machine Learning technique. Knowledge about the distribution of Cystoseira canopies was available for about the 14% of the Mediterranean coastline. Absence data were available only for the 2% of the basin. Despite these gaps, our HSM showed high accuracy levels in reproducing Cystoseira distribution so that the first continuous maps of the habitat across the entire basin was produced. Misclassification errors mainly occurred in the eastern and southern part of

The Role of Sea-Urchins in Marine Forests From Azores, Webbnesia, and Cabo Verde: Human Pressures, Climate-Change Effects and Restoration Opportunities

“…Modification of continuous natural rocky platforms can reduce the development of macroalgae and reduce the habitat available for canopies colonization (Cacabelos et al, 2016). Vertical substratum slope, pollution and urbanization are the main drivers involved in the distribution of Fucales (Fabbrizzi et al, 2020), although in the Azores, limited-dispersal capacity from adults has been also cited as a relevant factor limiting its ability to colonize artificial coastal defense structures (Cacabelos et al, 2016). In fact, in Madeira, extensive development and construction in marine and coastal systems (the so-called "ocean sprawl") has destroyed some of the scarce natural rocky platforms in the island, diminishing the suitable habitat available for canopy-forming macroalgae communities.…”

Distribution of Cystoseira s. l. species in the Sea of Azov

“…Поширенню представників Cystoseira s. l. в Атлантично-Середземноморському регіоні присвячено чимало публікацій. Навіть їхній простий перелік буде завеликим, проте інформацію, що вони містять, досить повно узагальнено в роботі E. Fabbrizzi et al (2020). У той самий час, єдиною спробою узагальнення даних про поширення «цистозір» в АМ донедавна була стаття О.В.…”

Photosynthetic performances of two deep‐water canopy‐forming fucoid algae across a depth gradient: Interspecific variability and short‐term adaptation to the light environment

“…Available distribution models have recently been developed for the genera Cystoseira sensu lato (Fucales) at the Mediterranean scale by using a large amount of predictor variable layers, but Fabrizzi et al. (2020) address the necessity of assessing the distribution at the species level. To do so, we need the refinement of the spatial information of presence/absence data on each species (Fabrizzi et al., 2020) but also information about ecophysiological responses (Franco et al., 2018; Martínez et al., 2015).…”

“…(2020) address the necessity of assessing the distribution at the species level. To do so, we need the refinement of the spatial information of presence/absence data on each species (Fabrizzi et al., 2020) but also information about ecophysiological responses (Franco et al., 2018; Martínez et al., 2015).…”