Modeling macroalgal forest distribution at Mediterranean scale : present status, drivers of changes and insights for conservation and management

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 basin, where large gaps of knowledge emerged. The most relevant drivers were the geomorphological ones, followed by anthropogenic variables proxies of pollution and urbanization. Our model shows the importance of data sharing to combine a large number of spatial and environmental data, allowing to individuate areas with high probability of Cystoseira occurrence as suitable for its presence. This approach encourages the use of this modeling tool for the prediction of Cystoseira distribution and for supporting and planning conservation and management initiatives. The step forward is to refine the spatial information of presence-absence data about Cystoseira canopies and of environmental predictors in order to address species-specific assessments.peer-reviewe

Advancing marine conservation in European and contiguous seas with the MarCons Action

Cumulative human impacts have led to the degradation of marine ecosystems and the decline of biodiversity in the European and contiguous seas. Effective conservation measures are urgently needed to reverse these trends. Conservation must entail societal choices, underpinned by human values and worldviews that differ between the countries bordering these seas. Social, economic and political heterogeneity adds to the challenge of balancing conservation with sustainable use of the seas. Comprehensive macro-regional coordination is needed to ensure effective conservation of marine ecosystems and biodiversity of this region. Under the European Union Horizon 2020 framework programme, the MarCons COST action aims to promote collaborative research to support marine management, conservation planning and policy development. This will be achieved by developing novel methods and tools to close knowledge gaps and advance marine conservation science. This action will provide support for the development of macro-regional and national policies through six key actions: to develop tools to analyse cumulative human impacts; to identify critical scientific and technical gaps in conservation efforts; to improve the resilience of the marine environment to global change and biological invasions; to develop frameworks for integrated conservation planning across terrestrial, freshwater, and marine environments; to coordinate marine conservation policy across national boundaries; and to identify effective governance approaches for marine protected area management. Achieving the objectives of these actions will facilitate the integration of marine conservation policy into macro-regional maritime spatial planning agendas for the European and contiguous seas, thereby offsetting the loss of biodiversity and ecosystem services in this region

Seascape genetics and connectivity modelling for an endangered Mediterranean coral in the northern Ionian and Adriatic seas

[Context]: Spatially heterogeneous oceanographic properties such as currents, waves, and biogeochemical gradients control the movement of gametes and larvae of marine species. However, it is poorly understood how such spatial dynamics may shape the genetic connectivity, diversity, and structure of marine populations.[Objectives]: We applied a seascape genetics framework to evaluate the relationships between marine environmental factors and gene flow among populations of the endangered Mediterranean pillow coral (Cladocora caespitosa). Methods: We modelled gene flow among locations in the Adriatic and northern Ionian Seas as a function of sea surface temperature, salinity, currents and geographic distance. Isolation by distance and isolation by resistance hypotheses were then compared using model optimization in a generalized linear mixed effects modelling framework.[Results]: Overall genetic differentiation among locations was relatively low (F = 0.028). We identified two genetic groups, with the northernmost location segregating from the rest of the locations, although some admixture was evident. Almost 25% of the individuals analysed were identified as putative migrants and a potential barrier to gene flow was identified between the northern and central-southern basins. The best gene flow models predicted that genetic connectivity in this species is primarily driven by the movement along the coastlines and sea surface currents. Conclusions: A high percentage of self-recruitment and relatively low migration rates has been detected in the studied populations of C. caespitosa. Its fragmented distribution along the coast can be predicted by stepping-stone oceanographic transport by coastal currents among suitable habitat patches.This research was funded by the European project CoCoNET ‘‘Towards COast to COastNETworks of marine protected areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential’’ from the VII FP of the European Commission (Grant Agreement No. 287844) and the Spanish Ministry of Economy and Competitiveness (Grant reference: CTM2014-57949-R)

Highly restricted dispersal in habitat-forming seaweed may impede natural recovery of disturbed populations

Cystoseira sensu lato (Class Phaeophyceae, Order Fucales, Family Sargassaceae) forests play a central role in marine Mediterranean ecosystems. Over the last decades, Cystoseira s.l. suffered from a severe loss as a result of multiple anthropogenic stressors. In particular, Gongolaria barbata has faced multiple human-induced threats, and, despite its ecological importance in structuring rocky communities and hosting a large number of species, the natural recovery of G. barbata depleted populations is uncertain. Here, we used nine microsatellite loci specifically developed for G. barbata to assess the genetic diversity of this species and its genetic connectivity among fifteen sites located in the Ionian, the Adriatic and the Black Seas. In line with strong and significant heterozygosity deficiencies across loci, likely explained by Wahlund effect, high genetic structure was observed among the three seas (ENA corrected F-ST = 0.355, IC = [0.283, 0.440]), with an estimated dispersal distance per generation smaller than 600 m, both in the Adriatic and Black Sea. This strong genetic structure likely results from restricted gene flow driven by geographic distances and limited dispersal abilities, along with genetic drift within isolated populations. The presence of genetically disconnected populations at small spatial scales (< 10 km) has important implications for the identification of relevant conservation and management measures for G. barbata: each population should be considered as separated evolutionary units with dedicated conservation efforts

Adriatic \u2018opisthobranchs\u2019 (Gastropoda, Heterobranchia): shedding light on biodiversity issues.

We herein review the Adriatic opisthobranch fauna, provide an updated checklist of 223 species and assess their distribution at regional and country levels. New Adriatic records are provided for 67 opisthobranch taxa, adding three new records for the Italian coastline, five new records for Albania, eight for Croatia and 15 for Montenegro. The presence of Hermaea bifida (Montagu, 1815), Hermaea variopicta (Costa A., 1869) and Facelina annulicornis (Chamisso &amp; Eysenhardt, 1821) is reported for the first time from anywhere in the Adriatic Sea. Including the new findings, our inventory includes 28 species from Albania, 163 from Croatia, 178 from the Italian coastline of the Adriatic, 41 from Montenegro and 74 from Slovenia. No records were available from Bosnia and Hercegovina. Ninety species (40.4%) are widespread, and were recorded from all three main divisions (Northern, Western and Eastern Adriatic), whilst 79 species (35.4%) were reported from only one of them. At sub-division levels, the Albanian inventory is the most dissimilar to the other country/regional lists, presumably because of the lack of targeted field surveys. The highest similarity is observed amongst the Western Adriatic, Croatia and the Italian Ionian coastline. Seven alien, one possible alien and three cryptogenic opisthobranchs were reliably recorded from the Adriatic Sea. The first Mediterranean records of five species were in the Adriatic Sea, of which four species have not been found elsewhere in the Mediterranean. Shipping and aquaculture are the probable pathways for most of the alien species. A steady rate of one to two alien introductions per decade since the 1970s was evident. The Northern Adriatic coasts are the most affected by alien invasions, probably due to repeated local introductions along with shellfish transfers (oysters, mussels, Manila clams), and heavy maritime transport

Data from: Contemporary genetic structure and postglacial demographic history of the black scorpionfish, Scorpaena porcus, in the Mediterranean and the Black Seas

Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level

SeaUrchin_272samples_1122markers

Tab delimited text file containing general information about 1122 2bRAD SNPs in 272 individuals. The file is organized with a first raw containing headers followed by 1122 rows containing the loci. The first 17 loci are outliers as described in the paper. Headers are: - Catalog ID: locus ID in the Stacks catalogue; - File genepop ID: locus ID in the accompanying genepop file (same as before but with the SNP position embedded in the name); - Consensus sequence: the reference sequence for the locus determined. - Num SNPs: Number of SNPs detected at the locus; - SNPs: position and alleles for all the SNPs detected at the locus; - Num Alleles: total number of alleles for the locus; - Selected SNPs: position used for population analyses; - Alleles in GENEPOP file: correspondence with the alleles in the accompanying genepop file; - 272 columns reporting the genotype for each individuals; missing genotypes are blanks

mt_POWSIM

Text file used as input for POWSIM forward-time simulations with mtDNA. The file is based on cytochrome b haplotypic frequencies in 7 Adriatic-Ionian populations (Santa Caterina di Nardò, Brindisi, Manfredonia, Lesina, Ancona, Mljet, Miramare), obtained from Maltagliati et al. (2010, Biological Journal of the Linnean Society, 100, 910–923. Rename the file to POWSIM.IN to run POWSIM

SNPs_POWSIM

Text file used as input for POWSIM forward-time simulations with SNPs. The file is based on 8 Adriatic-Ionian populations and 1122 loci. Rename it to POWSIM.IN and use powsim_b to run POWSIM

Management priorities for marine invasive species

Managing invasive alien species is particularly challenging in the ocean mainly because marine ecosystems are highly connected across broad spatial scales. Eradication of marine invasive species has only been achieved when species were detected early and management responded rapidly. Generalized approaches, transferable across marine regions, for prioritizing actions to control invasive populations are currently lacking.Here, expert knowledge was elicited to prioritize 11 management actions for controlling 12 model species, distinguished by differences in dispersion capacity, distribution in the area to be managed, and taxonomic identity. Each action was assessed using five criteria (effectiveness, feasibility, acceptability, impacts on native communities, and cost), which were combined in an ‘applicability’ metric. Raising public awareness and encouraging the commercial use of invasive species were highly prioritized, whereas biological control actions were considered the least applicable. Our findings can guide rapid decision making at an early stage when reducing managers’ response time is critical.JRC.D.2-Water and Marine Resource