Downslope processes, deep ventilation and meridional overturning circulation

The processes governing the continental shelf break and deep ocean interactions are crucial to an understanding of the global climate system. In particular, downslope processes, deep ocean ventilation and meridional oceanic overturning circulation control the main exchange between the Southern Ocean and the Atlantic, Indian and Pacific Oceans. However, the Southern Hemisphere is often given too little weight in our analyses and this leads to an underestimation of the role of these processes in global climate evolution at the right time scale

Geographic distance, water circulation and environmental conditions shape the biodiversity of Mediterranean rocky coasts

11 páginas, 2 tablas, 3 figuras.Ecological connectivity is important for effective marine planning and biodiversity conservation. Our aim was to identify factors important in influencing variation in benthic community structure on shallow rocky reefs in 2 regions of the Mediterranean Sea with contrasting oceanographic regimes. We assessed beta (β) diversity at 146 sites in the littoral and shallow sublittoral from the Adriatic/Ionian Seas (eastern region) and Ligurian/Tyrrhenian Seas (western region) using a null modelling approach to account for variation in species richness. The distance decay relationship between species turnover within each region and geographic distance by sea was determined using generalised linear models. Mantel tests were used to examine correlations between β diversity and connectivity by ocean currents, estimated from Lagrangian dispersal simulations. Variation in β diversity between sites was partitioned according to environmental and spatial components using a distance-based redundancy approach. Species turnover along a gradient of geographic distance was greater by a factor of 3 to 5 in the western region than the eastern region, suggesting lower connectivity between sites. β diversity was correlated with connectivity by ocean currents at both depths in the eastern region but not in the western region. The influOPEN ACCESS ence of spatial and environmental predictors of β diversity varied considerably between regions, but was similar between depths. Our results highlight the interaction of oceanographic, spatial and environmental processes influencing benthic marine β diversity. Persistent currents in the eastern region may be responsible for lower observed β diversity compared to the western region, where patterns of water circulation are more variable.This work was supported by the European Community’s 7th Framework Programme (FP7/ 2007−2013) under Grant Agreement No. 287844 for the project ‘Towards COast to COast NETworks of marine protected areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential (CoCoNet)’.Peer reviewe

An integrated assessment of the Good Environmental Status of Mediterranean Marine Protected Areas

Este artículo contiene 11 páginas, 2 figuras, 2 tablas.Local, regional and global targets have been set to halt marine biodiversity loss. Europe has set its own policy targets to achieve Good Environmental Status (GES) of marine ecosystems by implementing the Marine Strategy Framework Directive (MSFD) across member states. We combined an extensive dataset across five Mediterranean ecoregions including 26 Marine Protected Areas (MPAs), their reference unprotected areas, and a no-trawl case study. Our aim was to assess if MPAs reach GES, if their effects are local or can be detected at ecoregion level or up to a Mediterranean scale, and which are the ecosystem components driving GES achievement. This was undertaken by using the analytical tool NEAT (Nested Environmental status Assessment Tool), which allows an integrated assessment of the status of marine systems. We adopted an ecosystem approach by integrating data from several ecosystem components: the seagrass Posidonia oceanica, macroalgae, sea urchins and fish. Thresholds to define the GES were set by dedicated workshops and literature review. In the Western Mediterranean, most MPAs are in good/high status, with P. oceanica and fish driving this result within MPAs. However, GES is achieved only at a local level, and the Mediterranean Sea, as a whole, results in a moderate environmental status. Macroalgal forests are overall in bad condition, confirming their status at risk. The results are significantly affected by the assumption that discrete observations over small spatial scales are representative of the total extension investigated. This calls for large-scale, dedicated assessments to realistically detect environmental status changes under different conditions. Understanding MPAs effectiveness in reaching GES is crucial to assess their role as sentinel observatories of marine systems. MPAs and trawling bans can locally contribute to the attainment of GES and to the fulfillment of the MSFD objectives. Building confidence in setting thresholds between GES and non-GES, investing in long-term monitoring, increasing the spatial extent of sampling areas, rethinking and broadening the scope of complementary tools of protection (e.g., Natura 2000 Sites), are indicated as solutions to ameliorate the status of the basin.This article was undertaken within the COST Action 15121 MarCons (http://www.marcons-cost.eu, European Cooperation in Science and Technology), the Interreg MED AMAre Plus (Ref: 8022) and the project PO FEAMP 2014-2020 Innovazione, sviluppo e sostenibilita ` nel settore della pesca e dell’acquacoltura per la Regione Campania (ISSPA 2.51). M.C.U., A.B. have been funded by the project MEDREGION (European Commission DG ENV/MSFD, 2018 call, Grant Agreement 110661/ 2018/794286/SUB/ENV.C2). Aegean Sea data were retrieved from the project PROTOMEDEA (www.protomedea.eu), funded by DG for Marine Affairs and Fisheries of the EC, under Grant Agreement SI2.721917. JB acknowledges support from the Spanish Ministry of Science and Innovation (Juan de la Cierva fellowship FJC 2018-035566-I).With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S).Peer reviewe