The Mediterranean Sea under siege: spatial overlap between marine biodiversity, cumulative threats and marine reserves

Abstract

A large body of knowledge exists on individual anthropogenic threats that have an impact on marine biodiversity in the Mediterranean Sea, although we know little about how these threats accumulate and interact to affect marine species and ecosystems. In this context, we aimed to identify the main areas where the interaction between marine biodiversity and threats is more pronounced and to assess their spatial overlap with current marine protected areas in the Mediterranean. Mediterranean Sea.\ud We first identified areas of high biodiversity of marine mammals, marine turtles, seabirds, fishes and commercial or well-documented invertebrates. We mapped potential areas of high threat where multiple threats are occurring simultaneously. Finally we quantified the areas of conservation concern for biodiversity by looking at the spatial overlap between high biodiversity and high cumulative threats, and we assessed the overlap with protected areas.\ud Our results show that areas with high marine biodiversity in the Mediterranean Sea are mainly located along the central and north shores, with lower values in the south-eastern regions. Areas of potential high cumulative threats are widespread in both the western and eastern basins, with fewer areas located in the south-eastern region. The interaction between areas of high biodiversity and threats for invertebrates, fishes and large animals in general (including large fishes, marine mammals, marine turtles and seabirds) is concentrated in the coastal areas of Spain, Gulf of Lions, north-eastern Ligurian Sea, Adriatic Sea, Aegean Sea, south-eastern Turkey and regions surrounding the Nile Delta and north-west African coasts. Areas of concern are larger for marine mammal and seabird species.\ud These areas may represent good candidates for further research, management and protection activities, since there is only a maximum 2% overlap between existing marine protected areas (which cover 5% of the Mediterranean Sea) and our predicted areas of conservation concern for biodiversity

From the Levant to Gibraltar: A Regional Perspective for Marine Conservation in the Mediterranean Sea

“…Literature on MPA design and management highlights the importance of: (1) connectivity when reserves are small and representation among eco-regions (Adulla et al 2008;Guarderas et al 2008;Gaines et al 2010); (2) suitable management regimes (e.g., Friedlander et al 2003;Vella et al 2009;Olsen et al 2011); and (3) MPA distribution vis-á-vis areas of cumulative impacts (e.g., Planes et al 2000;Coll et al 2011). The first issue assumes principles of biological conservation, especially for the marine environment (Gaines et al 2010).…”

“…What constitutes an MPA is a subject not sufficiently dealt with by most past inventories of MPAs in the Mediterranean (Abdulla et al 2008;Coll et al 2011) or in other parts of the world (e.g., Guarderas et al 2008;Weeks et al 2010), yet it is fundamental for assessing the extent of protection in order to improve on it. 1 Variability in definitions impedes assessment of large-scale networks as each country, or region, focuses on varied landscape types and a variety of goals and purposes for their MPAs (Gaines et al 2010).…”

“…This can provide insights to protection tendencies, i.e., whether or not PAs tend to be accessible to nearby populations or whether they are located in pristine, undisturbed areas far from centers of human activities. Documentation of MPA coverage in the Mediterranean that considers human impact levels fails to consider terrestrial activities (e.g., Coll et al 2011) yet the synthesis of marine and terrestrial layers of human impacts is important. Integrative approaches such as ecosystem-based management, integrated coastal zone management and marine spatial planning (MSP) call for the crossing of land and sea boundaries (Olsen et al 2011;Portman and Fishhendler 2011).…”

Evaluating the potential for transboundary management of marine biodiversity in the Western Indian Ocean

“…Political and ecological regions outside the WIO show similar political complexities, where multiple countries, which are highly diverse socio-economically, share marine space and species. For example, the Mediterranean Sea has high diversity, is shared by 20 countries, and is subject to multiple anthropogenic threats (Coll et al 2012). While both the Mediterranean Sea and the WIO incorporate many countries of varying economic power and political organisation, there are significant differences between the two regions.…”

Exchange Dynamics Reveal Significant Accumulation of Dimethylated Sulfur by Mediterranean Benthic Communities

“…However, rates of biogeochemical processing remains a grand challenge in marine science (Achterberg, 2014), and deficiencies in observational data and multidisciplinary research strategies in the Mediterranean limits our modeling capacity for the region (De Madron et al, 2011). Acute anthropogenic pressures that threaten the long-term survival of Mediterranean coastal and shelf benthic ecosystems (Coll et al, 2010(Coll et al, , 2012 further call for a detailed understanding of coastal / shelf biogeochemistry (Doney, 2010). The impact of long-term projected climate change on these ecosystems is likely to be complex and interactive (Lejeusne et al, 2010)-some species may be "winners" (e.g., seagrasses, fleshy macroalgae), whilst others may be "losers" (e.g., calcifying macro-and microorganisms) (Kroeker et al, 2013).…”