The Status of Coastal Benthic Ecosystems in the Mediterranean Sea: Evidence From Ecological Indicators

Abstract

The Mediterranean Sea is subject to multiple human pressures increasingly threatening its unique biodiversity. Spatially explicit information on the ecological status of marine ecosystems is therefore key to an effective maritime spatial planning and management, and to help the achievement of environmental targets. Here, we summarized scientific data on the ecological status of a selection of marine ecosystems based on a set of ecological indicators in more than 700 sites of the Mediterranean Sea. For Posidonia oceanica seagrass beds, rocky intertidal fringe, and coastal soft bottoms, more than 70% of investigated sites exhibited good to high ecological conditions. In contrast, about two-thirds of sites for subtidal rocky reefs were classified to be in moderate to bad conditions, stressing the need for prioritizing conservation initiatives on these productive and diverse environments. Very little quantitative information was available for the southern Mediterranean Sea, thus monitoring programs and assessments in this area are essential for a representative assessment of the health of marine coastal ecosystems in the whole basin. This overview represents a first step to implement a baseline that, through georeferenced data on ecological status, could help identifying information gaps, directing future research priorities, and supporting improvements to spatial models of expected cumulative impacts on marine ecosystems.

A Marine Biodiversity Observation Network for Genetic Monitoring of Hard-Bottom Communities (ARMS-MBON)

“…A key limitation to improved understanding of the impact of human activities on marine ecosystems is the ability to generate comparative biological time-series data at a large spatial scale (Richardson and Poloczanska, 2008;Dailianis et al, 2018;Guidi et al, 2020). There is therefore strong pressure on biological monitoring programs to implement standardized and scalable methods to assess status and change in marine biological communities in order to support marine research and policy (Bourlat et al, 2013;Borja et al, 2016;Danovaro et al, 2016;Bean et al, 2017;Bevilacqua et al, 2020). These methods need to fulfill several important criteria, including the implementation of common standards and protocols and to generate material samples and data that are FAIR: findable, accessible, interoperable, and re-usable (Tanhua et al, 2019).…”

Are Mediterranean marine threatened species at high risk by climate change?

“…To this direction, the neritic zone represents a hotspot of human pressure (Coll et al, 2012), and high climate risk species are predicted to occur in higher concentrations in the Mediterranean neritic zone based on our assessment. Although two‐thirds of subtidal rocky reefs are classified to be in moderate to bad conditions, a great part of the Mediterranean coastal environments are still considered to be in relatively good ecological status (Bevilacqua et al, 2020). This highlights the need and opportunity for integrated conservation planning, including conflict‐solving management and species monitoring under climate change challenges.…”

The impact assessment of thermal pollution on subtidal sessile assemblages: a case study from Mediterranean rocky reefs

“…The Mediterranean Sea is undergoing to increasing levels of human pressures threatening its unique marine biodiversity (Lejeusne et al, 2010;Micheli et al 2013;), with non-native species introduction and climate change being the most alarming threats to this basin due to their potential to cause regime shifts to marine ecosystems (Rilov & Galil, 2009;Mannino et al, 2017;Bevilacqua et al, 2019). Subtidal rocky reefs are of crucial importance for the functioning of coastal ecosystems and they are particularly sensitive to the ongoing environmental changes (Sala et al, 2011;Strain et al 2014), which place this marine habitat among the most endangered ones at a basin scale (Bevilacqua et al, 2020). Our findings demonstrated that thermal pollution from coastal power plants could play a role in modifying the structure of sessile assemblages on subtidal reefs.…”