47 research outputs found

    Long-term scenarios of mercury budgeting and exports for a Mediterranean hot spot (Marano-Grado Lagoon, Adriatic Sea)

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    The Marano-Grado Lagoon (MGL) is extensively contaminated by mercury (Hg) from local sources and long-term (500 years) tidally delivered inputs from the Idrija Hg mine (Slovenia) through Isonzo River suspended loads. A multibox WASP-7 (Water Analysis Simulation Program) model was used to simulate the long-term dynamics of the mercury cycle in the MGL. Scenario simulations were used to compute changes in the system over 100 years. Present and future Hg concentrations in water, sediment, and Hg budgets were compared, including evasion and MeHg inputs to the Mediterranean Sea, based on climate changes and mercury capping in tributary rivers. Using the Ref baseline scenario, the model computes a general decrease in HgT of 13% in the water column and of 80% in sediment and a strong MeHg increase in sediment (+73%). The net sea export of HgT decreases by 77% to up to 48 kg/y while MeHg increases by 10% to up to 0.63 kg/y. The lagoon sediment recovery time of HgT up to a target level of 0.3 mg/kg is computed over 570 years for surface sediments (1750 for subsurface sediments). When removing Hg from boundaries, the same target value for surface sediments is reached within 110 years

    Cultural Ecosystem Services Provided by Coralligenous Assemblages and Posidonia oceanica in the Italian Seas

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    Posidonia oceanica meadows and coralligenous reefs are two Mediterranean ecosystems that are recognized as suppliers of valuable ecosystem services (ESs), including cultural services. However, valuation studies on these ecosystems are scarce; rather, studies have mainly focused on provisioning and regulating services. Here we focus on the cultural services provided by P. oceanica and coralligenous assemblages by addressing a specific group of users. Through an online survey submitted to Italian scuba divers, we assess their willingness to pay for a dive in the two ecosystems and how their preferences will change under different degradation scenarios. Diving preferences are assessed using a discrete choice experiment. The results confirmed that ecological knowledge is associated with higher ecosystem values. Moreover, the results confirm and assess how a high degradation of coralligenous and P. oceanica habitats would reduce the value of the underwater environment, by decreasing scuba diver satisfaction and their rate of return visits. Considering a 50% reduction in the coverage of keystone species, the marginal willingness to pay decreased by approximately (sic)56 and (sic)18 for coralligenous reefs and P. oceanica, respectively, while the willingness to pay decreased by approximately (sic)108 and (sic)34, respectively, when there was a total reduction in coverage. Our results can be used to support marine ecosystem based management and the non-destructive use of Mediterranean Posidonia oceanica meadows and coralligenous reefs

    direct and indirect impacts of marine acidification on the ecosystem services provided by coralligenous reefs and seagrass systems

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    Increasing emissions of CO2 and the resultant ocean acidification (OA) will have large implications for the marine ecosystems sustained by habitat-forming species and their related ecosystem services (ES), with potentially significant impacts on human well-being. Here, we provide an assessment of the direct and indirect impacts of OA on ES. The changes in the functioning of coralligenous reefs and Posidonia oceanica meadows promoted by OA were investigated by i) synthesizing current knowledge into conceptual models. The models were then used to, ii) assessing the impacts of exposure of the selected taxa at the acidification level associated with two CO2 emission scenarios and iii) using the conceptual model outputs to project the cascading impacts from individuals to functions to ES.The results highlight that the combination of the direct and indirect effects of acidification will alter many functions of both coralligenous and P.oceanica systems, triggering habitat modifications and the loss of highly valuable ES.While the exact timing of the expected changes will depend on the severity of the emission scenarios, significant and hardly reversible changes can be expected as quickly as a few decades under the business-as-usual scenario, and many ecosystem services are at risk even under much more conservative scenarios. Keywords: Ocean acidification, Posidonia oceanica, Coralligenous, Ecosystem services, Mediterranean sea, Conceptual model

    Nephrops norvegicus in the Adriatic Sea: Connectivity modeling essential fish habitats and management area network

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    AbstractKnowledge of connectivity among subpopulations is fundamental in the identification of the appropriate geographical scales for stock status evaluation and management, the identification of areas with greater retention rates, and space‐based fisheries management. Here, an integration of hydrodynamic, biological, and habitat models results is used to assess connectivity and support the definition of essential fish habitats (EFH) in the Adriatic Sea, with reference to Nephrops norvegicus, an important benthic commercial resource, the recruitment of which is strongly related to larval dispersal from spawning to recruitment areas. We explored oceanographic and biological connectivity in the Adriatic Sea under a wide and representative variety of oceanographic conditions (winters 2006–2012) by tracking 3D trajectories of larvae released from different areas. We used a Lagrangian model that features a specific larval behavior module with explicit dependence on environmental parameters (i.e., temperature and sediment type) and that is driven by high‐resolution hydrodynamic and meteorological data. The results were used to partition the area in which Nephrops was observed into 20 homogenous management subareas; to assess the connection between spawning, recruitment, and harvesting grounds; and to identify potential subpopulation boundaries as well as the connectivity among the potential subpopulations. The results suggest the presence of at least three distinct subpopulations, which need to be independently managed and conserved, and confirms that the Jabuka‐Pomo pit is the most important spawning area, but alone it cannot sustain Nephrops populations throughout the Adriatic Sea. The results also show the importance to move from particle‐tracking to approaches based on integrated models

    Assessing, quantifying and valuing the ecosystem services of coastal lagoons

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    The natural conservation of coastal lagoons is important not only for their ecological importance, but also because of the valuable ecosystem services they provide for human welfare and wellbeing. Coastal lagoons are shallow semi-enclosed systems that support important habitats such as wetlands, mangroves, salt-marshes and seagrass meadows, as well as a rich biodiversity. Coastal lagoons are also complex social-ecological systems with ecosystem services that provide livelihoods, wellbeing and welfare to humans. This study assessed, quantified and valued the ecosystem services of 32 coastal lagoons. The main findings of the study are: (i) the definitions of ecosystem services are still not generally accepted; (ii) the quantification of ecosystem services is made in many different ways, using different units; (iii) the evaluation in monetary terms of some ecosystem service is problematic, often relying on non-monetary evaluation methods; (iv) when ecosystem services are valued in monetary terms, this may represent very different human benefits; and, (v) different aspects of climate change, including increasing temperature, sea-level rise and changes in rainfall patterns threaten the valuable ecosystem services of coastal lagoons.DEVOTES project, from the European Union's Seventh Framework Programme for research, technological development and demonstration [308392]; networks and communities of Eurolag; Future Earth Coasts; SCOR; Fundacao para a Ciencia e a Tecnologia (FCT) Investigador Programme [IF/00331/2013]; Fundacao para a Ciencia e a Tecnologia [UID/MAR/04292/2013]; CESAM by FCT/MEC national funds (PIDDAC) [UID/AMB/50017/2013 - POCI-01-0145-FEDER-007638]; FEDER; European Commission, under the 7th Framework Programme through the collaborative research project LAGOONS [283157]; FCT [SFRH/BPD/107823/2015, SFRH/BPD/91494/2012

    Simulating the Effects of Alternative Management Measures of Trawl Fisheries in the Central Mediterranean Sea: Application of a Multi-Species Bio-economic Modeling Approach

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    In the last decades, the Mediterranean Sea experienced an increasing trend of fish stocks in overfishing status. Therefore, management actions to achieve a more sustainable exploitation of fishery resources are required and compelling. In this study, a spatially explicit multi-species bio-economic modeling approach, namely, SMART, was applied to the case study of central Mediterranean Sea to assess the potential effects of different trawl fisheries management scenarios on the demersal resources. The approach combines multiple modeling components, integrating the best available sets of spatial data about catches and stocks, fishing footprint from vessel monitoring systems (VMS) and economic parameters in order to describe the relationships between fishing effort pattern and impacts on resources and socio-economic consequences. Moreover, SMART takes into account the bi-directional connectivity between spawning and nurseries areas of target species, embedding the outcomes of a larvae transport Lagrangian model and of an empirical model of fish migration. Finally, population dynamics and trophic relationships are considered using a MICE (Models of Intermediate Complexity) approach. SMART simulates the fishing effort reallocation resulting from the introduction of different management scenarios. Specifically, SMART was applied to evaluate the potential benefits of different management approaches of the trawl fisheries targeting demersal stocks (deepwater rose shrimp Parapenaeus longirostris, the giant red shrimp Aristaeomorpha foliacea, the European hake Merluccius merluccius, and the red mullet Mullus barbatus) in the Strait of Sicily. The simulated management scenarios included a reduction of both fishing capacity and effort, two different sets of temporal fishing closures, and two sets of spatial fishing closures, defined involving fishers. Results showed that both temporal and spatial closures are expected to determine a significant improvement in the exploitation pattern for all the species, ultimately leading to the substantial recovery of spawning stock biomass for the stocks. Overall, one of the management scenarios suggested by fishers scored better and confirms the usefulness of participatory approaches, suggesting the need for more public consultation when dealing with resource management at sea

    European policies and legislation targeting ocean acidification in european waters - Current state

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    Ocean acidification (OA) is a global problem with profoundly negative environmental, social and economic consequences. From a governance perspective, there is a need to ensure a coordinated effort to directly address it. This study reviews 90 legislative documents from 17 countries from the European Economic Area (EEA) and the UK that primarily border the sea. The primary finding from this study is that the European national policies and legislation addressing OA is at best uncoordinated. Although OA is acknowledged at the higher levels of governance, its status as an environmental challenge is greatly diluted at the European Union Member State level. As a notable exception within the EEA, Norway seems to have a proactive approach towards legislative frameworks and research aimed towards further understanding OA. On the other hand, there was a complete lack of, or inadequate reporting in the Marine Strategy Framework Directive by the majority of the EU Member States, with the exception of Italy and the Netherlands. We argue that the problems associated with OA and the solutions needed to address it are unique and cannot be bundled together with traditional climate change responses and measures. Therefore, European OA-related policy and legislation must reflect this and tailor their actions to mitigate OA to safeguard marine ecosystems and societies. A stronger and more coordinated approach is needed to build environmental, economic and social resilience of the observed and anticipated changes to the coastal marine systems
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