European Marine Strategy Framework Directive Research Articles

Addressing the cumulative impacts of multiple human pressures in marine systems, for the sustainable use of the seas

Human activities at sea have increased, causing subsequent degradation of ocean health and affecting ecosystem services and societal goods and benefits. Climate change further exacerbates the cumulative effects of these activities and their associated pressures. Hence, effective management of these multiple activities is imperative to ensure the sustainable use of the ocean. In response to these challenges, we have developed a comprehensive conceptual framework model within an ecosystem-based approach. This framework encompasses a versatile toolbox designed to assess cumulative pressures effects and the environmental status under the European Marine Strategy Framework Directive, in compliance with the Birds and Habitats Directives requirements and the need to secure the maintenance of ecosystem services and provision of societal benefits. Although we use European examples in the current discussion, we consider that there are similar challenges in many seas worldwide and so the recommendations here are widely applicable. Our aim is to facilitate the validation, harmonization, and demonstration of this toolbox across European regional seas and several countries, at different scales, from local to regional, including overseas territories. This approach aims to foster comparability in environmental status assessments. We anticipate that the proposed methodologies will serve as a foundational benchmark against which progress can be assessed in line with expectations and policy requirements. Additionally, this work prepares the groundwork for the forthcoming evaluation of the suitability, robustness, and applicability of these solutions and tools, thereby assisting managers in achieving Good Environmental Status (GES), both in European and wider global contexts, to address challenges which are common worldwide.

New tools and recommendations for a better management of harmful algal blooms under the European Marine Strategy Framework Directive

Marine harmful algal blooms (HABs), caused by various aquatic microalgae, pose significant risks to ecosystems, some socio-economic activities and human health. Traditionally managed as a public health issue through reactive control measures such as beach closures, seafood trade bans or closure of mollusc production areas, the multifaceted linkages of HABs with environmental and socio-economic factors require more comprehensive ecosystem-based management approach tools to support policies. This study promotes a coordinated understanding and implementation of HAB assessment and management under the Marine Strategy Framework Directive (MSFD), targeting the achievement of Good Environmental Status (GES) in European marine waters. We introduce two novel tools: GES4HABs (GES for HABs) decision tree, and MAMBO (environMental mAtrix for the Management of BlOoms), a decision support matrix. These tools aim to streamline HABs reporting and prioritize resource allocation and management interventions. The GES4HABs decision tree defines a sequence of decision steps to identify HAB management strategies according to their state (evaluated against predefined baselines) and causes (anthropic or natural). MAMBO is proposed to address different HABs and their interaction with human and environmental pressures. The matrix utilizes two axes: natural trophic status and level of human influence, capturing major aspects such as nutrient supply. While acknowledging the limitations of this simplified framework, MAMBO categorizes marine regions into quadrants of varying management viability. Regions with high human influence and eutrophic conditions are identified as most suitable for effective management intervention, whereas regions with minimal or mixed human influence are deemed less amenable to active management. In addition, we explore and describe various indicators, monitoring methods and initiatives that may be relevant to support assessments of HAB status and associated pressures and impacts in the MSFD reporting. Finally, we provide some recommendations to promote the consideration of HABs in ecosystem-based management strategies, intensify efforts for harmonizing and defining best practices of analysis, monitoring and assessment methodologies, and foster international and cross-sectoral coordination to optimize resources, efforts and roles.

Habitat mapping of Portugal’s north-western continental shelf and its application to implement the European Marine Strategy Framework Directive

Seafloor habitat maps allow to integrate various data layers and compare areas, being valuable tools for assessing environmental quality. Although the European Nature Information System (EUNIS) was created to catalogue habitats throughout Europe, its use in ecological assessment is relatively uncommon. This work proposes a EUNIS, level 5, benthic habitats map for the Portuguese continental shelf North of Nazaré canyon. Seven EUNIS level 5 habitats were identified, of which six were new to EUNIS, as this catalogue is less complete for southern Europe. Hereafter this map was used to assess the environmental status (ES) within the Marine Strategy Framework Directive (MSFD), which was developed to help European Union countries achieve a good environmental status (GES) in their marine ecosystems. In this sense, eleven quality descriptors (and respective criteria) were set to assess the environmental status (ES), which can be performed using diverse indicators. In this study, the ES status was assessed for two of such descriptors, namely D1, Biodiversity, which was assessed using the Marine Biological Value (MBV); and D6, Seafloor Integrity, which was assessed through the AZTI Marine Biotic Index (AMBI) and Multivariate-AMBI (M-AMBI). For both descriptors, an overall GES (or higher) was determined for this study area. These results set a baseline for future ES assessments within the MSFD, while the use of the EUNIS habitat maps can be expanded to assess the ES of other descriptors, namely D2, non-indigenous species, D3, commercially exploited fish and shellfish and D4, food webs.

The Solent Strait: Water quality trends within a heavily trafficked marine environment, 2000 to 2020

This study presents an important long-term historical analysis of water quality in an internationally crucial waterway (the Solent, Hampshire, UK), in the context of increasing adoption of open-loop Exhaust Gas Cleaning Systems by shipping. The pollutants studied were acidification (pH), zinc, and benzo [a] pyrene, alongside temperature. We compared baseline sites to locations likely to be impacted by pollution. The Solent's average water temperature is slightly increasing, with temperatures at wastewater sites significantly higher. Acidification suggests a complex story, with a highly significant small overall increase in pH during the study period but significantly different values at wastewater and port sites. Zn concentrations have significantly reduced but increased in enclosed waters such as marinas. BaP showed no long-term trend with values at marinas significantly and consistently higher. The findings provide valuable long-term background data and insights that can feed into the upcoming review of the European Union's Marine Strategy Framework Directive and ongoing discussions about the regulation of, and future monitoring and management strategies for coastal/marine waterways.

Coastal rocky reef fish monitoring in the context of the Marine Strategy Framework Directive: Environmental DNA metabarcoding complements underwater visual census

Efficient biodiversity monitoring programs are essential to assess the ecological status of marine ecosystems. In the context of the European Marine Strategy Framework Directive (MFSD), coastal rocky reef fish assemblages are most often surveyed using underwater visual census (UVC). While UVC is well-suited to monitor conspicuous fish, it underestimates hidden, vagrant and/or elusive fishes. Hence, complementary methods are needed to survey the whole fish assemblage. Environmental DNA (eDNA) metabarcoding is increasingly used in this context. Here, we evaluated the effectiveness of eDNA metabarcoding collected from water to provide sound and complementary diversity data to UVC in support of the MFSD. Both methods were used to examine coastal rocky reef fish assemblages in one bay of Brittany (France), along an inshore-offshore gradient and during two seasons. eDNA metabarcoding was carried out following different water sampling strategies: small water volumes (2L) from stationary sampling at the surface and bottom and large water volume (30L) filtered at the surface while moving in close vicinity of the sampling site. A total of 93 (including 57 species) and 33 (including 27 species) taxa were detected with eDNA metabarcoding and UVC, respectively. Eleven species were only recorded by UVC, a result explained for nine of them by a lack of taxonomic resolution of the markers used (12S and 16S) and/or the unavailability of reference sequences. eDNA metabarcoding allows to recover species expected to be present, such as demersal rocky specialist fishes, at a similar species richness level than UVC (14 species for UVC and 12 species for eDNA). It however also unveiled other taxa (pelagic, bentho-pelagic and others demersal fishes) inhabiting the bay and rarely reported through UVC (18 species for UVC and 45 species for eDNA). Despite these differences in species identified by UVC vs. eDNA, both survey methods were consistent in characterizing spatio-temporal variabilities of fish assemblages, highlighting strong site fidelity of eDNA to the source communities. In a well-mixed water column, the eDNA signal was very homogeneous, allowing the use of the cost-effective small water volume eDNA sampling method. eDNA metabarcoding is thus particularly promising to study coastal rocky reef assemblages, and when coupled with UVC, it improves monitoring surveys.

Multiple approach for assessing lagoon environmental status based on water bodies quality indices and microplastics accumulation

Lagoon environments, like all the marine-coastal areas, offer a wide variety of ecosystem services, but at the same time are affected by pressing human activities that lead to deterioration of the environmental quality, loss of biodiversity, habitat destruction and pollution. Since the well-being of population and local economy depend on the environmental status of these ecosystems, it is essential to adopt long-term management tools to achieve the Good Environmental Status sensu European Marine Strategy Framework Directive and Water Framework Directive. A Nature 2000 site (Lesina lagoon, south Italy) was assessed within a project aimed at protecting and restoring biodiversity and lagoon habitat through integrated monitoring, suitable management, and good practices. Here we provide an assessment of the lagoon integrity based on a multi-metrics approach, highlighting match/mismatch among environmental quality indicators and microplastics (MP) pollution. Some environmental quality indices based on ecosystem components as vegetation, macroinvertebrates and water trophic variables were applied together with an accurate evaluation of MPs abundance, distribution, and composition to assess the ecological status of Lesina lagoon before and after cleaning actions with litter removal. Overall, all the ecological descriptors outlined a clear lagoon spatial gradient, with a western saltier and organic-enriched area characterized by the absence of vegetation, macrozoobenthos with lower diversity and richness and high MPs occurrence. The focus on macrozoobenthos, considered as a key component of the lagoon ecosystem, identified much more sites in “poor” status than the other indicators here considered. Moreover, it was found a negative relationship between the Multivariate Marine Biotic Index and MPs items in sediment, suggesting that MP pollution has a negative impact on macrobenthic fauna, concurring to the deterioration of the benthic ecological status.

Conservation Status Assessment of Demersal Elasmobranchs in the Balearic Islands (Western Mediterranean) over the Last Two Decades

More than half of the Mediterranean sharks and rays are threatened by fishing exploitation. However, population assessments are limited by the scarcity of specific data on fishing catches. In this study, we assessed temporal trends of the indicators developed within the European Marine Strategy Framework Directive over the last two decades in order to assess the conservation status of demersal sharks and batoids in the Balearic Islands, which represent an important fraction of the bycatch of bottom trawling in this area. On the basis of a georeferenced, fishery-independent dataset of 19 species of elasmobranchs, we analyzed 20 year time series (2002–2021) of nine indicators regarding area distribution, population size, population status, and community structure. Between 30% and 50% of the elasmobranch species and functional groups showed increasing trends in distribution area and population size. This was especially true for batoids, whereas the distribution area and population size of most sharks remained stable over the study period. The remaining indicators showed stability or, in some cases, variable trends. Only in one case did we find a negative trend sustained all along the time series (i.e., the proportion of R. radula large individuals in relation to the reference period). Overall, our results suggest that the populations of elasmobranchs from the Balearic Islands show stable or recovery trends, mainly in terms of distribution area and density. However, it remains elusive whether this community can recover to the levels of more than half a century ago, before the development of the bottom trawl fishery, or whether this apparent current steady state should be interpreted as a new equilibrium.

NAMBER: A biotic index for assessing the ecological quality of mesophotic biogenic reefs in the northern Adriatic Sea

Abstract The aim of the present study was to propose a biotic index (North Adriatic Mesophotic BiogEnic Reefs, NAMBER) suitable for assessing the ecological quality of the mesophotic biogenic reefs of the northern Adriatic continental shelf based on photographic sampling. At each of the 20 study sites, the degree of bioconstruction (expressed as percentage cover of crustose coralline algae), the α‐diversity (expressed as the mean number of taxa), and the degree of sensitivity to human disturbance and climate change (based on literature data and expert judgement) of the benthic assemblages were selected as descriptors and combined in the NAMBER index, using the best values that the three metrics can currently achieve in the studied region as a reference. The study highlighted that there was large spatial heterogeneity among reefs and high variability in the ecological quality values obtained by NAMBER, ranging from bad to high. The index indicates that reefs lying furthest from the coast, under substantially lower anthropogenic pressure, have a generally higher status of environmental quality. However, a clear geographical pattern did not emerge, as reefs close together often had different ecological qualities. The NAMBER index, which combines three ecological descriptors, in accordance with the requirements of the European Marine Strategy Framework Directive, represents a specific adaptation to the northern Adriatic Sea of a multimetric index previously developed for the north‐western Mediterranean Sea, capitalizing on previous knowledge and research efforts. This multimetric biotic index provides an effective standardized tool for monitoring programmes and environmental impact assessments in the northern Adriatic mesophotic biogenic reefs and lays the foundation for ecosystem‐based management and conservation in this basin.

Floating Riverine Litter Flux to the White Sea: Seasonal Changes in Abundance and Composition

Arctic rivers bring litter from their basins to the sea, but accurate data for the Arctic do not exist yet. This study presents the first assessment of floating macro litter input (>2.5 cm) from the Northern Dvina and Onega rivers to the White Sea. The observations were performed based on the European Marine Strategy Framework Directive (MSFD) methodology and using the mobile application of the Joint Research Centre (Ispra, Italy). The results of observations from May 2021 to November 2021 show that 77% of floating objects were of natural origin (mainly leaves, wood and bird feathers). Of the particles of anthropogenic origin, 59.6% were represented by various types of plastics, 27.7% were processed wood, 8.5% paper/cardboard, 2.7% metal, 1.1% were rubber and <1% textiles. The average monthly input of anthropogenic macro litter by the Northern Dvina varies from 250 to 1700 items/hour, and by Onega from 520 to 2350 items/hour. The level of pollution of the studied rivers was found to be higher than in some Europeans rivers but lower than in China. The mass discharge of macroplastics in the Northern Dvina River was compared with the estimates of the discharge of meso- and microplastics; that allowed us to show that the discharge of macroplastics in mass units is much higher than of micro- and mesoplastics.

Cephalopods, a gap in the European Marine Strategy Framework Directive and their future integration

With the aim of maintaining or obtaining good environmental status in the Northeast Atlantic and northern Mediterranean Sea, the European Marine Strategy Framework Directive (EU-MSFD) came into force in 2008. All EU Member States (MS) have the task of assessing the current state of their adjacent waters to guarantee sustainable use of marine resources and healthy ecosystems for the current and future generations. Although the MSFD has been implemented for over a decade, there are still gaps in the assessment of various ecologically and commercially important marine species, such as cephalopods. Here we describe the status of cephalopods, a key component of marine ecosystems and a valuable fishing resource, within the MSFD. To do so, we review how MS deal with this group in their reporting and identify and explain the gaps in the cephalopod assessment. We describe the main challenges including the limited data and the rarity of dedicated surveys on cephalopods. However, we argue that cephalopods can be partially integrated into the EU-MSFD assessment, illustrating the current opportunities and future possibilities of their integration into the MSFD, mainly using Descriptors 1–4.Graphical abstract

First baseline assessment of seafloor litter on Italian coralligenous assemblages (Mediterranean Sea) in accordance with the European Marine Strategy Framework Directive

A monitoring programme for coralligenous assemblages was carried out in Italy for implementation of the Marine Strategy Framework Directive (MSFD), aiming to characterise the coralligenous' environmental status and litter distribution. A standardised monitoring protocol, based on ROV-imaging, has been applied; this paper analyses the data obtained during the first MSFD cycle (2015–2019). Ninety-five areas were monitored at depths ranging between 14 and 199 m in the three subregions bordering Italy. Overall, 4316 macrolitter items were recorded. The median litter density was 2 items 100 m−2 (range: 0–120 items 100 m−2), but significant subregional differences emerged in litter quantities and composition. Fishery-related litter (mainly lines and ropes) was the most common type (86 %), affecting vulnerable coralligenous reefs. A first baseline is proposed for assessing achievement toward Good Environmental Status and evaluation of the efficacy of the Italian MSFD measures aiming to eliminate the negative effects of marine litter on vulnerable reefs.

Characteristic regional differences in trace element pattern of 2014 German North Sea surface Wadden sediments - A judge and assessment.

The European Marine Strategy Framework Directive (MSFD) requires good ecological status of the marine environment. This also includes the Wadden Sea located in the southeastern part of the North Sea and its chemical status of sediments. Based on results from campaigns conducted in the 1980s, 32 surface sediment samples were taken in 2014 to check whether the sampling strategy required for characterizing the trace element content in sediments is representative and to determine the degree of pollution and potential changes over the last decades. For this purpose the elemental mass fractions of 42 elements were assessed in the ≤20μm grain size fraction of the surface sediments. Based on cluster analysis a clear correlation between the element distribution and the geographical location of the sampling locations of the German Wadden Sea could be found. As a result of the principal component analysis, three sub-catchments were significantly separated from each other by the characteristic element distributions in the sediments (Norderney and Weser, Elbe and offshore areas, and North Friesland). With the help of discriminant analysis, the classification was confirmed unambiguously. Small anomalies, such as potentially contaminated sites from WWII, could be identified. This proved that the sampling strategy for sediment characterization with reference to trace elements in the Wadden Sea of the German Bight is representative. The impact of regulation and changes on the overall sediment quality is most evident when looking at the environmentally critical elements such as As, Cd, Hg, and Cr. For these elements the mean mass fractions show a significant reduction over the last three decades. Current sediments feature only slightly elevated mass fractions of Ag, Cd, Ce, Cs, Nd, Pb and Se at some sampling locations.

Public preferences for marine plastic litter management across Europe

Plastic pollution is one of the most challenging problems affecting the marine environment of our time. Based on a unique dataset covering four European seas and eight European countries, this paper adds to the limited empirical evidence base related to the societal welfare effects of marine litter management. We use a discrete choice experiment to elicit public willingness-to-pay (WTP) for macro and micro plastic removal to achieve Good Environmental Status across European seas as required by the European Marine Strategy Framework Directive. Using a common valuation design and following best-practice guidelines, we draw comparisons between countries, seas and policy contexts. European citizens have strong preferences to improve the environmental status of the marine environment by removing and reducing both micro and macro plastic litter and implementing preventive measures favouring a pan-European approach. However, public WTP estimates differ significantly across European countries and seas. We explain why and discuss implications for policymaking.

Trace elements, dioxins and PCBs in different fish species and marine regions: Importance of the taxon and regional features

Chemical contaminant concentrations in wild organisms are used to assess environmental status under the European Marine Strategy Framework Directive. However, this approach is challenged by the complex intra- and inter-species variability, and the different regional features. In this study, concentrations in trace elements (As, Cd, Hg and Pb), polychlorinated biphenyls (PCBs), polychlorodibenzo-para-dioxines (PCDDs) and polychlorodibenzofuranes (PCDFs) were monitored in 8 fish species sampled on the continental shelf of three French regions: the Eastern English Channel (EEC) and Bay of Biscay (BoB) in the Northeast Atlantic Ocean, and the Gulf of Lions (GoL) in Western Mediterranean Sea. Our objectives were to identify species or regions more likely to be contaminated and to assess how to take this variability into account in environmental assessment. While concentrations were higher in benthic and demersal piscivores, PCB and PCDD/F concentrations (lipid-weight) were similar in most teleost species. For Cd, Hg and Pb, the trophic group accumulating the highest concentrations depended on the contaminant and region. Concentrations in Hg, PCBs and PCDD/Fs were higher in the EEC and/or GoL than in BoB. Cadmium and Pb concentrations were highest in the BoB. Lipid content accounted for 35%–84% of organic contaminant variability. Lipid normalisation was employed to enhance robustness in the identification of spatial patterns. Contaminant patterns in chondrichthyans clearly differed from that in teleosts. In addition, trophic levels accounted for ≤1% and ≤33% of the contaminant variability in teleost fishes in the EEC and BoB, respectively. Therefore, developing taxa-specific thresholds might be a more practical way forward for environmental assessment than normalisation to trophic levels.

Integrated chemical status of the Italian marine waters sensu Descriptor 8 of the Marine Strategy Framework Directive

The European Marine Strategy Framework Directive (MSFD) required Member States to define the concept of Good Environmental Status (GES) of their marine waters in quantitative terms and to achieve it through the assessment of 11 descriptors by 2020. ISPRA (Italian Institute for Environmental Protection and Research), on behalf of the Ministry of the Environment, carried out the Initial Assessment (2012) and the evaluation of the first cycle of the MSFD (2012–2018) to understand the achievement of GES Descriptor 8 (“Contaminant concentrations are at levels that do not give rise to pollution effects”) and, now, in this second cycle of the MSFD (2018–2024), is conducting monitoring of D8C1 criterion elements (“Contaminant concentrations”). In this paper, the approach, integrating data on chemical contaminants (metals and polycyclic aromatic hydrocarbons and organochlorine compounds) in different matrices (water, sediment and biota), adopted by Italy since 2012 to study GES for the MSFD-D8C1 criterion in national marine water is described. This approach, based on the use of a dimensionless, zero-centered index, allows one to assess all regulatory contaminants as a whole. The improvements in the monitoring strategy and the GES evaluation between the Initial Assessment, the first cycle, and the beginning of the second cycle of the MSFD for the Adriatic Sea subregion are presented.

Toward a common approach for assessing the conservation status of marine turtle species within the european marine strategy framework directive

Environmental policies, including the European Marine Strategy Framework Directive (MSFD), generally rely on the measurement of indicators to assess the good environmental status (GES) and ensure the protection of marine ecosystems. However, depending on available scientific knowledge and monitoring programs in place, quantitative GES assessments are not always feasible. This is specifically the case for marine turtle species, which are listed under the Biodiversity Descriptor of the MSFD. Relying on an expert consultation, the goal of this study was to develop indicators and a common assessment approach to be employed by European Union Member States to evaluate the status of marine turtle populations in the frame of the MSFD. A dedicated international expert group was created to explore and test potential assessment approaches, in coherence with other environmental policies (i.e. Habitats Directive, OSPAR and Barcelona Conventions). Following a series of workshops, the group provided recommendations for the GES assessment of marine turtles. In particular, indicators and assessment methods were defined, setting a solid basis for future MSFD assessments. Although knowledge gaps remain, data requirements identified in this study will guide future data collection initiatives and inform monitoring programs implemented by EU Member States. Overall this study highlights the value of international collaboration for the conservation of vulnerable species, such as marine turtles.

Multi-source and multi-scale data integration for the assessment of the marine environmental status of the Basque Coast (SE Bay of Biscay)

In the context of the European Marine Strategy Framework Directive (MSFD, 2008/56/EC), Member States are required to assess the environmental status of marine waters. With the aim to support practitioners in this effort, and guide them in the identification of management solutions, a team of researchers has brought together available information for the Basque coastal zone (SE Bay of Biscay), and assessed the marine environmental status of these waters. To undertake the study, the area was divided into Marine Reporting Units (MRUs), following the MSFD terminology, which had specific areas assigned. The information used for the assessment was obtained from a variety of open sources (i.e., in-situ long-term monitoring data, biological data from annual/triannual surveys, multibeam echosounder data, satellite data, and had been collected at different spatial scales, from the coastline to offshore, covering the whole Exclusive Economic Zone. A total of 67 indicators were used, covering some ecosystem components: physico-chemistry of sediments and waters, phytoplankton, benthic fauna and flora, fish, birds, mammals, and alien species. The associated data, for 2010 to 2019, were then collated and integrated to assess the environmental status in a holistic way, using NEAT (Nested Environmental status Assessment Tool). The analyses included spatial scenarios (coastline to offshore), as well as filtering by different MSFD descriptors (i.e., biodiversity, alien species, eutrophication, seafloor integrity and contamination). Overall, the Basque coast is in good status, with no clear spatial gradient. But when focusing on specific ecosystem components (e.g., seabirds, mammals, some commercial fish species), it is possible to identify some components in bad status, with scope for improvement through the implementation of management measures. The integrated assessment approach presented and the outputs that are obtained can be used to guide European practitioners in their efforts to prioritize management measures. Furthermore, results are comparable to those reported in official MSFD assessments, confirming the power of the NEAT software.

Dumping of Dredge Spoil in the Pelagic Habitat: Focus on Trophic Status, Phytoplankton Diversity Responses and Generation of Blooms

This study presents the impacts of dredge spoil dumping in the pelagic habitat during a 27-month monitoring survey in eastern Mediterranean coastal waters (Saronikos Gulf, Aegean Sea), with a focus on changes in trophic status and eutrophication levels, phytoplankton diversity and bloom dynamics. A number of environmental parameters and phytoplankton metrics were significantly influenced by the dumping operations, specifically phytoplankton diversity indices (number of species, Diatoms:Dinoflagellates ratio) and total abundance, Chlorophyll-a, light transmission, dissolved oxygen and inorganic nutrients, N:P ratio, and the Eutrophication Ιndex (a metric for trophic status assessment). Phosphates started to increase after the first year of dumping operations, shifting the N:P ratio to values lower than 10. A similarity cluster analysis highlighted that the phytoplankton community structure during the pre-dumping and the early-dumping period was clearly discriminated from the period during and after the dumping operations. A clear shift with an increase in the Diatoms:Dinoflagellates ratio was observed immediately after the initiation of dumping operations, which maximized in the dumping site after two years of operations. Diatoms dominated the phytoplankton communities, reaching ~ 95% relative abundance in the dumping site. High biomass producers or potentially toxic diatom species proliferated forming blooms. Pseudo-nitzschia multiseries was the most frequent potentially toxic species. A multivariate analysis (RDA) highlighted that among a suite of phytoplankton metrics plotted against stressors relevant to dumping, the Eutrophication Index, Chlorophyll-a, the diversity index Diatoms:Dinoflagellates ratio and the abundance of the potentially toxic diatom P. multiseries emerged as the most suitable to reflect the responses of phytoplankton communities to dumping. Dredge spoil dumping at sea poses pressures to ecosystem components addressed by the European Marine Strategy Framework Directive (MSFD) monitoring programs. In such a context, this study further supports the role of phytoplankton diversity and blooms as sensitive monitoring elements for the environmental status assessment and dumping management in coastal waters.

Spatio-temporal trends of the bottom trawling activity in a mud volcano field of the north-eastern Gulf of Cádiz (south-western Iberian Peninsula)

Multi-species bottom trawl fisheries are one of the human activities with a great impact on the benthic habitats and their associated biota. This study provides estimates of the bottom trawling activity (effort), catches and landings of the main commercial species as well as an estimation of the total revenue (TR) generated inside a mud volcano field located in the Spanish margin of the Gulf of Cádiz, during a time series from 2007 to 2012. To date, no studies have been carried out to analyse the temporal evolution of bottom trawling activity and TR in a mud volcano fied, or the economic consequences of possible potential bottom trawling regulation of certain sectors harbouring vulnerable and/or threatened habitats. In this study, Vessel Monitoring System data, logbooks and sales slips were used. The spatial distribution of the bottom trawling activity, catches and TR were related to the seafloor morphology and specific bottom types of the mud volcano field. During the time series, a high bottom trawling activity and associated catches was detected in flat sandy and muddy bottoms, including the Anastasya sector and between the Guadalquivir and Cádiz Diapiric Ridges. Low bottom trawling activity and catches were detected in the deepest areas but also in areas with hard and detritic bottoms such as Gazul and Chica sectors as well as in the Diapiric Ridges. A similar spatial pattern was detected for the TR asociated with these bottom trawling fisheries. An increase in bottom trawling activity was detected during the time series, mainly at the end, probably for increasing the TR and mantaining the economic profit due to the instability and increases in fuel prices and offset the increased costs. Based on the obtained information, bottom trawling regulations should be implemented in certain sectors harboring singular and/or threatened habitats and species. In some of these sectors, a low TR from bottom trawling was detected and, bottom trawling regulation may potentially have a low socioeconomic impact. This specific bottom trawling regulation could provide a sustainable balance between bottom trawling activities and habitat conservation in this mud volcano field according to the aims of the Habitats Directive (92/43/EEC) and the European Marine Strategy Framework Directive (2008/56/EEC).

Environmental Impact of Underwater Noise

The description of sound as a form of energetic pollutant is very complex as is also its impact on aquatic life. Human activities causing continuous and implosive underwater noise, such as marine traffic, maintenance of ships, coastal tourism, marine research, military, offshore energy platforms, generation of ocean energies and construction operations are expected to increase. The paper analyses current approach to minimise the impact of underwater noise and limit its emissions, examines regulatory approach and discusses the possibilities to control this type of pollution in order to ensure the preservation of natural underwater soundscape. The timely implementation and further development of the European Marine Strategy Framework Directive and its provisions related to underwater noise is of exceptional importance for the Adriatic Sea, which is facing increasing pressure from various industries generating underwater noise.