Lagoon Ecosystem Research Articles

Short-term desalination of Pulicat lagoon (Southeast India) due to the 2015 extreme flood event: insights from Land-Ocean Interactions in Coastal Zone (LOICZ) models

IntroductionWe investigated the magnitude and duration of desalination of Pulicat—a coastal lagoon ecosystem connected to the Bay of Bengal on the South-eastern coast of India—during the 2015 South India flood event which was a period of high-magnitude precipitation and riverine flooding.MethodsWe estimated freshwater runoff into the lagoon using flow accumulation models for a period of 55 days (November 1 to December 25, 2015) using daily gridded precipitation data from the Global Precipitation Measurement and a digital elevation model. Using the estimates of freshwater runoff, direct precipitation and observed salinities, we simulated water and salinity fluxes of the lagoon using the Land-Ocean Interactions in the Coastal Zone model. Further, we also used Monte Carlo simulation to estimate the uncertainty in system salinity, the residual salinity at the boundary and the freshwater residence times in the lagoon.ResultsWe estimated that a high volume (~ 760 × 106 m3) of relatively low salinity waters (residual salinity = 23.47 psu) had been exported from the lagoon to the Bay of Bengal during the period which is likely to have caused a strong dip in the daily salinity profile of the coastal sea. We contend that the lagoon experienced ~ 40% desalination due to the 2015 event with a freshwater residence time of 18.5 days.ConclusionsThe study highlighted the short-term, high-magnitude desalination undergone by Pulicat lagoon during the 2015 South India floods. Considering the high residual and exchange volumes obtained from the study, we conclude that Pulicat could be a major exporter of relatively low salinity waters to the Bay of Bengal during monsoons.

Influence of environmental variation on the bacterioplankton community and its loss to viral lysis in the Curonian Lagoon

Coastal lagoons are continuously exposed to strong environmental gradients that determine the distribution and trophic interactions of microbial communities. Therefore, in this study we assessed whether and how environmental changes influence the bacterial community and its vulnerability to viral infection and lysis along the major environmental gradient in the Curonian Lagoon. We found significant differences in bacterial community profiles, their richness and evenness between the riverine, freshwater southern part and the Baltic Sea water intrusion-influenced northern part of the lagoon, suggesting strong environmental control of the structure of bacterial communities. Viruses were found to be play an important role in bacterial mortality in the Curonian Lagoon, being responsible for the removal of 20–50% of the bacterial standing stock. We observed differences in virioplankton decay rates and virus burst sizes between the northern and southern parts of the lagoon. However, no relationships were found between viral activity and bacterial communities within the lagoon ecosystem. The frequency of infected cells and virus-mediated bacterial mortality (VMBM) remained constant among the sampling sites irrespective of differences in bacteria community assemblages and environmental conditions. The results indicate that factors determining changes in bacterial diversity are different from the factors limiting their vulnerability to viral infection and lysis. This study also suggests that under changing environmental conditions, virus-bacteria interactions are more stable than the interacting viral and bacterial communities themselves. These findings are important for understanding the functioning of the coastal ecosystems under the rapidly changing local (spatial and temporal) and global (e.g. eutrophication, climate change) conditions.

How much can the occurrence and coverage of charophytes in an estuarine lagoon (Curonian Lagoon) be explained by environmental factors?

Aquatic macrophytes play an important role in the structure and functioning of lagoon ecosystems. We assessed the importance of biotic and abiotic environmental factors in controlling spatial patterns of charophyte occurrence and coverage in the Curonian Lagoon. The relationships among five charophyte species, abiotic and biotic environmental factors were assessed using canonical correspondence analysis and multivariate regression trees. Salinity and wave exposure were the most important environmental factors explaining the occurrence and coverage of charophytes species in the estuarine part of the lagoon. The salinity gradient restricted the occurrence of brackish water species (especially Chara baltica and Tolypella nidifica) and freshwater species (especially Nitellopsis obtusa). The occurrence and coverage of C. contraria and T. nidifica were positively associated with the wave exposure and related factors (the bottom slope and grain size of sediments). The cover of N. obtusa could be suppressed by shading and/or space limitation by dense stands of Potamogeton perfoliatus. Relatively low explained variation in the occurrence and coverage (respectively, 28 and 19%) of charophytes by environmental factors highlights the need for analysis of other important factors (e. g. chemical content of sediments, dynamics of propagule bank and herbivory), and better resolution in linking macrophyte community composition with environmental data.

Hydrology and heterogeneneous distribution of water quality characteristics in the complex Porto-Novo Lagoon ecosystem

A study was carried out on the hydrology and heterogeneous distribution of water quality characteristics in the Lagoon of Porto-Novo between July 2014 and June 2015. The water body was stratified into 12 strata for sampling. Data and samples were collected based on season and stations. The results were analyzed in the laboratory and interpreted using ANOVA.Water parameters and annual range was obtained . Temperature (25.81 oC – 31.03 oC), dissolved oxygen (4.85 mg/L- 7.74mg/L), salinity (0.10%o,- 8.34a%o), electrical conductivity (8.12 μS/cm-37.68 μS/cm), pH (6.74 – 7.0), transparency (0.18- 0.77 m),total dissolved solids (4.09 mg/L-26.18 mg/L), total hardness (39.92 mg/L-7624.47 mg/L), biological oxygen demand (9.76 mg/L - 4.83 mg/L), and chemical oxygen demand (18.32 mg/L - 11.59 mg/L).Temperature, salinity, electrical conductivity, total dissolved solids, total hardness, biological oxygen demand, chemical oxygen demand were significant at probality level of 5% while dissolved oxygen and pH were not significant at p<0.05 by using Duncan Post Hoc tests for the homogeneous subset respectively. The results attested that the water quality characteristics from Porto-Novo Lagoon were influenced by hydrological cycle and highly polluted and the annual range obtained are above the international legislation limits. It is therefore recommended that the activities of reparian on Porto-Novo Lagoon should be curtailed for adequate revamping.Keywords: Physico-chemical parameters, hydrology, heterogeneous, Porto-Novo

Linking pipefishes and seahorses to seagrass meadows in the Venice lagoon: Implications for conservation

Abstract Seagrass meadow degradation and loss is one of the major threats to fish biodiversity in coastal marine and lagoon ecosystems in the Mediterranean. Pipefishes and seahorses (family Syngnathidae) are particularly affected by loss of seagrass meadows and other structured habitats, on which they rely for survival and reproduction. Despite their charismatic appearance and peculiar behaviour, their habitat ecology is still poorly understood in Mediterranean coastal waters. This study focuses on syngnathid assemblage composition and diversity in the shallow waters of the Venice lagoon (Italy), aiming at highlighting habitat preferences and providing insights into the conservation of biodiversity in these ecosystems. Generalized Additive Models were used in order to disentangle the potential effect of habitat typologies and different architectures of seagrass meadows from that of other environmental parameters. Most abundant taxa and whole syngnathid assemblage indicators were positively associated with seagrass meadows. Only few species, however, were seagrass specialists in shallow waters, and preferred meadows with taller canopies. Despite that, other structured habitats including short‐leaved seagrass meadows and macroalgal beds were important for some species and overall assemblage diversity. Managers in Mediterranean coastal lagoons should thus limit human pressures that lead to the depletion of seagrass meadows, with particular attention to long‐ and broad‐leaved species in less confined areas. Nevertheless, syngnathid assemblages would benefit from the preservation and restoration of the overall habitat diversity characterizing shallow waters in coastal lagoon. Future studies should aim at investigating the potential role of habitats at greater depths in supporting syngnathids.

Haematological and Genotoxic Indices of Two Cichlid Fish Species from a Tropical Estuarine Lagoon

The study evaluated the health status of commercially important edible species of fishes Sarotherodon melanotheron and Tilapia guineensis from a highly impacted tropical Lagoon ecosystem

Economic Valuation of Urban Coastal Ecosystem Services and Scenic Beauty

A lagoon ecosystem provides a variety of ecological functions that directly or indirectly translate to economic services and values. The impact of the loss of cultural services is scarce in literature and particularly difficult to measure. This study generates monetary value for urban ecosystem services specifically the aesthetic value of a natural asset according to the perception of the adjacent community. The data were gathered by using a pre-structured, questionnaire-based personal interview carried out with 300 households representing 15 ‘Thotupola’ areas adjacent to the estuary. Choice Experiment (CE) was used to determine the preferences and the willingness to pay for conservation of urban ecosystem services and natural view. Highest value (530.75) was recorded for provisioning services. Marginal willingness to pay (MWTP) for prawns (272.25) was higher than the value of (258.50) crabs. Second highest MWTP (309.50) was acquired by recreation attribute, scenic beauty of the lagoon. Moreover, local fishing community does not willing to pay for regulatory services such as reduction of flood damage by mangrove and cleaning of polluted lagoon water. Understanding the degree and order of importance of ecosystem non-use values for its direct users is critical for planning for optimum and sustainable management, as properly managed ecosystem can provide continued returns to future generation without diminishing its productivity. The study generates information for decision makers with regard the monetary values for conservation of different ecosystem services and estuary view, to protect the estuary ecosystem through implementing policies and management plans, on urban estuaries and mangrove environment protection.

Peculiarities of the Structure of and Trends in the Macrobenthos Community of the Ermolinskaya Bay Lagoon Ecosystem, Kandalaksha Bay, White Sea

The species composition and spatial and trophic structures of the macrobenthos communities of the Ermolinskaya Bay were studied, and the main changes that had occurred since previous explorations (the 1960s) were analyzed. The most significant changes in the spatial structure of the macrobenthos community (species diversity, population density and biomass, and similarities of the species’ distribution) were observed with regard to the sea level zone: the most pronounced at the upper littoral, followed by the middle littoral, lower littoral, and sublittoral. The longitudinal gradient of the community structure (from the innermost area seaward) was pronounced less strongly. Altogether, four macrobenthos communities can be identified in Ermolinskaya Bay; they differ in species composition, diversity, population density and biomass, and trophic structure: (1) community of the upper littoral with the dominance of collecting deposit feeders, Hydrobia ulvae, and scrapers, Littorina saxatilis; (2) community of the middle littoral with the prevalence of deposit feeders, Hydrobia ulvae and Macoma balthica, seston feeders, Mya arenaria, and, to a lesser extent, Mytilus edulis; (3) community of the lower littoral with the domination of the filtering organisms, Mytilus edulis, to a lesser extent collecting deposit feeders, Hydrobia ulvae and Macoma balthica, and scrapers, Littorina littorea; and (4) community of the sublittoral, where the leading positions belong to the group of collecting deposit feeders, Macoma balthica, to a lesser extent also Hydrobia ulvae (in the innermost area) and Capitella capitata, Arenicola marina (in the marine part of the bay). The gradual siltation of the bay and the reduction of its connection to the sea have led to the development of a littoral complex of species in the sublittoral, whereas the species typical at the sublittoral in the 1960s are now mainly found at the outlet of the bay.

Ecosystem services and main environmental risks in a coastal lagoon (Mar Menor, Murcia, SE Spain): The public perception

Coastal lagoons count among the marine habitats with the highest biological productivity, playing an important ecological role. Together with wetlands in general and coral reefs, they are also amongst the habitats with the highest value derived from the services they provide. This work aims to assess the natural goods and services provided by the Mar Menor coastal lagoon in Murcia (Spain), as well as the environmental risks it is exposed to. This ecosystem, as many coastal lagoons throughout the world, supports a great variety of important services but the resulting pressures are also the reasons that have led to its deterioration, showing signs of impact, whether environmental, social and even economic. In 2011 the European Commission proposed a common strategy on biodiversity, in an attempt to avoid its decline, and claim it as one of the main bases for sustainable economic development. In this context, this work also looks at the socioeconomic value of this emblematic environment using the contingent valuation method (CVM). A questionnaire was developed and presented to inhabitants and visitors of the Mar Menor area, including a broad representation of professions and activities, to identify stakeholder perception of the environment and how they evaluate the importance of ecological processes for maintaining ecosystem functioning and the goods and services provided.The perception and valuation of goods and services provided by ecosystem functioning and biodiversity in the Mar Menor lagoon depended on the different groups considered (by age, professional activity, residence, educational background or sex), although in general, stakeholders, including fishermen, perceived that tourism services are the most important. Interestingly, the sectors related to construction and fishing were well aware of the risks derived from their own activities.The evaluation of services and the perception of the principal environmental risks and impacts were high for all the groups of users considered, and the indirect use and non-use value of the lagoon ecosystem conservation was established in 43,326,181 Euros/year.

Multi-criteria assessment of a proposed ecotourism, environmental education and research infrastructure in a unique lagoon ecosystem: The Encañizadas del Mar Menor (Murcia, SE Spain)

Coastal lagoons host important values and provide irreplaceable services to society. Communication areas with the sea (gullets, ‘golas’ in Spanish) are dynamic environments with a key role in their overall functioning, often representing also strongholds of biodiversity, which increases their conservation value and social demand for nature-based activities. In 2013 the Regional Assembly of the Autonomous Community of Murcia adopted unanimously the creation of a pedestrian walkway to promote ecotourism, environmental education and research in the area of the ‘Encañizadas del Mar Menor’ (EMM, thereafter), a space between the aforementioned lagoon and the Mediterranean Sea. The agreement was conditioned upon the completion of an environmental feasibility study which was commissioned to the University of Murcia. The area affected concentrates several habitats and species of community importance listed in EU Habitat and Bird Directives, including habitat 1140 (Mudflats and sandflats not covered by seawater at low tide) and many seabird and waterbirds. Traditional fishing has not only preserved its ecological uniqueness but increased cultural value. The multi-criteria evaluation developed by a multidisciplinary team has combined the basic information available with specific models of response to the presence of the infrastructure and its use by visitors, especially regarding hydrological and sediment dynamics, and biodiversity (birds and habitats). Although constrained by the complex regulatory and administrative framework, and by the quality of the environmental information available, the design and development of this study provides a model for the evaluation of projects with strong public demand in ecologically sensitive areas of Mediterranean coastal lagoons. The assessment was made on the basis of four groups of viability criteria (socioeconomic, environmental, administrative and legal, technical), weighted by expert panels to rate the alternatives previously drafted. A specific social consultation provided information on the preferences and attitudes of actual users and the regional public on the intervention and its alternatives. A combined analysis of socioeconomic (positive) and environmental (negative) impacts was used to select the alternative that concurrently maximized social preferences and environmental integration. Although the possibility of building a footbridge was rejected, the selected alternative (peripheral boat itinerary) still had good social acceptance, was consistent with ecotourism policies and matched experiences carried out elsewhere. Additional utilities of such multidisciplinary assessments are their performance as public information and participation processes, and the possibility to use them as a basis for drafting initiatives for the valorisation or restoration of other sections of lagoon complexes.

The Future of Giant Clam-Dominated Lagoon Ecosystems Facing Climate Change

Several small isolated Pacific Ocean atoll lagoons were characterized by their unique abundances of giant clams for at least 35 years, but they were recently affected by massive mortalities. We review evidences that confirm collapses in the past 10 years, discuss the likely causal factors based on current knowledge, and assess the consequences for management. Recent in situ and modeling research have focused on how management, natural processes, and climate change can influence the population trajectories. Projections suggest increasing risks with limited management options to reverse the trend. The various documented cases support the hypothesis that mass mortalities of giant clams are triggered by climate variability, enhanced by the geomorphological specificities of these atolls. The exact mechanisms leading to mortalities and consequences for the whole ecosystem remain unknown and are probably case-dependent. These collapsing ecosystems represent well the fast impact that climate change can have on reef ecosystems.

Status and Trends of Hard Clam, Mercenaria mercenaria, Populations in a Coastal Lagoon Ecosystem, Barnegat Bay–Little Egg Harbor, New Jersey

ABSTRACT Bricelj, V.M.; Kraeuter, J.N., and Flimlin, G., 2017. Status and trends of hard clam, Mercenaria mercenaria, populations in a coastal lagoon ecosystem, Barnegat Bay–Little Egg Harbor, New Jersey. In: Buchanan, G.A.; Belton, T.J., and Paudel, B. (eds.), A Comprehensive Assessment of Barnegat Bay–Little Egg Harbor, New Jersey. This review examines the historical and current status of hard clam, Mercenaria mercenaria, populations in the Barnegat Bay–Little Egg Harbor (BB-LEH) Estuary using New Jersey State stock assessments and published studies and evaluates their potential for rehabilitation under present environmental conditions. This estuary has experienced increasing urbanization, population growth, bulkheading, and changes in watershed use. Clam populations have decreased markedly since the 1960s, and in LEH, substantial areas are now devoid of clams. Landings of wild-caught hard clams, and commercial and recreational clam licenses have all declined. There is no evidence that eutrophication an...

An ecological evaluation using fisheries landings time-series data: A case study of two coastal lagoons in the Ionian sea (E. Mediterranean, Greece)

Landing time series in Paleo and Avlemon lagoons (Lefkada Island, NW Greece) were analyzed for the time period 1989–2014 in order to estimate the environmental status and the fishing pressure imposed on the studied lagoon ecosystems in relation to fisheries production. In both lagoons the fishing yield and the Fishing in Balance index (FiB), showed a significant decreasing trend. In contrast, the mean trophic level index (mTL) increased with throughout the study period likely influenced by detrivorous trends and mid-level carnivorous trophic groups. The relative biomass trophic level spectra (BTLS) index analysis for the sub periods 1989–1998, 1999–2001 and 2002–2014 indicated no major shifts in the trophic structure. Meta analysis of indicators between the two target lagoons with other similar lagoon systems in Greece, based on their average physical and chemical variables, showed that Paleo lagoon is characterized by the temperature, the dissolved oxygen and ammonium concentrations while the Avlemon lagoon by the salinity values. The combination of the used indicators revealed a contracting fishery activity in both lagoons but a Gordon-Schaefer analysis, according to CPUE indicator (t/fisherman/year), showed that the Paleo lagoon is an underexploited system, while in the Avlemon lagoon fishing pressure is close to the optimum values noted during the study period. An ARIMA forecasting model indicates that the fishing yield will decline and at low levels for the next five years period (2015–2019). Thereafter, we assume that time series landing data and the ecological indices could be proposed, under certain preconditions, as a supplementary tool for the typing transitional water bodies, in the context of the European Water Frame Directive (WFD), and for future coastal management decisions.

Characterization of benthic habitat settings in a lagoonal ecosystem using free-living nematodes as proxy

Free-living nematodes are sensitive to most of the disturbances and therefore have ability to reflect direct structural and functional changes in an ecosystem. We studied nematode assemblages of Chilika Lagoon, the largest lagoon of Asia, across spatio-temporal scales in link with environmental variables and evaluated nematode assemblages as a proxy to characterize lagoonal benthic habitat settings. Our results revealed that nematode communities showed significant variation spatially and temporally in terms of mean density (16–854/10 cm2) and mean number of species (7–74). Salinity is the key factor that controls nematode community structure across this lagoon and was strongly supported by statistical analyses. The observed nematode assemblages were further used as a proxy to assign benthic habitats of Chilika into distinct biological, topographical and hydrological settings. This study showed that nematode assemblages could be effectively used for long term ecological monitoring of dynamic sedimentary environment of lagoons globally.

Marine Biodiversity - Warming vs. Biological Invasions and overfishing in the Mediterranean Sea: Take care, ‘One Train can hide another’

Biodiversity means the variety of life, encompassing levels of complexity from within species to across ecosystems. Biodiversity therefore includes several dimensions: evolutionary scale (genetic, species, higher taxonomic levels and phylogenetic diversity), functional scale, organizational scale (patch, ecosystem, landscape/seascape diversity), spatial scale (from sample to local, regional and global richness) and heterogeneity diversity. Biodiversity can therefore be measured in different and complementary ways, thus involving the use of at least 200 different metrics, which can suggest different and contrasting conclusions. It is worth emphasizing that species richness may be the least appropriate metric, despite its popular acceptance. There is a growing tendency for stakeholders, managers, government officials, environmentalists, scientists, politicians and the media to focus, as concerns threats to biodiversity, on species richness and climate change. However, focusing on climate warming can mask other stressors that, today, and perhaps for decades to come, may have more impact on ecosystems than global warming. In the Mediterranean Sea, the overall impact of Non-Indigenous Species (NISs) and overfishing on species diversity, ecosystem diversity and ecosystem functioning exceeds to a greater or lesser degree the direct impact of warming. Drastically altered functioning patterns, and even new ecosystems are spreading throughout the Mediterranean Sea. This trend is likely to become more pronounced over the next decades. Ecosystem goods and services are also being profoundly altered, generally towards a decline, as illustrated by the overgrazed barren grounds of the eastern basin, which no longer support fisheries, by the impact of the Caulerpa meadows on the scuba diving business and the economic value of the fisheries of the western basin, by the brackish lagoon ecosystems and by the blooms of the introduced comb jelly Mnemiopsis leidyi in the Black Sea, before the arrival of its predator Beroe ovata. Here, we draw attention to the fact that, at this moment and probably also in the future, the huge flow of NISs and overfishing constitute worrying issues, although largely ignored by stakeholders and political authorities. Take care: Un train peut en cacher un autre (one train can hide another; i.e. one danger may hide other unsuspected dangers), that is to say the impact of warming may contribute to hiding other effects, of at least equal gravity, such as biological invasions and overfishing.

Diversity and abundance of sulfate-reducing microorganisms in a Mediterranean lagoonal complex (Amvrakikos Gulf, Ionian Sea) derived from dsrB gene

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 79:209-219 (2017) - DOI: https://doi.org/10.3354/ame01829 Diversity and abundance of sulfate-reducing microorganisms in a Mediterranean lagoonal complex (Amvrakikos Gulf, Ionian Sea) derived from dsrB gene Christina Pavloudi1,2,3,*, Anastasis Oulas1, Katerina Vasileiadou1, Georgios Kotoulas1, Marleen De Troch3, Michael W. Friedrich2, Christos Arvanitidis1 1Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, PO Box 2214, 71003 Heraklion, Greece 2Microbial Ecophysiology Group, Faculty of Biology/Chemistry and MARUM, University of Bremen, 28359 Bremen, Germany 3Marine Biology Research Group, Department of Biology, Faculty of Sciences, University of Ghent, 9000 Ghent, Belgium *Corresponding author: cpavloud@hcmr.gr ABSTRACT: Sulfate-reducing microorganisms (SRMs) are a phylogenetically and physiologically diverse group of microorganisms, responsible for the dissimilatory reduction of sulfate. SRMs thrive under anaerobic conditions with high availability of organic matter. Such conditions characterize lagoonal ecosystems which experience regular dystrophic crises. The aim of the present study was to explore the biodiversity patterns of SRMs and to examine the extent to which these patterns are associated with biogeographic and environmental factors. Sediment samples were collected from 5 lagoons in the Amvrakikos Gulf (Ionian Sea, western Greece). DNA was extracted from the sediment and was further processed through pyrosequencing of a region of the dissimilatory sulfite reductase β-subunit (dsrB). The results of this exploratory study show that the majority of the observed operational taxonomic units (OTUs) belong to the Deltaproteobacteria supercluster and more specifically, to the Desulfobacteraceae family. Salinity and ammonium ions are the environmental factors that best correlated with the SRM community pattern. Furthermore, the SRM community of the brackish lagoons is differentiated from that of the brackish-marine lagoons and the studied lagoons have distinct SRM communities. KEY WORDS: dsrB gene · Amvrakikos Gulf · Lagoon · Pyrosequencing · Sediment · Sulfate-reducing microorganisms Full text in pdf format Supplement 1 Supplement 2 Supplement 3 PreviousNextCite this article as: Pavloudi C, Oulas A, Vasileiadou K, Kotoulas G, De Troch M, Friedrich MW, Arvanitidis C (2017) Diversity and abundance of sulfate-reducing microorganisms in a Mediterranean lagoonal complex (Amvrakikos Gulf, Ionian Sea) derived from dsrB gene. Aquat Microb Ecol 79:209-219. https://doi.org/10.3354/ame01829 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 79, No. 3. Online publication date: June 12, 2017 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2017 Inter-Research.

Spatiotemporal dynamics of submerged macrophyte status and watershed exploitation in a Mediterranean coastal lagoon: Understanding critical factors in ecosystem degradation and restoration

Increases in the intensity of disturbances in coastal lagoons can lead to shifts in vegetation from aquatic angiosperms to macroalgal or phytoplankton communities. Such abrupt and discontinuous responses are facilitated by instability in the equilibrium controlling the trajectory of the community response. We hypothesized that the shift in macrophyte populations is reversible, and that this reversibility is dependent on changes in the pressures exerted on the watershed and lagoon functioning. Biguglia lagoon (Mediterranean Sea, Corsica) is an interesting case study for the evaluation of long-term coastal lagoon ecosystem functioning and the trajectory of submerged macrophyte responses to disturbances, to facilitate the appropriate restoration of ecosystems. We used historical data for a two hundred-year period to assess changes in human activities on the watershed of the Biguglia lagoon. Macrophyte mapping (from 1970) and monitoring data for dynamics (from 1999) were used to investigate the trajectory of the community response. The changes observed in this watershed included a large number of hydrological developments affecting salinity and resulting in changes in macrophyte distribution. Nutrient inputs over the last 40 years have led to a shift in the aquatic vegetation from predominantly aquatic angiosperm community to macroalgae and phytoplankton in 2007 (dystrophic crisis). Changes in hydrological management and improvements in sewage treatment after 2007 led to a significant increase of aquatic angiosperms over a relatively short period of time (4–5 years), particularly for Ruppia cirrhosa and Stuckenia pectinata. There has been a significant resurgence of Najas marina, due to changes in salinity. The observed community shift suggests that Biguglia lagoon is resilient and that the transition may be reversible. The restored communities closely resemble those present before disturbance. These findings demonstrate the need to understand watershed exploitation and ecosystem variability in lagoon restoration.

Rapid assessment of non-indigenous species in the era of the eDNA barcoding: A Mediterranean case study

With only a narrow opening through the Gibraltar and Suez Canals, the Mediterranean Sea is one of the largest semi-enclosed seas. The marine flora and fauna are some of the richest in the world, relative to its size, particularly in the coastal habitats, which are also characterized by numerous endemic species although the introduction of non-indigenous species threatens its rich and unique biodiversity. Following the opening of the Suez Canal, and in combination with shipping and aquaculture activities, non-indigenous species (NIS) introduction has had measurable impacts on the Mediterranean. Lagoon ecosystems along the French coastline, with approx. 100 NIS identified, are considered hot-spot areas for these species. Rapid assessment sampling for sessile benthic species together with DNA barcoding is a rapid, easy and cheap method to detect non-indigenous species. Two nearby and different ecosystems were sampled for invertebrate species: Saint-Nazaire lagoon, a Special Protection Area within the Natura 2000 Network and Canet port, a marina in a small village. The DNA barcoding tool for species identification was used for confirming the taxonomy. This showed that, despite the Saint-Nazaire Lagoon classification within the Natura 2000 network, it is already contaminated with a single NIS that was found in high densities and is clearly beginning to dominate the system. It is proposed that a rapid assessment of the sampled environment and the DNA barcode approach are efficient and can provide sufficient information on the new target species to be used in conservation planning and ongoing management efforts.

Model-based assessment of groundwater vulnerability for the Dalyan Region of southwestern Mediterranean Turkey

The Dalyan Region that drains into a complex lagoon system is located on the Mediterranean Sea coast of southwest Turkey. There are no large streams in the area, indicating that a considerable amount of freshwater draining into the lagoon is expected to be based on groundwater inflows and that groundwater quality is an important issue for the lagoon ecosystem. Since the lagoon and its watershed are within an environmental special protection area, planning preventive and mitigative measures toward water quantity and quality, including groundwater, is crucial. Since an important step in such a study is the generation of vulnerability map of groundwater pollution, this study aims at the generation of an intrinsic groundwater vulnerability map and its assessment for the first time in the study area based on the DRASTIC method. Since the DRASTIC method requires recharge rates for the calculation of groundwater pollution potential index, these were obtained from a previous modeling study conducted in the same area, where SWAT model was used. The intrinsic vulnerability maps generated were overlaid with current land-use maps to evaluate actual groundwater pollution risk. Our analyses showed that 46% of the study area is under the high risk of groundwater pollution, where 62% of the vulnerable high-risk area is agricultural land.

Climate variability in SE Europe since 1450 AD based on a varved sediment record from Etoliko Lagoon (Western Greece)

To achieve deeper understanding of climate variability during the last millennium in SE Europe, we report new sedimentological and paleoecological data from Etoliko Lagoon, Western Greece. The record represents the southernmost annually laminated (i.e., varved) archive from the Balkan Peninsula spanning the Little Ice Age, allowing insights into critical time intervals of climate instability such as during the Maunder and Dalton solar minima. After developing a continuous, ca. 500-year-long varve chronology, high-resolution μ–XRF counts, stable-isotope data measured on ostracod shells, palynological (including pollen and dinoflagellate cysts), and diatom data are used to decipher the season-specific climate and ecosystem evolution at Etoliko Lagoon since 1450 AD. Our results show that the Etoliko varve record became more sensitive to climate change from 1740 AD onwards. We attribute this shift to the enhancement of primary productivity within the lagoon, which is documented by an up to threefold increase in varve thickness. This marked change in the lagoon's ecosystem was caused by: (i) increased terrestrial input of nutrients, (ii) a closer connection to the sea and human eutrophication particularly from 1850 AD onwards, and (iii) increasing summer temperatures. Integration of our data with those of previously published paleolake sediment records, tree-ring-based precipitation reconstructions, simulations of atmospheric circulation and instrumental precipitation data suggests that wet conditions in winter prevailed during 1740–1790 AD, whereas dry winters marked the periods 1790–1830 AD (Dalton Minimum) and 1830–1930 AD, the latter being sporadically interrupted by wet winters. This variability in precipitation can be explained by shifts in the large-scale atmospheric circulation patterns over the European continent that affected the Balkan Peninsula (e.g., North Atlantic Oscillation). The transition between dry and wet phases at Etoliko points to longitudinal shifts of the precipitation pattern in the Balkan Peninsula during the Little Ice Age.