Database.use.hdl: https://hdl.handle.net/20.500.14172/20963
Now showing 1 - 10 of 18
  • In coastal lagoons, eutrophication and hydrology are interacting factors that produce distortions in biogeochemical nitrogen (N) and phosphorus (P) cycles. Such distortions affect nutrient relative availability and produce cascade consequences on primary producer's community and ecosystem functioning. In this study, the seasonal functioning of a coastal lagoon was investigated with a multielement approach, via the construction and analysis of network models. Spring and summer networks, both for N and P flows, have been simultaneously compiled for the northern transitional and southern confined area of the hypertrophic Curonian Lagoon (SE Baltic Sea). Ecological Network Analysis was applied to address the combined effect of hydrology and seasonality on biogeochemical processes. Results suggest that the ecosystem is more active and presents higher N and P fluxes in summer compared to spring, regardless of the area. Furthermore, larger internal recycling characterizes the confined compared to the transitional area, regardless of the season. The two areas differed in the fate of available nutrients. The transitional area received large riverine inputs that were mainly transferred to the sea without the conversion into primary producers' biomass. The confined area had fewer inputs but proportionally larger conversion into phytoplankton biomass. In summer, particularly in the confined area, primary production was inefficiently consumed by herbivores. Most phytoplanktonic N and P, in the confined area more than in the transitional area, were conveyed to the detritus pathway where P, more than N, was recycled, contributing to the unbalance in N:P stoichiometry and favouring N-fixing cyanobacteria over other phytoplankton groups. The findings of this study provide a comprehensive understanding of N and P circulation patterns in lagoon areas characterized by different hydrology. They also support the importance of a stoichiometric approach to trace relative differences in N and P recycling and abundance, that promote blooms, drive algal communities and whole ecosystem functioning.
      9WOS© IF 9.8WOS© AIF 6.5Scopus© SNIP 2.026
  • Introducing ESTAS-AQUABC, a new software tool designed for modelling nutrient cycles and eutrophication in highly-eutrophic estuaries. Our focus on replicating intense cyanobacteria blooms and N2-fixation sets us apart from other estuary models. We account for N2-fixation by cyanobacteria, the inorganic carbon cycle, non-conservative alkalinity, and pH calculations through CO2SYS integration. AQUABC also includes ammonia-stripping at high pH in its kinetic sub-model. ESTAS-AQUABC uses box modelling approach where the fluxes between boxes are calculated by a hydrodynamical model, in our case the SHYFEM model. This approach is robust, especially when field data for calibration is scarce, saving computational time. While our model accurately reproduced pelagic N2-fixation rates, inorganic nutrient dynamics were less precise, mainly due to the absence of bentho-pelagic exchange processes. ESTAS-AQUABC provides a useful tool to investigate nutrient retention from land to open sea, which could be important to mitigate eutrophication in estuarine systems and the adjacent coastal areas.
      7WOS© IF 3.1WOS© AIF 3.9Scopus© SNIP 1.062
  • research article
    Fernández-Alías, Alfredo
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    Ibáñez-Martínez, Helena
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    Muñoz, Irene
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    Marcos, Concepción
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    Pérez-Ruzafa, Angel
    Marine environmental research. Oxford : Elsevier, 2022, vol. 181, art. no. 105732., p. 1-10
    The assessment of connectivity in marine ecosystems is a requirement to adequate fisheries management. In this study we have selected two commercially exploited migratory species, European perch (Perca fluviatilis) and European smelt (Osmerus eperlanus), to evaluate the connectivity between the Curonian Lagoon and the coastal Baltic Sea. Our results indicate that isolation between the coastal lagoon and the adjacent sea area does not lead to the formation of genetic structure in migratory fish species. However, both species do register subpopulations coexisting in the area without interbreeding. This indicates that the fisheries management for migratory fishes in coastal lagoons affects a wider area than just the coastal lagoon. European perch, being a postglacial recolonizer from various refugees, has four different subpopulations, while the mechanism that maintains this division remains unexplored. The feeding migrations of European perch to the coastal zone suggest that the reproduction might occur elsewhere and that the factors for genetic structure suggested at the Baltic Sea scale might operate during these migrations. For European smelt, we discuss the existence of two different ecotypes, one lagoonal and one diadromous, and the different registered spawning locations as explicative causes for the maintenance of two genetically divergent clusters. The lagoonal ecotype reproduces and spawns inside the Curonian Lagoon while the diadromous one lives in the open Baltic Sea, performing spawning migrations to the lagoon and the mouth of Nemunas river, thus, maintaining the genetic divergence among them. However, our results indicate that there are no differences in size between both clusters, while the lagoonal population is expected to be smaller, forbidding the determination of two genetically different ecotypes. We conclude that there are no geographically and genetically separated populations of these two species in the lagoon-sea- terrestrial inlets continuum, and unified stock management for the coastal Baltic Sea and the Curonian lagoon is required.
      9WOS© IF 3.3WOS© AIF 4.567Scopus© SNIP 0.946
  • research article
    Hummel, Herman
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    Kalle, Valerie
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    Bienfait, Louise
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    Boyer, Yolande
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    Heurich, Marco
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    Svajda, Juraj
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    Adamescu, Mihai
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    Cazacu, Constantin
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    Medina, Félix Manuel
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    Poursanidis, Dimitris
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    Tasevska, Orhideja
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    Al Malla, Ajman
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    Stritih, Ana
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    Rossi, Christian
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    Arenas-Castro, Salvador
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    Carvalho-Santos, Claudia
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    Smit, Izak P.J.
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    Valentini, Emiliana
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    Xuan, Alessandra Nguyen
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    Orenstein, Daniel
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    Provenzale, Antonello
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    de Wit, Rutger
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    Hummel, Christiaan
    Environmental and sustainability indicators. Amsterdam : Elsevier, 2022, vol. 14, art. no. 100179., p. 1-14
    Assessing the environmental status of Protected Areas (PAs) is a challenging issue. To indicate that status, the identification of a common set of variables that are scientifically sound, and easy to assess and monitor by the PA practitioners, is particularly important. In this study, a set of 27 Essential Variables (EVs) for PA management was selected in a bottom-up process from 67 harmonised variables that describe the status of Ecosystem Functions and Structures, Ecosystem Services, and Threats in PAs. This bottom-up process involved 27 internationally recognised PAs, mostly European, with different level of protection, different extent, and a wide range of human-nature interactions. The EVs were selected by more than 120 practitioners, i.e. PA managers and rangers, as well as scientists, working in terrestrial and aquatic PAs. Across both terrestrial and aquatic PAs, scientists and practitioners largely identified the same variables as important. Data availability for these 27 EVs varied between PAs and av eraged 67% across all studied PAs. As this set of EVs for PAs is defined through a bottom-up approach considering variables already in use both in management and research, it is more than for previous EVs likely to be adopted, applied and developed to record the status and changes in the ecological and socio-economic conditions of PAs and to forecast future changes. Thereby, the EVs for PAs present a common vocabulary and tool to enhance in a uniform way the (inter)national communication, exchange and comparison of information on the status of PAs between policy makers, scientists and PA managers. The perceived status of the EVs, on an average 3.6 on a scale to a maximum of 5, indicates the surveyed PAs are in a moderate to good environmental condition. Moreover, the EVs for PAs form a cost- and time-efficient tool for PA managers to monitor developments in essential elements of their PAs, including the potential for Societal Goods and Benefits (SG&B), and to (pro-)actively tackle the potential threats that may arise in their area. Likewise, for policy makers EVs for PAs may support decision making on ecosystem management, spatial planning, and predictive modelling on the future status and requirements of PAs in their country or region.
      7WOS© IF 4.3WOS© AIF 2.9Scopus© SNIP 1.408
  • research article
    Pérez-Ruzafa, Angel
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    Marcos, Concepción
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    Pérez-Ruzafa, Isabel M.
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    Marine environmental research. Oxford : Elsevier Ltd, 2020, vol. 153, art. no. 104824., p. 1-19
    Coastal lagoons are among the most productive systems in the world. Many marine species make use of this by entering the lagoons as juveniles for nursery and growth before returning to the sea for reproduction. Humans take advantage of such fish migration processes by fishing, and exploit the high productivity for aquaculture activities. The Mar Menor is one of the largest coastal lagoons in the Mediterranean, sustaining relatively high fishing intensity despite the fact that it has traditionally been characterized as highly oligotrophic. However, in the last decades, this lagoon has suffered drastic changes induced by human activities. This has led to eutrophication, which started mainly as a consequence of changes in agricultural practices in the lagoon watershed, and triggered such fundamental changes in the system, as the mass development of jellyfish. The aim of this work is to capture and analyse the structure and functioning of the trophic web of the Mar Menor when it was still, in contrast to other coastal lagoons, oligotrophic, to provide a start point for analysing the consequences of changes in the distribution of macrophyte meadows and of eutrophication. We have compiled a detailed trophic model of this lagoon, comprising 94 compartments, using an ECOPATH model to capture the period 1980–1995. At this time the lagoon was an autotrophic system with a high net surplus of production that reached 9124.31gC/m2/year, while the production/biomass (P/B) ratio reached 34.56 and the total primary production/total respiration ratio was 7.01. The lagoon exported a 38.46% of total flows, including the catch by fishing, and 44.40% went to detritus. The primary production was mainly benthic (99.4%) due to the microphytobenthos and macrophytes. However, despite the fact that total fishery landings in the study period ranged between 144,835.5 and 346,708.5 kg, the gross efficiency was low, making up only 0.005% of the net primary production. This could partly be explained by the high trophic level of the fish catch (2.9), but mainly because most of the primary production (10,532.06 gC/m2/year) went directly to the detritus pool and was accumulated in the sediment in the Caulerpa prolifera meadows. We suggest several reasons why such high productivity coincided with low chlorophyll concentrations and good overall water quality: 1) the domination of both benthic biomass and primary production over pelagic ones with a high biomass of filter feeders, detritus feeders and scavengers, 2) high species diversity, complex and long food webs characterized by low connectance,3) the export of a significant part of the production from the system, and 4) the accumulation of surplus organic matter (as detritus) in sediments. We compare the food web of the Mar Menor in this mentioned oligotrophic stage to those of ten other lagoons in pursuit of more general implications regarding lagoon ecosystem functioning.
    Scopus© Citations 19WOS© IF 3.13WOS© AIF 4.144Scopus© SNIP 1.122
  • research article
    Karstens, Svenja
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    Nazzari, Cristina
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    Bâlon, Carmen
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    Bielecka, Malgorzata
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    Grigaitis, Žilvinas
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    Schumacher, Johanna
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    Stybel, Nardine
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    Marine policy. Oxford : Elsevier, 2018, vol. 97., p. 51-60
    Lagoons often suffer from eutrophication. Floating islands planted with native emergent macrophytes offer a solution for internal nutrient removal. These’active barriers’ have been applied in various inland waters, but never in coastal and marine environments. First coastal floating wetlands were installed in different lagoons along the Southern Baltic Sea. However, prior to these installations a comprehensive site selection and permit process had to be carried out. Participatory mapping was performed, law regulations in five European countries investigated and open-source data was integrated to evaluate where suitable installation sites would be. Regional environmental conditions influence how a floating wetland is designed, planted and installed, but do not limit the choice of installation sites explicitly. Restrictions and site choices depend largely on ‘social preferences’ and legal requirements. The participatory mapping showed that visibility of the floating wetlands is important. The proximity to the shore, and hence to potential bathing sites, as well as the proximity to larger cities or tourist destinations are important decision-making factors. The legal steps in the permit process differ in European countries and transferability is difficult. However, all case studies share in common that open waterways and undisturbed maritime traffic are a priority. All investigated lagoons belong to the European Natura 2000 network and are protected habitats. Nevertheless, this does not per se have to complicate the permit process for floating wetlands as the aim of the macrophyte islands is in accordance with the regional, national and European laws on nature protection. A variety of scientific articles proved the usefulness of floating wetlands for nutrient removal in mesocosm experiments. It is time to pave the way for pilot installations in coastal waters. [...]
    Scopus© Citations 8WOS© IF 2.865WOS© AIF 2.581Scopus© SNIP 1.346
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    Estuarine, coastal and shelf science. London : Elsevier, 2017, vol. 195., p. 110-123
    A macroscopic food web network for the exposed sandy coastal zone of the south-eastern Baltic Sea was reconstructed using ECOPATH software to assess the matter and energy balance in the ecosystem. The model incorporated 40 living functional groups representing the Baltic Sea coastal system of Lithuania during the first decade of 21rst century. The overall pedigree index of our model was relatively high (0.66) as much of the input data originated from the study area. The results indicate net heterotrophy of the coastal zone due to strong influences from the nearby river – lagoon system (Curonian Lagoon). The majority of fish species and waterbirds were present in the coastal system on a seasonal basis and their migrations contributed to heterotrophic conditions. Among fish, the freshwater stragglers possibly contribute to the reversal of flow in biomass and energy from the coastal zone to the river-lagoon system. Top predators such as breeding and wintering piscivorous waterbirds and large pike-perch were identified as keystone species. There was a clear negative balance for the biomass of small marine pelagic fishes such as smelt, sprat and Baltic herring which represent the main prey items in this system.
    Scopus© Citations 8WOS© IF 2.413WOS© AIF 2.089Scopus© SNIP 1.18
  • research article; ;
    Mazur-Marzec, Hanna
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    Oceanologia. Sopot : Polish Academy of Sciences, 2015, vol. 57, iss. 1., p. 93-101
    In the current study we present the first report on the bioaccumulation of microcystins (MC) in zebra mussel Dreissena polymorpha from the eutrophic brackish water Curonian Lagoon. The bioaccumulation capacity was related to age structure of mussels and ambient environmental conditions. We also discuss the relevant implications of these findings for biomonitoring of toxic cyanobacteria blooms in the Curonian Lagoon and potential consequences for D. polymorpha cultivation activities considered for the futures as remediation measure. Samples for the analysis were collected twice per year, in June and September, in 2006, 2007 and 2008, from two sites within the littoral zone of the lagoon. The highest microcystin concentrations were measured in mussels larger than 30 mm length and sampled in 2006 (when a severe toxic cyanobacteria bloom occurred). In the following years, a consistent reduction in bioaccumulated MC concentration was noticed. However, certain amount of microcystin was recorded in mussel tissues in 2007 and 2008, when no cyanotoxins were reported in the phytoplankton. Considering high depuration rates and presence of cyanotoxins in the bottom sediments well after the recorded toxic blooms, we assume mechanism of secondary contamination when microcystin residuals could be uptaken by mussels with resuspended sediment particles.
    Scopus© Citations 26WOS© IF 0.935WOS© AIF 1.945Scopus© SNIP 0.788
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    Ocean & coastal management. Oxford : Elsevier, 2014, vol. 101, pt A., p. 14-23
    The term transitional waters embraces a wide array of ecosystems’ types, including river mouth ecosystems, lagoons, coastal lakes, rias, fjords and fjards, brackish wetlands and hyper-saline ecosystems. The paper analyzes the challenges of integrated environmental planning of the transboundary transitional waters based on the case study of the Curonian Lagoon, which is the largest coastal lagoon in Europe shared by Lithuania and Russia. In terms of the water quality management framework on the basin level, the Russian Neman river water management district is by and large complementary to the Lithuanian Nemunas River Basin District. Yet, differently from the European Union, transitional or coastal waters are not integrated into the river basin management schemes or action programmes in Russia. [...]
    Scopus© Citations 14WOS© IF 1.748WOS© AIF 2.013Scopus© SNIP 1.29
  • research article
    Newton, Alice
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    John, Icely
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    Cristina, Sónia
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    Brito, Ana
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    Cardoso, Ana Cristina
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    Colijn, Franciscus
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    Riva, Simona Dalla
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    Gertz, Flemming
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    Hansen, Jens Würgler
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    Holmer, Marianne
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    Ivanova, Kateryna
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    Leppäkoski, Erkki
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    Canu, Donata Melaku
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    Mocenni, Chiara
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    Mudge, Stephen
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    Murray, Nicholas
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    Pejrup, Morten
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    Reizopoulou, Sofia
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    Pérez-Ruzafa, Angel
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    Schernewski, Gerald
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    Schubert, Hendrik
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    Carr, Laishalla
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    Solidoro, Cosimo
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    Viaroli, Pierluigi
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    Zaldívar, José-Manuel
    Estuarine, coastal and shelf science. London : Academic Press, 2014, vol. 140., p. 95-122
    The paper gives an overview of some of the large, shallow, semi-enclosed coastal systems (SECS) in Europe, These SECS are important both from the ecological and the economic perspective (socioecological systems) and provide many valuable ecosystem goods and services. Although some of the systems are transitional waters under theWater Framework Directive, this is not the case for all of the systems. The paper adopts a Driver-Pressure-State-Impact-Response approach to analyse the ecological status, vulnerability and future perspectives of these systems in the context of global change.
    Scopus© Citations 240  1WOS© IF 2.057WOS© AIF 1.953Scopus© SNIP 1.237