Distribution patterns of fish assemblages in an Eastern Mediterranean intermittent river

The distribution patterns of fish assemblages within streams can provide insights for river type classifications and may warrant specific conservation actions. However, there is limited knowledge of how fish assemblages assort along a longitudinal axis in Mediterranean intermittent streams. Patterns in spatial and temporal distribution of fish communities were analysed in a Mediterranean intermittent river (Evrotas River) located in Southern Greece, hosting three endemic range restricted species of high conservation concern, during the period 2007−2009, with 80% of the river’s total length desiccating in the 2007 and 2008 droughts. The general trend was an increase in fish density and species richness along an upstream-downstream gradient. Fish assemblages from upstream to downstream were characterized by a decrease of the most rheophilic species (Squalius keadicus) and an increase of the most stagnophilic species (Tropidophoxinellus spartiaticus). Three river segments, characterized by a high degree of homogeneity were delineated. Habitat and environmental preferences for the studied fish species were identified, with elevation and low flowing habitats being the most important environmental factors affecting fish distribution patterns. The current study provides evidence that even in an intermittent river an assemblage pattern following a longitudinal gradient can be identified, mainly due to the lack of instream barriers that allows recolonization after flow resumption

Desarrollo de modelos de idoneidad de hábitat para la trucha balcánica (Salmo fariodes, Karaman) y estimación de caudales ecológicos en ríos de montaña de Grecia

[EN] Esta investigación, enmarcada en el proyecto ECOFLOW (Grecia), está enfocada a la estimación de caudales ecológicos en ríos de Grecia. La alteración hidrológica y la degradación de los hábitats fluviales han sido escasamente estudiados en este país, y permanecen aún fuera de su legislación. En este trabajo se aplicó el enfoque de la simulación del hábitat físico, basado en simulación hidráulica y del hábitat. Por primera vez para la trucha balcánica occidental (Salmo fariodes, Karaman) adulta, se realizó un modelo de idoneidad del hábitat multivariante (a escala de microhábitat) mediante modelos generalizados aditivos (GAM). Dichos adultos escogían principalmente los microhábitats con escasa corriente, profundos y con abundante refugio. Un tramo del río Acheloos se escogió para la simulación del hábitat físico. La falta de hábitats con abundante refugio y las pozas poco desarrolladas no llegaron a aportar una idoneidad alta. Esta primera aplicación en Grecia remarca la necesidad de ampliar y extender los enfoques de caudales ecológicos basados en estudios científicos locales y regionales, basados en hidrología y en eco-hidráulica. Estos métodos suponen avances importantes y son relevantes para mejorar el estado ecológico de los ríos y para la aplicación de las actuales políticas europeas sobre el agua.Este estudio se enmarca dentro del proyecto ECOFLOW patrocinado por la Secretaría General Griega para la investigación y la Tecnología en el marco de NSRF 2007-2013.Papadaki, C.; Muñoz Mas, R.; Ntoanidis, L.; Martínez Capel, F.; Zogaris, S.; Dimitriou, E. (2015). Desarrollo de modelos de idoneidad de hábitat para la trucha balcánica (Salmo fariodes, Karaman) y estimación de caudales ecológicos en ríos de montaña de Grecia. Cuadernos de la Sociedad Española de Ciencias Forestales. (41):253-268. http://hdl.handle.net/10251/60208S2532684

Residents' views on landscape and ecosystem services during a wind farm proposal in an island protected area

Industrial wind farms are being developed within many protected areas, such as in EU Natura 2000 sites; this includes proposals on small Mediterranean islands, such as Samothraki in Greece. Scarce wild land areas on islands may be particularly vulnerable to landscape-scale degradation; this may have serious negative societal impacts. Samothraki's resident perceptions were surveyed in the wake of such a proposal, in June 2018. Of 98 respondents, 48% reported they were against the wind farm plan, while 22% did not take sides. We compare for-and-against sub-group perceptions of the proposed wind farm with potential impacts on the landscape and explore residents' opinions on ecosystem services and environmental pressures and threats. Conflict over the wind farm was prevalent; residents most frequently reported that the proposal threatens aesthetic and landscape qualities. Aesthetic qualities were also the second highest ranked ecosystem services, after freshwater provision. However, other threats, such as livestock overgrazing, top residents' opinion of major environmental problems on the island. The questionnaire survey used provides a scoping assessment, which may assist in identifying "conflict hotspots" for wind farm development. A critical review of wind farm planning in protected areas is presented in light of insights gained from this survey and other relevant studies

Determination of environmental flows in rivers using an integrated hydrological-hydrodynamic-habitat modelling approach

[EN] We propose the novel integrated modelling procedure 3H-EMC for the determination of the environmental flow in rivers and streams; 3H-EMC combines Hydrological, Hydrodynamic and Habitat modelling with the use of the Environmental Management Classes (EMCs) that are defined by the Global Environmental Flow Calculator. We apply 3H-EMC in the Sperchios River in Central Greece, in which water abstractions for irrigation cause significant environmental impacts. Calculations of the hydrodynamic-habitat model, in which the large and the small chub are the main fish species, suggest discharge values that range from 1.0 m3/s to 4.0 m3/s. However, hydrological modelling indicates that it is practically difficult to achieve discharges that are higher than approximately 1.0-1.5 m3/s. Furthermore, legislation suggests significantly lower values (0.4-0.5 m3/s) that are unacceptable from the ecological point of view. This behaviour shows that a non-integrated approach, which is based only on hydrodynamic-habitat modelling does not necessarily result in realistic environmental flows, and thus an integrated approach is required. We propose the value of 1.0 m3/s as the "optimum" environmental flow for Sperchios River, because (a) it satisfies the habitat requirements, as expressed by the values of weighted useable area that are equal to 2180 and 1964 m2 for the large and small chub, respectively, and correspond to 82 and 95% of their respective maximum values, (b) it is consistent with the requirements of Environmental Classes A and B, whose percentiles are higher than 75% for discharge (77.2%) and for habitat availability (>83.5% for the large chub and >85.0% for the small chub), (c) it is practically achievable from the hydrological point of view, and (d) it is higher than the value proposed by the Greek legislation. The proposed modelling approach can be applied to any river or stream using the same or similar modelling tools, which should be linked via suitable coupling algorithms.Hydraulic field measurements were performed within the framework of a research project by the Hellenic Centre of Marine Research (HCMR) entitled KRIPIS “Development of an integrated management system for river basin, coastal and marine zones” (http://imbriw.hcmr.gr/en/). Fish habitat data were collected within the framework of the ECOFLOW research project (www. ecoflow.gr). A part of the modelling work has been performed, while the first author was a visiting professor at the Technical University of Munich (TUM); thanks are due to the Bavarian State Ministry of Education and Cultural Affairs and the German Academic Exchange Service (DAAD).Stamou, A.; Polydera, A.; Papadonikolaki, G.; Martinez-Capel, F.; Muñoz Mas, R.; Papadaki, C.; Zogaris, S.... (2018). Determination of environmental flows in rivers using an integrated hydrological-hydrodynamic-habitat modelling approach. Journal of Environmental Management. 209:273-285. https://doi.org/10.1016/j.jenvman.2017.12.038S27328520

New boundaries: Redefining the geographical range of a threatened fish through environmental DNA survey

Accurate data on the distribution and population status of threatened fish species are fundamental for effective conservation planning and management. In this work, in order to reassess the distribution of the globally threatened Evia barbel, Barbus euboicus, we undertook an environmental DNA (eDNA) survey coupled with conventional electrofishing, focusing on major river basins in Evia Island in proximity to its known occurrence in a single Evian basin (Manikiatiko stream). For comparison purposes, we conducted eDNA sampling in several locations in the geographically closest continental river basin, the Sperchios basin (Central Greece) which hosts the closely related Barbus sperchiensis. Our results expand the known range of the Evia barbel on Evia adding four new river basins, apart from its type locality (Manikiatiko stream (EV3)). In a single Evian River, where the species had never been located before, there was also a positive eDNA signal for Barbus sperchiensis within the same basin. The research confirms the occurrence of Evia barbel in a wider geographical area, highlighting however the sensitive conservation status of the species due to its still very narrow geographical distribution. The biogeographical implications of our study, as well as potential conservation interventions, are discussed

Potential impacts of climate change on flow regime and fish habitat in mountain rivers of the southwestern Balkans

The climate change in the Mediterranean area is expected to have significant impacts on the aquatic ecosystems and particular in the mountain rivers and streams that often host important species such as the Salmo farioides, Karaman 1938. These impacts will most possibly affect the habitat availability for various aquatic species resulting to an essential alteration of the water requirements, either for dams or other water abstractions, in order to maintain the essential levels of ecological flow for the rivers. The main scope of this study was to assess potential climate change impacts on the hydrological patterns and typical biota for a south-western Balkan mountain river, the Acheloos. The altered flow regimes under different emission scenarios of the Intergovernmental Panel on Climate Change (IPCC) were estimated using a hydrologicalmodel and based on regional climate simulations over the study area. The Indicators of Hydrologic Alteration (IHA) methodology was then used to assess the potential streamflow alterations in the studied river due to predicted climate change conditions. A fish habitat simulation method integrating univariate habitat suitability curves and hydraulic modeling techniques were used to assess the impacts on the relationships between the aquatic biota and hydrological status utilizing a sentinel species, the West Balkan trout. The most prominent effects of the climate change scenarios depict severe flow reductions that are likely to occur especially during the summer flows, changing the duration and depressing the magnitude of the natural low flow conditions. Weighted Usable Area-flow curves indicated the limitation of suitable habitat for the native trout. Finally, this preliminary application highlighted the potential of science-based hydrological and habitat simulation approaches that are relevant to both biological quality elements (fish) and current EUWater policy to serve as efficient tools for the estimation of possible climate change impacts on the south-western Balkan river ecosystems.This study was supported by the ECOFLOW project funded by the Hellenic General Secretariat of Research and Technology in the framework of the NSRF 2007-2013. The W. B. trout data collection was partially funded by the Spanish Ministry of Economy and Competitiveness with the project SCARCE (Consolider-Ingenio 2010 CSD2009-00065).Papadaki, C.; Soulis, K.; Muñoz Mas, R.; Martinez-Capel, F.; Zogaris, S.; Ntoanidis, L.; Dimitriou, E. (2016). Potential impacts of climate change on flow regime and fish habitat in mountain rivers of the southwestern Balkans. Science of the Total Environment. 540:418-428. https://doi.org/10.1016/j.scitotenv.2015.06.134S41842854

A distinct island population of threatened freshwater fish: to split or lump?

© 2016, Springer International Publishing Switzerland. Freshwater fishes in the Balkans display high percentages of endemic species, many being limited to restricted distributions. Their management, for example, through identification of priority areas for conservation or through re-introduction, is hampered by a poor understanding of their taxonomic diversity and interrelationships. We evaluate the identity of a sand goby belonging to Knipowitschia, limited to a single wetland on the Greek island of Zakynthos. Its representatives morphologically differ sufficiently from their congeners to qualify as a separate species. However, in view of the similarity in mitochondrial ribosomal DNA sequences, the evolutionary plasticity of said morphological characters, and in the absence of a taxonomic revision of the Ionian Ecoregion’s Knipowitschia gobies, describing it as a new species seems unjustified and premature. Rather, we advocate that its unique habitus and its vulnerability as the island’s only resident freshwater fish necessitate conservation efforts as a kind of “phenotypically significant unit”. We also propose sand gobies as flagships for wetlands in the region. This case study suggests a possible approach for fish conservation prioritization in the region, taking a precautionary angle in order to avoid taxonomic inflation, which is an imminent risk given the importance of nominal species and endemics in conservation policy.status: publishe

The racer goby,

The discovery of the racer goby Babka gymnotrachelus in the transboundary Evros river basin, collected on September 10th 2018 at two locations very close to the Greek-Bulgarian and Greek-Turkish borderlines, is reported. This is a new addition to the non-native ichthyofauna of Greece and the Aegean Sea drainages, and it is the second non-native Ponto-Caspian goby to enter this river. Boat-based electrofishing sampling, following the EU Water Framework Directive monitoring program, provides first evidence of what is presumed to be a recently established population; most of the 13 collected specimens are juveniles and the species has not yet been located in the river's tributaries. Further study and international cooperation in monitoring and management of this and other alien species in the Evros are proposed