Technical Solutions to Mitigate Shifting Fish Fauna Zones Impacted by Long Term Habitat Degradation in the Bistra Mărui River – Study Case

Abstract The Bistra Mărului River fish fauna has been severely impacted by man-made activities, especially through longitudinal fragmentation, over the past 40 years. Fish fauna monitoring revealed structural changes and technical methods have been proposed, in order to restore the natural connectivity and the conservation of fish species. Benefits should accrue for key species: Salmo trutta fario, Cottus gobio, Thymallus thymallus, Eudontomyzon danfordi, Eudontomyzon vladykovi, Gobio uranoscopus, Barbus meridionalis, and Condrostoma nasus.

The Lower Danube River-Danube Delta-North West Black Sea: A pivotal area of major interest for the past, present and future of its fish fauna--A short review.

The complex Danube-Black Sea geoecosystem, created by a unique combination of integrated biotopes and biocoenoses related forces and counter-forces in time and space, forms a rich "ichthyosystem". The equilibrium among the fish species captured in the Danube Delta reveals its structural and functional roles in the connectivity of the Danube and Black Sea. The key role of the delta is evidenced by the fact that 57.26% of the Lower Danube-Danube Delta-North West Black Sea fish species use two or three of the subsystems in terms of habitats. Therefore, this convergence area can be considered to be a dynamic and rich "ichthyosystem", with three subsystems. All three evolved interdependently, wh…

Proposed Environmental Risk Management Elements in a Carpathian Valley Basin, within the Roşia Montană European Historical Mining Area

Non-ferrous metals mining activities have long accompanied people, and began in the study area of South East Europe over 2000 years ago. The environment quality is significantly affected by both historic mining activities and contemporary impacts. All these problems, inducing synergic negative effects on local organism communities, have created a chronic state of pollution. The Corna Valley has one of the oldest historical human impacts in Romania due to the influence of mining. Fish and benthic macroinvertebrates have exhibited significant responses to long term mining effects on lotic systems. The analysis of macroinvertebrate communities, correlated with the lack of fish and some biotope…

Upper Caraş River (Danube watershed) fish populations fragmentation – technical rehabilitation proposal

Abstract We propose a technical solution for fish movement based on the flow of water over a spill threshold. Such barriers are common in the Danube system. The proposed system has a range of operating components which are easily detachable from the spill threshold, are resistant to corrosion and will not harm the fish. In fact, if designed to complement swimming abilities of target fish, it should provide adequate passage for both adults and juveniles. If implemented correctly, the design may offer a solution to help displaced fish recolonize upstream habitats.

Gobio Genus Species Integrated Management System – Târnava Rivers Study Case (Transylvania, Romania)

Abstract The lotic habitats quality indicative congeners species Gobio gobio, Gobio kessleri and Gobio albipinnatus populations’ dynamic in time (2004-2019) and space revealed a decreasing trend in these rivers ecological status. The ADONIS:CE tool has been used to build a backing management system model, based on these indicative fish species habitat needs, indicators for favourable conservation status, pressures and threats. This management system implementation in the field will favour the amelioration of lotic habitats and the ecological status recovering of two of the local fish species of conservative interest (G. kessleri and G. albipinnatus).

The Status of Romanogobio uranoscopus (Agassiz, 1828) Species, in Maramureş Mountains Nature Park (Romania)

Abstract The condition of aquatic habitats typically occupied by Romanogobio uranoscopus within the Maramureş Mountains Natural Park fluctuates, in the best cases, between reduced to average. Good or excellent conservation status is now absent for populations of this species in the researched area. The identified human impact types (poaching, minor riverbeds morphodynamic changes, solid and liquid natural flow changes, destruction of the riparian vegetation and bush vegetation, habitat fragmentation/isolation of population, organic and mining pollution and displaced fish that are washed away during the periodic flooding in the lotic sectors uniformized by humans) are contributing to the dim…

Sediments as Factor in the Fate of the Threatened Endemic Fish Species Romanichthys Valsanicola Dumitrescu, Bănărescu and Stoica, 1957 (Vâlsan River Basin, Danube Basin)

Abstract The main emphasis of this paper is on the negative effects of sedimentation on the most highly endangered fish of Europe Romanichthys valsanicola and the habitats of its main trophic resource Rhithrogena semicolorata. Some inexpensive and easy-to-implement solutions are identified and proposed (dam reservoir related recommendations for basin sediments management, forestry related recommendations for sediment basin management, basin sediments general management recommendations, riverbed ecological reconstruction approach proposal, etc.) in the paper with the same conservative purpose for Romanichthys valsanicola species in the actual situation of habitat loss and drastic regress of …

Proposal to Achieve Floodplain Connectivity in Alțâna Sector on Hârtibaciu River (Transylvania, Romania)

Abstract The process of supplying water to the new anthropogenic wetland is achieved gravitationally, and the excess water in the wetland will be directed towards the Hârtibaciu River in a similar natural way. The fish and fauna of the Hârtibaciu River have a disrupted lateral connectivity due to its banks embanking including in the proximity of the Alţâna locality. The newly proposed anthropogenic wetland would improve habitat quality for the fish species of conservation interest, Rhodeus amarus (Bloch, 1782), and increase its population numbers. A new fish species, Chondrostoma nasus, was identified for the first time in the Hârtibaciu River.

Hucho hucho (Linnaeus, 1758): last natural viable population in the Eastern Carpathians - conservation elements

There is great variation in the conservation status of the last habitats with long-term natural viable populations of the salmon species Hucho hucho in Maramureş Mountains Nature Park, Eastern Carpathians (Romania). According to the specific guidelines for Natura 2000, 42.11% are in good conservation status, 31.57% are of average status, and 26.32% are in a partially degraded condition. In this study area, 6 main risk elements were identified related to human impact on the environment: poaching, minor riverbed mor-phodynamic changes, liquid and solid natural flow disruption, habitat fragmentation leading to isolation of fish populations, organic and mining pollution, and destruction of ripa…

Human Impact Effects on Târnava River Basin Aquatic Biodiversity (Transylvania, Romania)

Today the following categories of human impact are present in the Tarnava Watershed: hydrotechnical works, insufficiently treated/cleaned sewage, river substratum mineral exploitation/over-exploitation, manure leakage, artificial standing water, industry, river embankment, deforestation, pouching, etc., the first three of these inducing the highest impact on the lotic systems habitats and biodiversity.

The “Porţile de Fier/Iron Gates” Nature Park (Romania) Some Danube Northern Tributaries Fish Fauna

Abstract The relative larger size of the Berzasca River, respectively the relatively constant environmental conditions, with relatively stenotopic ichthyocenosis, suffered small qualitative and quantitative fish fauna modifications in time, compared to the smaller rivers such as Sirinia, Liubcova/Oreviţa and Mraconia. The Danube “Iron Gates” I Lake influences the lower sectors of the studied rivers in term of fish species exchange. The accidental droughts in the karstic zones of the studied lotic sectors have a negative influence on the spatial continuity of the local fish fauna, and the climate change can increase these influence in the future. All the studied rivers play an important role…

Adding the Mureş River Basin (Transylvania, Romania) to the List of Hotspots with High Contamination with Pharmaceuticals

Background: The Mureș River Basin is a long-term heavily polluted watershed, in a situation of climate changes with increasing water flow and related decreasing dilution capacity. Here, a mixture of emerging pollutants such as pharmaceuticals were targeted to reveal potential risks regarding the natural lotic ecosystems. Due to the continuous discharge into the environment, pharmaceuticals are gaining persistent organic pollutant characteristics and are considered emerging pollutants. Based on the hazard quotient, this research highlights the dangerous concentrations of carbamazepine, ibuprofen, furosemide, and enalapril in river water. Results: High levels of four pharmaceutical compounds …

Benthic Macroinvertebrate Communities in the Northern Tributaries of the “Iron Gates” Gorge (Danube River)

Abstract The paper presents the structure of the benthonic macro-invertebrates communities in the Berzasca, Sirinia, Liubcova, and Mraconia rivers. The results are based on quantitative benthos samples (95 samples), collected in July 2014 from 19 sampling stations within the study area. In longitudinal profile, the benthonic macro-invertebrate communities of the Sirinia, Liubcova and Berzasca rivers displays relatively large structural variability, while the communities of the Mraconia River displays smaller structural variability. The structure of the benthonic macro-invertebrate communities correlated with the biotope characteristics indicates the good ecological status of the analysed ri…

The Role of Aquatic Refuge Habitats for Fish, and Threats in the Context of Climate Change and Human Impact, during Seasonal Hydrological Drought in the Saxon Villages Area (Transylvania, Romania)

In spite of the obvious climate changes effects on the Carpathian Basin hydrographic nets fish fauna, studies on their potential refuge habitats in drought periods are scarce. Multiannual (2016–2021) research of fish in some streams located in the Saxon Villages area during hydrological drought periods identified, mapped, and revealed the refuge aquatic habitats presence, management needs, and importance for fish diversity and abundance for small rivers. The impact of increasing global temperature and other human activities induced hydrologic net and habitats alteration, decreased the refuge habitats needed by freshwater fish, diminished the fish abundance, and influenced the spatial and te…

Management Elements for Two Alburninae Species, Alburnus alburnus (Linnaeus, 1758) and Alburnoides bipunctatus (Bloch, 1782) Based on a Decision-Support System Study Case

Abstract ADONIS:CE has been used as a base to create a support-system management decision-making model for Alburnus alburnus (Linnaeus, 1758) and Alburnoides bipunctatus (Bloch, 1782) species. Investigation of the habitat necessities and the identification of the necessary elements for a good status of conservation of these two fish species populations has revealed the pressures and threats to these congener species, for which specific management activities have been finally recommended.

Genetic analysis of populations of brown trout (Salmo truttaL.) from the Romanian Carpathians

The Carpathian Mountains are one of the most complex orogenetic areas of Europe, with unique fauna, including the brown trout (Salmo trutta). In this study we performed population genetic analysis of 12 differentS. truttapopulations using two types of molecular markers: nine microsatellites and mitochondrial D-loop sequences. The following working hypothesis was considered: the Romanian Carpathians and their surrounding lowlands can be key relief units based on which theS. truttagenetic diversity, spread, distribution, connectivity, relative isolation and genetic divergence can be at least partially explained. The phylogenetic analysis revealed that the majority of sequences were grouped in…

Bitterling Populations in The Sighisoara-Târnava Mare Natura 2000 Site ‒ A Support System for Management Decisions

Abstract The predominant threats to the Bitterling populations in the Sighisoara-Târnava Mare Natura 2000 site are the hydro technical modifications of the river channels, organic contamination and illegal fishing. ADONIS:CE is applied commonly for business processes modelling, however, in this study case was applied in an ecology/biology sphere of interest. The authors acquired a Bitterling model which contained all of the identified habitat species’ necessities, the specific indicators that give good preservation status and the present pressures and threats. The keeping of the riverbed morphodynamics is especially necessary - the meanders existence is significant for the aquatic mollusc s…

The Indicator Role of Algae in Assessing the Organic Pollution in the Lena River Delta, the Russian Arctic

The Lena River forms a delta, one of the largest in the world. The entire territory of the delta is part of the Ust-Lensky State Natural Reserve. The delta is located beyond the Arctic Circle in a continuous permafrost zone. The delta is crossed by numerous channels and has lakes, streams, hollows, and swamps. In the Russian Arctic sector, ambitious plans for the development of the oil industries are being implemented. This study goal was to determine the species composition of algae in the Lena River delta and to use their properties as indicators of organic water pollution as evidence of water ecosystem stress. The results of the study revealed 700 species from 10 phyla. Statistical analy…

Eudontomyzon danfordi (Regan, 1911) Species Populations Ecological Status in Maramureş Mountains Nature Park (Romania)

Abstract The Eudontomyzon danfordi characteristic habitats state of Maramureş Mountains Nature Park varies greatly, 19.05% are in excellent conservation status, 47.62% are in good/average status and 33.33% are in a partially degraded condition. The identified human impact categories which induced the decreasing of Eudontomyzon danfordi species habitat state in the studied area are: poaching, minor riverbeds morphodynamic changings, liquid and solid natural flow disruption, destruction of riparian trees and bush vegetation, habitat fragmentation-fish populations isolation, and organic/mining pollution activities.

Thymallus thymallus (Linnaeus, 1758), Ecological Status in Maramureş Mountains Nature Park (Romania)

Abstract Thymallus thymallus is considered a species of significant protective importance within the Vişeu Watershed. The state of habitats characteristically inhabited by Thymallus thymallus within the Maramureş Mountains Nature Park is balanced between reduced (one third of the lotic sectors where the species was identified), average (one third) and good (one third). The excellent conservation status is currently missing for populations of this fish in the Vișeu Basin. Human impact types identified as contributing towards the decreasing state of Thymallus thymallus habitats and therefore populations in the studied area in comparison with its natural potential are: poaching, minor riverbed…

Environmental Aspects of Implementation of Micro Hydro Power Plants – A Short Review

Abstract The economic importance of micro hydro power plants is obvious around the world and the development trend will continue well into the future. Unfortunately the effects on the local lotic systems habitats and biocoenosis are not studied, and in some cases or are known only to a small degree. A variety of taxa were identified in the study case areas as being significantly affected by the micro hydro power plants: macrophytes, macroinvertebrates and fish.

ECOLOGICAL ASSESSMENT AS A FIRST STEP IN THE EVALUATION OF ECOSYSTEM SERVICES PROVIDED BY LOTIC ECOSYSTEMS

ABSTRACT The ecosystems offer to the socio-economic system a series of goods and services derived from their processes and biodiversity. Ecosystem services offered by a river are at their highest potential when the river status is close to the natural one. Once the river is affected by human impact due to resources exploitation, hydro technical works, water abstraction or improper land use, the ecological status declines and the ecosystem services become scarce. This is why an ecological assessment is necessary in order to establish the connection between the ecosystem services and the human impact. In this paper, the ecological assessment of Timiș River was done, allowing the classificatio…

Flash-Floods Influence Macroinvertebrate Communities Distribution in Lotic Ecosystems

Abstract Stream dwelling invertebrate populations are facing an ample array of stressors including the habitat imbalance caused by important floods. In this research we used a novel way to estimate the impact of floods upon the substrate, by utilising a remote variable named “flash-flood potential” (FFP), which accounts for the site slope and the average slope of the upstream catchment. The results showed that certain groups are sensitive to the influence of the FFP whereas other are not. We propose this remote variable as a surrogate for assessing stress imposed by floods and sediment scouring for lotic macroinvertebrates.

A review of hydropower plants in Romania: Distribution, current knowledge, and their effects on fish in headwater streams

Abstract Hydropower is currently experiencing a boom in southeast Europe. For Romania, the number of hydropower plants is estimated to be between 545 and 674, but little has been published about their environmental impact. We provide the first overview of the geographical distribution of hydropower plants in Romania, supplemented by a review of current knowledge about their environmental impact, and present case study evidence on the effects of small hydropower plants on fish in headwater streams of the Carpathian Mountains. We show that 49% of the documented 545 hydropower plants in Romania are located in Natura 2000 or other protected areas, 5% are located in water bodies with ‘very good’…

Bioaccumulation of persistent organic pollutants in the gonads of Barbus barbus (Linnaeus, 1758)

Maps with grey or even white spaces are still present in spite of the fact that persistent organic pollutants (POPs) are at the forefront of research in aquatic toxicology and environmental safety. This is also the case for the Mureș River basin. The intensive use of industrial substances such as polychlorinated biphenyls (PCBs) and pesticides such as organochlorine compounds (OCPs) has caused global contamination of the aquatic environment. In our study we have found very high concentrations of both PCBs (2110-169,000 ng/g lipid weight ΣPCB, 1950-166,000 ng/g lipid weight ΣPCB7) and OCPs (1130-7830 ng/g lipid weight ΣDDT, 47.6-2790 ng/g lipid weight ΣHCH, 5.53-35.6 ng/g lipid weight ΣChlor…

Barbus meridionalis Risso, 1827 populations status in the Vişeu River basin (Maramureş Mountains Nature Park)

Abstract The ecological state of lotic ecosystems occupied naturally by Barbus meridionalis, in the Vişeu Basin within the Maramureş Mountains Natural Park, vary among good to reduced. The inventoried human activities which negatively influence the ecologic state of the Barbus meridionalis species habitats and populations are the organic and mining pollution, and poaching. The habitats with low and inadequate conditions created a reduced status of the Barbus meridionalis populations; the status of Barbus meridionalis populations is not so much affected in the cases of habitats of average to good condition. Barbus meridionalis is considered a relatively common fish species in the researched …

Suport System for the Management of the Sabanejewia aurata (De Filippi, 1863) Populations of the ROSCI0227 – Sighișoara-Târnava Mare

Abstract ADONIS:CE was used to design a computer model for the management of Sabanejewia aurata (De Filippi, 1863) populations in the Natura 2000 site of Sighişoara-Târnava Mare (ROSCI0227). The recommended management model is based on the environmental needs of the species, inventoried according to the local habitats, as well as the indicators of conservation status and relevant management measures, and takes into account human pressures and threats identified in the research area. Such computer models were established for all protected fish species found at the site ROSCI0227.

Remote sensing and in-situ approach for investigation of pelagic communities in the reservoirs of the electrical power complex

Improvement of lateral connectivity in a sector of River Hârtibaciu (Olt/Danube Basin)

Abstract The Hârtibaciu River in the Alţâna area has a disturbed lateral connectivity owing to its lateral embankments, as a result of which fish communities in this river sector are negatively influenced. The method of obtaining the water supply for a new proposed wetland is by gravitation, and any excessive water supply to the wetland will be controled and directed to the Hârtibaciu River in a natural manner. A state-of-the-art man-made wetland should increase the quality of the habitat for local fish communities, especially for the Rhodeus sericeus population, which is a species of conservation interest.

Diversion of Fishing Pressure on the Economically Important Species Barbus barbus (Linnaeus, 1758) to Protect the Community Interest Congeneric Barbus meridionalis Risso 1826, Based on a Decision-Support Management System

Abstract The ADONIS:CE instrument has been used in the field of congeners species, Barbus barbus – of economic interest and Barbus meridionalis – of conservation interest, to build a support-system model for management decision-making. Analysis of the habitat needs and the indicators for favorable conservation status have identified pressures and threats to these fish species for which management actions have been proposed. This management system favors the decrease of fishing pressure on Barbus meridionalis species by its transfer to Barbus barbus species.

Sabanejewia Aurata (De Filippi, 1863) Populations Management Decisions Support System for Rosci0132 (Olt River Basin)

Abstract The ADONIS: CE was used to design a specific management model for the Sabanejewia aurata (De Filippi, 1863) populations. The proposed model is based on this species, in situ identified biological/ecological necessities in relation to the habitats, the conservation status indicators and appropriate management actions and the pressures and threats founded in the study area. Such on species, on habitats and on site based management system was done to complete this approach for ROSCI0132, the other fish species which are living there being treated already in this respect.

Biotope Determinants of EPT Assamblages Structure – Târnava Watershed (Transylvania, Romania) Case Study

Abstract This study aims to analyze the biotopic factors affecting the EPT assemblage diversity in the rivers of the Târnava Watershed. Our research revealed that the high diversity of the Plecoptera communities is associated with river reaches with boulder and cobble lithological substrate, accentuated slope and natural bank dynamics, and also it is directly correlated with dissolved oxygen and inversely correlated with chemical and biochemical oxygen demand, total hardness, nitrates and total nitrogen in the water. The high diversity of the Trichoptera communities is associated with water which presents moderate quantities of nutrients (total phosphorus, phosphates) and with river reaches…

Assessment of the ecological sustainability of river basins based on the modified the ESHIPPOfish model on the example of the Velika Morava basin (Serbia, Central Balkans)

This study examines the ecological sustainability of the Velika Morava River Basin (Serbia, Central Balkans) under modern conditions of multiple freshwater stressors, including climate change. The impact of stressors on the ecological services of the river basin is considered, including: drinking water, irrigation, recreation, tourism, ecotourism, and fishing. In order to assess the ecological sustainability of the river basin, a modification of the ESHIPPO model was performed. The essence of the modification is a change to the ES component, which, in the basic model, assesses the degree of ecological specialization of a taxon; and in the modified assessment of the ecological stability of t…

Management Elements Proposal for Sutla Natura 2000 Site

Abstract Following the accession of Croatia to the EU, a study was carried out on a Croatian Natura 2000 site which includes habitats used by the following fish species of conservation interest: Eudontomyzon vladykovi, Rhodeus sericeus amarus, Gobio uranoscopus, Romanogobio kesslerii, Barbus meridionalis, Zingel streber and Cottus gobio. Harmful effects on fish fauna were found due to: poorly-integrated water management, over-extraction of water for irrigation, fragmentation of riparian vegetation, low cooperation between environment institutions in Croatia and Slovenia, abuse of pesticides, uncontrolled waste water, sources of chemicals and heavy metals, leakage of nitrogen, habitats fragm…

Use of DNA barcoding in the assignment of commercially valuable fish species from Romania

DNA barcoding is a molecular technique frequently used either for biodiversity monitoring and fish conservation or in the identification of the species of origin for raw and processed food from restaurants or fish markets. The most important aspect of this technique is that it works for all stages of life and can be used to distinguish between closely related taxa. Also, the technique has been used to unmask attempts of frauds in fish markets where more desirable and expensive fish are sometimes substituted with lower valued species. Our study aims to test the utility of the COI barcoding gene in the correct identification of several economically and ecologically valuable fish species, and …