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Răzvan Voicu and Liliana Voicu

Abstract

The channel of the river Crișul Repede inside the town affects both the biodiversity and implicit functionality of Crișul Repede River, therefore, this article aims to provide a solution for fish fauna migration in a system designed to restore longitudinal connectivity. The proposed migration system is based on the gravitational fall of water and will lead to the restoration of the longitudinal connection of Crişul Repede River near the weir selected as the study case. It will reconnect approximately three kilometers of habitat that will contribute to ensuring the optimal conditions for the development of migratory fish species present in the area.

Open access

Răzvan Voicu and Liliana Voicu

Abstract

The Hârtibaciu River is channelled (covered by concrete) near the city of Agnita and represents the confluence of numerous sources of local pollution having a negative impact both qualitatively and quantitatively. Lack of riparian vegetation gives the Hârtibaciu River an unpleasant aspect and cannot provide an efficient filter.

This ecotechnical method helps to protect the special protected areas (SPAs) into Hârtibaciu River basin and to clean the river in the city of Agnita. By the means of this method the quality of the Cibin River can also be improved, as the Hârtibaciu River is a tributary of it

Open access

Răzvan Voicu and Eric Merten

Abstract

The paper presents a case study that proposes a technical solution to facilitate fish migration upstream the discharge sills located on Someşul Mic River, near the Mănăştur Dam from the Cluj Napoca Town. The proposed solution provides building of a system to facilitate fish migration, placed on the left bank of Someşul Mic River, meant to restore the longitudinal connectivity of Someşul Mic River in front of the Mănăştur Dam discharge sills and to facilitate the access of the migratory fish species to upstream breeding habitats. The proposed migration system is based on using traction of winches and the gravitational fall of water and will lead to the restoration of the longitudinal connection of the Someşul Mic River near the weir selected as case study, and will reconnect a habitat with a length of around one km, that will contribute to insuring of optimal conditions for developing migratory fish species present in the area.

Open access

Răzvan Voicu and Pete Baki

Abstract

Retis (dam Retis), hydro-technical development like many other transverse hydraulic structures cancel the longitudinal connectivity of Hârtibaciu water course, blocking the migration of different (migrating) species of fish in the river. Also, the lateral connectivity was heavily affected on this water course at a rate of 60%. Therefore, proposing engineering solutions to recover both (lateral and longitudinal) types of connectivity is vital to restore the local ecobiom. The purpose of this article is to establish longitudinal connectivity through an engineering solution that facilitates the fish migration upstream - downstream of Retis dam. This paper proposes an engineered fish passage solution for Retiș Dam on the Hârtibaciu River, using the criteria described in the Water Framework Directive 2000/60/EC document. Anthropogenic barriers located in the Hârtibaciu River disrupt and delay movement of local fish fauna including: Alburnoides bipunctatus (Bloch, 1782), Squalius cephalus (Linnaeus, 1758), Alburnus alburnus (Linnaeus, 1758), Rhodeus amarus (Bloch, 1782), Gobio gobio (Linnaeus, 1758), Romanogobio kessleri (Dybowski, 1862), Barbatula barbatula (Linnaeus, 1758), Barbus meridionalis Risso, 1827 Misgurnus fossilis (Linnaeus, 1758), Cobitis taenia Linnaeus, 1758, Cobitis romanica (Băcescu, 1943), and Cobitis aurata (De Filippi, 1863).

Open access

Răzvan Voicu and Lawrence G. Dominguez

Abstract

Longitudinal connectivity restoration of watercourses is a major duty for scientists (biologists, hydro engineers, chemists etc.) that, by the means of technical exchange via conferences, projects, workshops, universities, and institutions demonstrate the major importance of a natural (non-anthropic) function of the lotic ecosystems. On the Ialomiţa River, the discharge sills located downstream from Padina chalet block the migration of some fish species, such as the brown trout (Salmo trutta) and the bullhead (Cottus gobio), prohibiting access to foraging areas and springs. Water Framework Directive 60/2000 / EC provides a legal framework for restoring “good status” of longitudinal and lateral connectivity of watercourses. Our proposed solution I can be applied to other discharge sills and dams sized between 3m and 6m high, and, where feasible can utilize existing power sources of some discharge sills. Solution II’s concepts allow the dimples inside the concrete plate to serve as a rest and recovery area for migratory species. Such benefits that ensure upstream/downstream fish migration while allowing discharge management to continue is unattainable in conventional systems. After solution II is applied the discharge sill does not lose any baseline characteristics while maintaining the original hydro-technical design objective, flood dissipation.

Open access

Răzvan Voicu, Doru Bănăduc, Lee Jason Baumgartner, Liliana Voicu and Angela Curtean-Bănăduc

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.

Open access

Răzvan Voicu, Linda Heron, Angela Curtean-Bănăduc and Doru Bănăduc

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.

Open access

Răzvan Voicu, Kelly Miles, Robbin Sotir, Angela-Curtean Bănăduc and Doru Bănăduc

Abstract

The fish fauna of the Hârtibaciu River has experienced a disrupted connectivity due to the hydrotechnical works and the Brădeni/Retiş Dam located across the Hârtibaciu watercourse being one of this significant obstacles. The newly proposed constructed wetlands can improve the habitat quality for the fish species of conservative interest sampled in the Brădeni/Retiş Dam proximity Rhodeus amarus, and can increase the individuals’ number of this population. Also can benefit the local populations of Phoxinus phoxinus and Gobio obtusirostris. Using gravitational force and also the underground layout, a proposed technical solution gives maximum safety regarding the water supply for the newly proposed to be created wetlands.

Open access

Doru Bănăduc, Răzvan Voicu, Lee Jason Baumgartner, Saša Marić, Alexandru Dobre and Angela Curtean-Bănăduc

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.

Open access

Răzvan Voicu, Doru Bănăduc, Eric Kay, Erika Schneider-Binder and Angela Curtean-Bănăduc

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.