Main Threats

In general terms, the International Union for Conservation of Nature (IUCN) identifies as threats to the survival of the barbel habitat alteration / fragmentation (A2) and water pollution (A3). The main threats are described below for the target species in the investigated area:

THREAT 1. Excessive water intakes and consequent reduction in water flow

  • Description. Along the rivers numerous water intake facilities are present in order to satisfy the multiple uses of water resources for human activity, such as: 1) human consumption (drinking water and mineral waters plants); 2) irrigation purposes; 3) energy purposes (power plants)
  • Impact on the species. The effects of flow reductions are many and range from reduction of aquatic spaces available, reduction of diluent power, increase in temperature, change of water conditions (depth, speed, current), as well as the interruption of river continuum with direct consequences on the decrease in size of populations and indirect consequences (ref. threats n. 1, 2 and 5). When talking of water management any funding of the project will represent a cultural and operating tool of remarkable relevance to focus on governance and local associations at a local and regional level. The introduction of the AdbPO (PO river basin authority) partnership is primarily aimed at the strategic planning in this direction (C6). The implementation of a LIFE project in areas affected by uncontrolled construction of hydroelectric power plants, will be a useful tool to apply for a stricter enforcement and monitoring of correct DMV (minimum vital flow), while also introducing the concept of Minimum Ecological Flow for the self-sustaining of reintroduced populations of barbels . The DMV will be studied (A3) and monitored (D1) in the course of the project in all target sites.

THREAT 2. Fragmentation of habitats/populations.

  • Description. The river continuum is interrupted by transversal barriers on the watercourses (dams, weirs etc.) and dry watercourse beds (ref. threat n.5). Within the study area n.13 main discontinuities have been identified. In detail, two barriers on the Cedra river in Selvanizza, downstream the Provincial road bridge and next to the intake of the hydroelectric power plant in a section of the river between SCI IT4030013 and SCI IT4020020 respectively; a barrier in Loc. Piane di Carniglia on the Taro river where one of the last populations of Southern Barbel with reproductive potential of the Parma province is present; the railway and the via Emilia axes which in particular cause discontinuities on the Taro (between SCI IT4020021 and SCI IT4020022) and Enza (SIC IT4030023) rivers. On the Enza river, on the SCI, n.9 barriers interrupting the river continuum have been identified which separate isolated populations and prevent regular movement of fish fauna both upstream and downstream.
  • Impact on the species. Discontinuities in watercourses prevent migration and access of species in the spawning area, during the breeding season, therefore limiting their reproductive potential. Furthermore, in the long term, fragmentation of the populations leads to a density decline, and a consequent biodiversity loss / loss of genetic diversity and thus to local extinction. An increase in local extinction causes the contraction and fragmentation of the entire range of the species, therefore hindering genetic exchange between populations forming it and increasing the risk of extinction.
  • Project interventions to counter the threat. The project will plan and enforce interventions to restore river continuity (removal of barriers which are not used, implementation of an appropriate DMV and/or preparation of “artificial passages for fishes”) as well as management interventions. In particular, specific interventions for ecological reconnection will be implemented next to the main discontinuities identified . Ref. to actions A4, A5, C2, C6 and E4.

THREAT 3. Alteration of habitats.

  • Description. The increasing alteration of the natural characteristics of watercourses is caused by:
    • Pollution of water and fluvial environments (introduction of toxic substances and/or heat in the river bed and/or along the banks) caused by urban, livestock, industrial and agricultural settlements;
    • Extraction of inert materials (gravels and stones)
    • overbuilding and canalization of rivers;
    • urbanization of foothill and lowland areas.

    THREAT 4. Introduction of alien species; wrong management of fish fauna for fishery purposes.

    • Description. Public bodies and fishing societies follow the old saying “the more fish you introduce in the river the more fish is available for fishing” and are used to introduce fish fauna of ‘interest’ in the water streams, in particular salmonids but also other taxa. A risk to the target species is the recent increase in the basin of the Po river of the common Barbus barbus or European Barbel, widely present in the Parmesan stretch of the Po river.
    • Impact on the species. Alien species which are introduced often: are able to acclimatize by competing with native species and causing: alteration of interspecific relationships, "genetic pollution", pathogens spreading. Southern Barbel, in particular, sharing the same habitat of salmonids, has been highly affected by massive restocking schemes with brown trout and rainbow trout, of which it is a potential prey and with which it can compete for food.
    • Project interventions to counter the threat. Within the project, a technical debate will be opened with the main stakeholders (C6). Moreover, a specific action (C7) will aim at monitoring and eradicating non-native species of barbel also with reference to the new regional law of the Emilia Romagna region on fishery (L.R. 07-11-12, n. 11) and associated outstanding regulations which are by far more restrictive towards alien species, both as to control of the populations and proposing true eradication in areas featuring special natural features, such as SCIs.

    THREAT 5. Climate changes.

    • Description. Climate changes have highlighted in recent years a global warming of the planet. As far as water streams are concerned, this has resulted in an increase in water temperatures and a decrease in water flows, with dry periods / areas in summer.
    • Impact on the species. The increase in temperatures also contributes to: formation of dry areas/river fragmentation (ref. to threat n.1), reduction of water flows (ref. to threat n.3) and variation in the vital conditions of the species. The latter might push the target species to migrate to the upper reaches of rivers therefore causing an overlapping of spawning areas and ecological niches with salmonids and alien species (such as the European Barbel and/or Spanish Barbel).
    • Project interventions to counter the threat. Measures for the reduction of fluvial fragmentation and a better management of water resources as a whole will be taken. Ref. to actions A3, A4, C2, C6 and E4.