Projects / Programmes
ELABORATION OF EXPERTISE FOR HUCHEN HABITAT AND POPULATION CONSERVATION IN THE MIDLLE SAVA RIVER
| Code |
Science |
Field |
Subfield |
| 1.03.03 |
Natural sciences and mathematics |
Biology |
Ecosystems |
| Code |
Science |
Field |
| B260 |
Biomedical sciences |
Hydrobiology, marine biology, aquatic ecology, limnology |
| Code |
Science |
Field |
| 1.06 |
Natural Sciences |
Biological sciences |
Danube salmon, huchen, Hucho hucho, management plan, conservation, ecology, genetics, habitat, modeling
Researchers (14)
Organisations (3)
Abstract
The huchen - Hucho hucho (Linnaeus, 1758) is the largest species of trout living in Slovenia. To date research estimates the huchen population in the middle Sava River (Sava-Medvode-Kresnice) as the most vital population in Slovenia. This population was protected in 2003 with the establishment of Natura 2000 site within its distribution area. The main threat to the huchen population in Slovenia is the habitat deterioration and the modifications of river flow resulting from the construction and operation of hydroelectric power plants. Due to the obvious conflict of interests - protection of the huchen populations on the one hand and the use of hydroelectric potential of the Sava River on the other - we want to prepare a scientific foundation, based on ichthyological and genetic research of the huchen in the Sava River, and to assist in decision-making on the energy utilization of the Sava River with respect to the conservation of the habitat and the populations of the huchen. By analyzing the existing ichthyological research and data available we will determine the ''gray areas'' and devise a new ichthyological survey involving the targeted sampling and the inventory of the spawning grounds of the species. Based on the analysis of the newly obtained data we want to assess the quality and strength of the huchen population in the middle Sava River and create an action plan for its conservation. In addition, we want to perform a habitat modeling to assess changes in the habitat of the selected section of the middle Sava River as a result of a reduced water flow in the event of the extraction of water for energy production (derivation type hydropower plant) and the construction of reservoirs ( reservoir flow-through type hydropower plant).
The project will yield new information on the population of the huchen in the middle Sava River such as new data on its occurrence, a rough estimate of its abundance and size distribution, a more recent geographical distribution and new information on spawning grounds. We will asses the viability of the population and its reproductive capacity, investigate the impact of stocking and the relationship between natural and stocked populations, prepare a check-list of water obstructions on the middle Sava River with assessment of their passability and present an overview of the mitigation measures on other European rivers with hydropower plants. In addition, we will evaluate the adequacy of existing and propose new measures for recovery of the huchen in the wild and create an action plan to preserve this species in Slovenia. We will examine the impact of reduced water flow on the primary river bed and the impact of an accumulation on the habitat suitability for the huchen in the selected section of the middle Sava River by means of habitat modeling. This project will lay foundations for the determination of technological solutions for the implementation of new hydropower plants on the middle Sava River .
Due to the extensive field work required for the collection of the data and consequently the dependence on the weather and hydrological conditions the project is scheduled to last 24 months. This will ensure the coverage of two huchen spawning seasons in which we will be able to obtain a required number of samples for the analysis.
The results of the project will be presented separately to the contracting authority and to the professional public. We also plan to publish the results in a scientific journal.
We estimate that the results of the project will be of great importance for the competent institutions such as the Ministry of Agriculture and the Environment and the Ministry of Infrastructure and Spatial Planning when deciding on the future of the hydropower exploitation of the Sava River as well as on the renovation of the National Energy Program (NEP), which is already being prepared. The results will also serve as an important scientific basis for the National managing institutions such as the
Significance for science
Since it is a targeted research project with specific content, the results of the project have no significant influence on science development. Nevertheless, scientific publication including the main findings on population structure of the huchen in Slovenia is in preparation. The results of the project have a greater significance for the development of the profession. Slovenia has taken part in Natura 2000 as an obligation when it joined the EU and proposed a list of sites whose preservation is important at European level. Natura 2000 area was also declared in the middle Sava river in order to protect the population of huchen. Despite the inclusion of huchen as Natura 2000 species much less projects were designed to learn about the biology, distribution, genetic structure, etc., of huchen so far in Slovenia as compared to some other European countries. Professional importance of the project results is in the acquisition of new information on the biology, ecology and genetics of huchen in Slovenia. Current threats to the huchen as a species are high, and according to the plans for new hydropower plants construction it is likely to be even higher in near future. This aspect gives even more weight to obtained new data on species and populations in the area of the Sava river. Since huchen are in general among the less studied salmonid species, the results of the project, including data about its distribution, biology, phylogeography also contribute to its wider recognition, especially in terms of vulnerability and consequently conservation of this species. The proposed study contributes to: (1) the achievement of the level of knowledge on the biology of the Danube salmon (distribution, inventory of spawning grounds, migration, contribution of stocked specimens to natural populations) in Slovenia, comparable with the rest of the world, (2) a better understanding of the genetic structure of the huchen and (3) understanding of potential impacts of habitat fragmentation on huchen survival. In the framework of the project a great emphasis on putting knowledge into practice and linking science and profession in the field of fisheries biology, ecology, modeling, and energy was laid. The project is an example of the integration of modern multidisciplinary approaches in the evaluation of the impact of different measures to improve the situation, hydro morphological changes due to new interventions and mitigation measures (biological aspect, hydraulic modeling, habitat modeling ...).
Significance for the country
The results of the project were before each phase report presented to the contracting authority of the project, representatives of the Institute of RS for Nature Conservation and HSE; and to the general public on the professional meetings, including the forum on the topic of threatened huchen - an indicator of the critical state of the fish populations in the Danube basin, which took place on 19 April 2016 at European Parliament in Brussels. Publication of results in scientific and professional journals is in preparation. We estimate that the competent institutions such as the Ministry of Environment and the Ministry of Infrastructure, will benefit from the results of the project, particularly during the process of deciding on hydropower use of the Sava River and improving the ecological status of Natura 2000 areas within which we protect the habitat and population of huchen in the area of middle Sava river with its tributaries. Consequently, the results are also important for the renovation of the National Energy Program (NEP), and will also be an important technical basis for other professional institutions (eg. Institute of RS for Nature Conservation). New data on the biology, ecology and genetics of huchen, which, despite of its attraction are still relatively poorly understood, are important as the scientific basis for its preservation in Slovenia and beyond. In the framework of the project we presented the professional basis necessary to make strategic decisions about the proper use of hydro potential of the Sava River, which enable conservation of this vulnerable species. As the last chapter of the final report [COBISS.SI-ID 3764616] we presented the Action Plan for the conservation of huchen in Slovenia. The results of the project therefore represent an important contribution which can have a positive impact on nature awareness of stakeholders as well as the general public. Sustainable use of energy resources is a key element of all strategic documents Slovenia. In the case of exploitation of hydropower the environmental aspect was so far insufficiently taken into account. We expect that the results of the project will contribute to better knowledge and greater integration of environmental considerations in plans for utilization of water potential in Slovenia.
Most important scientific results
Most important socioeconomically and culturally relevant results
Final report
