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Description
The main purpose of this project is to protect the fishpond ecosystem in nature protection areas and to present a combine nature conservation with sustainable fish management not only for professional fishing companies. We are going to prove alternative fish management and its sustainability on our own and partner ponds. This type of management will fully meet the criteria of good functioning and biologically rich ecosystems. The acquired knowledge will be presented not only to professionals but also to the general public as examples of good practice. The process of alternative fish management provides a great opportunity to reproduce and release different species of fish back to their original habitats. This will increase the impact of this project on the protection of ecosystems and regional species diversity of fish.
Summary of project results
The goal of the project was the protection of valuable or restoration of degraded pond sites in the form of alternative pond management. In the project, we tested the use of alternative fish stocks and verified a sustainable method of management on our own or partner reservoirs, so that the ponds meet the criteria of well-functioning and species-rich ecosystems. We have presented the gained experience and procedures as examples of good practice to professionals and the wider public. The process of testing alternative crews opened, but not completely, the possibility of introducing disappearing, native fish species and thus increased the impact of the project not only on the protection of the ecosystem, but also on the preservation of native ichthyofauna species. As part of the project, we managed to connect the requirements of nature protection with economic activities, and not only fishing entities.
The aim of the management activities at 11 model sites (in the Brdy, Třeboňsko, Slavkovský les and PR U Sedmi rybníků protected areas) was to achieve a balance between the set fish population, water quality, vegetation growth with support for the occurrence of amphibians, aquatic insects and protected plant species. For these reasons, we coordinate activities in cooperation with the Nature and Landscape Protection Agency (AOPK), or directly with the administrations of individual PLAs in which the model sites are located.
Management interventions at individual locations included the following activities:
- Definition and setting of fish stock
- Fish spawn
- Deploying fish
-Management of littorals and surrounding vegetation
-Measures to prevent the entry of invasive species
- Control catches of fish
- Catching fish
Water sampling, phyto and zooplankton monitoring, and physical-chemical water parameters took place at each location once a month. We adjusted the stock according to the continuous control catches. At the same time, we continuously monitored selected species of amphibians, aquatic insects and plants. The base model cases were: unstocked pond x stocked pond; planted predatory fish x herbivorous fish; pond with invasive species x without invasive species; pond with freezing after harvesting x filled immediately. With the help of management interventions, we tried to eliminate the invasive species of silver crucian carp, eastern minnow, variegated sunflower and American catfish. To support the spread of Carassius carassius and Gobio gobio, we tested the possibilities of artificial reproduction, including the mass production of pouch fry, which can be used for deployment in ponds or other rearing facilities. After obtaining the generation material and verifying the genetic purity of the carassius, we carried out several separate experiments and monitoring. In the final phase of the project, we summarized the data of examples of different types of farming practices in ponds, from the production of fry or hatchlings to the catch and economic evaluation of breeding.
The results from the model examples showed how the interests of nature protection and the economic sustainability of pond management can be reconciled with the help of close-to-nature management. These activities resulted in several outputs. The proposal of the Regional action plan carassius in the Karlovy Vary Region is an important document that should lead to the rescue of the last, regionally native population of common crucian carp in the Karlovy Vary Region. However, it is expected to be supplemented during the 2024 season. Only after the completion of further monitoring, the plan will be handed over to the AOPK in the Karlovy Vary region. As part of the project, we also set up and tested a methodology for obtaining quantitative data that can be used as an input to the subsequent assessment of the impact of farming on amphibians and aquatic insects.
For five model ponds in the Brdy PLA, which are owned by Military Forests and Farms of the Czech Republic s.p. (VLS) a Care plan for sustainable management of ponds was developed. Semi-intensive fish farming dominated by hatchery carp and a significant proportion of invasive weed fish (Eastern tench, perch) or Canadian water plague was replaced by an alternative method of farming for the protecting amphibians. In the future, this system should ensure the possibility of eliminating invasive species, with economic sustainability on the one hand and the support of biodiversity on the other. The management setting recommendation was forwarded to VLS ČR, s.p. with the fact that in the 2024 season the management system on the ponds will be fully determined by VLS.
The results of the project were presented to various target groups at the final conference, whose professional program was divided into two days due to the great interest in the topic. 4 professional articles were published (another submitted), two films were created, the results were (and will be) presented at conferences.
The results of the monitoring of selected locations confirm the generally accepted fact that each pond has specific characteristics. This is reflected in the different nature of the key communities, and therefore also in the differences in how these ponds are perceived from the point of view of nature conservation. In all the monitored areas, it is evident that the current state of the monitored ponds is the result of a combination of longer-term effects of external conditions (landscape character and hydrological conditions) and the method of fisheries management. The monitoring results show that such a situation can be strengthened, and a sustainable form of economic use can be found through targeted fishing management. The project showed the necessity and, at the same time, the way to establish a compromise between the economy of management, water quality, the occurrence of protected species on the one hand, or the necessity of eliminating invasive species on the other.
From an economic point of view, it is necessary to secure additional financial resources for "thrifty" management of ponds. Financing only from the breeding and subsequent sale of fish represents an unsustainable and highly risky model. High costs are the rental of ponds and transport costs. It is necessary to create a functional "market" (supply and demand) for selected fish species that do not have direct economic importance, so that they can be bred and maintained on the largest possible area (locations). It is necessary to find funds from public sources and create a suitable subsidy scheme with annual support for selected ponds at the level of 25-30 thousand. CZK/ha.
The sites evaluated were extreme cases, from several points of view. These were relatively remote locations, with the occurrence of non-native invasive fish species, the elimination of which was necessary for successful farming. The entire project represented a relatively short time frame for achieving a stable, meaningful management that will be productively and economically optimal. Obstacles were various management restrictions from nature conservation and intervention in fish stocking proposals. Failed to obtain permission to stock and breed minnow. It is necessary to cooperate with the Czech fishing union (ČRS) when obtaining generation fish from the wild. For these reasons, the question arises - is nature conservation really interested in the renaturalization of endangered fish species into the wild? How to finance programs in the future that would compensate for the possible loss of natural management on ponds? The project showed that it is possible to reconcile the interests of nature protection and sustainable pond management. However, it is necessary to find an appropriate compromise of economic and ecological aspects.