Aquaculture in service of edangered fish species protection in Serbia

Abstract

Aquaculture is a type of food production with the highest rate of growth. Each year, compared with the previous, 9% more aquatic organisms are produced. Considering limited fish catch from world seas, increased consumption, as well as human population increase on the planet, it is realistic to expect that in the next period the need for fish from aquaculture will raise from year to year. However aquaculture importance is not only as food supply, but also reproduction and culture (farming) of aquatic organisms in order to protect and preserve endangered species of aquatic organisms in natural water ecosystems. Out of approximately 100 fish species inhabiting waters of the Republic of Serbia, 63 are under certain regime of protection (34 species in the status of "strictly protected" wild fish species and 29 wild species in the status protected"). Reasons for decrease of fish diversity in Serbia are many: often there is influence of various factors, seldom one can be sorted out as dominant. Factors most often influencing one or more fish species can be grouped as those originating from changes in the biotope, water quality deterioration, arrival of alochthonous fish species, spreading of diseases and increased pressure on fish resources from men and piscivorous animals. After elimination of factors endangering fish diversity, processes of natural recovery of the biocenosis, primarily fish fauna, mainly requires a long period. However natural recovery not only lasts too much, but this process can be unstable since fish abundance may vary, sensitivity can increase due to different reproductive characteristics, and different fish species have different diseases resistance. All this make natural recovery vulnerable to the negative influences. In such situation it is advisable to help endangered aquatic ecosystems. Among most simple ways, sometimes unique, is restocking with fish obtained from aquaculture. Aquaculture is of greatest importance for endangered fish species protection, but also for preservation of stability of economically important species that are under pressure higher than their natural reproductive potential. Although there are more than 200 fish farms in Serbia, small number of those is oriented towards reproduction and culture of endangered fish species. There are only two coldwater farms of small capacity continuously producing fry of coldwater species (Salmo trutta; Hucho hucho; Thymallus thymallus). Two hatcheries for warmwater fish are caring out artificial spawning from time to time, several warmwater farms periodically and casually produce fry of a small number of strictly protected and protected wild warmwater fish species (Cyprinus carpio; Esox lucius; Sander lucioperca; Silurus glanis), mainly for restocking of fishing waters. Reasons why a small number of farms are oriented towards reproduction and fry culture of endangered species lies primarily in the fact that there is no continual demand for strictly protected and protected wild fish species for restocking fishery waters, i.e. lack of economical reasons for such continuous activity. Although fish farms cooperate sometimes with experts and research institutions, there is a lack of programs and particularly financial support, therefore results are missing. Fry production is based mainly on a small number of broodstock caught from natural environment. There is also lack of genetic analyses and information on "species purity" and genotypes. The importance of restocking with autochthonous genotypes is not taken into account. So far the management of fishery waters has resulted in poor condition of the fish fund in majority of our natural aquatic ecosystems, therefore there is a need to increase protection of fish biodiversity. In order to ensure a more effective system it is necessary to obtain financing for new program realization. Two types of programs should be envisaged: those oriented towards economically important and those oriented towards economically not important fish species. For programs supposed profitable, financing could be assured from users of fishery waters. They could obtain a right to use parts of fishery waters for a limited period. Programs for economically not important species should be by financed by the state. The State will compensate from taxes collected from companies that endanger biodiversity with their wastewater. Programs for economically important autochthonous endangered fish species should be realized based on experiences from many western European countries that are attractive destinations for fishery tourism. Such programs are connecting ecological and economic interests. Economic interests are the basis of the decrease or elimination of migrations from small rural areas to big cities. Fishery tourism is a stimulus to economic development, but also to sustainability of aquatic ecosystems, since these ecosystems are in the focus of development. All this contribute to the tourism of the country, as well. Establishment of profitable programs in Serbia could be based on both autochthonous coldwater and warmwater fish. Programs for coldwater fish will be realized on many attractive hilly mountain destinations, where there are rivers: Drina, River Radovanska, Gradac, Grza, Temska, Veliki Rzav, Moravica, Uvac, Djetinja, Lipatnica, Jerma, Vlasina, Rasina etc. Programs based on warmwater fish species will be realized on lowland rivers, primarily on the Danube, where, besides recreational and sport fishery a new touristic product - economic/professional fishery could be introduced. It is almost impossible to realize all the mentioned programs without aquaculture, more precisely, aquaculture should be established on protection of autochthonous genotypes and species of each river basin, based on knowledge, skills, and values; on ecologically responsible protection of endangered fish species; and economically realistic. Firstly, tax should be paid by farms that omitted to build fish passes, and reproduction sites for migratory species should be revitalized. In addition a support should be given for the existing farms, institutions and teams, and help their activities to become sustainable. Than, new centers for reproduction, culture and restocking fish species should be established. In order to set up and maintain such programs it is indispensable to finance research institutions through new project calls in order to solve the problems and gain new technologies for reproduction and breeding primarily species in focus of the programs.