Das Schicksal der großen Störarten in der Oberen Donau.
Denisia 33, zugleich Kataloge des oberösterreichischen Landesmuseums Neue Serie 163 (2014): 423-442.
Durch Fischfang und Gewässerverbauung sind die Störartigen in der Donau inzwischen stark gefährdet und teilweise nahe der Ausrottung. In der österreichischen Donau kommt als kleinste autochthone Art nur noch der Sterlet vor. In der Oberen Donau sind die vier großen Störartigen durch Migrationshindernisse und Überfischung inzwischen ausgestorben. Die Analyse historischer Quellen belegt aber zumindest für manche Arten wie den Hausen in der Vergangenheit eine große wirtschaftliche Bedeutung dieser Tiere, vor allem im Raum Wien. Die hohe Anzahl gehandelter Tiere lässt dabei auf relativ hohe Bestandsdichten in früheren Zeiten schließen. Während für den Hausen eine relativ gute Datengrundlage vorliegt ist die Zuordnung anderer Störarten aus taxonomischer Sicht deutlich schwieriger, da eine große Anzahl von Fehlbestimmungen vorliegt. Die vorliegenden Daten lassen jedoch darauf schließen, dass zumindest der Waxdick und möglicherweise der Glattdick in der Oberen Donau regelmäßig anzutreffen waren, während es keinen dezidierten Nachweis des Sternhausens für diesen Abschnitt gibt. Der Europäische Stör war in seinem Vorkommen auf die Untere Donau beschränkt und spielte für die Störfischerei in der Oberen Donau keine Rolle.
The fate of the large sturgeon species in the Upper Danube. The Danube is home to six sturgeon species, all of which are highly endangered and in some cases already extinct. Through overfishing in the past centuries, four species went almost extinct in the Upper Danube; later the construction of power plants and dams made spawning migrations impossible and led to their doom in the Upper and Middle Danube. In the lower part of the Danube longer spawning runs of diadromous species have been made impossible with the construction of the hydropower plants at the Iron Gate. The sterlet ( Acipenser ruthenus), the last representative of this fish family in the Austrian Danube, is ‘Fish of the Year 2014’ in Austria, while the European sturgeon
(Acipenser sturio) is ‘Fish of the Year 2014’ in Germany. This article is a compilation of three articles (S CHMALL & F RIEDRICH
2014a, 2014b; F RIEDRICH et al. 2014) and deals only partly with autecological issues but rather examines the former range limits and economic importance of these fish, and further identifies the current situation of sturgeon species in the whole Danube basin and efforts to protect them. In terms of historical sources the focus lies on the catchment of the Austrian Danube.
Störarten in der Donau.
Auenmagazin 20: 42-45.
Störe sind ein wesentliches Faunenelement der Donau und stellten in der Vergangenheit durch ihre Migration eine Verbindung zwischen dem alpinen Donauraum und dem Schwarzen Meer her. Heute sind zwei von sechs Donaustören bereits ausgestorben und die verbliebenen Arten sind durch Wilderei, Beifang, Migrationsbarrieren und Habitatverlust vom Aussterben bedroht. Eine Vielzahl von Projekten forciert Bemühungen zum Schutz und zur Wiederansiedelung, welche jedoch nur koordiniert und in internationaler Kooperation Aussicht auf Erfolg haben.
Conservation Status of the “Piracanjuba” Brycon orbignyanus (Valenciennes, 1850) (Characiformes, Bryconidae): Basis for Management Programs.
Revista Biodiversidade Brasileira – BioBrasil, 7(1): 18-33,
The excessive exploitation of freshwater resources has been caused by many impacts on natural populations, especially on fish. Different factors related to pollution, overfishing, introduction of exotic species, construction of dams, and destruction of riparian vegetation can cause changes on the current populations and interfere with their equilibrium. In this context, Brycon orbignyanus, popularly known as “piracanjuba”, is an endangered fish species affected by overfishing and environmental degradation. The quality of the meat and its aggressive behavior in the practice of sport and professional fishing, occurring concomitantly to continuous changes in the habitat, has resulted in the fast depletion of natural stocks and resulted in its addition to the list of endangered Brazilian fish species. The species has its distribution along the La Plata River basin, which has in its upper parts highly impacted by demographic occupation, dam constructions, and agricultural farm activities in marginal areas. Habitat changes lead the wild groups of this species to shift to less affected regions, being presently restricted to a few far rivers and small tributaries that remain in preserved environmental conditions. In order to obtain a better view of the real situation of B. orbignyanus populations, the aim of this work is the development of effective management programs for the conservation of this species. The article brings together information available in the literature and provides biological and population information about its current geographic distribution, the main threats to the equilibrium in the changing environments of occurrence, the genetic characteristics of populations, and the prospects for use in conservation programs.
Resfriamento e congelamento de embriões de Dourado (Salminus brasiliensis), Piracanjuba (Brycon orbignyanus) e Piapara (Leporinus obtusidens).
Vet. med. Dissertation, Universidade Federal de Lavras.
A criopreservação de gametas e embriões de espécies aquáticas oferece muitos benefícios para as áreas de conservação da biodiversidade, mas, até o momento, nenhum protocolo foi capaz de obter embriões viáveis após o congelamento com a reprodutibilidade e eficiência desejadas. O dourado (Salminus brasiliensis), a piracanjuba (Brycon orbignyanus) e a piapara (Leporinus obtusidens) são espécies de peixes reofílicas e compartilham praticamente o mesmo habitat na América do Sul. A construção de barragens e o desmatamento da mata ciliar são alguns dos fatores descaracterizadores do ambiente aquático natural, e explicam porque, nas últimas décadas, suas populações têm diminuído intensivamente. Nestes estudos, objetivou-se estudar os efeitos do resfriamento e do congelamento sobre os embriões de dourado, piaracanjuba e piapara. Foram utilizados embriões de quatro casais de cada espécie, mergulhados em soluções cont endo metanol ou dimetilsulfóxido (DMSO) 5, 8 ou 11%, sob resfriamento (-2°C) ou não. Os demais grupos controle foram compostos por embriões não adicionados de crioprotetor e incubados à temperatura ambiente ou resfriados. Outro grupo de embriões foi congelado em N2(l) após banho nas mesmas soluções do resfriamento. Ambos os crioprotetores apresentaram-se pouco tóxicos à temperatura ambiente para os embriões das três espécies. O metanol promoveu as maiores taxas de eclosão médias para os embriões resfriados de dourado e de piracanjuba e com preservação das características morfológicas para esta última independentemente da concentração. Já os embriões de piapara foram muito sensíveis ao resfriamento, exceto quando adicionados de DMSO. A adição de crioprotetores nestes embriões não implicou no aparecimento de lesões durante o resfriamento. Por sua vez, regularidade entre as camadas de blastômeros e da membrana sincicial do vitelo, além de glóbulos de vitelo dispersos para a periferia do saco vitelínico foram observadas após o resfriamento dos embriões das demais espécies. Três embriões de piracanjuba tratados com metanol 8% e quatro com metanol 11%, além de cinco embriões de piapara também tratados com metanol 11% foram recuperados e incubados após o descongelamento. Deles, dois da primeira e quatro da segunda espécie desenvolveram-se até a formação da placa neural e dos dois primeiros somitos, respectivamente, demonstrando ser possível a preservação de seus embriões de por meio do congelamento rápido. Antes disso, porém, é imprescindível que se aprimore o conhecimento sobre as características biomoleculares destes embriões a fim de se explorar o potencial dos procedimentos aqui utilizados.
Long-term investigation on fish migration patterns between pre-alpine lakes and their major tributaries with special focus on protected species within SAC areas.
Conference Paper 9th ISE 2012, Vienna. (PDF)
In the designated SAC (Special Area of Conservation) site“Mond-und Attersee” (comprising two large pre-alpine lakes in Upper Austria and the mouths of their major tributaries) the spawning migration of the protected species pearlfish (Rutilus meidingeri) and Danube bleak (Alburnus mento) was investigated in the years 2004 and 2010. For this purpose, a dynamic fishweir with an integrated trap for catching upstream migrating fish was installed near the mouths of the respective rivers. The main factor correlating with the spawning migration turned out to be the water temperature of the rivers. Furthermore, differences between sexes were found concerning body length and weight as well as the main immigration period into the streams.
Il recupero dello storione cobice in Italia - ACTION PLAN -Progetto Life 04NAT/IT/000126 "Conservation and Breeding of Italian Cobice Endemic Sturgeon".
160 Seiten. DOI: 10.13140/2.1.1085.7286.
In the Italian waters there were historicaly three species of sturgeon: Huso huso (Beluga sturgeon), Acipenser sturio (common sturgeon) and Acipenser naccarii (Cobice sturgeon). The first two species are considered as locally extinct, while the Cobice sturgeon is still signalled, even if seldom. There is moreover a population of this species banished to the fresh waters of the Tessin river, an affluent of the Po river, due to the building of the barrage of Serafini Island on the Po river. The main reason that brought the Cobice sturgeon to the danger of extinction is the eccessive fishing pression. Just in recent times legislation protected all three species, completely forbidding their fishing. Different factors contributed to the decline of population, among them the interruption of the fluvial continuity which, preventing the going back up of some intervals of rivers reduced the number of reproductive sites. The biological cycle of the Cobice sturgeon is very long, male specimens reach sexual maturity at 7-11 years of age, with a total length of at least 80 cm, and female specimens at 12-14 years of age, with a length of at least 1 m. The Cobice sturgeon has been object of numerous studies and projects, both of research and conservative. During the years, single Administrations on the whole territory, in particular in Lombardy, Veneto and Emilia-Romagna, have been engaged in local conservation interventions, even with repopulation programs. The population restricted to fresh waters of Tessin has then been object of a specific conservation program guided by the Lombardy Park of the Tessin Valley and co-financed by the European Community through the project LIFE03NAT/IT/000113. Only with the project LIFE04NAT/IT/000126 a common and coordinated commitment on a big area has been started, almost the areale of distribution of the species. This project that lasted three years involved Lombardy, Veneto and Emilia-Romagna. The involvement of regional Bodies, Parks and Province Authorities of three regions has represented a successful prerequisite, as the Cobice sturgeon moves and migrates on a big area, not belongig to a unique jurisdition. The project realization was possible thanks to three solid fundamentals: the experience of the Public Authorities, the availability of a stock of Cobice sturgeon, the gained and consolidated technology for its reproduction and breeding. The stock specimens were captured in the 1970s in the same project area and since then maintained in captivity. This stock and its descendants built the only and fundamental tank for the species rescue. All specimens now kept ex-situ, both by public authorities and private citizens, come from that original centre, whose specimens, still living, are bred and belong to the Azienda VIP of Orzinuovi in Lombardy, breeding site with CITES authorization. The technology for the reproduction and breeding in all life stages of the Cobice sturgeon was worked out in the same facility that was the first to realize the bloodless reproduction of A. naccarii in the 1980s. Afterwards, thanks to the LIFE project, artificial reproduction was carried out also at the public centre of Quinto di Treviso, in Veneto. Thanks to the project LIFE04NAT/IT/000126 the genetic characterization of a part of the specimens kept ex-situ has been carried out and a crioconservation technique of the seed of the Cobice sturgeon has been worked out realizing the germoplasm bank. Thanks to the reproductions of the two breeding centres, an important repopulation effort has been performed. Seeding of 66,038 Cobice sturgeon specimens has been carried out: 17,038 of them had an average length of 50 cm and an average weight of 900 gram, the remaining 49,000 specimens were put at the post-larva stage. The post-larva seeding has been performed according to a successful reproduction of the two centres, so that it goes beyond the plant potentiality to wean a so high number of alevins. For this reason the choice was to release the specimens at this life stage. Before carrying out the repopulation program, the watercourses have been studied in detail, showing important features of the habitat for the Cobice sturgeon, as for example substratum granulometry, stream velocity and bathymetry. Particular attention has been drawn to the presence of holes. In the three regions involved in the project, following rivers have been studied: Po, Adda, Oglio, Mincio, Adige, Bacchiglione, Brenta, Sile, Piave, Livenza, Lemene, Tagliamento. For the evaluation of the repopulation program both campaigns of direct sampling with nets and electrofishing and monitoring campaigns through a national networtk that have involved fishermen for leisure, professional fishermen, volunteers and the staff of the security service of the different Bodies have been carried out. The monitoring network was previously organised, with informative meetings and distribution of materials. Thanks to this organisation, in case a sturgeon was accidentally captured, it was possible to signal it calling the nearest referring centre. As soon as the nearest surveyor received the call, he immediately went to the capture place to verify, with an adequate reader, the presence of microchip and to survey the biometric measures. If no microchip was present, a fin fragment of around 1 cm2 was taken for genetic tagging. The genetic tagging, thanks to the results of the genetic characterization analysis, made it possible to recognise the specimens analysed as descendants of the stocks kept in captivity (F0), deriving then from previous repopulation programs, or as wild. Out of 38 analysed animals, 23 have resulted not assignable to the F0. The organization of the monitoring network had also the aim of awakening the fishermen, but dissemination of the project was spread also among schools, carrying out a specific program of environmental education in which around 500 school groups corresponding to the total involvement of around 10,000 students have been met. The results of the repopulation and of the monitorings carried out both directly and through the survey network have been organized in a Geographical Information system (GIS). The GIS was developed on a geo-database with a geographical reference of the seeding points and the points of capture, to which following information has been added: information of the single specimens sown or captured, as the microchip number, length, weight, genetics of origin, date and place of seeding/capture, etc. These tables were linked with the points with a geographical reference and among them, in order to access all available information through GIS for each of the thousands of specimens having a microchip. This Action Plan for the Cobice sturgeon is the result of the same project but it also considered the Action Plan produced by the Tessin Park for the repopulation at the moment banished to the fresh waters of that river. The action plan was performed on the model of the management Plan and is therefore structured in four sections: knowledge framework; evaluation of the ecologic needs; aims; management strategy. Thanks to this structure one clear general goal was set: the conservation of the A. Naccarii in a satisfying state, as defined by the Habitat Directive. To this follow 14 detailed aims that are functional to the general aim: giving the Sile river the fluvial continuity back; monitoring on some rivers of the dangerous structures for the species; facilitation to the overcoming of barrages; conservation of the habitats where the Cobice sturgeon lives; reduction of the competition with the silurus; reduction of the poaching; awakening of the population to the topic of the conservation; awakening of the authorities; progressive increase of the natural population; ex-situ stock conservation; increase of the genetic diversity of the natural population; increase of the knowledge about the bio-ecology; promotion of a regional, provincial and sector planning and programming system; conservation of the species in the Ticino River. The management stategy analysed moreover the value of the Action Plan, integrating it in the regulations, as the areale of the Cobice sturgeon covers three different regions and it is not restricted to the sites of Rete Natura 2000. Periodical deadlines for the review of the Action Plan have been furthermore set, having the aim of adjusting it to the development of the conservation status of the natural population. Depending on such periodical reviews, some detailed aims have been selected: they cannot be faced in the first deadline, but it will be certainly necessary to consider them in the following reviews. In order to clearly identify how to reach those goals, the management activities were outlined and organized according to the types selected in the “Manual for the management of the Nature Sites 2000” of the Italian Ministry for the Environment: active intervention (IA); regulations (RE); monitoring and/or research programs (MR); didactic programs (PD). Each goal goes back to a structured table with the following items: Goal; Activity description; Implementation timetable; Indicators and parameters; Priorities; Expected results; Costs estimate; Potential programmatic references and financial funds; Person in charge of the implementation.
Managing Polyploidy in Ex Situ Conservation Genetics: The Case of the Critically Endangered Adriatic Sturgeon (Acipenser naccarii).
PLoS One. 2011; 6(3): e18249. Published online 2011 Mar 29. doi: 10.1371/journal.pone.0018249
While the current expansion of conservation genetics enables to address more efficiently the management of threatened species, alternative methods for genetic relatedness data analysis in polyploid species are necessary. Within this framework, we present a standardized and simple protocol specifically designed for polyploid species that can facilitate management of genetic diversity, as exemplified by the ex situ conservation program for the tetraploid Adriatic sturgeon Acipenser naccarii. A critically endangered endemic species of the Adriatic Sea tributaries, its persistence is strictly linked to the ex situ conservation of a single captive broodstock currently decimated to about 25 individuals, which represents the last remaining population of Adriatic sturgeon of certain wild origin. The genetic variability of three F1 broodstocks available as future breeders was estimated based on mitochondrial and microsatellite information and compared with the variability of the parental generation. Genetic data showed that the F1 stocks have only retained part of the genetic variation present in the original stock due to the few parent pairs used as founders. This prompts for the urgent improvement of the current F1 stocks by incorporating new founders that better represent the genetic diversity available. Following parental allocation based on band sharing values, we set up a user-friendly tool for selection of candidate breeders according to relatedness between all possible parent-pairs that secures the use of non-related individuals. The approach developed here could also be applied to other endangered tetraploid sturgeon species overexploited for caviar production, particularly in regions lacking proper infrastructure and/or expertise.
Paddlefish (Polyodon spathula) in Europe: An aquaculture species and a potential invader.
Journal of Applied Ichthyology 35 (1): 267-274. https://doi.org/10.1111/jai.13672
The paddlefish (Polyodon spathula) was first introduced to Europe in 1974, mainly due to its potential for rearing in natural polyculture ponds and large temperate reservoirs. The information on the history of paddlefish aquaculture efforts in Europe is scarce, as well as data on current paddlefish aquaculture status and trends. In addition, there is a lack of data on its presence and potential establishment in the wild, while its invasive potential and associated risks and impacts are largely unknown. In order to evaluate its current status in Europe, we conducted a survey among scientists, aquaculture producers and other stakeholders, and reviewed literature and data on the Internet. Based on the results obtained, we discuss the potential and the challenges in European paddlefish aquaculture development, and analyze paddlefish invasive potential and risks associated with its naturalization. Paddlefish aquaculture is well established only regionally in Europe, but offers relatively high potential for further development in pond farms. Nevertheless, future development will require careful planning, especially regarding market development and improved marketing strategies. While paddlefish likely represents a low‐risk invader, improved control and reporting on trade and intentional and unintentional releases will be required. Given the lack of knowledge on potential impacts following its introduction, due caution seems highly advisable.
The living marine resources of the Western Central Atlantic.
Volume 2: Bony fishes part 1 (Acipenseridae to Grammatidae).
FAO Species Identification Guide for Fishery Purposes and American Society of Ichthyologists and Herpetologists Special Publication No. 5.Rome, FAO. 2002. pp. 601-1374.
This 3 volume field guide covers the species of interest to fisheries of the major marine resource groups exploited in the Western Central Atlantic. The area of coverage includes FAO Fishing Area 31. The marine resource groups included are the bivalves, gastropods, cephalopods, stomatopods, shrimps, lobsters, crabs, hagfishes, sharks, batoid fishes, chimaeras, bony fishes, sea turtles, nd marine mammals. The introductory chapter outlines the environmental, ecological, and biogeographical factors influencing the marine biota, and the basic components of the fisheries in the Western Central Atlantic. Within the field guide, the sections on the resource groups are arranged phylogenetically according to higher taxonomic levels such as class, order, and family. Each resource group is introduced by general remarks on the group, an illustrated section on technical terms and measurements, and a key or guide to orders or families. Each family generally has an account summarizing family diagnostic characters, biological and fisheries information, notes on similar families occurring in the area, a key to species, a checklist of species and a short list of relevant literature. Families that are less important to fisheries include an abbreviated family account and no detailed species information. Species in the important families are treated in detail (arranged alphabetically by genus and species) and include the species name, frequent synonyms and names of similar species, an illustration, FAO common name(s), diagnostic characters, biology and fisheries information, notes on geographical distribution, and a distribution map. For less important spe-cies, abbreviated accounts are used. Generally, this includes the species name, FAOc ommon name(s), an illustration, a distribution map, and notes on biology, fisheries, anddistribution. The final volume concludes with an index of scientific and common names.
Rote Liste der Fische (Pisces) Österreichs.
In: Zulka, K. P. (Red.): Rote Liste gefährdeter Tiere Österreichs, Teil 2. Grüne Reihe des Lebensministeriums Band 14/2. Böhlau-Verlag, Wien, Köln, Weimar.
Die vorliegende Arbeit folgt den Richtlinien zur Fortschreibung der Roten Liste gefährdeter Tiere Österreichs (Zulka et al. 2001). Die aktuelle Checkliste der Fische Österreichs umfasst 84 Taxa. Im Vergleich zur letzten Roten Liste (Spindler et al. 1997) wurden einige Taxa aufgrund aktueller nomenklatorischer und taxonomischer Entwicklungen, auf die gesondert eingegangen wird, neu aufgenommen. Zwei Taxa werden als weltweit ausgestorben (Kategorie EX; Extinct) beurteilt, fünf Taxa sind regional ausgestorben (Kategorie RE; Regionally Extinct). In der Gefährdungs-kategorie „Critically Endangered“ (CR, vom Aussterben bedroht) finden sich sechs Ar-ten, 18 in der Kategorie „Endangered“ (EN; stark gefährdet) und 15 in der Kategorie „Vulnerable“ (VU; gefährdet). Neun Arten stehen auf der Vorwarnliste (Kategorie NT; Near Threatened), 17 weitere Arten, also rund ein Fünftel der aufgenommenen Taxa, sind in Österreich der Kategorie „Least Concern“ (LC; nicht gefährdet) zugeordnet. Für drei Taxa mit äußerst unsicherer taxonomischer Situation reicht die Datenlage für eine Einstufung nicht aus (Kategorie DD; Data Deficient). Bei weiteren neun in die Checkliste aufgenommenen Arten handelt es sich um überregional verbreitete und reproduzierende Neozoen, die explizit nicht in die Beurteilung im Rahmen der Roten Liste einbezogen werden (Kategorie NE; Not Evaluated). Aufgrund geänderter Definitionen der Gefährdungskategorien ist die vorliegende Arbeit mit der Roten Liste von Spindler et al. (1997) nur bedingt vergleichbar. Die meisten Unterschiede der Gefährdungseinstufung sind auf methodische Änderungen oder eine geänderte Datenlage zurückzuführen.