Coregon project at the NHM Vienna: From the archives to applied species conservation Biodiversity monitoring of coregons in Austria
11. July 2024
Coregons, usually referred to as Reinanken, Riedling
or Kröpfling in Austria, have a high economic value and are intensively fished. However, intensive fishing, environmental
changes and the repeated long-term introduction of non-native coregons have severely impaired the genetic and phenotypic integrity
of several native species. At the same time, coregons represent one of the most taxonomically complex groups among freshwater
fishes in Europe. Opinions about their phylogeny, their taxonomic status and their infra- and intraspecific structure are
diametrically opposed. The question arises as to how many native species (under which scientific names) and ecological varieties
still exist in Austria and by which characteristics they can be precisely defined. Some are even categorised as extinct according
to the Austrian Red
List of Fish, while others are highly endangered and on the brink of extinction. A revision of knowledge about the historical
vs. modern diversity of Coregonus in Austria (in the context of all pre-alpine lakes) is currently underway under the direction
of the fish collection of the Natural History Museum Vienna.
What are coregons?
Coregons are fish from the salmonid family that are known by many different names in Austria, Germany and Switzerland: Rhine whitefish, whitefish, whitefish, whitefish, vendace and houting. This diversity of names also reflects the diversity in nature, as the names vary from region to region and refer to different-looking forms that live in different lakes. In Austria, coregons mostly live in deeper lakes (from approx. 20 metres), for example in Lake Constance, the Salzkammergut lakes, the Salzburg lakes and the Carinthian lakes. In some lakes, e.g. Lake Attersee and Lake Traunsee, there is also more than one form of coregon. The record holder in Austria is Lake Constance with four different forms.
Coregons are highly endangered
The coregonids, which differ significantly in appearance, often eat different foods and have different spawning site requirements and spawning times, which is why scientists often refer to them as different species. Many of these species are now categorised as endangered fish species. Causes of endangerment are water pollution, habitat change and destruction or deterioration as well as warming due to climate change.
Because coregons have been an important commercial fish species in Austria for centuries, they are also heavily affected by overexploitation/overfishing and especially by the introduction of alien species. The natural stocks have been subjected to a variety of management measures dating back to the 16th century. While the original stocks are used for stocking in some lakes, commercially available fry are used in others. The vendace (Latin: Coregonus maraena), for example, was exported from Lake Miedwie (Poland, German: Madü-See) to Bohemian aquaculture in the 19th century. This Baltic stock has been used intensively in Austrian aquaculture for at least 50 years and is a main source for stocking coregons, which may have interbred with the native forms. It is therefore questionable how many of the original forms/species are still present in Austrian lakes.
From the archives to applied species conservation
Zoological collections are the most important archives for evidence of biodiversity in the animal kingdom, especially in view of the current massive decline in biodiversity worldwide. The fish collection of the Natural History Museum Vienna is the second largest fish collection in Europe. It comprises more than 100,000 catalogued series (alcohol specimens, skeletons and stuffed specimens) with around 1 million specimens, including endangered, rare and even extinct fish species or fish species from areas that are inaccessible today. The fish collection is therefore a real scientific treasure that enables researchers to trace the development of fish stocks back up to 200 years. It also includes the most important collection of coregons from Austrian lakes, which were collected before the massive stocking.
Recognising and separating different species
Species are categories that scientists use to identify and distinguish between reproductively related groups of organisms in nature. Species are artificial categories that are established according to different definitions. However, they reflect the diversity in nature, which does not occur continuously but in reproductively separate units. The species is the most important natural taxonomic unit, designated by a Latin binomial (genus and species name), e.g. Homo sapiens. The identification of species is important in order to be able to describe biological diversity.
In principle, species can be distinguished on the basis of differences in physical characteristics (e.g. gill arch structure, scale arrangement, number of vertebrae, etc.), genetic characteristics (genetic material) or behaviour. In the case of coregonids, however, it is difficult to separate the species according to their external appearance, as they differ only in the number, shape and arrangement of the gill ray spines, for example. On the other hand, there are populations that can be easily separated on the basis of external characteristics but hardly differ genetically. Coregons therefore present taxonomists with great difficulties.
Protecting coregons - or is it already too late?
In order to obtain reliable information for long-term and efficient monitoring, the original, autochthonous species population of coregons must first be determined. This is done by analysing historical specimens that are kept in the fish collection and date from the time before the massive introduction of alien species. Analyses are then carried out on fresh material. By comparing the old stocks with the newly collected material, the current situation in the Austrian lakes can then be estimated. Unfortunately, an analysis from 2011 has already shown that the diversity of coregons has declined sharply.
The first results of the coregon project at the NHM Vienna
The morphological examination of the available historical specimens of coregons from the various lakes has been completed. A total of over 700 specimens from seven different Austrian lakes were morphologically analysed (according to external characteristics). In Mondsee, Wolfgangsee, Hallstätter See and Wörthersee, one species of coregon could be identified in each case, whereby all species differ from each other. Two species each were detected in Lake Attersee and Lake Traunsee and four species in Lake Constance. Genetic analyses are now being carried out on the basis of these results. However, it appears that an incredible 12 different coregon species lived in Austria in the 19th century.
The team
Scientists from the fish collection of the Natural History Museum Vienna, the Research Institute for Limnology, Mondsee of the University of Innsbruck and the Institute for Aquatic Ecology and Fisheries Management of the Federal Agency for Water Management Scharfling have expertise in cryptic biodiversity surveys, taxonomic work based on morphological and molecular genetic methods as well as in the field of aquatic ecology. The aim of the project is to create a basis for the sustainable and long-term protection of coregons.
This project is funded by the Biodiversity Fund of the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology. Financed by the European Union, NextGenerationEU.
Website of the project: https://coregonus.at/
Press material: www.nhm-wien.ac.at/presse/pressemitteilungen2024/coregonen
Scientific enquiry note:
Dr Anja Palandacic
Fish Collection, NHM Vienna
https://www.nhm.at/anja_palandacic
Tel.: + 43 (1) 521 77 DW 212
Anja.palandacic@nhm.at
General enquiry:
Irina Kubadinow
Head of Press & Public Relations, Press spokesperson, NHM Vienna
https://www.nhm.at/irina_kubadinow
Tel.: + 43 (1) 521 77 DW 410
irina.kubadinow@nhm.at
Nikolett Kertész-Schenk, Bakk. BA MAS
Press & Public Relations, Press Officer, NHM Vienna
https://www.nhm.at/nikolett_kertesz
Tel.: + 43 (1) 521 77 DW 626
nikolett.kertesz@nhm.at
Nadja Kraski
Press & Public Relations, Press Officer, NHM Vienna
Tel.: + 43 (1) 521 77 DW 680
nadja.kraski@nhm.at
Coregons are fish from the salmonid family that are known by many different names in Austria, Germany and Switzerland: Rhine whitefish, whitefish, whitefish, whitefish, vendace and houting. This diversity of names also reflects the diversity in nature, as the names vary from region to region and refer to different-looking forms that live in different lakes. In Austria, coregons mostly live in deeper lakes (from approx. 20 metres), for example in Lake Constance, the Salzkammergut lakes, the Salzburg lakes and the Carinthian lakes. In some lakes, e.g. Lake Attersee and Lake Traunsee, there is also more than one form of coregon. The record holder in Austria is Lake Constance with four different forms.
Coregons are highly endangered
The coregonids, which differ significantly in appearance, often eat different foods and have different spawning site requirements and spawning times, which is why scientists often refer to them as different species. Many of these species are now categorised as endangered fish species. Causes of endangerment are water pollution, habitat change and destruction or deterioration as well as warming due to climate change.
Because coregons have been an important commercial fish species in Austria for centuries, they are also heavily affected by overexploitation/overfishing and especially by the introduction of alien species. The natural stocks have been subjected to a variety of management measures dating back to the 16th century. While the original stocks are used for stocking in some lakes, commercially available fry are used in others. The vendace (Latin: Coregonus maraena), for example, was exported from Lake Miedwie (Poland, German: Madü-See) to Bohemian aquaculture in the 19th century. This Baltic stock has been used intensively in Austrian aquaculture for at least 50 years and is a main source for stocking coregons, which may have interbred with the native forms. It is therefore questionable how many of the original forms/species are still present in Austrian lakes.
From the archives to applied species conservation
Zoological collections are the most important archives for evidence of biodiversity in the animal kingdom, especially in view of the current massive decline in biodiversity worldwide. The fish collection of the Natural History Museum Vienna is the second largest fish collection in Europe. It comprises more than 100,000 catalogued series (alcohol specimens, skeletons and stuffed specimens) with around 1 million specimens, including endangered, rare and even extinct fish species or fish species from areas that are inaccessible today. The fish collection is therefore a real scientific treasure that enables researchers to trace the development of fish stocks back up to 200 years. It also includes the most important collection of coregons from Austrian lakes, which were collected before the massive stocking.
Recognising and separating different species
Species are categories that scientists use to identify and distinguish between reproductively related groups of organisms in nature. Species are artificial categories that are established according to different definitions. However, they reflect the diversity in nature, which does not occur continuously but in reproductively separate units. The species is the most important natural taxonomic unit, designated by a Latin binomial (genus and species name), e.g. Homo sapiens. The identification of species is important in order to be able to describe biological diversity.
In principle, species can be distinguished on the basis of differences in physical characteristics (e.g. gill arch structure, scale arrangement, number of vertebrae, etc.), genetic characteristics (genetic material) or behaviour. In the case of coregonids, however, it is difficult to separate the species according to their external appearance, as they differ only in the number, shape and arrangement of the gill ray spines, for example. On the other hand, there are populations that can be easily separated on the basis of external characteristics but hardly differ genetically. Coregons therefore present taxonomists with great difficulties.
Protecting coregons - or is it already too late?
In order to obtain reliable information for long-term and efficient monitoring, the original, autochthonous species population of coregons must first be determined. This is done by analysing historical specimens that are kept in the fish collection and date from the time before the massive introduction of alien species. Analyses are then carried out on fresh material. By comparing the old stocks with the newly collected material, the current situation in the Austrian lakes can then be estimated. Unfortunately, an analysis from 2011 has already shown that the diversity of coregons has declined sharply.
The first results of the coregon project at the NHM Vienna
The morphological examination of the available historical specimens of coregons from the various lakes has been completed. A total of over 700 specimens from seven different Austrian lakes were morphologically analysed (according to external characteristics). In Mondsee, Wolfgangsee, Hallstätter See and Wörthersee, one species of coregon could be identified in each case, whereby all species differ from each other. Two species each were detected in Lake Attersee and Lake Traunsee and four species in Lake Constance. Genetic analyses are now being carried out on the basis of these results. However, it appears that an incredible 12 different coregon species lived in Austria in the 19th century.
The team
Scientists from the fish collection of the Natural History Museum Vienna, the Research Institute for Limnology, Mondsee of the University of Innsbruck and the Institute for Aquatic Ecology and Fisheries Management of the Federal Agency for Water Management Scharfling have expertise in cryptic biodiversity surveys, taxonomic work based on morphological and molecular genetic methods as well as in the field of aquatic ecology. The aim of the project is to create a basis for the sustainable and long-term protection of coregons.
This project is funded by the Biodiversity Fund of the Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology. Financed by the European Union, NextGenerationEU.
Website of the project: https://coregonus.at/
Press material: www.nhm-wien.ac.at/presse/pressemitteilungen2024/coregonen
Scientific enquiry note:
Dr Anja Palandacic
Fish Collection, NHM Vienna
https://www.nhm.at/anja_palandacic
Tel.: + 43 (1) 521 77 DW 212
Anja.palandacic@nhm.at
General enquiry:
Irina Kubadinow
Head of Press & Public Relations, Press spokesperson, NHM Vienna
https://www.nhm.at/irina_kubadinow
Tel.: + 43 (1) 521 77 DW 410
irina.kubadinow@nhm.at
Nikolett Kertész-Schenk, Bakk. BA MAS
Press & Public Relations, Press Officer, NHM Vienna
https://www.nhm.at/nikolett_kertesz
Tel.: + 43 (1) 521 77 DW 626
nikolett.kertesz@nhm.at
Nadja Kraski
Press & Public Relations, Press Officer, NHM Vienna
Tel.: + 43 (1) 521 77 DW 680
nadja.kraski@nhm.at
Dr. Anja Palandacic
© NHM Wien
Dr. Anja Palandacic und Min Chai, MSc
© NHM Wien
Map Distribution Coregonus Austria
© NHM Wien
Species separation
© NHM Wien
Coregons
© NHM Wien
Biodiversity monitoring of coregons in Austria
© NHM Wien
Coregons in Austria
© NHM Wien
