Fish community structure and depth-related trends on the continental slope of the Balearic Islands (Algerian basin, western Mediterranean) Mediterranean).

Mar. Ecol. Prog. Ser. 171: 247-259

Abstract:

A total of 13 026 fishes belonging to 82 species and 43 famllies were collected in a continuous transect between depths of 200 and 1800 m south of the Baleanc Islands (Algerian basin, western Mediterranean). The analysis of 32 bottom trawls showed the existence of 4 groups associated with the upper slope (groups 1 and 2, from 200 to 400 and 400 to 800 m, respectivelv), middle slope (group 3, from 800 to 1400 m) and lower slope (group 4, below a depth of 1400 m) Thc differcnces in the mean values of the ecological parameters species richness, abundance, biomass and mean fish weight were also indicative of distinctive characteristics between these fish assemblages. Species richness decreased significantly with depth. The highest values of diversity corresponded to the samples from group 2. Biomass did not show any specific trend throughout the whole bathymetric range. Mean fish weight show 2 different trends along the continental slope: a bigger-deeper phenomenon at the upper 1000 to 1200 m depth. and a smaller-deeper phenomenon below this depth. Our results are compared with those obtained in the north Atlantic basin and in the western Mediterranean (Balearic basin), and the main factol-s affecting these deep-sea fish assemblages are discussed.

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Donnerstag, 14 Juni 2018 07:49

WELCOMME, R. L. (1988)

International Introductions of Inland Aquatic Species.

FAO, Rom. M-44, Gedruckte Version ISBN 92-5-102664-5.

Large scale introductions of fish species into areas outside their native range is a comparatively recent phenomenon. Some transfers of fish may be considered ancient, in that they date from the middle ages in Europe but the majority of such movements date from the end of the last century. The detrimental effects of some introductions soon became apparent, but until recently were insufficient to cause widespread concern. However, with the development and spread of aqua-culture and an increasing public awareness of the environment fears of the impacts of introductions of fish species have grown. This lead the International Council for the Exploration of the Sea (ICES) to form a Working Group on the introduction and Transfer of Marine Organisms which formulated a Code of Practice which was adopted by ICES in 1973. The International Consultation on Fishery Resources Allocation (Vichy, France, 1980) and the Eleventh Session of the European Inland Fisheries Advisory Commission (EIFAC) held during 1980 both recommended that the procedures for introducing fish species into freshwaters be reviewed. As a result EIFAC adopted a Code of Practice based on the ICES model at its Fourteenth Session (Bordeaux, France, 1987). All other FAO Regional Fishery Bodies dealing with inland waters have also expressed their concern about introductions at their sessions and are currently investigating the relevance of the ICES/EIFAC Code to their own situations.

Ganzes Dokument

 

welcomme-biblio

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Donnerstag, 14 Juni 2018 10:16

FREYHOF, J. & BROOKS, E. (2011)

European Red List of Freshwater Fishes.

viii + 60 Seiten, mit Grafiken, Farbfotos, Verbreitungskarten und Tabellen.
Publications Office of the European Union, Luxemburg. ISBN 978-92-79-20200-1; doi:10.2779/85903.

Executive Summary:

Aim: The European Red List is a review of the conservation status of c. 6,000 European species to date (dragonflies, butterflies, freshwater fishes, reptiles, amphibians, mammals and selected groups of beetles, molluscs, and vascular plants) according to IUCN regional Red Listing guidelines. It identifies those species that are threatened with extinction at the regional level – in order that appropriate conservation action can be taken to improve their status. This Red List publication summarizes the results for all described native European freshwater fishes and lampreys (hereafter referred to as just freshwater fishes).

Scope: All species of freshwater fishes recorded from European freshwater waters are included. Marine migrants and species of brackish waters are also included if they regularly enter freshwater habitats. Species are only included if the record is based on individuals with locality data and reliable identification.

Red List assessments were made at two regional levels: for geographical Europe, and for the 27 current Member States of the European Union. The distribution of freshwater fishes is considered at the sub-river basin level. Therefore the distribution included here sometimes extends beyond the political boundaries.

Status assessment: The status of all species was assessed using the IUCN Red List Criteria, which are the world’s most widely accepted system for measuring extinction risk. All assessments followed the Guidelines for Application of IUCN Red List Criteria at Regional Levels.

The status of species endemic to the Mediterranean basin is based on evaluations made during an IUCN workshop held in Malaga (Spain) in December 2004. All European sturgeons were assessed at a workshop held in Wuhan (China), during the 6th International Symposium on Sturgeon in October 2009. The status of all other European species has been evaluated when preparing the Handbook of European Freshwater Fishes during an IUCN workshop held in Berlin (Germany) in December 2006, in coordination with the IUCN Freshwater Biodiversity Assessment Unit. All species present in the 27 Member States of the EU were re-assessed for their regional conservation status in 2010. Assessments are available on the European Red List website and data portal: http://ec.europa.eu/environment/nature/conservation/species/redlist and http://www.iucnredlist.org/europe.

The status of all European freshwater fish species has been reviewed. For certain species groups of Mediterranean river basins, the taxonomy has been revised since the  2004 Malaga workshop, requiring an update of their Red List status. Also, several species have been newly described since 2007. All this is leading to an improved understanding of their conservation status. Up-to-date information for all these species is included in this report. Evaluations have mostly been done through the formal IUCN validation procedure, except for a few species still awaiting comments by relevant specialist groups of the IUCN Species Survival Commission.

Freshwater fishes in Europe: As part of this Red List assessment, 531 native and described European species have been assessed, of which 381 are present in the 27 Member States of the European Union. Almost 80% of the European species are endemic to Europe (which means that they are unique to Europe and are found nowhere else in the world). About 50% of the species found in the 27 Member States of the EU are endemic to the EU. Seven species occur only marginally on the European continent, and are considered as Not Applicable in this assessment.

Results: Overall, at least 37% of Europe’s freshwater fishes are threatened at a continental scale, and 39% are threatened at the EU 27 level. A further 4% of freshwater fishes are considered Near Threatened. This is one of the highest threat levels of any major taxonomic group assessed to date for Europe. The conservation status of Europe’s eight sturgeon species is particularly worrying: all but one are Critically Endangered. By comparison, 44% of freshwater molluscs, 23% of amphibians, 19% of reptiles, 15% of mammals and dragonflies, 13% of birds, 9% of butterflies and 7% of aquatic plants are threatened at the European level.

Despite a lack of good trend data for certain countries, the current assessment shows that about 17% of Europe’s freshwater fish species have declining populations, whereas only 1% are on the increase, and 6% are considered stable. For the remaining 76%, the current level of knowledge is insufficient to define their population trends.

The highest levels of species diversity are found in the lower parts of the rivers draining into the Black and Caspian Seas. However, a number of species with restricted ranges are also encountered in the Alps, in Great Britain and Ireland, and around the Mediterranean and Black Seas. Most of the threatened species are confined to certain areas in southern Europe.

Most freshwater fishes are in some way affected by pollution of domestic, industrial and agricultural origin. Another primary threat to Europe’s freshwater fishes is habitat loss due to over-abstraction of water. Additional major threats are the introduction of alien species, overfishing (particularly in the larger rivers of Eastern Europe) and a massive increase in the construction of dams, blocking migration and altering stream habitats.

Conclusions and recommendations:

  • Freshwater fishes are one of the most highly threatened species groups in Europe. At least 37% of all European species are threatened at a continental scale, and 39% are threatened at the EU 27 level. Of all assessed species groups, this level of threat is second only to the one for freshwater molluscs. The conservation status of Europe’s eight sturgeon species is particularly worrying: all but one are Critically Endangered.
  • There is an ongoing extinction crisis affecting Europe’s freshwater fishes. At least 13 species are now globally Extinct. Five additional species are Possibly Extinct, but the information is currently inadequate to certify their extinction. Furthermore, several freshwater fish species are currently under immediate threat of extinction, amongst them several species of sturgeons, and certain species of the Mediterranean river basins.
  • The high overall threat level of Europe’s freshwater fishes is an indicator for the exceptional vulnerability of Europe’s freshwater habitats, and of their poor state of protection. The main threats to Europe’s freshwater fishes are pollution, habitat loss due to over-abstraction of water, and the introduction of alien species. Alien species introduction, especially where these are of European origin, is almost totally uncontrolled. The main vectors of alien species introduction are recreational fisheries and the connection of formerly separate river basins by manmade canals.
  • An increased frequency and intensity of droughts is already impacting freshwater systems and the species that rely on them, especially in the Mediterranean region. The predicted impact of climate change is likely to worsen the situation in the future.
  • While many freshwater fishes are protected under national legislation or under the EU Habitats Directive, the majority of threatened species still remain unprotected. Furthermore, where legal protection does exist, it often remains ineffective against threats such as alien species introduction or water abstraction.
  • In order to improve the conservation status of European freshwater fishes and to reverse their decline, ambitious conservation actions are urgently needed. In particular: ensuring adequate protection and management of key freshwater habitats and of their surrounding areas, drawing up and implementing Species Action Plans for the most threatened species, establishing monitoring and ex-situ programmes, finding appropriate means to limit further alien species introductions, especially by anglers, and revising national and European legislation, adding species identified as threatened where needed.
  • The identification, establishment and management of a network of Freshwater Key Biodiversity Areas in Europe is urgently needed.
  • This project contributes to improving and updating the coverage of fishes on the global IUCN Red List, thanks to the assessment of endemic European freshwater fishes.

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Distribution of arapaima (Arapaima gigas) (Pisces: Arapaimatidae) in Bolivia: implications in the control and management of a non-native population

BioInvasions Records (2012) Volume 1 (2): 129–138
doi: http://dx.doi.org/10.3391/bir.2012.1.2.09

Abstract :

The introduction and establishment of arapaima (Arapaima gigas) in southeastern Peru and northwestern Bolivia is an example of a fish species that appears to be increasingly common and widespread in non-native portions of its range, but whose populations are on the decline within its native range. The arapaima is overfished and considered threatened throughout its native range in the Central Amazon. We gathered and examined data on the distribution of fish and wildlife in the Takana II Indigenous Territory in Bolivia, near the arapaima’s reported initial invasion zone in Peru. Results confirmed the presence of arapaima in several water bodies where local people have also reported a strong decline in native fish populations. Further south in the Takana I Indigenous Territory, monitoring of fisheries by local communities (2002-2008), including observations on arapaima catches, indicate that until 2008 arapaima had not been reported in the area. However in 2009, there were reports of arapaima in the Undumo stream. Our results demonstrate that since the first presence of arapaima in Bolivia at the beginning of the 1980s, it has steadily expanded its distribution. We propose actions to mitigate this situation by managing and controlling populations of this invasive and endangered species, as well as improving income for indigenous communities.

miranda-chumacero-biblio

22.02.2016 - 255

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Biologie, Gefährdung und Schutz der Groppe (Cottus gobio) in der Schweiz.

Mitt. zur Fischerei 77: 1-73. Hrsg. Bundesamt für Umwelt, Wald und Landschaft (BUWAL), Bern.

Zusammenfassung:

Die Groppe oder Koppe (Cottus gobio, L. 1758) ist in der Schweiz der einzige Vertreter der Familie der Cottidae. Dieser Kleinfisch bewohnt einen Teil der Schweizer Bäche und Seen. Obschon die Groppe in der Schweiz noch häufig vorkommt, wird sie infolge eines deutlichen Bestandesrückgangs innerhalb der letzten 50 Jahre zu den potenziell gefährdeten Fischarten gezählt. Da sie keine wirtschaftliche Bedeutung hat, ist sie nur selten in den Mittelpunkt spezifischer Forschungen gerückt.

Die Körperform der Groppe ist der bodenorientierten Lebensweise besonders gut angepasst. Der Körper ist länglich und zylinderförmig, mit einem breiten, abgeflachten Kopf, der etwa ein Drittel der Gesamtlänge einnimmt. Die beiden grossen Brustflossen erlauben eine gute Grundhaftung. Weitere Merkmalen sind das Fehlen einer Schwimmblase, eine glatte, schuppenfreie Haut und durch eine doppelte Cornea geschützte Augen.

Die Groppe ist eine europäische Art, die in kontinentalen Gewässern von Nordspanien bis in den Ural und von Südskandinavien bis Nordgriechenland vorkommt. Sie hält sich vorzugsweise in Forellengewässern auf, kommt jedoch auch in grossen Fliessgewässern und in Seen vor.

Mit zunehmendem Alter verlagern sich die ökologischen Ansprüche der Groppe bezüglich der Substratbenutzung, da dieses im Verhältnis zu ihrer Grösse steht. Die Jungfische bevorzugen grobkörnigen Schotter, während sich die grösseren Exemplare unter Steinen verbergen, welche ihren Dimensionen entsprechen. Zur Vollendung des Lebenszyklus benötigt die Groppe deshalb auf beschränktem Lebensraum ein Mosaik verschiedener Habitatstrukturen.

Die Nahrung der Groppe besteht hauptsächlich aus Invertebraten wie Trichopteren, Ephemeropteren und Dipteren. Sie selbst ist Beute für andere Fischarten (Forelle, Hecht, Aal, Barsch, Alet) sowie fischfressenden Vögel (Gänsesäger, Graureiher, Eisvogel). Der Eintritt in die Geschlechtsreife sowie die Laichzeit der Groppe variieren je nach Gewässer. Die Lebensdauer kann 3 bis 10 Jahre betragen; im Allgemeinen ist der Fisch mit 2 Jahren geschlechtsreif. Die Laichzeit findet zwischen Februar und Juni statt. In dieser Zeit legt das Weibchen seine Eier in einer vom Männchen bewachten Höhle an die Unterseite eines Steins ab. Die vom Männchen bewachte Brut wird durch Fächelbewegungen der Flossen mit ausreichend sauerstoffreichem Wasser versorgt. Die Entwicklungszeit der Eier beträgt rund 275 Tagesgrade.

Die Groppe wird von denselben Faktoren bedroht wie andere Fischarten. Habitatveränderungen (Gewässerunterhalt, Querbauten, Stauhaltungen, etc.) ziehen den Verlust der natürlichen Lebensraumvielfalt sowie der Fliessgewässer-Dynamik nach sich. Hindernisse verschiedener Art beeinträchtigen ihre Wandermöglichkeiten, trennen Populationen ab oder verhindern eine natürliche Neubesiedlung bestimmter Strecken. Ein stets aktuelles Thema bleibt die Gewässerbelastung durch Stoffe, deren Auswirkungen teilweise noch unbekannt sind.

Die wichtigsten Schutzmassnahmen für diese Fischart bestehen in der Renaturierung von stark verbauten Fliessgewässern, der Abschaffung oder Sanierung von Wanderhindernissen sowie der Bekämpfung der Gewässerverschmutzung.

Bestellung

 

zbinden-biblio

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“Freshwater Killer Whales”: Beaching Behavior of an Alien Fish to Hunt Land Birds.

PLoS ONE 7(12): e50840. doi:10.1371/journal.pone.0050840. Published: December 5, 2012,

Abstract:

The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ13C and δ15N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

cucherousset-biblio

18.11.2015 - 345

Cucherousset, J., Boulêtreau, S., Azémar, F., Compin, A., Guillaume, M. & Santoul, F. (2012)

“Freshwater Killer Whales”: Beaching Behavior of an Alien Fish to Hunt Land Birds

PLoS ONE 7(12): e50840. doi:10.1371/journal.pone.0050840. Published: December 5, 2012

Abstract

The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ13C and δ15N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

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Donnerstag, 14 Juni 2018 08:28

Anadrome Fische

Anadrome Fische leben primär im Meer, wandern aber zur Laichablage aus dem Meer in Süßgewässer und suchen dort geeignete Laichplätze auf. Die Fische wandern bereits als Jungfische ins Meer zurück.

Beispiele: Maifisch, Atlantischer Stör, Waxdick, Lachs, Meerforelle.

 

anadrom-term

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Donnerstag, 14 Juni 2018 08:24

Katadrome Fische

Katadrome Fische sind Wanderfische, die den größeren Teil ihres Lebens im Süßwasser verbringen und  oft Tausende Kilometer von ihrem Heimatfluss entfernt liegende Laichplätze im Meer aufsuchen. Beispiel: Euopäischer Aal

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Donnerstag, 14 Juni 2018 11:15

MUUS, B. J. & NIELSEN, J. G. (2013)

Meeresfische Europas - Nordsee, Ostsee, Atlantik.

337 Seiten, mit 1159 Farbabbildungen, Strichzeichnungen und 280 Verbreitungskarten.
Franckh-Kosmos-Verlags-GmbH & Co. KG, Stuttgart. ISBN 978-3-440-13515-0.

Kundenrezension:

Das die Dänen ein fischendes Völkchen sind, merkt man dem Buch über die Meeresfische Europas von Muus und Nielsen deutlich an. Das Buch bietet von Lebensweise bis Fangtechnik, viel Hintergrundinformationen zu den einzelnen Fischen. Die jeweilige Verbreitungskarte erschließt sich dem Leser ebenso wie Nahrung, Verwendung und Larvendarstellungen. Die Betrachtung der Arten von Nord-, Ostsee und Atlantik bietet einen der größten Artenüberblicke. Großes Manko sind die Zeichnungen und das Register. Auch fehlen die in der früheren BLV Version vorhandenen Bestimmungsschlüssel. Trotzdem bietet es dem interessierten Angler, Taucher oder sonstigem Natur interessierten Leser gegenüber anderen Büchern teilweise deutlich weitergehende Informationen zu den einzelnen Tieren.

muus-biblio

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Faunistischer Bericht über die Thermen in Warmbad Villach.

Carinthia II, 176./96. Jahrgang: 231-239.

Kurzfassung:

Eine  erste  umfassende  Liste der Tierwelt im Bereich der Thermen von Warmbad  Villach publizierte  STROUHAI (1934); seither gelangte eine Reihe von tropischen Organismen in den Thermenbereich, wobei sich die Artenzusammensetzung  ständig verändert. Im Rahmen  dieser  Arbeit  soll ein kurzer  Überblick über  die derzeit  herrschenden faunistischen Verhältnisse gegeben werden. Die Aufsammlungen  und Beobachtungen stammen vom 10. 12. 1985, wobei folgende Arten besonders hervorgehoben werden sollen: zwei tropische  Buntbarsche (Hemichromis bimaculacus und Hemichromis fasciatus) sowie der Seefrosch (Rana ridibunda ridibunda).

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© Peter Dollinger, Zoo Office Bern hyperworx