Presentation on theme: "Fishes in th Barents Sea Species list: Dolgov (2002) Stiansen and Filin (2007,2008) Joint report 204 species of fish in the BS Andriashev and Chernova."— Presentation transcript:
Fishes in th Barents Sea Species list: Dolgov (2002) Stiansen and Filin (2007,2008) Joint report 204 species of fish in the BS Andriashev and Chernova (1995) list 163 species in seven zoogeographical groups
The Barents Sea is the boundary area between Arctic and boreal fauna the southern boundary of Arctic fishes and northern boundary of Boreal fishes (Michael Sars,1851, G.O. Sars 1857)
Species list: Dolgov (2002) modified in Stiansen and Filin (2007,2008) Joint report 204 species of fish in the BS Andriashev and Chernova (1995) list 166 species in seven zoogeographical groups
Ecosystem survey data (2004-2009) The most spatially extensive survey in the BS ever
Species recorded at the Ecosystem survey classified according to Rijnsdorp et al. (2010) Arctic: southern limit off northern Norway Boreal: extends into colder areas Southern limit around British isles and west of Brittany Lusitian: Abundant from the Iberian peninsula to the britsh isles Atlantic: Mostly pelagic or deep water, widespread in the North Atlantic
Atlas of the Barents Sea fishes Authors IMR – Rupert Wienerroither, Edda Johannesen, Herdis Langøy, Kirsti Børve Eriksen, Thomas de Lange Wenneck, Åge Høines and Otte Bjelland PINRO – Andrey Dolgov, Dmitry Prozorkevich, Tatiana Prokhorova and Konstantin Drevetnyak Bergen Museum - Ingvar Byrkjedal and Gunnar Langhelle
Structure of the Atlas 249 pages 2952 bottom trawlings 101 species
Data gridding Data were gridded into a 35 nm by 35 nm grid with 384 grid cells based on our survey design and calculated average catch rates per grid cell.
Problem species the genus Careproctus the genus Gymnelus the Ammotydes genus - they are difficult to distinguish and because there are no confirmed observations of A. tobianus after 1998. all Myctophidae since they are in a poor condition after trawling and difficult to identify to the species level, however, we show observation at the species level recorded by taxonomists, showing that most of the Myctophidae in the Barents Sea is Benthosema glaciale. the Icelus genus (I. spatula and I. bicornis), since they are difficult to separate morphologically. data on Cottunculus microps and Cottunculus sadko on the same maps since recent research indicates that these are indeed one species. In addition to maps of the Sebastes species, we also provide a map on Sebastes spp., representing juveniles.
Community structure of demersal fish in the BS n=82 Species rank log rel abundance Colour coding according to Andriyashev & Chernova: arctic = blue, mainly arctic = green, arcto-boreal = purple, mainly boreal = red, boreal = orange, south boreal = yellow, widely distributed or missing = grey Johannesen et al. In prep. => Biomass cod is dominating
0 1 0 1 Longitude Latitude Depth Salinity Temperature Colour coding according to Andriyashev & Chernova: arctic = blue, mainly arctic = green, arcto-boreal = purple, mainly boreal = red, boreal = orange, south boreal = yellow, widely distributed or missing = grey
Variables ranked according to importance and added % variation explained Total model: 17.3 % explained Years explain 1,1 % All variables are significant! Var DfAICFN.PermPr(>F)Add % expl.Acc. % Temperature112531178.1711990.005 **6,249057 latitude112571135.7681990.005 **3,3430199,592076 depth112580126.4751990.005 **4,13925313,731329 longitude112604100.5991990.005 **1,65983615,391165 year11269013.3681990.005 **1,06070717,3120475 salinity11264658.0811990.005 **0,860175516,2513405
Geograpical patterns in species density and body size Strongly correlated With individual density
Cluster analysis -Biomass -Abundance -Presence-absence Biomass/Abundance: more important from an ecological point of view