Biotic components

Phytoplankton

Thu, 03 Dec 2009 15:50:35 +0000

There is large interannual and geographical variation in the distribution and abundance of phytoplankton species with in the area. However, the main pattern in the annual succession pattern is rather stabile despite variability in abiotic factors (e.g. temperature) between the years. The starting point of the spring bloom will vary between years, a variation that in large degree is controlled by the onset of necessary stability of the water column for bloom formation. Large blooms, with exception of the spring and autumn situation, might occur some years along the coast or in the open waters of the Barents Sea.

Zooplankton - Meso-zooplankton

Thu, 03 Dec 2009 15:53:10 +0000

The horizontal distribution of mesozooplankton in 2008 is shown at the Figure 4.3.4. According to the joint ecosystem survey, the average zooplankton biomass was clearly below the long-term mean, and the spatial coverage revealed very low zooplankton biomass in the central parts of the Barents Sea – but with some scattered higher values recorded in the central part of the Barents Sea and along the border of the Russian zone.

Zooplankton - Macroplankton

Thu, 03 Dec 2009 15:54:31 +0000

During the PINRO atumn bottom trawl survey in 2007-2008, samples were collected as a basis for estimation of pre-spawning stock of euphausiids (Figure 4.3.7 A, B). The study showed that the abundance of euphausiids crustaceans was higher than the long-term means from the sampling area, and the arctoboreal species Thysanoessa inermis was the most dominating species.

Zooplankton - Gelatinous zooplankton

Thu, 03 Dec 2009 15:55:49 +0000

The results showed a higher abundance of gelatinous zooplankton species in 2007 compared to 2008. This was particularly evident between longitudes 30-40ºE and 75ºN. In 2008, the highest abundance of gelatinous zooplankton was found more south and west in the Barents Sea than the previous year. Both in 2007 and in 2008, the distribution of “jellyfish” showed a considerable overlap with regions poor in mesozooplankton biomass.

Zooplankton - Zooplankton community in the Kola Peninsula offshore zone in 2007-2008

Thu, 03 Dec 2009 15:57:10 +0000

According to the zooplankton observation in 2007-2008 at the different parts of the Kola Peninsula coastal areas, there are between 19-30 species and higher taxonomic groups of zooplankton. The abundance varied from 2500 – 38 500 individuals per m3 with a pronounced decrease in abundance eastward. Copepods were the dominating species in the samples with up to 90 % of total number of individuals. Boreal species as C. finmarchicus, T. longicornis, A. longiremis and C. hamatus were particular dominant compared to the cold waters species С. hyperboreus, M. longa, P. minutus and Microcalanus sp.

Zooplankton - Fugløya-Bear Island (FB) transect

Thu, 03 Dec 2009 15:58:26 +0000

The stations in the Fugløya-Bear Island (FB) transect are taken at fixed positions located at the western entrance to the Barents Sea. The numbers of sampled stations are normally 5 to 8 depending on the weather conditions. In this study, four stations, representing different water masses (coastal; Atlantic; and mixed Atlantic/Arctic water) in 1996 and 2007, were analyzed for species composition of the two abundant species C. finmarchicus, and C. glacialis, and the occurrence of C. helgolandicus in the March and August.

Zooplankton - Kola section

Thu, 03 Dec 2009 15:59:45 +0000

C. finmarchicus was a dominant species among copepods on the Kola section, which is located further east of the Fugløya-Bear Island (FB) transect. Comparison of C. finmarchicus abundance and life stage structure are here studied in two relatively warm years (1983, 1992) and in an abnormally warm year (2008, Figure 4.3.12, Russian data). The results for 2008 showed that all C. finmarchicus stages, including nauplii and young copepodites, were more abundant this year along the whole section than in 1992 and in particular for 1983 (Figure 4.3.12).

Zooplankton - Expected situation

Thu, 03 Dec 2009 16:01:40 +0000

The average mesozooplankton biomass in August and September 2008 for the Norwegian sector of the Barents Sea was below the long-term mean, and was in fact the lowest ever measured since 1997. The highest biomass was found in the Atlantic water masses which designate the importance of zooplankton transport from the Norwegian Sea into central and western parts of the Barents Sea. The continual declining of mesozooplankton biomasses since mid 1990s suggests that the condition for local production could be less favourable also in 2009.

Benthos - JAES long term monitoring program

Thu, 03 Dec 2009 16:02:59 +0000

To track environmental impacts on benthic assemblages, large scale, long-term monitoring of the Barents Sea bentos has been underway since 2005. The “Russian-Norwegian Joint Annual Ecosystem Surveys” (JAES) project addresses the need by providing both spatial and temporal data of benthic fauna from more than 400 stations annually since 2006.

Benthos - The Shtokman Gas exploration field and Kola section -long term monitoring program

Thu, 03 Dec 2009 16:04:52 +0000

The Shtokman license area (Figure 4.3.14a) has been monitored by MMBI from 2002-2007. The location is deeper that 300m in the eastern Barents Sea. The relief of the sea bottom is monotonous, together with monotonous sediment and benthic communities (Denisenko, 1996, Pavlidis, 1995, Frolova et al, 2004). At present, pollution of the near bottom waters and sediments of this area is insignificant (Ivanov, 2003). Furthermore strong disturbance of sea floor by fish trawling was not recorded in this area (Aibulatov et al 2005).