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Contributors: J. Alvarez, B. Bogstad, Dalpadado P., E. Eriksen, Gjøsæter H., Heldal H.E., Jørgensen L.I., Knudsen T., Mauritzen M., B. Røttingen, S. Tjelmeland.

The fourth joint ecosystem survey was carried out during the period 8th of August to 5th of October 2006. Results of investigations 0-group, the acoustic survey for pelagic fish, main oceanographic were included in Vol.1 of Report. This volume include other materials of eco-survey 2006. and investigations have always formed a part of these surveys, and studies on plankton have been included for many years. In recent years, observations of sea mammals, seabirds, bottom fishes, and benthos have been included. Consequently, from 2003, these surveys were called ―ecosystem surveys‖. It is results from the investigations on plankton, bottom fishes, benthos and etc. A list of the participating vessels with their respective scientific crews is given in Survey report Vol.1. In addition to, the following specialists took part in preparing the Survey report vol.2: C. Hvingel (IMR), E. Orlova (PINRO),B. Bogstad (IMR),A. Dolgov (PINRO), A.Hoines (IMR).

The main aim of the ecosystem survey was to map the distribution and abundance of the young and adult stages of several demersal and pelagic fish species, and in addition to gather information about hydrographical features, zooplankton, benthos, seabirds and sea mammals. The water temperature in all observed areas was still higher (+0.7-+1.2 0C) than the long term mean but somewhat lower than in the same period 2006. The 2007 year-class of capelin and redfish are rich. 0-group of haddock, herring, eastern component of polar cod and sandeel are below average. 0-group of cod, Greenland halibut, saithe, long rough dab, wolffish and western component of polar cod were estimated to be poor. The total capelin stock was estimated to be 1.9 million tonnes, which is 2.4 times higher than last year. About 0.84 million tonnes were assumed to be maturing. However, the stock is still at a low level compared to the long term mean. The polar cod stock was estimated to be 1.2 million tonnes, which is less than last year but still higher than the long term mean. The abundance of juvenile Norwegian spring spawning herring was estimated to 1.22 million tonnes. Large parts of the numberous 2004 year-class migrated to the southeastern part of the Barents Sea, usually dominated by younger year-classes. Blue whiting of age groups 1 to 9, but mostly age 3 and 4, were observed in the western and southwestern parts of the surveyed area, and the biomass of this stock component was estimated to be 0.66 million tones, which is the third following year of decline since 2004, where the stock reached 1.4 mill. tonnes.

The third joint ecosystem survey was carried out during the period 1 super(st) of August to 5 super(th) of October 2005, This survey encompasses various surveys that previously have been carried out jointly or at national basis. Joint investigations include the 0-group survey, the acoustic survey for pelagic fish (previously known as the capelin survey), and the investigations on young Greenland Halibut north and east of Spitsbergen. Oceanographic investigations have always formed a part of these surveys, and studies on plankton have been included for many years. In recent years, observations of sea mammals, seabirds, bottom fishes, pollution and benthos have been included. Consequently, from 2003, these surveys were called "ecosystem surveys".

The main aim of the ecosystem survey was to map the distribution and abundance of the young and adult stages of several demersal and pelagic fish species, and in addition to gather information about hydrographical features, zooplankton, benthos, seabirds and sea mammals. The water temperature in all observed areas was higher (+0.5-1 °C) than the long term mean and somewhat higher than in the same period 2005. The 2006 year-class of capelin, haddock, herring, long rough dab and sandeel are rich. 0-group of eastern component of polar cod is near the average level. The 2006 cod and redfish year-class is below than average. 0-group of Greenland halibut, saithe, western component of polar cod, wolffishs and Gonatus were estimated as poor. The total capelin stock was estimated near 0.8 million tonnes, which is 2.4 times higher than last years estimate. About 0.44 million tonnes were assumed to be maturing. The polar cod stock was estimated to be 1.9 million tonnes, which is 0.14 million tonnes higher than last year, but by numbers it was two times lower then in 2005. Juvenile Norwegian spring spawning herring was estimated in the southern part of the Barents Sea to be 0.643 million tonnes. Blue whiting of age groups 1 to 14 were observed in the western and southwestern parts of the surveyed area, and the biomass of this stock component was estimated to be 0.770 million tonnes.

The main aim of the ecosystem survey was to map the distribution and abundance of the young and adult stages of several demersal and pelagic fish species, and in addition to gather information about hydrographical features, zooplankton, benthos, seabirds and sea mammals. The water temperature in all observed areas was higher (+0.5-1 degree C) than the long term mean but somewhat lower than in the same period 2004. The 2005 haddock year-class is very rich. The 2005 year-class of cod, herring, capelin and is near the average level. 0-group of the western component of polar cod is below the average level. 0-group of Greenland halibut, redfish, saithe and the eastern component of polar cod were estimated to be poor. The total capelin stock was estimated to be 0.3 million tonnes, which is 50% lesser than last years estimate. About 0.17 million tonnes were assumed to be maturing. The polar cod stock was estimated to be 1.8 million tonnes, which is 0.7 million tonnes higher then last year. Juvenile Norwegian spring spawning herring was estimated in the southern part of the Barents Sea to be 2.8 million tonnes. Blue whiting of age groups 1 to 9 were observed in the western and southwestern parts of the surveyed area, and the biomass of this stock component was estimated to be 1.1 million tonnes.

The main aim of the ecosystem survey was to map the distribution and abundance of the young and adult stages of several demersal and pelagic fish species, and in addition to this gather information about hydrographical features, zooplankton, benthos, seabirds and sea mammals. Depleted content of oxygen in the bottom layer of the southern Barents Sea that started in 1998 has continued in summer and autumn 2004. Phosphate content in the Barents Sea in summer was close to the long-term mean and reduced in autumn because of late termination of water blooming. Total abundance indices of 0-group fish were estimated by new Norwegian-Russian method used two ways. The new indices show the same richness of year classes as was found by traditional indices. Total cod numbers was estimated to be 1544 million individuals. Numbers of haddock was estimated near 791 million individuals. Assessments of other species biomass were estimated correspondingly: Redfish Sebastes marinus - 12 thousand sp., Sebastes mentella - 317 thousand sp., long rough dab - 3096 million individuals, Greenland halibut - 139 thousand sp. In addition, three species of catfish were also estimated.

The 2nd joint ecosystem survey was carried out during the period 1st of August to 4th of October 2004. This survey encompasses various surveys that previously have been carried out jointly or at national basis. Joint investigations include the 0-group survey, the acoustic survey for pelagic fish (previously known as the capelin survey), and the investigations on young Greenland Halibut north and east of Spitsbergen. Oceanographic investigations have always formed a part of these surveys, and studies on plankton have been included for many years. In recent years, observations of sea mammals, seabirds, bottom fishes, and benthos have been included. Consequently, from 2003, these surveys were called "ecosystem surveys". The present report from the survey will cover many but not all the aspects of the survey. Main focus is on the hydrographical conditions of the Barents Sea, the results from the 0-group investigations and from the acoustic investigation on pelagic fish (capelin, young herring and polar cod). Materials on sea mammals and seabird observations are also presented in volume 1 of the report. Results from the investigations on plankton, bottom fishes and benthos will only be briefly mentioned, since the reporting of these investigations will have to await further working up of material in the laboratories. Those investigations will be included in volume 2. The 1st volume of the report was made during a meeting between scientists participating in the survey, in Kirkenes 5-8th October.

The joint ecosystem survey carried out during the period 27th of July to 2nd of October 2003 encompasses various surveys that previously have been carried out jointly or at national basis in previous years. Joint investigations include the IMR/PINRO 0-group survey and acoustic survey for pelagic fish (also known as the capelin survey). Oceanographic investigations have always formed a part of both these surveys, and in recent years, studies on plankton and sea mammals have been included. In addition, a herring survey in the western parts of the Barents Sea and parts of the Norwegian Sea, a survey for bottom fishes in the western Barents Sea and a survey for young Greenland halibut north and east of Spitsbergen were also included in the ecosystem survey. The present report from the survey will cover many but not all the aspects of the survey. Main focus is on the hydrographical conditions of the Barents Sea, the results from the 0-group investigations and from the acoustic investigation on pelagic fish. Results from the investigations on plankton, bottom fishes and sea mammals will only be briefly mentioned, since the reporting of these investigations will have to await further working up of material in the laboratories. The report was made during a meeting between scientists participating in the survey, in Murmansk 3-9th October.