ICES Advice 2006, Book 8 - Baltic Sea

8 THE BALTIC SEA 1

8.1 Ecosystem Overview 1

8.1.1 Ecosystem Components 1

8.1.2 Major environmental influences on ecosystem dynamics 3

8.1.3 The major effects of the ecosystem on fish stocks 3

8.2 The human impacts on the ecosystem 5

8.2.1 Fishery effects on benthos and fish communities 5

8.2.2 Other effects of human use of the ecosystem 6

8.3 Assessments and advice 11

8.3.1 Stock Trends 11

8.3.2 Mixed fisheries and fisheries interactions 12

8.3.3 Special requests 27

8.3.3.1 HELCOM request to coordinate quality assurance activities on biological and chemical measurements in the Baltic marine area and report routinely on planned and ongoing ICES inter-comparison exercises, and to provide a full report on the results 27

8.4 Stock summaries 30

8.4.1 Cod in Subdivisions 22-24 (including Subdivision 23) 30

8.4.2 Cod in Subdivisions 25-32 38

8.4.3 Herring in Subdivisions 22-24 and Division IIIa (spring spawners) 47

8.4.4 Herring in Subdivisions 25-29 (excluding Gulf of Riga herring) and 32 48

8.4.5 Herring in the Gulf of Riga 55

8.4.6 Herring in Subdivision 30, Bothnian Sea 61

8.4.7 Herring in Subdivision 31, Bothnian Bay 69

8.4.8 Sprat in Subdivisions 22-32 74

8.4.9 Flounder 83

8.4.10 Plaice 89

8.4.11 Dab 91

8.4.12 Turbot in Subdivisions 22 to 32 93

8.4.13 Brill in Subdivisions 22 to 32 95

8.4.14 Salmon in the Main Basin and the Gulf of Bothnia (Subdivisions 22-31) 97

8.4.15 Salmon in the Gulf of Finland (Subdivision 32) 111

8.4.16 Sea Trout in the Baltic