The Baltic Sea Environment and Ecology Editors: Eeva Furman, Mia Pihlajamäki, Pentti Välipakka & Kai Myrberg Index Preface 1 The Baltic Sea region: its subregions and catchment area 15 Food and the Baltic Sea 2 The Baltic Sea: bathymetry, currents and probability of 16 The complex effects of climate change on the Baltic Sea: winter ice coverage eutrophication as an example 3A The Baltic Sea hydrography: horizontal profile 17 Eutrophication and its consequences 3B The Baltic Sea hydrography: horizontal profile 18 The vicious cycle of eutrophication 4 The Baltic Sea hydrography: vertical profile 19A Baltic Sea eutrophication: sources of nutrient 5 The Baltic Sea hydrography: stagnation 19B Baltic Sea eutrophication: sources of nutrient 6 The distribution and abundance of fauna and flora 20 Alien species in the Baltic Sea in the Baltic Sea 21 Hazardous substances in the Baltic Sea 7A The Baltic Sea ecosystems: features and interactions 22 Biological effects of hazardous substances 7B The Baltic Sea ecosystems: features and interactions 23 The Baltic Sea and overfishing: 8A The archipelagos: Topographic development and gradients The catches of cod, sprat and herring in 1963–2012 8B The zonation of shores 24 Environmental effects of maritime transportation 8C Land uplift in the Baltic Sea 25 Protection of the Baltic Sea: 9 The Baltic Sea coastal ecosystem HELCOM – the Baltic Sea Action Plan 10 Shallow bays and flads: the developmental stages of a flad 26 Protection of the Baltic Sea: the European Union 11 The open sea ecosystem: seasonal cycle 27 Protection of the Baltic Sea: 12 The open sea ecosystem: the grazing chain A new mode of environmental governance and microbial loop 28 What can each of us do to improve the state of 13 The open sea ecosystem: scales and proportions the Baltic Sea? 14 The impact of human activities on the Baltic Sea References ecosystem TEXT ▶ INDEX 1 The Baltic Sea region: its subregions and catchment area Estimated 2010 population density Capital cities in the Baltic Sea Area Other Cities 2 Inhabitants per km Sub-basins (PLC) 0–10 Drainage area extent 11–50 National borders 51–100 101–500 501–1,000 1,001–5,000 5,001–10,000 10,001–50,000 50,001–100,000 Bay of Bothnia Finland Norwegian Sea Sea of Bothnia Sweden Norway Archipelago Russia Åland Sea Sea Gulf of Finland Northern Estonia Gotland Basin Gulf Western of Riga Skagerrak Gotland Basin Latvia Eastern Kattegat Gotland North Basin Sea Denmark Lithuania Öresund Bornholm Bay of Basin Gdansk Arkona Belt Basin Sea Belarus Poland Germany Ukraine A KK ETRI KUO ETRI Czech Republic P PHOTOS: PHOTOS: Based on HELCOM 2011 TEXT ▶ INDEX 2 The Baltic Sea: bathymetry, probability of winter ice coverage and currents 0–25 m 25–50 m 50–100 m >90% 100–200 m 200–459 m Probability of winter ice Ulvö Deep cover in % 249 m 50%–90% Åland Deep >90% 290 m 50%–90% Landsort Deep 10%–50% 459 m >90% <10% 50%–90% Gotland Deep 239 m <10% >90% 10%–50% Bathymetry (m) Long-term mean surface circulation Jouni Vainio/ Finnish Meteorological Institute Jouni Vainio/ Leppäranta and Myrberg, 2009 TEXT ▶ INDEX 3A The Baltic Sea hydrography: horizontal profile m Kattegat Great Belt Darss Sill Bornholm Stolpe Channel Gotland Deep Gulf of Finland 0 >17 15 15 16 17 >18 16 16 16 20 15 11 13 14 10 <10 10 5 5 9 <4.5 40 13 9 8 3.5 12 <2 <8 7 3 60 6 4 <3.5 5 4 >3 80 <4.5 100 5 120 140 >5 160 180 Temperature °C August 200 m Kattegat Great Belt Darss Sill Bornholm Stolpe Channel Gotland Deep Gulf of Finland 0 26 18 16 14 12 10 9 8 2 4 3 20 31 7.5 6 5.5 5 4.5 32 28 6.5 30 26 40 33 7 12 7.5 60 34 8 14 10 9 80 16 100 120 >10 140 160 >12 180 Salinity ‰ August 200 TEXT ▶ INDEX 3B The Baltic Sea hydrography: horizontal profile m Åland Sea Sea of Bothnia Northern Quark Bay of Bothnia m Åland Sea Sea of Bothnia Northern Quark Bay of Bothnia 0 0 14 13 15 14 13 12 5 3 20 10 11 10 20 4.5 3.5 8 5.5 7 6 5 7 6 3.5 4 40 4 5 3 40 2.5 6 >5.5 3.5 6.5 60 2 2.5 2 60 2 80 <1.5 <1.5 80 >4 100 100 2 7 120 120 7.5 140 >2 140 160 160 180 Temperature °C 180 Salinity ‰ August August 200 200 0 0 8 8 20 20 6 6 40 40 4 4 60 60 5 5 80 80 0 0 100 100 -2 -2 120 ml/l 120 ml/l 140 140 160 160 180 180 200 Oxygen 200 Oxygen August, 2012 220 August, 2012 220 Gotland Deep Gulf of Finland Gotland Deep Åland Sea Sea of Bothnia Bay of Bothnia TEXT ▶ INDEX 4 The Baltic Sea hydrography: vertical profile Gotland Deep (August) Sea of Bothnia (August) 0 5 10 15 20 0 5 10 15 20 depth (m) 0 depth (m) 0 Thermocline 20 20 Thermocline 40 40 60 60 Halocline 80 80 100 100 120 120 140 140 o O2 ml/l S (‰) T ( C) H2S S & T: Leppäranta & Myrberg, 2009 O2: Jan-Erik Bruun / SYKE TEXT ▶ INDEX 5 The Baltic Sea hydrography: stagnation Danish Kattegat Straits Bornholm Deep Gotland Deep Gulf of Finland Surface layer Permanent halocline A Deep water layer Upwelling Old, stagnant bottom water of high density. Permanent Surface layer halocline B Deep water layer Oxygen-rich cold Upwelling saline water of high density flows down into the Bornholm Deep and Old stagnant water replaces the old stagnant water. Permanent Surface layer Upwelling halocline C Deep water layer The stagnant H2S-rich water Oxygen-rich cold saline water of is forced into the deep-water layer, high density flows down into the Gotland Deep moving towards the inner Baltic and and replaces the old stagnant water. near the coast to the surface. Kattegat Danish Bornholm Deep Gotland Deep Gulf of Finland Straits TEXT ▶ INDEX 6 The distribution and abundance of fauna and flora in the Baltic Sea Painter’s mussel Unio pictorium Bladder wrack Fucus vesiculosus Turbot Psetta maxima Vendace Coregonus albula Pacific blue mussel Mytilus trossulus Bay barnacle Amphibalanus improvisus Common shrimp Crangon crangon Eelgrass Zostera marina Common reed Plaice Phragmites australis Pleuronectes platessa Fennel pondweed Potamogeton pectinatus Water louse Asellus aquaticus Common shore crab Marine species Carcinus maenas Fresh water species Fresh Brackish water water fauna fauna Common starfish Asterias rubens Marine fauna TEXT ▶ INDEX 7A The Baltic Sea ecosystems: features and interactions Characteristic organisms and processes 1 2 11 3 6 12 5 4 7 8 9 10 1 Plankton 5 Loose macroalgae 9 Meiofauna 2 Filamentous algal zone 6 Sedimentation 10 Marenzelleria 3 Bladder wrack zone 7 Bacterial decomposition 11 Fish 4 Red algal zone 8 Macrofauna 12 Circulation of nutrients TEXT ▶ INDEX 7B The Baltic Sea ecosystems: features and interactions SUN Circulation of nutrients Grazing chain Coastal Pelagic Con- PP PP sumers DIN DOM Bacteria Decomposition Con- Microbial Bacteria Organic sumers material loop Sedimentation Mixing Decomposition Sedimented Con- organic sumers Bacteria material Bacteria DOM PP = Primary Production DOM = Dissolved Organic Matter DIN = Dissolved Inorganic Nutrients Microbial loop TEXT ▶ INDEX 8A The archipelagos: topographic development and gradients Open sea zone Outer Inner Mainland zone Mainland archipelago zone archipelago zone Bedrock rises Seafloor becomes land above sea level Shelter from wind Wind exposure Gradually sloping shores Steep shores Sediment shores Rocky shores Proportion of land Open water Increasing Decreasing Shallow water areas Depth Influence of freshwater Salinity Freshwater species Marine species Water temperature Secchi depth TEXT ▶ INDEX 8B The zonation of shores Extreme high water Epilittoral Geolittoral Littoral Hydrolittoral Filamentous Extreme low water algal zone Bladder wrack zone Sublittoral Phytal Red algal zone Extreme high water Epilittoral Geolittoral Littoral Extreme low water Hydrolittoral Non-vegetated zone Phytal Elittoral Sublittoral Red algal zone Profundal TEXT ▶ INDEX 8C Land uplift Land uplift along the Baltic Sea coastline (mm/year) LENA BULYCHEVA E Source: Vestöl, Ågren, Svensson TEXT ▶ INDEX 9 The Baltic Sea coastal ecosystem 23 18 25 17 Hard bottom habitat A Soft bottom habitat 24 1 B 11 2 Algal community 4 Aquatic community 7 3 12 13 8 5 16 15 14 Pacific blue mussel community 9 10 20 21 19 Benthic 22 6 invertebrate community TEXT ▶ INDEX 10 Shallow bays and flads: the developmental stages of a flad Juvenile flad m 0 1 2 3 4 5 Flad Glo-flad Glo TEXT ▶ INDEX 11 The open sea ecosystem: seasonal cycle The seasonal cycle of phytoplankton Winter Spring Summer Autumn Spring bloom Blue-green algal bloom Dino- flagellates Diatoms Sedimentation Microzoo- plankton Rotifers Upwelling Micro- Thermocline flagellates Crustaceans Sedimentation Blue-green algae Overwintering resting stages Resting eggs TEXT ▶ INDEX 12 The open sea ecosystem: the grazing chain and microbial loop Grazing food chain Phytoplankton Zooplankton Fish (primary production) Herbivores Predators Inorganic nutrients Dissolved organic Zooplankton matter Cyanobacteria (blue-green algae) Larger flagellates Bacteria and ciliates Flagellates Microbial loop TEXT ▶ INDEX 13 The open sea ecosystem: scales and proportions AUTOTROPHS RELATIVE SCALE HETEROTROPHS Decomposers & consumers Primary producers From earth to moon 20,000 – 200,000 km IPEDIA K Mammals WI To the other side of the planet 2,000 – 20,000 km IPEDIA K Fish WI From St. Petersburg to Copenhagen 200 – 2,000 km IPEDIA K Macrozooplankton > 2 mm WI From Helsinki to Tallinn 20 – 200 km IPEDIA K Mesozooplankton 200–2,000 µm WI From the suburb to the city centre 2 – 20 km Microphytoplankton 20–200 µm Microzooplankton 20–200 µm OUTI SETÄLÄ OUTI SETÄLÄ OUTI A KK UO K From home to a local shop 200 m – 2 km Nanophytoplankton 2–20 µm Nanozooplankton 2–20 µm SEIJA HÄLLFORS SEIJA PATTERSON J.