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WELCOME to OCB 2018. The Baltic Sea. Ida Carlén Ida.carlen@ccb.se. The Baltic Sea. Enclosed sea Surrounded by nine nations Environmental issues. Bothnian Bay, The Quark Bothnian Sea Åland Sea Archipelago Sea Gulf of Finland Northern Baltic Proper Western Gotland Basin
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WELCOME to OCB 2018
The Baltic Sea Ida Carlén Ida.carlen@ccb.se
The Baltic Sea • Enclosed sea • Surrounded by nine nations • Environmental issues • Bothnian Bay, • The Quark • Bothnian Sea • Åland Sea • Archipelago Sea • Gulf of Finland • Northern Baltic Proper • Western Gotland Basin • Eastern Gotland Basin • Gulf of Riga • Southern Baltic Proper • Gdansk Basin • Mecklenburg Bight • Kiel Bight • Little Belt • Great Belt • The Sound • Kattegat
Covered by ice • The entire Baltic region wascovered by iceduring the last ice age. • The icestartedmeltingapproximately 15 000 yearsago • The icewascompletelygone 10 000 yearsago Ancylus lake ~10 500 yr BP The Yoldia Sea ~11 000 yr BP Littorina sea ~6500 yr BP Baltic ice lake ~12 000 yr BP
Physical conditions • Land still rising • Series ofbasins • Salinity gradient • Limitedexchangewith Atlantic • Anoxicbottomwaters 5
Physical conditions • Series ofbasinswithshallowunderwater sills • Kattegat max 124 m • Belt Sea max 80 m • Inner Baltic Sea max 459 m • Sills between 18-50 m depth
Physical conditions Ice and currents
Physical conditions • Salinity gradient
Physical conditions • Limitedexchangewith Atlantic • Anoxicbottomwaters
Physical conditions • Limitedexchangewith North Sea • Anoxicbottomwaters No influx of saline waters Oxygen to bottom waters Influx of saline water Stronger density gradient Anoxia in deep areas of the Baltic No mixing of waters
Habitats and species • Salt water species • Freshwater species • Hard bottom habitats • Soft bottom habitats • Habitat building species - eelgrass - bluemussel - bladder wrack 12 12
Species Brackish water environment Saltwater and freshwater species Relatively few species Sensitive ecosystem ”New” ecosystem 13 13 13
Species Saltwater species Freshwater species Insert pic of perch, pike, sik etc
Species Soft substrate species Hard substrate species
Habitat building species • Bladder wrack • Structureprovidesshelter for juvenile fish and other organisms
Habitat building species • Bluemussel • Food source for manyseabirds • Creating hard substrate, almost like reefs 18
Habitat building species • Eelgrass • Important for juvenile fish • Binds the substrate, hindering erosion 19
Pressures • Eutrophication • Environmentalcontaminants • Underwaternoise • Overfishing • Invasive species 20 20
Pressures Eutrophication
Pressures Eutrophication Oxygen used in the decomposition of excess growth Oxygen to bottom waters No influxofsalinewaters Influxofsalinewater Strongerdensity gradient Anoxia in deep areas of the Baltic No mixingofwaters 22
Pressures Underwater noise • Affects marine mammalsbutalsofish species such as cod • Engine noise • Echosounders • Constructions • Piling • Active sonars • Explosions
Pressures Invasive species
Pressures Environmental contaminants
Pressures • Overfishing • Overfishing
Pressures • Overfishing
Pressures Overfishing Environmental contaminants Lack of top predators Fundamental changes to the ecosystem Flip from top-down to bottom-up control
Relevant policy HELCOM Baltic Sea Action Plan
Relevant policy European Union strategies and directives 31
Marine protected areas 12% of Baltic Sea protected in MPAs