The biggest treat to the Baltic Sea is entrophication, in other words watervegetation's
overgrowing. Symptoms of it are: watervegetations multiplying amounts, plancton in
florescences strengthening, certain species/organisms becoming more common
and certain indestructbility (e.g. bladderwrack), water becoming muddy,
lack of oxygen from deeps –> alga inflorescences, hydrogen gulphides and nets
becomes slimy. What causes entrophication? Nutrients, centers of population, vastewater
of industries, fertilizers and environmental poisons. Heavymetals like nitrogen and phosphorus
drift to the Baltic Sea mostly from catchment area and lakes and centers of population. In
year 1995 nitrogen was produced by Russia 80300, Finland 18000 and Estonia 17200
tons/year.
Alga inflorescences are harmful when they slime the water, soil beaches cause bad taste
to fishes or poisons other organisms. When inflorescence is over, algas sink to the bottom. There
their breaking up wear off the oxygen. Worstly the lack of oxygen might destroy
animals and fishes which live at the bottom of the sea. For example on case from year
1996 when the whole East part of the Gulf of Finland went unoxygen. Then from the
boom released below normal amounts of phosphorus what helps algas growing because
poisonous blue-green algae can take and store phosphorus. The mass occurrences of blue-green algaes irritate making process of drinking
water because they multiply amount of organic substances of water and they stuck the filters of hydraulic
morters.
There is also a danger that the poisons of blue-green algaes pierces handling of the water and poison
water fall into wasterpipenetwork. Alga infloresces limit also the use for relaxation
, e.g swimming in the water that includes blue-green algaes migth cause allergic reactions
eyesymptoms and flu. Taking by mouth it might cause stomach pain or even
poisoning. Water including blue-green algae has caused in Finland many animal deaths.
It is expecially the problem of the Gulf of Finland. Oxygen disappear from deeps where only remain
the dead bottom. The salty water comes to Baltic Sea from Atlantic. The growing of salinity brings also new species to Baltic Sea –
temporary or permanent, e.g. planctoncrustacean, cod and mackerel.
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