Most of the nutrients in the area known as the Västerhav (Kattegat,
Skagerrak and Öresund) are brought in from the Atlantic in the north,
from the south via the English Channel, and by currents
from Baltic via the Öresund and the Great Belt. Thus, the majority
of nutrients in the Västerhav do not originate from Sweden, but coastal
areas are effected locally by the run-off from Swedish rivers and basins.
This is also true of the Baltic, where countries to the east and south are
the largest contributors of nutrients to the Baltic.
|Those nutrients that contribute most to over-fertilization
of the seas around Sweden are believed to be nitrogen
and phosphorous. The principal sources of nutrient input are from
agriculture, sewage and atmospheric fallout.
Nutrients from agriculture
The majority of nutrients that effect the
sea come from agriculture. With intensive animal farming, manure
is a waste product that is thought to be problem and often needs to be disposed
of at the lowest cost. Manure contains amongst other things, nitrogen in
the form of nitrates and ammonia. Most of the manure is spread out on the
fields as a liquid-like fertilizer, but unfortunately the liquid-like
consistency has a tendency to clog, rather than improve the soil, which
does not happen with normal manuring. This liquid-like manure can even be
flushed out of the earth and end up in the ground water, rivers and streams
and take the nutrients with it. Finally, these nutrients end up in the sea.
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