POLLUTION BY THE REJECTIONS OF URBAN
EFFLUENTS
This pollution is
caused by waste waterof domestic and industrial origin. During the estival season, one
notes on the north-Mediterranean coasts, due on massive arrival of the tourists, an
increase in the marine water pollution by fermentable organic matter more especially as
the stations of purifications are saturated.
Consequences
of this organic pollutionare catastrophic for almost all the organizations constituting
the settlements of the mediums neritic. Studies of rejections of the Toulonnaise
agglomeration in the Cape Sicié, showed that the discharge of urban effluents at a rate
of only 7.5 cubic meters / dry with is enough to degrade to see to completely destroy the
under water settlement on more than one hundred of hectares until a 40 meters depth. Thus,
this pollution destroyed herbaria of Posidonies, these large plants with the under water
flowers which constitute one of the alive communities richest and most productive of all
water of the Mediterranean littoral. The rejections of the agglomeration of Marseille
caused damage even more catastrophic thus the settlements infra-littorals in Cysioseira stricta a large
brown alga was deteriorated by this pollution dice 1975 on a score of square kilometres.
Fortunately, the start up of a station of purification treating 53% of waste water of the
area of Marseille, already made it
possible significantly to reconstitute marine communities on a significant part of the
degraded zone .
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