Positive news for oxygenation solutions for the Baltic Sea have been published in Swedish newspaper Sydsvenskan. The original text can be found here (in Swedish):
Sydsvenskan – Ingenjörskonst motar algsörja.
The Swedish Ministry of the Environment proposes that Helcom should consider methods in the open sea to decrease eutrophication and stop vast cyanobacteria blooms. It is about trying to speed up the recovery of the Baltic says Senior administrative officer Mr Anders Alm who will present the suggestion at the forthcoming Helcom meeting.
The outlet of phosphorus from sewage treatment plants, industries and agriculture has decreased strongly the last twenty years. In spite of this the number and strength of algal blooms increase. Anders Alm says that it might take fifty or one hundred years for the Baltic to recover if efforts are limited to decrease land sources. The countries around the Baltic do it well in building sewage treatment plants and decreasing the leakage from agriculture but in spite of this the situation has not improved.
The bottoms contain huge amounts of phosphorus that is released under anoxic conditions. According to Professor Anders Stigebrandt is the phosphorus supply from bottoms about three times greater than the supply from water rivers and other sources on land. According to Stigebrandt and his research group is the solution to pump oxygen rich water down into the deepwater to bind the phosphorus. The method has been tested in smaller scale in the By Fjord at Uddevalla and he sees only positive effects. In large scale the method should also be of benefit for cod.
Anders Alm has a small bundle of suggestions to Helsinki that he hopes that Helcom’s experts can evaluate. One method is the Stigebrandt oxygenation pump. Another method aims at chemically bind phosphorus to the bottom sediment. A third method is to dredge the uppermost nutrient rich layer of the bottom sediment. The method sucks the sediment layer without spreading sediment particles Anders Alm says. He don’t consider it obvious that Helcom will welcome thoughts of using engineering methods to decrease algal blooms and bottom death.
Those who want to make scaremongering of this call it geoengineering and says that we manipulate natural systems. But we manipulate in many other ways, for instance through large scale fisheries and our farming landscapes, senior administrative officer Mr Anders Alm says.