"The blooms are now in most of the southern and southeastern areas of the Baltic Sea with the largest spread offshore midway between the southern tip of Öland and the Gdansk bay off north-eastern Poland," according to an SMHI statement.
July is the month when the cyanobacteria, which can be poisonous for animals and small children, spread the most and can make taking a holiday dip a less than refreshing experience.
The algal blooms have started to move further north in recent days and are nearing the southern coast of popular holiday island Gotland, the report stated.
"Here it is so far mostly a matter of cyanobacteria in the water, but if the calm weather continues, the surface water blooms can start coming here," explained oceanographer Jörgen Öberg.
Northern areas of the Baltic Sea are so far showing no indications of pending algal blooms, according to the report.
Scientists have identified the cause of algal blooms to be levels of phosphorous in the water. Phosphorous is typically discharged into the Baltic Sea as a bi-product of farming and the use of fertilizers.
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