Sea areas expected to have more abundant blue-green algae than last year
According to the Finnish Environment Institute, poisonous blue-green algal blooms are expected to flourish in Finnish marine waters in this summer more abundantly than last year.
According to the blue-green algae forecast released by the Finnish Environment Institute, the largest mats of blue-green algae are expected to be found in the Archipelago Sea, with a considerable risk of blue-green algal blooms.
In the other parts of the Gulf of Finland the number of algae appearances is predicted to be moderate.
”Compared with last year, the risk of blue-green algal blooms is considerable in a smaller sea area, while in larger marine areas the risk is moderate”, says Vivi Fleming-Lehtinen from the Finnish Environment Institute.
The quantities of algal blooms may even in this summer remain smaller than in the worst years of the current decade.
In the end, the weather conditions control the occurrence of blue-green algae to a very large degree.
”Cool and windy weather is the best to hold back the growth of blue-green algae”, Fleming-Lehtinen notes.
The algae forecast of the Finnish Environment Institute is based on the nutrient conditions in the sea during the winter, as well as on its changes over the spring.
When monitoring the occurrence of poisonous blue-green algae, the most important thing is to observe the phosphorus concentrations in the marine waters.
The recent mild winters free from ice have decreased the nutrient concentrations of the sea, as the marine waters have been mixed around the year and more oxygen has entered the deeper cavities on the sea-bed.
Oxygen has helped to decompose the nutrients more efficiently, which is why less phosphorus has risen from the cavities to stimulate blue-green algal blooms.
”However, climate change has increased winter precipitation and raised temperatures, which tends to increase the running of nutrients into waterways, thus decreasing the positive impact of the absence of ice”, notes limnologist Seppo Knuuttila from the Finnish Environment Institute.
The blue-green algae situation in the open sea will improve in the future, when the wastewater treatment in St. Petersburg improves.
Closer to the coast, water protection measures by agriculture have a greater bearing on the incidence of algae, through the directing of environmental supports towards areas with particular nutrient run-off problems.
Previously in HS International Edition:
Summer will bring on moderate amount of blue-green algae (3.6.2008)
WWF: Climate change to increase amount of algae in Gulf of Finland (29.5.2008)
Finnish Environment Institute: Current information on algal blooms