The environmental measures of the Lappeenranta and Imatra region and Eksote provide instructions for identifying blue-green algae and assessing the associated risks

The blue-green algae situation has caused people who spend the summer at the beaches of South Karelia to think.

The observation of blue-green algae in water areas is based on residents' observations and reports, as well as observations made in connection with sampling and monitoring by the authorities.

The blue-green algae situation can be monitored from the nationwide algae monitoring service in the Järviwiki service

The state environmental administration's Järviwiki service updates both assessments made by the authorities and observations made by citizens. In the service, you can also familiarize yourself with blue-green algae observations made by other residents.

Järviwiki service

You can record your algae observations in the Havaintolähetti service

The observations are published in Järviwiki's algae monitoring through the Havaintolähetti service. You should also always report blue-green algae sightings at public beaches to the health protection authority. The health protection authority's information can be found on the bulletin boards of swimming beaches and on the websites of municipalities.

Observation messenger service

The municipal health protection authority that supervises public swimming beaches does not visit the beaches every day to assess the presence of blue-green algae and does not provide information on the blue-green algae situation on a daily basis.

- It is also worth noting that only observations reported or made there are displayed on different monitoring websites. The blue-green algae situation may change quickly, says the Lappeenranta regional health inspector Taina Rajala and environmental engineer of the Imatra region Marcella Suomalainen.

- Swimmers should always visually assess the condition of the swimming water before diving in, they remind.

The environmental activities of the Lappeenranta and Imatra regions, together with Eksote, have worked on an information package for the residents on the identification and adverse effects of blue-green algae

What is blue-green algae?

Blue-green algae are a natural part of aquatic life, but when they become abundant they can cause problems, as some species are poisonous. Raija Aura The environmental department of the Lappeenranta region says that about half of the mass occurrences of blue-green algae have been found to be toxic.

- The toxicity of species varies and toxicity can only be determined with certainty in laboratory experiments or commercial poison tests. Some blue-green algae produce nerve and liver toxins, Aura explains.

Blue-green algae are microscopically small, single-celled algae that form colonies of various shapes. Depending on the species, the community can appear in the water as small flakes (genera Anabaena and Microcystis in inland waters, Nodularia in brackish waters) or as sharp sticks (Aphanizomenon in both inland and brackish waters). When it becomes abundant, it forms bands and algal rafts and colors the water, sometimes making it look like latex paint.

- The pulp is loose porridge, which can be brown or green in color, when it gets old and dry, the pulp can be turquoise or almost white. The blue-green algae mass smells very earthy and moldy, Aura explains.

The visible mass of blue-green algae is called a bloom, even though it does not actually form any flowers. According to Aura, it is difficult to predict and control the occurrence and duration of blooms, i.e. blue-green algae blooms.

- Winds and currents can move the blue-green algae mass, so the amount of blue-green algae in the water can change quickly even during the same day. Blue-green algae deposits start to appear when the waters warm up, usually around Midsummer, and they may continue well into autumn. The abundance and extent of the occurrences varies every year depending on weather conditions and nutrients, says Aura.

How can you identify blue-green algae?

Blue-green algae can be identified with a glass or stick test. During the drinking glass test, the water stands in the glass for about an hour, during which the blue-green algae rises to the surface. However, blue-green algae does not always rise to the surface, but is visible in the water as green bits. The water should therefore be examined carefully before possible use. The small green particles on the surface are blue-green algae.

In the stick test, you try to lift the algae mass into the air with a stick. If the algal mass breaks down into small green particles in the water, the alga is blue-green algae.

What are the side effects of blue-green algae and when should you seek treatment?

Some blue-green algae can produce liver or nerve toxins. In addition to toxins, blue-green algae can produce compounds that irritate the skin, among other things. Based on the appearance of the blue-green algae deposit, it is not possible to judge whether it is a toxin-producing blue-green algae species or not.

People's sensitivity to symptoms caused by blue-green algae varies. Symptoms usually appear within a few hours of exposure to blue-green algae.

Blue-green algae can cause skin symptoms, stomach symptoms (e.g. nausea, stomach pain, diarrhea, vomiting), or flu-like symptoms, such as runny nose, headache, eye irritation and fever.

If you have symptoms or suspect that you swam in blue-green water, wash thoroughly with plenty of clean water and soap.

Usually the symptoms go away without treatment, and if necessary, you can take fever and pain medicine.

If the symptom is also abundant vomiting and diarrhea, there is a risk of dehydration. In that case, you should seek treatment by calling Eksoten's emergency number 116 117. Similarly, skin swelling symptoms that require treatment combined with abundant redness or difficult respiratory symptoms are reasons to seek emergency care. You can also ask for advice from the HUS Poison Information Center on 0800 147 111.

How to avoid the side effects of blue-green algae?

It is impossible to estimate the duration of the presence of blue-green algae. If your water has, or you know has recently had, blue-green algae, remember these things:

• Do not swim in blue-green algae water
• Do not allow children or pets to play or swim in the beach water
• The water must not be used as drinking water for humans or animals, even when boiled
• The water must not be used as soaking water
• The water is not recommended as washing water
• The water is not recommended as dishwater
• Water is not recommended for watering edible plants

environmental engineer Marcella Suomalainen, Imatra regional environmental agency, tel. 020 617 4324, marcella. Finnishimatra.fi (marcella[dot]suomalainen[at]imatra[dot]fi)
health inspector Taina Rajala, Lappeenranta regional environmental agency, tel. 040 5100 265, taina. borderlappeenranta.fi (taina[dot]rajala[at]lappeenranta[dot]fi) (until 8.7.2022 July XNUMX)

health inspector Anni Antikainen, tel. 040 759 6746 anni.ancientlappeenranta.fi (anni[dot]antikainen[at]lappeenranta[dot]fi) (from 11.7.2022)

water resources expert Raija Aura, tel. 040 5843 278, raija. ploughlappeenranta.fi (raija[dot]aura[at]lappeenranta[dot]fi) (until 8.7.)