Before coming to Lake Baikal we read a lot about the ecological crisis and the lake turning into a swamp with overgrowing algae, particularly Spirogyra as a result of increased human activity and consequent phosphate content in the water from inadequate waste and sewage management. We were expecting to be diving in green "compot" as russian divers call it most of the time. Surprisingly and fortunately the problem is not as profound as was portrayed to us. On our way from Irkutsk to Severobaikalsk we collected green algae growing on the shore areas and some during our dives which we analyzed with our relic microscope. Most of the samples included different species of algae such as Ulothryx and Draparnaldia. The first sample of Spirogyra we found was in a very shallow bay in the middle of the Baikalo-lensky national park (quite far north). We started to see great amounts of Spirogyra in the shallow areas about 10km before reaching the town of Severobaykalsk. The most notoriously known affected area is the Senagda bay, with a long sandy and very shallow beach. It was a popular tourist spot as the water in summer warms up to temperatures close to 20°C allowing people to swim without freezing, a rare instance in Baikal. Shallow and warm waters are however also the natural habitat of Spirogyra, that in the past few years has expanded logarithmically fed by the increasing concentration of phosphates in water, flooding the beach with green mass. The shallow bottom in water is covered in green fluffy algae that then collect on the shore, dry and decompose quickly emitting an awful rotten smell.
This situation is similar in multiple places and beaches around Severobaikalsk as we had a chance to see during our quick excursion with a local eco-activist Angelica. The sources of the pollution or food for Spirogyra are multiple, including phosphates in the washing powders which are still allowed in Russia, inefficient sewage system and wagon depot using harsh chemicals to wash their trains which are directly flushed into the lake without any sort of processing.
The problem of Spirogyra expansion around Severobaykalsk is very severe, but also very localized. Upstream of the town and it river Tia the shores are immediately much cleaner. Local geography with shallow shores that allows water to warm up to temperatures favourable for Spirogyra growth combined with the phosphates that it needs for its growth create ideal conditions for its growth. The solution to stop its expansion and help the lake to recover is simple, stop feeding it, once it doesn't have phosphates in the water it cannot grow. This can be however a bigger problem than it seems. It would require major investments into upgrading the towns sewage treatment and the political will to ban the use of phosphates in washing powders and other house cleaning products, both currently lacking in Russia.