Annika Mikomägi – How Humans Affect Estonian Lakes
Most lakes in Estonia are over 10,000 years old. So far, they have been most influenced by changes in the climate. Annika Mikomägi, a doctoral student of ecology at the Tallinn University School of Natural Sciences and Health, claims that lately, the human being has increased its role in this influence.
Most lakes in Estonia are over 10,000 years old. So far, they have been most influenced by changes in the climate. Annika Mikomägi, a doctoral student of ecology at the Tallinn University School of Natural Sciences and Health, claims that lately, the human being has increased its role in this influence.
Changes in land usage (deforestation, irrigation trenches), the use of fertilisers in agriculture, and allowing waste water to seep into lakes are the main causes of anthropogenic eutrophication.
The first signs of human activity, which have been found from Estonian lake sediments during paleolimnological research, are over a thousand years old. Human activity and its influence on lakes has become a problem within the past half century – the rapidly degenerating quality of lake water promotes the growth of poisonous algae, mass death of fish, and a decrease in the quality of drinking water.
A good indicator of the ecosystem within a lake is the algae growing in it – the variety and volume of algae, to be exact. Algae leave a mark in the sediment, as sedimentary pigments and stable isotopes of carbon. Annika Mikomägi’s doctoral thesis researches the changes of these indicators in lake sediments.
They give us valuable information about the condition of the lake and the changes it has gone through in time. We can assess the condition of the lake before human influence and how human activity and changes in the climate affect lakes.
Around the world, the importance of lakes in the ecosystem has been acknowledged, and we have taken the responsibility, according to the European Water Framework Directive, to maintain the condition of the lakes.
We need to research and understand the processes that have taken place in the lakes in the past to maintain the good condition of our lakes in the future, and avoid anthropogenic eutrophication.
History is the teacher of life – “Historia est magistra vitae!”