Eutrophication, toxic cyanobacteria and cyanotoxins: when ecosystems cry for help

The natural evolution of aquatic ecosystems may lead to their eutrophication even when anthropogenic influence is scarce or absent. This is clearly seen in natural lakes and rivers in remote areas such as the Amazon region The runoff of nutrients and organic matter is due to accumulate especially in lakes and ponds or slow flowing rivers. This problem is accelerated whenever man influences the water quality of a river basin. In fact, we may consider that eutrophication has been accelerated and anthropogenic influence on water quality has its starting point, since early civilizations started to use manure to increase crops productivity, such