As they say: every action has an impact, although these consequences do not have to be negative, or at least not for everyone. Why do we say this? Because there is a process that is occurring today in many wetlands, such as swamps, lakes and even inland seas, that is changing those ecosystems.
It is known by the name of eutrophication and it is something that enriches the environment, but only in part. Let's see what it consists of.
What is eutrophication?
Image - Wikimedia / F. lamiot
Eutrophication, also known as a eutrophic or dystrophic crisis, It is the name given to the excessive enrichment of an aquatic environment. To be more specific, it is when an ecosystem, lake, sea, pond, etc., receives more nutrients than it really needs. In addition, this compost is usually rich in nitrogen and phosphorus, so that unicellular algae, such as diatoms and chlorophytes, begin to proliferate in fresh waters, ending up with cyanobacteria.
The latter will form a surface layer, preventing sunlight from reaching the depths. For this reason, from here on, what happens is that sediment is produced, more and more, until, after a time (years), a sufficiently firm soil is formed so that trees and other plants can grow up.
What are the causes?
The causes can be of two types: natural or of human origin. The natural They are, as their name suggests, those that come from nature itself, without human intervention. Plants need nitrogen and phosphorus to grow; in fact, they are so important to them that they are considered macronutrients by botanists. Therefore, as they die, these nutrients are released into the soil.
If the right conditions are met, that is, if the amount of plant organic matter that is returned to the earth is considerable, or at least, it is deposited constantly over time, it is to be expected that the ecosystem will change. This is normal. It happened in the past, it is happening now, and it will continue to happen until the last of days, so we don't have to worry.
But now let's talk about the causes anthropogenic, of what we humans do, and in particular gardeners or gardening enthusiasts. People who grow plants, in general, tend to buy fertilizers rich in nitrogen and / or phosphorus. It's not a problem: plants, as we said, need those nutrients. What is worrisome is the excessive use of fertilizers and manures, because without wanting to we can contaminate that water, altering the trophic chain and endangering the balance of the ecosystem. Why?
Well then all these nitrates can end up on the surface or underground, or can even be washed out to sea during a torrential rain, which is what happens for example in many parts of Spain. In this country there are many places where the earth remains dry for so many months of the year that it becomes very compact, waterproof, and also hot. Towards the end of summer, when currents of cold air begin to enter, so intense rains form that they wash away everything they can and carry it away.
It is rain, it is water. Yes. But the plants cannot take advantage of it practically nothing, since it takes with it the nutrients, from the water itself, and from those that we have added when we fertilize them.
Consequences of eutrophication
The effects of eutrophication are varied. But before naming them, I would like you to know something: if it is of natural origin, this process takes centuries. It is done slowly, long enough for everyone in that ecosystem to have time to adjust. In this way, the food chain is not altered, so life continues normally.
However when it is of human origin, that process takes only decades. A human life is long enough for an ecosystem to change. That is why it is important, now, to know the consequences of anthropogenic eutrophication (human):
- The smell of the waters acquire a very unpleasant smell. This is because rotting increases, and oxygen is depleted. Consequently, there may be economic losses in the tourism sector.
- The taste of the water is altered, becoming unfit for consumption.
- Due to the accumulation of sediment, a riverbed that was navigable may no longer be navigable.
- Invasive species appear, more prepared to live in that altered area than the native ones.
- In some cases, lack of oxygen stimulates the growth of toxic bacteria for birds and also for mammals. For example, him Clostridium botulinum, which causes botulism, a disease that especially affects human babies.
With all this in mind, we insist on the responsible use of fertilizers, and especially fertilizers. We only have one planet, and although we like to have well-cared plants, just by adding more compost or fertilizer, we are not going to make them grow faster, or bear more fruit. In fact, what usually happens is just the opposite: its roots are damaged, the leaves stop receiving food, and in severe cases, we are left without a plant.
Let's read the label of the agricultural products we buy and follow the instructions carefully, for the good of the crops, the planet, and ours.