Preserving the aquatic environment
The preservation of the environment is important for both animals (species) and humans.
Mangroves in Brazil, for example, are transitional ecosystems between land and sea. Its waters are rich in mineral salts and organic matter. However, pollution has been destroying our mangroves.
This pollution is caused by sewage thrown into the mangroves by ships, petrochemical industries, etc. We must be aware that the relationship between living beings with each other and with the environment allows the survival of species and that ecosystems need to be in dynamic equilibrium in order to offer good conditions for the development of life.
One of the causes of environmental depredation is the oil spill into the sea. Oil floats in water because it is less dense than water, forming a layer that prevents the penetration of oxygen gas and sunlight.
Without oxygen the fish die and without sunlight the plants do not perform photosynthesis. And animals also cannot feed on floating algae (the largest suppliers of oxygen to our planet).
Oil also sticks to the gills of fish, killing them by suffocation (lack of oxygen) and also sticks to the feathers of fish-eating birds, preventing them from flying. Thus, oil spilled into the sea compromises the aquatic life food chain and water oxygenation.
Oil is also thrown overboard by boats, as is oil. Another causative agent of pollution is detergents, which form a white foam over water. We often hear this foam called a 'swan'.
Biodegradable substance - are those that can be naturally broken down by microorganisms in the environment. Example: naturally rotting orange, biodegradable detergents.
Undegradable substance - they are those that take a long time to degrade or never to degrade. Example: glass bottle, which takes over 1000 years to decompose.
Most detergents and cleaners are non-degradable substances, so if thrown into the environment they cause pollution and serious damage to the water ecosystems of rivers, lakes and seas.
Like oil, detergents also reduce light penetration into water. They remove grease from seagull feathers, for example, which are waterproof. In this way the birds get wet, sink and die.
To combat living things that damage crops, man uses toxic substances, pesticides. They are fungicides (to kill fungi) and insecticides (to kill insects). These pesticides are released into crops, polluting food and soil.
Rain transports toxic substances to rivers, lakes and seas polluting their waters. May cause serious damage to health if swallowed by living things. It is important to wash food, fruits and vegetables well, both to get rid of microorganisms and to remove some of the pesticide that may contain in this food.
Residential, hospital and industrial sewage in rivers, lakes and seas increases the amount of organic matter (feces, for example) in the water, serving as food for bacteria. And so, they multiply, contaminating the water.
As these bacteria breathe, their proliferation increases the consumption of much of the dissolved oxygen gas in water, causing the death (by suffocation) of fish and other aquatic animals. Contaminated water may become cloudy, preventing light from entering and therefore preventing photosynthesis of algae and aquatic plants.
Sewage can also contaminate beach bathers, causing disease. Wastewater treatment and biodegradable toxic waste are left in treatment tanks as they are broken down by bacteria. When the water is clear, it is thrown into the rivers.