True, a lot of cultivated fields use fertilizers that can be harmful to fish
When large pieces of the Earth's outer layer move slowly by plate tectonics, surface features, such as mountains, earthquakes and volcanoes, are formed
I think it’s how they are inside and get stuck
They have increased need to carbohydrates, protein, water and iron.
Carbohydrates is the primary source for energy and active people apparently need more energy for their daily activities.
Protein helps build muscles, even though they only need a small amount more of protein than normal people, they still require protein for muscle buildings.
Water has to be needed as they may excrete more sweat by active activities in the day time. Water can also help remove waster material from body.
Iron helps the production of hemoglobin, which is in the red blood cells that help transport oxygen. As they exercise more, they need more oxygen supply for respiration, therefore there is a need for iron supply.