Well, first off, the sediments get brought down from the mountains after eroding away. Those sediments combine with others as it passes through the creeks and streams, rivers etc. Whatever dies, for example lets say chum salmon since they have nutrients within them. They aren't good swimmers so they are normally at the mouth of the river or in the small streams nearby. When they die, their nutrients go into the soil, that soil or whatever nutrients in that, could be swept out to the wetlands and piled up. Thus, adding rich nutrients. Adding the sediments from high up, you have a rich supply of nutrients from the wildlife that dies there as well.
Chemotaxis is movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance.
The answer to the question is C...........
The nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. Nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and DNA, the building blocks of all life .