Plants need nitrate ions in order to make proteins. a plant is growing in soil flooded water. explain why the plant cannot absorb enough nitrate ions.

Plants need nitrogen in order to form amino acids and absorb this in the form of nitrates from the soil. They do this with the help of their roots. In a waterlogged environment, roots start to decompose due to the lack of oxygen. This affects their nitrate absorption capacity and plant growth is stalled.

In some developing nations the percentage of the animal protein from fish in the diet can be as high as 25 percent.  about 85% of fish caught is used for human consumption.  the remainder is converted into fishmeal and fish oil.