The statement is true. Dead zones are the zones of oxygen depletion, which is caused by excessive running off of the fertilizers into the water body. These chemicals, particularly the nitrates, which are used by algae etc. which bloom by using the nitrates and use the oxygen present in the water. When they die, oxygen levels become critically low till then, for other aquatic animals like fishes etc., to survive.
The intermediate mesoderm connects the paraxial mesoderm with the lateral plate, eventually it differentiates into urogenital structures consisting of the kidneys, gonads, their associated ducts, and the adrenal glands.