Why might fatty acids, amino acids, and nucleic acids increase the hydrogen ion (h+) concentration of a solution?

Simply because fatty acids, amino acids and nucleic acids are acids that produce hydrogen +. In chemistry definitions, acids are substance that tastes sour that donates hydronium ions in a water solution. An acid is also a compound of substance that produce proton and embrace electrons. A proton according to science is something that has hydrogen but doesn't have electron. That's why when these acids are combined they increase the number of hydrogen + or (H+) in a certain substance.

Digestion because it removes waste

The open ocean begins at the low-tide mark and extends to the end of the continental shelf

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.