Waters in the coastal ocean tend to be more productive than waters of similar depth in the open ocean. What is the main reason for the productivity difference?

The coastal ocean seems to be more productive than the waters of the similar height in the open ocean due to ample availability of water, sunlight, and nutrients. The coastal ocean has more nutrients due to the process of upwelling, that is, movement of water offshore by the currents.

Also, water situated on the continental shelves is comparatively shallower and thus it is turbulent. This mixing or turbulence keeps settling the nutrients stirred up and accessible, and eventually, ample of nutrients erode off the continents themselves and so water nearby to the shore seems to be greater in nutrients.  

On the other hand, in the surface water away from the coastlines, usually, there is a lot of sunlight but no availability of adequate nutrients. Therefore, the majority of the ocean surface is not much productive.

Explanation:

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

answer:

the water molecules are transferred from the roots to the stem or top parts of the tall tree because of important properties of water which are adhesion, cohesion and capillary action. cohesion is the property of water molecules keeps water molecules in a combined state by sharing of bonds between them at the atomic level. adhesion allows the interaction of water molecules with other substances or substrate. adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. capillary action occurs when the adhesive force to the vessel wall is stronger than the cohesive force between water molecules. capillary action mimics the transfer of water from a tube or pipe. in this way water utilizes its property to transfer water from down to top level of the plant.