Which marine ecosystem depends on upwelling from the seafloor to maintain its high productivity?

When the wind blows parallel to a coastline, surface waters are pushed offshore and water is drawn from below to replace the water that has been pushed away. The upward movement of this deep, colder water is called upwelling.

The deeper water that rises to the surface during upwelling is rich in nutrients. These nutrients “fertilize” surface waters, encouraging the growth of plant life, including phytoplankton. These phytoplankton serve as the ultimate energy base in the ocean for large animal populations higher in the food chain, providing food for fish, marine mammals, seabirds, and other critters.

Coastal upwelling ecosystems, such as along the west coast of the United States, are some of the most productive ecosystems in the world and support many of the world's most important fisheries. Although coastal upwelling regions account for only one percent of the ocean surface, they contribute roughly 50 percent of the world's fisheries landings.

Upwelling can also play an important role in the movement of marine animals. Most marine fish and invertebrates produce microscopic larvae which, depending on the species, may drift in the water for weeks or months as they develop. For adult marine creatures that live in shallow waters nearshore, upwelling that moves surface water offshore can potentially move drifting larvae long distances away from their natural habitat, thus reducing chances for survival.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.