The main producers in aquatic environments are a. phytoplankton b. zooplankton c. kelp d. fish

The little organisms belonging to the plankton group known as phytoplankton are the major producers in all aquatic systems.

Phytoplankton are nearly microscopical organisms located on the waters surface that generate large amounts of oxygen.

I'll give you a little tip I've created to remember the answer to this question:

When I think of the word "phyto", it reminds me of the word "photo" which makes me think of light (you need light to make a photo) and light is directly related to producers (since it is what they use to create chemical energy).

The tip I've given you, is my creation and is not correct (but helpful) since "phyto" comes from the greek word phutón, meaning plant and is not related to the word light.

Hope it helped,

Happy homework/ study/ exam!

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.