Final answer:
Phytoplankton are the main producers in the ocean, capturing energy from the sun and turning it into glucose. Algae, including seaweed and kelp, are examples of phytoplankton.
Step-by-step explanation:
The main producers in the ocean are phytoplankton, which are tiny photosynthetic organisms. They are responsible for capturing energy from the sun and turning it into glucose, making them the most common producers in the oceans and lakes. Algae, including seaweed and kelp, are examples of phytoplankton.