What best describes heterotrophs in marine ecosystems?

Heterotrophs are organisms that obtain their food by consuming other organisms rather than producing it themselves. This characteristic is fundamental to their role in marine ecosystems, where they depend on primary producers, such as phytoplankton and algae, for energy and nutrients. Heterotrophs include a wide variety of organisms, from small zooplankton to large marine mammals, all of which play critical roles in the food web by transferring energy from primary producers to higher trophic levels.

In marine ecosystems, these consumers help maintain the balance of energy flow and nutrient cycling. By consuming organic matter, heterotrophs contribute to the overall productivity and health of the ecosystem, influencing population dynamics and the structure of marine communities.