Phytoplankton form the foundation of aquatic food webs, providing essential nutrition and energy for a wide range of marine organisms from microscopic zooplankton to commercially important fish and shellfish. They produce oxygen through photosynthesis, helping sustain marine and atmospheric life, and they play a key role in carbon sequestration by absorbing CO2 and transferring it to deeper waters when they die and sink.

In aquaculture and reef systems, cultured phytoplankton improves water quality by competing with harmful algae for nutrients, supports the growth and reproductive success of filter feeders and larvae, and supplies critical fatty acids and micronutrients that enhance survival, growth rates, and overall health of cultured species. Additionally, maintaining robust phytoplankton populations contributes to ecosystem stability and resilience against disease and environmental fluctuations.