Phytoplankton: Definition, Types, Examples and Facts

Discover what phytoplankton are, their role in aquatic ecosystems, and how they contribute to oxygen production, carbon cycling, and the marine food chain.

Table of Contents

Context: According to a new study, iron released due to human activities enhances spring phytoplankton blooms as well as speeds up the rate at which nutrients are consumed.

About Phytoplankton

Definition: Phytoplankton, or microalgae, are microscopic organisms that, like land plants, contain chlorophyll and rely on sunlight for photosynthesis.
Habitat: They float near the ocean surface where sunlight can reach.
Nutrient Requirements: They need inorganic nutrients like nitrates, phosphates, and sulfur to synthesise proteins, fats, and carbohydrates.

Types of Phytoplankton

Dinoflagellates: Move using whip-like tails called flagella.
- Have complex protective shells.
Diatoms: Possess rigid, interlocking shells made of a different material (silica).
- Do not have flagella; drift with ocean currents.
Ecological Role:
- Serve as a primary food source for marine animals like shrimp, snails, and jellyfish.
- Help sustain balanced marine ecosystems.
Harmful Algal Blooms (HABs): Occur when excess nutrients cause uncontrolled phytoplankton growth.
- Can release toxic substances harmful to fish, shellfish, birds, mammals, and humans.