Phytoplankton

Phytoplankton are tiny plants that float in oceans and lakes. They get their energy from sunlight through a process called photosynthesis, just like trees and flowers on land. Because they need sunlight, they live near the surface where light can reach.

These small plants are very important. They are the base of the food chain for many sea creatures. They also help our planet by taking in carbon from the air and giving out oxygen. Even though they are only a small part of all plant life, phytoplankton make up about half of the oxygen we breathe.

Phytoplankton come in many different types, including special tiny plants called cyanobacteria and diatoms. Most of them are too small to see, but when there are lots together, they can sometimes make the water look green or other colors.

Types

Phytoplankton are tiny plants and bacteria that float in the upper parts of oceans and lakes where sunlight reaches. Like plants on land, they make their own food using sunlight in a process called photosynthesis. They turn carbon dioxide from the water into food for themselves and become the first source of energy for many sea creatures.

Phytoplankton include different types of tiny living things, such as cyanobacteria and diatoms. Some other small organisms that were once considered phytoplankton can also eat other tiny creatures, so they are now called mixoplankton. These plants and tiny organisms are very important because they support the whole food chain in water and help control carbon in nature.

Main articles: Photosynthesis, Primary production, Food web, Carbon cycle

Ecology

Phytoplankton get their energy through the process of photosynthesis. Because of this, they can only live in the bright surface layer, called the euphotic zone, of an ocean, sea, lake, or other body of water. They are responsible for about half of all photosynthetic activity on Earth.

Phytoplankton live where there is enough light for photosynthesis. In this process, they take in carbon dioxide and give out oxygen. To grow, they need nutrients such as nitrate, phosphate, and silicic acid. These nutrients come from rivers, weather, and melting ice. Phytoplankton are the beginning of many food chains in the ocean. They provide food for small animals, fish, and even whales.

Diversity

Phytoplankton are tiny, plant-like organisms that float in water. They form the base of many food chains. They include many different types of microscopic life, such as diatoms, cyanobacteria, and dinoflagellates. These organisms are very important because they produce food for many sea creatures and also release gases that can affect the weather.

Some phytoplankton are very small and live in areas of the ocean with less food, while others are larger and are found in areas where there is more food available. Their work helps keep the water and air around them healthy.

Growth strategies

Phytoplankton have different ways to grow depending on what they need. Scientists found a special mix of nutrients in the ocean, like carbon, nitrogen, and phosphorus. This mix is called the Redfield ratio.

Phytoplankton can change how they use nutrients to survive. Some are very good at getting nutrients when there’s very little around, while others grow quickly when nutrients are plentiful. These tiny plants are clever in how they use what they have to stay alive and grow in the water.

Factors affecting productivity

Phytoplankton help move carbon around the Earth. Tiny animals like copepods, fish, and shrimp rely on them for food. Things like temperature, sunlight, nutrients, and carbon dioxide affect how well phytoplankton grow.

Because of changes in our climate, the oceans may warm up, and how the water mixes may change. This can affect how much light reaches the surface and how many nutrients are available for phytoplankton. These changes can impact the ocean's food web and how carbon moves through the ocean.

Main article: biological pump
Main articles: marine food chains, marine food webs, phytoplankton productivity

Role of phytoplankton

Phytoplankton are very important for the ocean and freshwater ecosystems. They make their own food from sunlight, just like plants on land. Because they make their own food, they are the first step in the ocean's food chain. Small animals called zooplankton eat phytoplankton, and then bigger animals eat the zooplankton.

When phytoplankton grow quickly in large numbers, it is called a bloom. Sometimes these blooms can be harmful to other sea creatures and the environment. Phytoplankton also help control gases in the air and provide food for many ocean animals.

Aquaculture

See also: Algaculture and Culture of microalgae in hatcheries

Phytoplankton are very important for farming animals in both aquaculture and mariculture. In mariculture, phytoplankton grows naturally in the water where animals live. In aquaculture, it is added directly to feed the animals. Phytoplankton helps feed many small creatures like rotifers and animals such as molluscs including pearl oysters and giant clams.

Phytoplankton can also be grown in special tanks for many uses. It can be food for other sea animals or a healthy addition for animals in aquaria. The tanks need clean water, the right nutrients, and the right amount of light to help the phytoplankton grow well.

Anthropogenic changes

Marine phytoplankton are very important for our planet. They help take in carbon dioxide and make oxygen for us to breathe. They do about half of this work, even though they are a very small part of all plant life on Earth. Because they can change quickly, they also show us how our climate is changing.

When the climate changes, it can affect how much food phytoplankton have and how warm their water is. Some warmer temperatures might help them grow more, but other changes might make it harder for them to get the nutrients they need. Scientists are still learning exactly how these changes will affect phytoplankton and the animals that depend on them.