AQUATIC FOOD CHAIN: LEVELS AND ORGANISMS - BIOLOGY - 2024

The aquatic or marine food chain shows how organisms that live in the sea get food and energy; it also exemplifies how this energy is passed from one living organism to another.

Food chains start with plants and end with large animals. Each chain contains producers, organisms that make their own food, and consumers, who eat food created by producers or who eat other animals.

Primary or autotrophic consumers are the organisms that produce their own food; Plants such as algae or phytoplankton fall into this category.

Secondary or heterotrophs are animals that eat primary consumers, such as oysters, shrimp, clams or scallops.

Tertiary (heterotrophic) consumers are animals that eat secondary organisms such as dolphins or sharks.

Predators are the animals that are at the top of the food chain and have no predators; sharks and dolphins also fall into this category.

Decomposers are the organisms that break down dead plants and animal materials and waste to release them again as energy and nutrients in the ecosystem. Crabs, fungi, worms, and bacteria fall into this category.

Levels of the aquatic food chain

First level: photoautotrophs

The base of the aquatic food chain is invisible. This is because it is made up of billions of trillions of single-cell organisms. These organisms, called phytoplankton, saturate the surface of the oceans around the world.

These small plants and some bacteria capture energy from the sun; Through photosynthesis they convert nutrients and carbon dioxide into organic compounds, just as plants do on land. On the coasts, algae carry out the same process.

Together these plants play an important role. These vegetables are the primary producers of the organic carbon that all animals in the ocean's food chain need to live. They also produce more than half the oxygen that humans breathe on Earth.

Second level: herbivores

The second level of the food chain is made up of animals that feed on the abundant plant life of the ocean.

On the surface of the ocean water, microscopic animals such as zooplankton, jellyfish and larvae of some fish such as barracudas, and mollusks float in the currents of the sea.

The largest herbivores include green turtles, manatees, parrotfish, and surgeonfish. Despite their differences in size, herbivores share a voracious appetite for oceanic vegetation.

Additionally, many of them share the same destiny: to become food for the carnivorous animals that are at the top of the aquatic food chain.

Third level: carnivores

Zooplankton at the second level of the chain support a large and diverse group of small carnivores, such as sardines and herring.

This level of the food chain also includes larger animals such as octopuses - which feed on crabs and lobsters - and many fish - which feed on small invertebrates that live near the coast.

Although these animals are very effective hunters, they usually tend to be preyed upon by predators by the simple rule that governs the ocean world: the largest fish eat the smallest fish.

Some carnivores that make up the third tier include squid, sardines, and snappers.

Fourth level: high level predators

The large predators at the top of the food chain are a diverse group that includes finned fish, such as sharks, tunas, and dolphins; feathered animals, such as pelicans and penguins; and finned animals like seals and walruses.

These top predators tend to be large, fast, and very efficient at hunting their prey. On the other hand, they do not live long and reproduce slowly.

Despite this, the predators at the top of the pyramid tend to be common prey for humans. When predatory species are hunted indiscriminately, their numbers drop rapidly.

It is very difficult for that number to grow again and the lack of these species can cause chaos in the entire food chain. This is why it is so important that humans do not hunt them indiscriminately.

Decomposers

Decomposers exist only at one trophic level. They are usually bacteria that break down dead organisms.

This process releases nutrients that help producers and consumers who feed themselves through the absorption of organic material in the water column.

This process is very important, as it indicates that even high-end consumers contribute to the completion of the food chain. Decomposers break down your waste or dead tissue.

Organisms that compose it

Marine consumers

Any organism that does not produce its own food is called a consumer. This means that they must turn to other organisms or dissolved organic materials to obtain food.

In aquatic habitats, both small and large animals can be consumers of phytoplankton. This includes everything from small animals like shrimp to manatees.

Animals that only eat primary animals are called primary consumers. For example, shrimp are primarily consumers. The animals that eat these primary consumers are the secondary consumers, such as starfish and whales.

Likewise, tertiary consumers feed on secondary ones and predators at the top of the food chain that feed on tertiary consumers.

Consumers can feed on only plants (herbivores) or they can feed on smaller animals (carnivores) or both, which would make them omnivores.

Marine herbivores

A herbivore is an animal that only eats plants. In the case of marine habitat, animals that only eat phytoplankton are considered herbivores.

Some examples are scallops, turtles, and oysters. Manatee and dugong are the only herbivorous mammals.

References

1. Marine Food Chain. Ocean Life. Recovered from ocean.nationalgeographic.com.
2. Marine Food Webs. Recovered from sciencelearn.org.nz.
3. Marine food web and food chain. (2006) Recovered from kids.britannica.com.
4. Marine Food Chains and Biodiveristy. Recovered from nationalgeographic.org.
5. Marine Food Chain Lessons for Kids. Recovered from study.com.