Marine ecosystems are the largest aquatic ecosystems on Earth and live in waters with a lot of salt in them, like the ocean. These ecosystems are very different from freshwater ecosystems, which have less salt in them. More than 70% of the Earth’s surface is covered by marine waters. They make up more than 97% of the Earth’s water and 90% of the space we can live in on Earth. In general, seawater has a salinity of 35 parts per thousand of water. Actual salinity is different in different types of marine environments. Marine ecosystems can be broken down into many different zones depending on the depth of the water and how the land looks. The oceanic zone is the part of the ocean where animals like whales, sharks, and tuna live. This is the part of the ocean that is wide open.

Marine ecosystems

Marine ecosystems are aquatic settings with high dissolved salt concentrations, such as those found in or near the ocean. Marine ecosystems are distinguished by their distinct biotic (living) and abiotic (nonliving) components. Plants, animals, and bacteria are examples of biotic influences; abiotic factors include the amount of sunlight in the environment, the amount of oxygen and nutrients dissolved in the water, closeness to land, depth, and temperature.

Sunlight is a critical abiotic variable for marine ecosystems. It’s so crucial that scientists divide marine habitats into three categories based on the quantity of light they receive. The euphotic zone is the uppermost section of a marine ecosystem, extending down to 200 metres (656 feet) below the surface. There is enough light at this depth for routine photosynthetic activity. This zone is home to the majority of marine life. The disphotic zone is located under the euphotic zone and can extend from 200 to 1,000 metres (656 to 3,280 feet) below the surface. Sunlight is still accessible at these depths, but only enough to allow for some photosynthesis. The aphotic zone is beneath the disphotic zone and receives no sunlight.

Marine Ecosystem Types

• Scientists classify marine ecosystems into several major groups, albeit there are differences depending on the source of what constitutes a marine ecosystem. The number of marine ecosystems is a point of contention. Although there is considerable debate, there are numerous types of marine ecosystems that are widely accepted: estuaries, salt marshes, mangrove forests, coral reefs, the open ocean, and the deep sea.
• An estuary is a coastal zone where rivers meet the ocean. In areas protected from extreme weather, nutrients and salts from the ocean mingle with those from the river. As a result, estuaries are among the most productive locations on the planet, supporting a diverse range of life. Furthermore, because estuaries are located where rivers meet the sea, they have traditionally supported many human populations and activities such as fishing, shipping, and transportation.
• Salt marshes form when the ocean meets the land, whereas estuaries form where the ocean meets the rivers. These areas are nutrient-rich because of the sediment brought in by the ocean. High tides regularly flood marshes, making the surrounding ground damp and salty. As a result, the soil is depleted of oxygen and overburdened with decomposing debris. Low-growing shrubs and grasses dominate these habitats.
• The mangrove forest is another coastal environment. Tropical locations are home to mangrove forests. These environments are frequently flooded by ocean water, drowning mangrove tree roots. Mangrove root systems filter away salt and sit above ground to receive oxygen. A variety of species call these trees home. Fish, crabs, shrimp, reptiles, and amphibians reside amid the mangrove roots, and its canopy serves as a nesting spot for birds.
• Coral reefs, euphotic-zone habitats formed from the exoskeleton secreted by coral polyps, can be found further out in the tropical oceans. These exoskeletons produce sophisticated structures that protect a variety of organisms. Coral reefs are incredibly diverse ecosystems that are home to sponges, crabs, mollusks, fish, turtles, sharks, dolphins, and a variety of other organisms. Coral reefs may account for a fifth of all ocean species, according to some estimates.
• The vast ocean lies beyond the coral reefs. The open ocean ecosystems change dramatically as the depth of the water changes. The environment at the ocean’s surface, known as the euphotic zone, receives a lot of light and oxygen, is quite warm, and is home to a lot of photosynthetic species. The open ocean is home to many of the creatures we identify with marine habitats, such as whales, dolphins, octopi, and sharks.
• As the water depth grows, it becomes darker, colder, and has less accessible oxygen. Organisms that live in deep-sea habitats in the disphotic and aphotic zones have peculiar adaptations that enable them to survive in these harsh settings. Some species have enormous mouths that allow them to catch whatever nutrients fall from deeper ocean depths. Others have evolved by obtaining energy through the chemosynthesis of chemicals from hydrothermal vents.

CONCLUSION:

From the following article we can conclude that the marine ecosystem is a complex network of interconnected energy producers—such as plants and phytoplankton—as well as consumers—ranging from plant-eating animals to meat-eating animals of various sizes and shapes.