explain how light and depth determine the distribution of organisms in marine ecosystems.explain how water pollution affects marine ecosystems.what are some major similarities and differences between freshwater and marine ecosystems? (site 1), estuaries serve which important role for marine ecosystems?only the water of marine ecosystems contains dissolved salt.what are some major similarities and differences between freshwater and marine ecosystems?human activity on land can have a profound influence on marine ecosystems.

 

Aquatic habitats with high dissolved salt concentrations, such those found in or close to the ocean, are known as marine ecosystems. The distinct biotic (living) and abiotic (nonliving) components of marine ecosystems distinguish them. Plants, animals, and bacteria are examples of biotic variables; the ecosystem's exposure to sunlight, the amount of oxygen and nutrients dissolved in the water, depth, temperature, and closeness to land are examples of significant abiotic factors.

One of the most crucial abiotic elements for marine ecosystems is sunlight. Scientists categorize marine ecosystem components into up to three groups based on how much light they receive, which is crucial. The euphotic zone, which reaches as deep as 200 meters (656 feet) below the surface, is the highest point in a marine ecosystem. There is enough light at this depth to support consistent photosynthetic activity. This area is home to the majority of marine life. The dysphotic zone, which can extend from 200 to 1,000 meters (656 to 3,280 feet) below the surface, is located beneath the euphotic zone. There is still sunlight at these depths, but it is insufficient to support much photosynthesis. The aphotic zone, which is shaded from sunlight, is located underneath the dysphotic zone.

Marine Ecosystem Types Although there are differences throughout sources regarding what constitutes a marine ecosystem, scientists classify marine ecosystems into a number of general categories. There is much discussion on the number of marine habitats. Estuaries, salt marshes, mangrove forests, coral reefs, the open ocean, and the deep-sea ocean are among the marine ecosystem categories that are generally accepted, despite some controversy.

A coastal area where rivers and oceans converge is called an estuary. Here, in areas protected from severe weather, salts and nutrients from the river combine with those from the ocean. Estuaries are therefore home to a wide variety of life forms and are among the most productive areas on Earth. Estuaries have also historically supported a variety of human populations and activities, including shipping, transportation, and fishing, due to their location where rivers meet the ocean.

Salt marshes form where the ocean meets the land, whereas estuaries form where the ocean meets rivers. Because of the sediment that the water brings in, these areas are rich in nutrients. High tides frequently flood marshes, leaving the surrounding terrain salty and damp. The soil is therefore rich in decaying materials and poor in oxygen. Low-growing grasses and shrubs are the predominant vegetation in these habitats. 

The mangrove forest is another type of coastal environment. Tropical regions are home to mangrove forests. The roots of mangrove trees are regularly submerged by the ocean water that floods these habitats. Mangroves' root systems sit above ground to obtain oxygen and filter away salt. Numerous species find a home in these trees. Fish, crabs, shrimp, amphibians, reptiles, and other animals reside among the mangrove's roots, while birds use its canopy as a place to nest.

Coral reefs, which are euphotic-zone ecosystems made of the exoskeleton secreted by coral polyps, are found a little further out in the tropical oceans. Numerous species are protected by the intricate structures formed by these exoskeletons. In addition to sponges, crabs, mollusks, fish, turtles, sharks, dolphins, and many other animals, coral reefs are incredibly varied ecosystems. According to some estimates, a fifth of all ocean species are found in coral reefs.

The water is open beyond the coral reefs. As the ocean's depth varies, so do the open ocean habitats. The euphotic zone, which is the ocean's surface, is a warm, light-and oxygen-rich environment that is home to a wide variety of photosynthetic species. The open ocean is home to many of the creatures we typically identify with marine environments, including sharks, octopi, dolphins, and whales.

The water becomes colder, darker, and has less oxygen available as its depth increases. The peculiar adaptations of organisms that inhabit deep-sea ecosystems in the aphotic and dysphotic zones enable them to endure in these harsh conditions. Some creatures can capture whatever nutrients fall from shallower ocean depths because of their incredibly big jaws. Others have adapted to obtain their energy through the chemosynthesis of hydrothermal vent chemicals.

There are numerous ways that marine ecosystems affect the economy, including: Food security: Millions of people throughout the world rely on fisheries and aquaculture for their food. Employment: Millions of jobs in industries including fishing, aquaculture, maritime transportation, and tourism are supported by the ocean economy. Trade: With over 90% of the world's trade volume handled via maritime transportation, it is the foundation of international trade. Tourism: One of the sectors of the world economy that is expanding the fastest is coastal and marine tourism. Energy: Offshore renewable energy sources like wind, gas, and oil can have a big economic impact.

Climate change: More than half of the oxygen we breathe is produced by the ocean, which also controls the climate globally. Biodiversity: A high level of biodiversity can be found in marine environments. However, pollution also poses a threat to marine ecosystems, which can diminish cultural heritage and economic prospects. For instance, communities, tourism, and fisheries can all be impacted by plastic waste.