The threats to marine ecosystems pose significant challenges to the delicate balance of our natural aquatic ecosystem. There are various environmental and human threats to marine ecosystems which include – climate change, plastic and ocean debris, fishing and fishing gear, shipping, and transport.

The Marine Ecosystem is a part of a natural aquatic ecosystem. It includes the sea, ocean, estuaries, salt marshes, lagoons, and some tropical ecosystems such as mangrove forests and coral reefs, rocky, subtidal ecosystems, and shores. The salt content of marine ecosystems is larger than that of fresh water which is the main difference among marine and other aquatic ecosystems. In this article, we will look into the meaning and threats to marine ecosystems along with the importance of marine ecosystems.

What is a Marine Ecosystem?

A marine ecosystem is made up of both living and non-living organisms in an environment of highly salted water. Among the marine ecosystems are the deep ocean, the surface of the ocean, estuaries, and other coastal locations. The largest aquatic ecosystems on Earth are marine ecosystems, which are found in waters with a high salinity content. Freshwater habitats are different from these systems in that they contain less salt. Over 70% of Earth’s surface is made up of marine waters, which also supply over 97% of the planet’s water supply and 90% of its livable space.

Threats to Marine Ecosystems

The threats to the marine water ecosystem are:

Climate Change

There is an interconnection between climate change and all marine ecosystems. There is a direct impact of climate change on marine ecosystem. Temperature rise is leading to huge damage to plants and animals living in marine waters. For example, Coral reefs are very sensitive to high temperatures and that’s why they get bleached and dried when the temperature rises. Ocean acidification is caused by increasing levels of carbon dioxide in the atmosphere which is absorbed by the ocean leading to a decrease in its pH. These decreased pH levels threaten the species living inside the ocean.

Marine Pollution

Many human activities lead to marine pollution. The human activities on land are responsible for plastic waste generation that later ends up in the ocean. The plastic waste mainly comes from disposable plastic items (food wrappings, razors, bottles, etc.) not disposed of properly, which in the end gets collected into the waterways. This plastic waste is carried all over the world by the rotating water current leading to the formation of garbage patches. The Great Pacific garbage patch between Hawaii and California is an example. This plastic pollution causes suffocation, infections, and internal injuries due to plastic ingestion which is mistaken for food, entanglement, and deep cuts in the skin of animals habiting the marine ecosystems.

Invasive Species

An invasive species can be defined as an organism that is not native to a particular area. Such species can cause much environmental and economic harm to the new area. But all non-native species are not considered as invasive species. To become an invasive species, a species has to get adapted to the new area easily. Its reproduction rate should be high. It should harm the property, the economy, or the native plants and animals of the region. As they compete with the native species for nutrition, space, etc, so if the native species fail to survive, the invasive species take over the area. And this leads to extinction of the native species.

Overfishing

Fishing is done for both food and leisurely purposes. But overfishing is not good for the ocean. Earlier the fishes that were very common, such as tuna, are now becoming endangered species. This is caused because of illegal and unregulated fishing practices and due to different government policies that provide subsidies to fisheries. The fishing gear used during fishing leaves harmful wastes into the water bodies which destroys the environment of the water bodies and threatens the marine ecosystems. Fishing nets are made of such materials that are harmful for marine animals as well as plants.

Eutrophication

Eutrophication can be defined as the process in which a water body gets extremely enriched with nutrients which leads to growth of simple plant life in excess. The indicators of this process are presence of algal bloom and plankton in a water body. This process is thought to be a serious environmental issue because it causes the deterioration of water quality and the depletion of dissolved oxygen in water bodies. The water where eutrophication occurs, it becomes a dead zone and no life is observed in such areas.

Sedimentation

Sediment refers to eroded soil and rock that is washed off the land due to rainwater and flooding. It travels along with the river water and stormwater and finally gets collected on the coastline. Sediments are known by different names based on their size. Very fine sediment is called mud and it feels slippery when taken in hand. Little coarse sediment is sandy. When too much sediment gets collected in the marine water then it is considered as a pollutant. Sediment cuts down the amount of light that reaches the underwater plantsthus harming their productivity. It causes reduced underwater visibility due to which those animals that need to see to hunt their prey get affected. These sediments also carry pollutants like phosphorus, toxins, bacteria, and metals into the marine waters.

Habitat Destruction

Many cases of habitat destruction occur mainly due to negligence of humans and as an effect of the harmful activities that they carry out. For example, oil spills that is caused due to human error leads to the immediate death of marine plants and animals. The area where this happens takes a lot of time to get back to normal conditions. In some severe cases the the habitat gets permanently destroyed. Pollution, logging, draining of wetlands, and construction and development in coastal areas are all responsible for marine habitat destruction.

Importance of Marine Ecosystems

Marine ecosystem are of immense importance for the life on earth. Some reasons that contribute to their importance are as follows:

• Home to Wide Variety of Flora and Fauna: Marine ecosystem provide home to a wide variety of aquatic flora and fauna and thus contribute in conservation of biodiversity which ultimately helps in survival of life on earth.
• Food Sources: Many organisms thriving in marine ecosystem serve as essential food resources. Fish and other seafood are important sources of protein and essential nutrients for many coastal communities and global populations.
• Regulation of Climate: The oceans play a critical role in regulating the Earth’s climate. They absorb a significant portion of the carbon dioxide emitted into the atmosphere, helping to mitigate climate change. Additionally, ocean currents transport heat around the globe, influencing regional climates and weather patterns.
• Economic Value: Marine ecosystems support a wide range of economic activities, including fisheries, aquaculture, tourism, shipping, and pharmaceuticals. These industries generate significant revenue and employment opportunities globally.
• Scientific Research: Marine ecosystems are valuable laboratories for scientific research, providing insights into biological diversity, ecosystem dynamics, climate change, oceanography, and biogeochemical cycles. Understanding marine ecosystems is essential for sustainable management and conservation efforts.
• Production of Oxygen: Marine photosynthetic organisms, such as phytoplankton and seaweed, produce a substantial portion of the Earth’s oxygen through the process of photosynthesis. They are crucial for maintaining the balance of atmospheric gases necessary for life.

Conclusion: Threats to Marine Ecosystem

Thus it can be concluded that there are some major threats to the marine ecosystem which need serious attention if marine life is to be saved. The threats like fishing and ocean transport can be reduced and a way should be found for reusing the waste so that it will not be released in the water directly. The poisonous waste can be converted into less harmful waste before dumping in the water bodies. Understanding and addressing these threats to marine ecosystem is crucial for safeguarding the integrity and resilience of aquatic ecosystem. Protecting marine ecosystems requires collective action and commitment to sustainable management and conservation efforts.

Also Read:

• Effect of Global Warming on Coral Reefs
• Effect of Light Pollution on Migratory Birds
• Climate Change and Its Impact

FAQs on Major Threats to Marine Ecosystem

How are Ships a Threat to the Marine Ecosystem?

Ships generate wastes that can cause serious injuries to marine life. It creates noise which causes behavioural changes in the marine organisms.

How is Plastic Pollution Harmful for Marine Life?

The disposable plastic waste which is not disposed properly gets collected into the water bodies and causes death of the marine animals. It leads to suffocation in them. Internal injuries are caused if they ingest it.

How is Fishing Harmful for the Marine Ecosystem?

Fishing is harmful as the gears used during fishing creates waste in the oceans. The other animals get entangled in the fishing nets and get killed.

Are Oil Spills Harmful for Oceans?

Yes, oil spills destroy the habitat of the affected area very rapidly. Animals as well as plants get killed and the area takes a long time to get back to normal condition.

How is Marine Transport Harmful for Marine Organisms?

Marine transport generates waste that disturbs marine life. It creates noise which also disturbs their communication and hunting activities.

How does Climate Change Affect Biodiversity of Marine Ecosystem?

Warming oceans, acidification, and altered currents disrupt habitats, food webs, and migration patterns, leads to species decline and ecosystem imbalance.

How does Pollution Affect the Marine Ecosystem?

Marine pollution from plastics and chemicals, harms ecosystems through poisoning organisms, habitat destruction, and water quality degradation, ultimately disrupting food webs and threatening biodiversity.

What is the Largest Threat to Ocean Ecosystem?

The largest threat to ocean ecosystems is human-induced climate change, causing rising sea temperatures and ocean acidification. Pollution from plastic waste and overfishing also pose significant risks to ocean health.