5 Biggest Threats to Marine Life

 It was widely assumed that with the depth and vast nature of the oceans that no matter how much trash and chemicals humans dumped into them, the effects would be negligible. Proponents of dumping in the oceans even had a catchphrase "The solution to pollution is dilution."

plastic pollution

Pollution is the introduction of harmful contaminants that are outside the norm for a given ecosystem. Common man-made pollutants that reach the ocean include pesticides, herbicides, chemical fertilizers, detergents, oil, sewage, plastics, and other solids. Many of these pollutants collect at the ocean's depths, where they are consumed by small marine organisms and introduced into the global food chain. Scientists are even discovering that pharmaceuticals ingested by humans but not fully processed by our bodies are eventually ending up in the fish we eat.

Many ocean pollutants are released into the environment far upstream from coastlines. Nitrogen-rich fertilizers applied by farmers inland, for example, end up in local streams, rivers, and groundwater and are eventually deposited in estuaries, bays, and deltas. These excess nutrients can spawn massive blooms of algae that rob the water of oxygen, leaving areas where little or no marine life can exist. Scientists have counted some 400 such dead zones around the world.

plastic pollution ocean

Solid waste like bags, foam, and other items dumped into the oceans from land or by ships at sea are frequently consumed, with often fatal effects, by marine mammals, fish, and birds that mistake it for food. Discarded fishing nets drift for years, ensnaring fish and mammals. In certain regions, ocean currents corral trillions of decomposing plastic items and other trash into gigantic, swirling garbage patches. One in the North Pacific, known as the Pacific Trash Vortex, is estimated to be the size of Texas. A new, massive patch was discovered in the Atlantic Ocean in early 2010.

Facts About Ocean Pollution and Threats to Marine Life

1. Plastics - These are the most common element that is found in the ocean. They are harmful to the environment as it does not get break down easily and is often considered as food by marine animals.

2. Land-Based Sources These include dirt, septic tanks, farms, ranches, motor vehicles, among larger sources. Thousands of tons of waste and trash are dumped into the ocean on a daily basis.

3. Oil - It is the fastest source of deterioration to the ocean, being far more harmful than trash and waste. However, only a small percentage of oil (around 12%) dumped in the ocean comes as a result of actual oil spills. Most oil causing harm in the ocean is a result of drainage from land. Oil spills suffocate marine life to death and lead to behavioral changes and a breakdown in thermal insulation to those that do survive. It essentially changes the entire ecosystem of an affected area, such as a long coastline or deep ocean.

4. Toxic Metals - Toxic metals can destroy the biochemistry, behavior, reproduction, and growth in marine life.

5. Sewage and Fertilizer - It leads to the decomposition of organic matter that in turn leads to a change in biodiversity. Even if the ocean’s ecosystem isn’t destroyed entirely, it is still changed drastically, and usually not for the better. Fertilizer runoff creates rapid increase or accumulation in the population of algae in aquatic systems which depletes the oxygen content in the water that affects marine life.


Consequences of Marine and Ocean Pollution

sign to keep beach clean

The majority of pollutants going into the ocean come from activities on land. Natural processes and human activities along the coastlines and far inland affect the health of our ocean. One of the biggest sources is called nonpoint source pollution, which occurs as a result of runoff. Nonpoint source pollution includes many small sources, like septic tanks, cars, trucks, and boats, plus larger sources, such as farms, livestock ranches, and timber harvest areas.

Pollution that comes from a single source, like an oil or chemical spill, is known as point source pollution. Often these events have large impacts, but fortunately, they occur less often. Discharge from faulty or damaged factories or water treatment systems is also considered point source pollution.

Marine debris is another persistent pollution problem in our ocean. Marine debris injures and kills marine life, interferes with navigation safety, and poses a threat to human health. Our oceans and waterways are polluted with a wide variety of marine debris, ranging from tiny microplastics to derelict fishing gear and abandoned vessels. Today, there is no place on Earth immune to this problem.

A majority of the trash and debris that covers our beaches comes from storm drains and sewers, as well as from shoreline and recreational activities. Abandoned or discarded fishing gear is also a major problem because this trash can entangle, injure, maim, and drown marine wildlife and damage property.

Plastic debris can absorb toxic chemicals from ocean pollution, therefore poisoning whatever eats it. In fact, plastic pollution is one of the most serious threats to the ocean. Plastic does not degrade; instead, it breaks down into progressively smaller pieces, but never disappears. They then attract more debris. It poses a significant health threat to the various sea creatures, and to the entire marine ecosystem. Overall, plastic is the number one source of pollution in the ocean.

Even though much the trash and waste dumped into the ocean is released hundreds of miles away from land, it still washes up on beaches and coastal areas, and affects everything in between. Every marine animal is affected by man-made chemicals released in the water. The dumping of radioactive waste from nuclear reactors, industrial race, and drained sewage are also heavy contributors to pollution.

Pollution can affect the food we eat. Heavy metals and other contaminants can accumulate in seafood and make it harmful to eat. More than one-third of the shellfish-growing waters of the United States is adversely affected by coastal pollution. Billions of tons of litter end up in the ocean each year, and it is substantially more than the 250 million tons of trash generated. This has led to a gradual loss in marine life and an increase in the number of endangered species.

The best way to stop the pollution is to start from ourselves! Check out our list of 6 Bamboo Products That Can Make Your Life Zero Waste!

Reference Links

  1. https://www.nationalgeographic.com/environment/oceans/critical-issues-marine-pollution/
  2. https://www.conserve-energy-future.com/various-ocean-pollution-facts.php
  3. https://www.noaa.gov/resource-collections/ocean-pollution

Leave a comment

Please note, comments must be approved before they are published