Effects of Ocean Pollution on Marine Life

Annette McDermott
oil-covered starfish

If you're worried about the effects of ocean pollution on marine life, you are not alone. The increase of pollutants in the world's oceans is effecting the variety of creatures that live there.

Various Pollutants

There are many of types of ocean pollutants that endanger marine life. Some of them are more obvious than others, but all contribute to an unhealthy ocean and many times, the death of its creatures.

Effects of Oil on the Ocean

Although the big oil spills from offshore drilling get a lot of attention, there are millions of gallons of oil dumped into the world's oceans every year from other sources.

A National Research Council report narrows oil in the ocean to four types:

  • Natural seeps
  • Petroleum extraction
  • Petroleum transportation
  • Petroleum consumption

Oil is dangerous to marine life in several ways. According to the National Oceanic and Atmospheric Administration (NOAA), if fur-bearing mammals or birds get oil on their fur or feathers, they may not fly or move properly, maintain body temperature, or feed. The oil washes up on beaches and contaminates nesting areas and feeding grounds. As marine mammals try to clean themselves, they may ingest oil which can poison them.

Although fish and shellfish aren't impacted immediately, long-term exposure may lead to organ damage, reduced growth, reduced respiration, and may adversely impact reproduction and larva development and survival.

Coral Reef Impact

Oil may impact coral reefs in a negative way. These reefs are not only beautiful, they provide a habitat for many sea creatures. NOAA indicates the impact of oil on coral reefs is difficult to predict. Oil also clogs up the gills of the fish that live there and suffocates them. When oil floats on the surface, it blocks sunlight and prevents marine plants from using light for photosynthesis. These plants are important parts of the food chain and the reef habitats found in the oceans.

Toxic Materials

Toxic materials are a side effect of modern living. Sea Web reports that, thanks to water's solvency, toxic pollution often ends up in the ocean, sediment, and the sea surface micro-layer. Toxic pollution sources include:

  • Industry and sewage waste discharge
  • Pesticides
  • Air emissions
  • Plutonium processing
  • Nuclear power plants
  • Nuclear waste dumps
  • Nuclear submarines
  • Household cleaning products

Pollutants find their way into the ocean and sink to the bottom. Bottom feeding organisms ingest these chemicals and contaminates the food chain. The smaller fish is eaten by the larger fish, which is then eaten by a human. Toxins build up in the tissues of the people who eat the contaminated fish and may lead to illnesses like cancer, reproductive disorders, birth defects, and other long-term health problems. The National Resources Defense Council offers a guide to fish you should be avoided due to high mercury and PCB content.

Trash and Other Debris

polluted beach

Plastic bags, balloons, medical waste, soda cans, and milk cartons all find their way into the oceans of the world. These items float in the water and wash up on beaches. According to the Environmental Protection Agency, marine debris creates health hazards for marine life.

Ocean mammals get entangled in old nets and drown because they cannot get to the surface for air. Birds, turtles, and fish ingest a variety of plastic items and their digestive systems become clogged. Sea turtles are attracted to floating plastic bags which appear to be jellyfish, one of their favorite treats. The plastic bags block their digestive system and cause a slow and painful death.

Various pieces of trash cause entanglement, starvation, drowning, and strangulation. When the trash washes up onto beaches and into marshes and wetlands, it ruins breeding grounds and habitats. Marine plants may be strangled by debris and die. Debris removal efforts may alter ecosystems.

How much plastic is in the ocean? Fortune reports there are 5.25 trillion pieces of plastic in oceans around the world and 8 million tons being added to that number each year.

Statistics on the Effects of Ocean Pollution

Statistics on the effects of ocean pollution on fish and other marine life are difficult to determine because of the number of animals involved and the size of the ocean. Scientifically, there are many unknowns. However, there have been some interesting studies done in small areas of the ocean and test groups of marine life.

  • Elliott Norse, president of the Marine Conservation Biology Institute, found plastic in the stomachs of 300 Albatross chicks on Midway Island, 1600 km from the nearest land.
  • According to a report published in the Review of Research Journal, the Marine Academy's Oceanography website reports "there are over 46,000 pieces of plastic floating in each square mile of ocean off of the Northeast coast of the United States." The plastic contributes to the death of millions of sea birds and 100,000 marine mammals each year.
  • A Center for Biological Diversity report states that within a year of the British Petroleum oil spill in the Gulf of Mexico, 82,000 birds of 102 species were likely harmed or killed. In addition, approximately 6,165 sea turtles, 25,900 marine mammals, and an unknown number of fish were harmed or killed. As of mid-June, 2010, the spill contributed to the death of 658 sea birds, 279 sea turtles, 36 sea mammals, and countless fish.
  • According to a New York Times report, on one Galapagos Island, the numbers a rare species of iguana dropped to 10,000 from 25,000 after an oil spill off the coast of those islands in 2001.

Research Helps Protect Ocean Life

The amount of research done by marine biologists, environmentalists, and others is staggering. There is worldwide concern over the growing problem of ocean and other water pollution and no clear and easy resolution to the problem in sight. The oceans are an important part of the earth's environment, and it is imperative they are protected and kept clean to protect marine health and ultimately, human health.

Effects of Ocean Pollution on Marine Life