These ocean threats are changing the planet
Human interference presents the biggest threat to oceans. Scientists and conservationists hope these solutions will help turn the tide.
Many things pose threats to the oceans, and most, if not all, are caused by human activities. Eighty percent of marine pollution comes from land-based activities, causing rapid changes to entire marine ecosystems.
Oceans cover 70 percent of Earth’s surface and provide immense benefits to the planet. In addition to contributing shelter and food, about half of the oxygen we breathe comes from the ocean. It’s also the chief climate regulator and one of the planet’s greatest tools for capturing carbon dioxide emissions and excess heat, notes the United Nations.
However, the world’s oceans can only absorb so much heat. Global warming is causing alterations in ocean chemistry and many oceanic processes. It’s threatening many species of marine animals that cannot cope with higher temperatures. Overfishing, invasive species, oil spills, and plastic pollution are all contributing to the declining health of our oceans.
But there are solutions. Conservationists advocate creating expansive marine reserves to protect marine biodiversity. Others are finding ways to reduce destructive fishing practices. Here are the major threats to the ocean and how to mitigate them.
Major ocean threats
1. Global warming
The widespread burning of fossil fuels, such as coal and oil, is increasing the average temperature of Earth and the ocean. Glaciers, polar ice caps, and ice sheets are melting due to these greenhouse gas emissions, leading to rising sea levels and threatening coastal populations. Roughly 40 percent of the world’s population lives within 62 miles of a coastline and just 15 percent of coastline are ecologically intact.
National Geographic History Magazine
(The Gulf of Maine is warming fast. What does that mean for lobsters—and everything else?)
2. Pesticides
Chemicals used in agriculture are effective at killing insects—and harming marine life. Pesticides like neonicotinoids, or neonics, have been linked to the collapse of a fishery in Japan. Surface water runoff and pesticide “spray drift” from farms end up in coastal waters, where it depletes oxygen, killing marine plants and shellfish.
3. Industrial waste
Factories and industrial plants discharge sewage, toxic chemicals, and even trash into the oceans causing significant harm to marine life. Factories release excess carbon dioxide into the air, too, which is absorbed into the ocean, causing ocean acidification and coral bleaching events. Wastewater from factories containing nitrogen and phosphorous can lead to algal blooms that block sunlight to marine plants.
(What fracking is doing to the Earth—and to our bodies)
4. Oil spills
According to the National Oceanic and Atmospheric Administration, thousands of oil spills occur in the United States each year. Though U.S. water-sewage treatment plants discharge twice as much oil each year as tanker spills, large spills are considered major environmental disasters that can have decades of negative impacts.
Oil spills not only harm animals by smothering them, they also cause health problems in fish, from birth defects to slowing swim speeds, especially in young fish.
(Thousands of oil rigs are nearing the end of their life—what will happen to them?)
5. Air pollution
Airborne pollutants are responsible for almost one-third of the toxic contaminants and nutrients that enter coastal areas and oceans. Despite years of progress, air quality is getting worse due to several factors, including more extreme wildfires that are more toxic than once thought. Increased air pollution makes oceans more acidic, killing coral and inhibiting many marine species from growing shells and skeletons.
(What causes coral bleaching? Here’s how it threatens ocean and human life)
6. Invasive species
Poisonous algae, cholera, and countless plants and animals have entered harbor waters and disrupted the ecological balance. One way invasive species travel to places they don’t belong is via ballast water. Ships take in water to help with buoyancy and balance, but marine life can be sucked in as well and released at far-off ports, where they can negatively impact the food chain.
7. Overfishing
One report by the United Nations Food and Agriculture Organization estimates the number of overfished fish stocks tripled in 50 years. Although overfishing overall has decelerated around the world, it has yet to meet adequate sustainability levels.
(How overfishing threatens the world's oceans—and why it could end in catastrophe)
8. Plastic pollution
The production of disposable plastics has risen to overwhelming levels, making plastic pollution one of the most pressing environmental issues today. It’s a problem that exists everywhere in the world, with especially harmful effects on the ocean.
Every year, eight million tons of plastic finds its way into the ocean. Plastic waste harms over 2,000 species of wildlife—most die from entanglement or starvation from ingesting it, but harmful chemicals from plastics can leach into the waters as well.
(For animals, plastic is turning the ocean into a minefield)
Solutions for protecting the ocean
1. Establish Marine Protected Areas
The ocean may seem vast but only 8 percent is protected. Marine Protected Areas (MPAs) are sections of ocean that governments designate for long-term conservation.
Establishing more marine parks and reserves (also called marine conservation areas and sanctuaries) can help protect marine wildlife and habitats from things like overfishing and pollution.
(The world’s biggest marine reserve seems to be doing its job)
2. Reduce destructive fishing practices
Trawling not only destroys marine environments and releases carbon dioxide, it can also lead to accidental catch. Alternatives such as gill nets can be better for marine habitats but come with other negative impacts. Scientists are investigating less-invasive methods, such as using artificial intelligence to target trawling areas and developing lower-impact drag gear.
(What is aquaculture? It may be the solution to overfishing.)
3. Foster local conservation
Supporting small-scale fishers helps maintain their livelihoods while reducing the environmental impact on the oceans. Including them in the decision-making process can also have a big impact on protecting our oceans in the long term.
Coastal conservation efforts and “volunteer science” can help promote ocean health in specific areas.
(Can restoring mangroves protect Miami from rising seas?)
4. Minimize the use of military sonar
Military sonar can harm or kill whales and other marine mammals. Sonar and other sounds can force animals to move away from feeding areas, cause stress, and even hearing loss. In recent years, the U.S. Navy has instituted sonar practices to help reduce negative impacts on marine life. These practices include reducing or shutting down sonar when marine animals are spotted.
5. Prevent accidental catch
Another way to help protect the oceans is to install measures that reduce the number of sea animals caught accidentally. Methods such as attaching green LED lights to gillnets may help prevent sea turtles from getting caught. Funding tracking and monitoring will also help produce new sustainable ways to reduce or even prevent bycatch.
6. Reduce pollution
Whether it’s toxic chemicals in the air or agriculture pesticide runoff, pollution in its many forms causes immense damage to the health of our oceans. While much of the work to reduce pollution must come from governments and industries, individuals can make an impact in many ways, from replacing single-use plastics in daily life to making responsible seafood choices.
(Mass extinction in oceans can be avoided by curbing fossil fuels)
