Our Oceans are Changing Rapidly. Here’s How.

Conservationists do a lot to protect terrestrial wilderness areas and animals, but when it comes to the marine world, it can be out of sight and out of mind.

There are different factors at play, but overfishing and climate change are laying waste to what used to be thriving coral reefs and abundant sea life. Coral bleaching is one of the most visually arresting effects; caused by higher water temperatures in recent years, there has been a widespread and significant amount of coral mortality around the world.

Increases in global temperatures also affect plankton, which is the basis of the marine food chain that includes coral, fish, polar bears, walruses, seals, sea lions, penguins, and sea birds. Marine animals lose their ideal habitat and are forced to migrate; the temperature changes also affect their metabolism, life cycle, and behavior.

Rising sea levels — estimated as high as 69 cm over the next 100 years — flood coastal habitats and decrease the amount of light reaching offshore plants and algae and diminishing the ecosystems.

To add to the problem, our oceans are becoming more acidic, which is akin to the air pollution humans experience. The acidification makes dissolved oxygen in the water more difficult to extract, meaning gilled animals like fish and squid will have a harder time “breathing,” and shellfish will have a more difficult time building calcium carbonate shells.

In 2016 alone, two vast areas were designated as marine reserves. The Obama administration set aside 1.5 million sq. km in the United States for protection, called the Papahānaumokuākea Marine National Monument. And the largest protected marine area yet was designated by the Commission for the Conservation of Antarctic Marine Living Resources, 1.54 million sq. km in Antarctica’s Ross Sea.