Today is World Oceans Day, and the theme of this year is Healthy Oceans, Healthy Planet. Many people across the globe are unaware or even indifferent to the role the oceans play in the ecological stability of our planet’s many ecosystems. If our oceans were to suddenly become toxic and unable to support oceanic life, life on land would soon degenerate as well. While the death of the oceans may not be exactly imminent, there is little doubt that human actions — or a lack thereof — are putting our oceans at risk. Let’s take a look at four of the biggest threats to our oceans.
According to UNESCO, more than 80 percent of ocean pollution is land-based, comprised of agricultural runoff, untreated sewage, and hundreds of millions of tons of plastics. Each of these forms of pollution have devastating chemical and physical consequences for ocean ecology, including the organisms that reside within and depend on ocean health for survival. This doesn’t even include the damage inflicted by oil and other toxic chemical spills that occur regularly.
Acidification is the result of carbon dioxide being dissolved into our oceans, lakes, and rivers, creating a chemical reaction that alters the pH level of these waterways. This alteration reduces the seas’ saturation of calcium carbonate minerals, which are fundamental to organisms that use these minerals to build their shells and skeletons, including corals and all shelled animals. Acidification also reduces oxygen levels, resulting in “dead zones” throughout the world’s oceans in which no life is supported.
While it may seem wonderful to live in a world where even the most landlocked areas can enjoy a seafood dish, our insatiable desire for it has led to vast overfishing, where indiscriminate fishing practices wipe out entire ecosystems in a short period of time. Reduction of pelagic stock means fishermen turn to trawling the seafloor for viable product, destroying fragile environments that can take decades or even centuries to recover, if they do at all. This is to say nothing of the millions of tons of non-targeted species that become bycatch, much of which is simply thrown away in an alarming display of waste.
Coral reefs aren’t just pretty sights under the surface — they directly impact life on land by protecting coastal shores from storm damage and providing habitat for a multitude of marine organisms that are all part of the planet’s intricate food web. Each of the aforementioned threats in this article have highly destructive effects on coral, some of which can never be reversed. Just as our lands suffer in multiple ways from the destruction of forests, our oceans suffer greatly from the destruction of coral reefs.