The ocean was once thought to be large enough to handle anything we threw at it – our trash would disappear into its depths and the fish would multiply to feed us. Unfortunately the ocean, too, has its limits and our effects on the sea are starting to be seen. Some issues are well known by the public – endangered whales and rising sea levels often get attention. However, the ocean is threatened by a host of problems, here are a few of the lesser known ones.
The Great Pacific Garbage Patch refers to a high concentration of trash in the Northern Pacific Ocean. Nobody knows just how large the patch is although one oft-cited claim says it’s at least as big as Texas. The swirls of small plastic particles, just under the ocean’s surface, are often mistaken as food by birds, fish, and other sea life – which can be a deadly mistake. Marine debris will continue to be a problem as long as people create massive amounts of plastic and packaging. Beach litter and illegal dumping are a few ways trash can enter the ocean. However, garbage entering rivers and storm drains far in-land can also end up at sea.
Carbon dioxide (CO2) emissions often get attention for their contribution to global climate change. Less well known is the effect these emissions have on the growth of shell-forming animals such as corals, oysters, and many types of plankton. As CO2 dissolves into the ocean, it creates carbonic acid, which makes the ocean more acidic. Today the ocean is about 30% more acidic than it was two hundred years ago, and this changing chemistry is affecting the ability of shell-forming animals to grow. Coral reefs and shellfish farms are already feeling the effects of ocean acidification.
Overfishing has received more attention over the past few years, but many people are still unaware of just how bad things have become. Fish populations have not been able to keep up with human appetites and now over 85% of the world’s fisheries are considered to be fished past their biological limits. Many species of fish are now considered endangered including Bluefin tuna, Goliath grouper, Atlantic halibut, and several species of shark. Moreover, fishing methods can often have disastrous consequences for marine habitats as fishing trawls bulldoze through the seabed. The best way to help is to download a safe seafood card (such as those from Monterey Bay Aquarium) and avoid eating threatened fish populations.
There are quite a few more problems the ocean is facing, including: climate change, pollution from agricultural runoff, the spread of invasive species, mangrove and wetland loss, and the effects of human made sound on marine mammals. Staying informed and speaking out against such ocean threats is the best thing an ocean-loving person can do. However, reducing consumption and being mindful of your environmental footprint is also a good idea. Even those who live far from the ocean can have a big impact in conserving it for the future.