The oceans often don’t get enough consideration when it comes to sexy environmental efforts. Sure, there’s the dolphins and the whales, et al. but what about the water itself?
The Louisiana Universities Marine Consortium reported earlier this month of a hypoxic, or low oxygen, zone the size of New Jersey in the Northern Gulf of Mexico. Much of this is due to the addition of nitrogen and phosphorus, delivered by rivers which empty into the ocean after collecting toxic amounts of chemicals from . Nitrogen and phosphorus contribute to rapid algae growth, which may be eaten by predators or may die and settle on the ocean floor. And at this point, it is the bacterial decomposition of algae and predator by-products which depletes dissolved oxygen.
This is bad news for oxygen-sensitive species which includes many types of commercial fish, shrimp and crab. As the oxygen levels decline, many species die off or leave the area in search of better habitats, resulting in a biological dead zone.
It’s not just oxygen depletion that oceans have to worry about – there’s also the incredible influx of carbon dioxide. Carl Zimmer wrote earlier this year on the effects fossil fuel consumption on ocean acidification. It’s even attracted the attention of popular media outlets such as The Economist.
In a nutshell, the oceans have become 30% more acidic since the Industrial Revolution. Scary! For animals with calcified shells, an increase in acidity can be lethal as their shells become more brittle and thin, through the process of dissolution.
Unfortunately, like many of the world’s problems, the best ways to fix the problem is to cut back on consumption and to exercise more restraint in usage. Chemical fertilizers are a big source of nitrogen and phosphate, though they can also come from industrial wastes. And fossil fuels… well. Consider it another (in a long list of) reasons to leave the car at home!