In the Gulf of Mexico, there are 7,500 square miles where nothing lives. Amberjack and other fish lay dead on the sea floor, their bodies feeding sulfur-oxidizing bacteria that turn the sand black for miles. The water is hypoxic, which means there's not enough dissolved oxygen in it to support marine life.
Sometimes, sea water gets hypoxic naturally. When rivers empty out into oceans, sometimes the fresh water doesn't mix. It creates a cover over the saltier water; algae grow on this cover. Gradually, the algae suck the oxygen out of the salt water; they choke the life right from it. It takes a storm, a big storm like a hurricane, to break the cover up, mix the water, and dissolve new oxygen.
Mainly, though, these hypoxic areas - dead zones, they're called - are caused by chemical fertilizers. See, it's not that the rivers have no oxygen. It's that they are crammed full of plant nutrients - like nitrogen - that force out the oxygen. The water gets so crowded there's just room for the oxygen to dissolve. So there's nothing for the animals to breathe.
The Black Sea used to have the largest dead zone in the world, until the Soviet Union collapsed. Fertilizer became too expensive to use, and the sea sprang back to life. It was an unintended consequence, but it showed pretty clearly that the only way to bring back these dead areas was to get rid of the stuff choking out the oxygen.
Hypoxia can also happen when the body doesn't get enough oxygen. This could happen at altitude or, because, just like the ocean, there's no oxygen in the air to breathe. Environmentally, this is a huge problem. And a growing one. As we deplete the soil, we're using more and more fertilizer to support "first-world" agricultural practices, . The runoff has more nutrients, which crowds out the oxygen, which makes the dead zones grow. And grow.
Even beyond that problem, there's a metaphor here, I think. Communities live on a kind of oxygen, which is the social relationships of the people within them. The commitment of those people grows the spirit of the community, makes it more cohesive. This cohesion won't just disappear; it's what put the community together in the first place.
Instead, cohesion gets pushed out by all the complication we put on life to maintain the system we live in. We lock ourselves in gated neighborhoods and behind headphones; we avoid eye contact and sit in our houses. We only associate with known quantities. Just like the rivers, we have jammed ourselves with activities and technologies that stop us from mixing.
Nowadays, researchers can tell that environmental stress is growing. As we stop mixing in our neighborhoods, they get more dangerous, which is hazardous to our health. Hazardous enough that Johns Hopkins made alleviating neighborhood stress their #1 way to improve urban health.
Community hypoxia is the state of a community, or a nation, where the different don't mix. Without that mixing, the community has no air, no way to live as an independent entity. The walls we have to put up to make that happen make us sick because, as humans, we need that interaction to survive.
If we let our communities go hypoxic, there will be casualties, make no mistake about it. We already have dead zones in communities all across the country. The question is, will we stop filling them with all the negative things that drive the air out - all the violence and the separation. Or will we let the oxygen in?
