Dead Zones - Oceanic Graveyards

WHAT are they?

Dead zones are areas in the ocean that can no longer support life- life that once flourished there. To put it bluntly - virtually everything in that area of the ocean is dead or has fled. (Little rhymes amid research are always fun)

A 2008 study counted 405 dead zones in the world. (A 2004 report counted only 150) Many are still small, but will undoubtably increase in size unless something is done.

One of the most concerning dead zones is in the Gulf of Mexico. It is over 22 000 square kilometers - the size of New Jersey. A main cause of this particular dead zone is the massive amount of agriculture that exists in the midwest, near the Mississippi river.

This satellite image shows the dead zone in the Gulf of Mexico, as well as two in Asia

Source

WHY does it happen?

Dead zones are oxygen depleted areas in the ocean that can no longer support the marine life that usually lives there. The water there can also be toxic to animal and human swimmers.

What's to blame?

• Human Activity, especially the agricultural industry. Excess chemicals like nitrogen and phosphorous that runoff from sewage, cars, factories and industrial farming operations either dumping or letting their waste seep into the water.

• Chemical fertilizers are considered to be the main cause of dead zones. There is simply too much toxic runoff for natural filters, like soil, to purify. Once the chemicals enter the water untreated, they eventually run into the ocean and cause an algal bloom; the bloom causes the oxygen-deprived dead zones. Plants and animals that are not able to escape usually die in the toxic environment, those that can flee go elsewhere.

Can this CHANGE?

Dead zones are reversible when the pesticides, manure, and other toxic chemicals that caused them are greatly reduced or eliminated. We just have to DO something about it! The Black Sea dead zone, which was once the largest dead zone in the world, mostly disappeared between 1991 and 2001 when fertilizers became too costly for farmers to use.

Moral of the story: Stop using pesticides, stop supporting the agricultural industry - go organic and local, eat less meat.

Great Pacific Garbage Patch - The Largest Landfill in the World

The Great Pacific Garbage Patch. Have you heard of it? Its is quite frankly one of the most alarming examples of marine pollution there is. And no surprises here, its caused by human activity.

Image via Kevin Krejci - Flickr

So WHAT is it?

The Great Pacific Garbage Patch (or Pacific Trash Vortex) is essentially a plastic graveyard in the ocean. Its full of junk like old footballs, kayaks, lego blocks, plastic bottles and pretty much anything else you can think of. 

The Garbage Patch covers anywhere from 700 000 square km to up to 15 000 000 square km. It is essentially the largest landfill in the world - the smallest estimates put it around the size of Texas and the largest estimates say it could be twice the size of the United States. This thing is HUGE! Why don’t we know how large it is? Because much of the plastic is not actually visible to the human eye if you are in an airplane, using satellite imagery, or are even on a boat deck. 

 Image via João Vianna / National Geographic

The plastic is mostly particles that have broken down to polymers, and much of it is under the surface of the water. In addition to plastic and polymers, you’ll find chemical sludge and other debris. This debris remains trapped in an area in the North Pacific because of ocean currents. 

Think that this problem is contained to the patch? Sadly, you’d be wrong. The UN estimates that there are 46 000 pieces of floating plastic in every square mile of ocean. 

Image via ingridtaylar - Flickr

Why does it MATTER?

If the thought of a floating plastic wasteland doesn’t phase you, then how about this: 

• Loss of life.  Animals eat the plastic, then starve, become dehydrated and die because of the chemicals that fill their stomach.
• Human consumption of toxins. Toxins are eaten by jellyfish, which are eaten by fish, which are eaten by humans. Yes, we are all interconnected. You trash an ecosystem thousands of kilometers away, you will still end up with the effects. Thats just how it works. 

Image via taylorandayumi - Flickr

WHY does it happen?

You know that 7/11 slurpee cup you just tossed because you couldn’t find a garbage? Well, it blew in the wind, then it made its way to a stream, which met up with a river, which traveled to the ocean. And now its one more piece of debris that is adding to the problem.

Image via Chris Jordan

Moral of the story  - We need to be thinking long term! Dispose of waste properly. Use reusable products. Consume less. Waste less. 

.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .

Want to learn more? 

Great Garbage Patch

MNN Article

Pictures of marine plastic pollution