Dead zones in the ocean


I was talking with someone recently about the Waikato River water that provides some 10% of the drinking water in Auckland. This was approved despite much protest, on the basis that Metrowater would only use it in emergencies. I suspect that Mayor George Wood at the time knew that it would end up being turned on all the time, as part of his deal with his crony mayors.

The water was declared safe by WHO standards, however councillor Joel Cayford, who is now employed by ARC said that it was unsafe. I attended the public meeting where he explained that WHO standards listed a number of quality requirements, but excluded many ingredients such as dioxins, heavy metals, fertiliser and more. In my opinion the meeting wasn’t helped by constant interjections from rent a protester, which didn’t help the cause.

Not long after approval was given by the regional mayors, including the Mayor Bob Harvey of Waitakere who approved it on the condition that Waitakere water would only come from local dams in the rainforest, thus not having to take this water.

What has this got to do with dead zones in the ocean? Well here’s the thing. A lot of the objections against using Waikato river water were because it contains huge amounts of leached chemicals from farms including fertiliser, antibiotics and much more. It appears that these same types of chemicals are flowing from rivers around the world into the sea and several studies are suggesting that the rise in industrial food production is increasing the number of dead zones rapidly.

Oceanic dead zones are areas where the oxygen levels in the water are so low that they kill of almost all forms of marine life. There are now more than 400 oceanic dead zones around the world and they are growing fast.

According to experts, including NASA a major contributor to these dead zones is fertiliser that flows to the ocean from farms both in the form of chemicals leaching from farms and from the animal manure which still contains these chemicals. The nitrogen and phosphorous feeds the algae and phytoplankton, making these plants grow rapidly.

In New Zealand, we have become aware of algal bloom. This is occurring more commonly now both in coastal waters, such as our local Waiheke Island, and also in freshwater lakes, including many in the Waikato, where 10% of our drinking water is coming from.

So what does this mean? We know that fresh water is going to be on of the important issues in the future, both from climate change and from man-made intervention. We know that our oceans are becoming polluted, much of it from man-made waste. We know that the fish stocks are becoming depleted in many parts of the world, due to over fishing, to feed growing nations. But fish are also now seriously at risk from the oceanic dead zones, where oxygen levels are so low that fish and other marine life can’t survive.

We seem to be in danger of creating the ‘unrealistic and unbelievable’ wasted planet that is often depicted on science fiction movies.Am I exaggerating? Well check these examples out:

A dead zone the size of New Jersey of the coast of Oregon and Washington, may be irreversible.

The Mississippi Delta dead zone is one of the smaller ones in the world, only 3,000 square miles. The US Government is investing $320 million to try to slow it down, but as long as the chemicals keep flowing down and farm production is increased, we have a problem.

The Baltic sea apparently contains 7 of the 10 worst oceanic dead zones and it appears that the surrounding countries haven’t been doing much about them. The end result could be the loss of almost all marine life in the area. This map shows how bad it is in places, where the red areas represent areas where the water essentially contains no oxygen.

It appears that the man-made damage to the oceans and lakes in the world could present an even greater problem than global warming and of course one that is compounded by it. If so much water ends up unable to sustain life, how will we survive, especially the poorer areas on the planet, where water is already scarce. The sea’s health is not something we can take for granted, no matter how vast it appears. The attractive colours of algae bloom that we sea coming back each summer in bigger areas, is evidence that we need to change some of our ways, and quickly.

I’ll leave the last word to Joanne from Rocketboom who explains it far more succinctly than I: