Too Much of a Good Thing?

In his classic Don Quixote, Cervantes poses the question, “Can we ever have too much of a good thing?”

One’s childhood instinct is, of course, to believe that it’s inconceivable! Too much candy?? But the wisdom of age and experience tells us otherwise.

© Bujará, Bolo Hauz

And so it is with nutrients. And especially with nutrients in our waters.  Nutrients are no more than chemicals found in everything alive which are necessary, in the right proportion and balance, to life itself – the life of people, plants and animals – indeed all organisms. Common nutrients are carbon, hydrogen, oxygen, nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur.  Some of these you may have seen on the list of ingredients in the fertilisers you use for your household plants, or in your garden or for your lawn.

Well, agriculture has used these fertilisers, initially over the eons from natural sources such as manure and decaying plants and other organic matter, and now in our modern chemical age from unlimited industrially created compounds.

So what does this have to do with wetlands? It turns out quite a lot. Not only do wetlands serve as a nature-based solution for the accelerating devastation caused by the climate emergency, but they also provide a filtering and cleansing function, similar to the human kidney, for our water that is more and more polluted by modern agriculture’s excessive dependence on chemical fertilisers. Our water is also increasingly degraded by urban development and the often untreated waste and pollution that results.

The fertilisers, primarily nitrogen and phosphorus, which farming and agriculture use in such abundance usually infiltrate into natural ecosystems and contribute to poor water quality. One devastating result is what’s called eutrophication.  This excess nitrification can easily create algal blooms and “dead zones” which we have all seen mentioned in the evening news. Indeed sometimes when we head to what we hope is a glorious beach, we find instead an unappetising soup of “scum” which can even be toxic to us.

A “dead zone” has excessively low oxygen concentrations and can lead to die-offs of marine life that cannot escape. One scientific study suggests that eutrophication may have created 245,000 square kilometers of “dead-zones” world-wide, about the size of the whole United Kingdom.

Wetlands’ complex makeup can remove these excess nutrients before they can do their deadly work. Through a blend of physical, chemical, and biological processes, the nutrients may be adsorbed (sticking to something solid), absorbed, transformed, sequestered and ultimately removed as the water slowly flows through the coastal wetland. The newly-cleansed water can then safely join the sea without killing everything with which it comes into contact.

So when you next head to the ocean and pass the adjacent wetlands, slow down and take a closer look at the hard work that’s taking place there to naturally clean our water. Restoring precious wetlands not only protects the water we drink, fish and swim in, but helps absorb carbon from our atmosphere to fight climate change, and absorbs and stores excess water from dramatic weather events such as flooding and drought. There is no such thing as much too much of this good thing, wetlands