The Oxygen Factory

I used to love going to my mother's Cousin's house while growing up. Coralie believed in eating a macrobiotic diet and so kept a wall full of interesting dried stuff in jars from which she would select to feed to us. It was there that I learned to love lentil soup on St. Patrick's Day. Little did I understand that some of what she served up for meals was macroalgae. Most people probably know it as Kelp, seaweed and other large aquatic plants. But why have I spent so much time writing about Algae?

Even though the news this time of year disappoints us with beach closings due to toxic algae blooms that contain cynaobacteria, it's important to note that algae is also an unsung hero. Algae is found naturally all over the world in both salt and fresh water. Through the process of photosynthesis, algae produces more than 75% of the oxygen required for animals and humans.* Perhaps this is why my fish pond algicide warns against using it in any place except my aquarium or fish pond. You might imagine that we would be goners if algicides were indiscriminately dumped into our oceans, lakes, ponds and streams! In fact, one would think that it's in our best interest that we understand the balance of  healthy ecosystems that both supports beneficial algae yet at the same time doesn't cause it to bloom out of control. 

This is why the State of Vermont has outlawed phosphorus in our detergents, restricts the use of fertilizers containing phosphorus and nitrogen to only those soils that have been tested as being deficient, developed extensive strategies to prevent water runoff and has become so persnickety about septic systems, animal waste and shoreline development. It's because the more nutrient pollution that enters the water, the more aquatic plants grow and eventually die. This die off provides food for more bacteria to grow which in turn uses up the dissolved oxygen in the water creating dead zones in which fish and insects cannot survive. These conditions also result in Red Tide and Blue-Green Algae.**

I have kept you eagerly waiting long enough for the results of my bottled water experiment! Three bottles of water, one unopened store bought (on the right), one filled with my well water with a cap on (middle), and finally one filled with well water with the cap off (on the left) Nothing added to the bottles. All were set outdoors next to my fish pond which is experiencing an algae bloom.  

My conclusion after viewing the results, is that I have more questions. I know that in order for algae to multiply to a number that we can see, it requires sunlight and must have carbon dioxide to consume for photosynthesis. While sunlight is available in a closed bottle, carbon dioxide is limited to what was in the trapped air in the bottle. This could explain why the capped bottles may still have naturally occurring algae but not change color. The uncapped bottle, while not the green I anticipated may still be algae from my well water, but also could be the result of a contaminate dropping into the bottle.  So if you will note that bottle almost out of the picture and behind the store bought water on the right.  I filled that uncapped bottle of well water 48 hours ago. This time however, I added one tsp of bone meal which is calcium, nitrogen and phosphorus. These nutrients combined with sunlight and carbon dioxide, hopefully will give me a beautiful green bottle of water within the week. You are just going to have to wait a little longer and maybe endure another blog on algae to find out. -Norma Manning

Resources

*About Algae and Cyanobactera, Algae PARC

Algae Bloom, Science Daily

**Nutrient Pollution, EPA