Nature Notes: Too Much of a Good Thing

    We cannot sustain ourselves without oxygen, and we can’t exist without nitrogen either, but too much nitrogen, and the balance of nature is seriously out of whack: Think red tide, brown tide, and other algae blooms.
    Psychologists and physiologists tell us that there are four primitive drives propelling us through life: food, sleep, reproduction, and shelter. For humans, shelter is protection from rain, snow, cold, high winds, very hot weather, and would-be enemies and attackers. These drives are rooted in our genes; all animal life forms have them, even single-cell animals, the protozoans such as amoebas and paramecia, are driven by these powerful urges. They exist in green plants, too, but much more passively. Plants don’t forage for food, they make it, and while plants may not sleep, they often become dormant.
    The genes that give rise to and shape these basic needs are made up of DNA and RNA nucleotides, composed of sugar and protein molecules. All life has the ability to reproduce itself. The most microscopic quasi-life forms, such as viruses, use the genes and enzymes of their hosts to reproduce themselves. The blueprints for life are in the arrangements of the proteinaceous nucleotides.
    Amino acids are the simplest of proteinaceous materials and amino acids all contain nitrogen atoms. The atmosphere is 78 percent nitrogen gas. Life can’t sustain itself on nitrogen gas the way it can on oxygen. We owe our existence to oxygen. We respire it. Plants respire oxygen, too, especially when it is dark and they are not photosynthesizing, or converting carbon dioxide into carbohydrates.
    On the other hand we can’t exist without the nitrogen atoms, either, but for it to be of any use to us, it first has to be “fixed,” i.e. combined with hydrogen, oxygen, and carbon atoms so that we can assimilate it into genes, enzymes, and the other proteinaceous materials.
    Too much oxygen is rarely a problem; it makes up about 20 percent of the atmosphere. Too much fixed nitrogen, however, can be a big problem. Salts of nitrogen such as nitrates, a common ingredient in just about all fertilizers, ammonia, which we secrete in our urine, and nitrites, are all important growth inducers. They are converted in one way or another by protoplasmic processes into amino acids, nucleotides, enzymes, hormones, and animal tissue building blocks.
    The threshold for potable water is no more than 10 parts of nitrogen in a million parts of water. Modern research is discovering that this level is much too generous, and the drinking water standard for nitrogen compounds will undoubtedly be lowered in the future.
    While we animals also make structural tissues such as skin, hair, fur, muscles, flagella, and cilia out of protein, plants synthesize the majority of their structural parts out of oxygen, hydrogen, and carbon, turning them into lignin and cellulose (the wood that we burn in our fireplaces, the paper we write on, etc.). However, they need the nitrogen to make genes and enzymes, and for respiration and energy production, just as we do.
    Too much of a good thing is not a good thing. While atmospheric nitrogen, N2, is not very soluble in water, the bottom level of the aquatic food chain, the phytoplankton and other microbes, get their nitrogen from organic and inorganic nitrogen compounds reaching the water by various means. Urea from mammals and uric acid from birds — including pets — is one source, atmospheric pollution in the form of nitrogen compounds (nitrogen dioxide, for example) is another. Some of that comes all the way from China, brought here by weather systems moving from west to east. Human septic systems are another source of dissolved nitrogen, and soluble fertilizers used by humans are a fourth source.
    Dissolved nitrogen gets to the aquatic system, say Lake Montauk or Georgica Pond, in rain or by way of runoff from roads and lawns or by welling up from the underlying water table, which is the main route for septic system nitrogen contributions. Think of it. There are 7 billion of us and we all urinate several times a day. Much of that goes into the groundwater untreated.
    These waste nitrogen compounds, whether they be from the air, the land, or underground, are many times more common than they were, say, 100 years ago. Certain phytoplankton suck it up and go amok. The result is extensive “blooms,” such as the reddish one that covered much of the western half of the Peconic Estuary in the late spring and early summer of 2010, no doubt at least partially driven by the runoff and upwelling from the record rainfall that March.
    Phytoplankton can divide and double in number once every hour if conditions are right, and it doesn’t take two of them to tango. A single one can get the ball rolling downhill and speeding up as it goes. Too much turkey today might give us a stomachache that might last until the next morning. Too much nitrogen in the water will give the Peconics a stomachache that could last for months.