Water is the most important compound on the planet and it makes our world unique from all the others and I have the luxury of working with it every day as a water feature designer and builder.
I couldn't think of a more important job as I have the ability to impact children, adults, animals and the planet.
Understanding water and its teeming life starts with a basic understanding of aquatic ecosystem classification. There are three main classifications to understand. The first is an oligotrophic system; the word comes from oligos = "few" and trophos = "feeding". It means there's very little food to support a food web.
Oligotrophic systems are created by glacial meltwater and spring-fed streams. The watersheds are nutrient poor with rocky substrates. The lack of nutrients means there's not enough food for plankton and algae to survive, which gives the water a very clear appearance. Without plankton, the rest of the food web is limited and the ecosystem has limited numbers of organisms.
Creating an oligotrophic system is the goal for most of our water feature projects. Our clients have a mental picture of what their pond or stream should look like and it's typically a cool, clear body of water found in the mountains.
Eutrophic systems are at the other end of the spectrum and the word means, "well fed" or
"well nourished." This system is characterized by an abundance of nutrients or food.
Nitrogen and phosphorus are the nutrients that are measured as they're the building blocks for life. When these nutrients are readily available, plankton and algae will be abundant, giving the water a murky greenish appearance with low visibility.
Aquatic plants and other organisms are widespread when nutrients are plentiful. A eutrophic system has a well-developed food web and is responsible for an important part of the biological community.
Mesotrophic systems are right in the middle of the two, with enough nutrients to support a diversity of life but not an overabundance to cause poor visibility. Mesotrophic systems will have good visibility, combined with sections of lush aquatic plants and other areas with sand and gravel substrates. This type of a system is the most common and if you're a fisherman you've probably visited some mesotrophic lakes. They're common in northerly states with clean watersheds.
So why the variety of aquatic ecosystems?
All aquatic systems are born to die; like everything else they have a very specific lifespan. Oligotrophic systems are basically young aquatic systems, the water is clean and clear, the bottom substrate is rock or gravel, and the watershed is pure, meaning there's no runoff from parking lots, factories or farm fields.
As the system ages, it collects sediments and organic matter from atmospheric deposition (blown in) and runoff from surrounding areas. This will become food for zooplankton, bacteria, aquatic insects and other organisms that will feed off of the introduced organic material.
The food web starts to develop and the population of these small organisms explodes. A fishery will soon follow as small fish are introduced by streams, birds, or other natural sources. The small fish will feed upon the aquatic insects and microorganisms and piscivorous (fish eater) fishes will soon follow.
The aquatic ecosystem is a prime example of the circle of life that exists on our planet. Every living organism is at some stage of development, and this self-sustaining process keeps repeating itself for our enjoyment. Nature is just incredible!