A Natural Aquaponic Ecosystem
An ecosystem is a biological community of interacting organisms and their physical environment. Incorporating liv- ing organisms into the environment around you can encourage a healthy ecosystem or damage it.
One type of manmade ecosystem, which mimics nature, is aquaponics. When a well-planned aquaponic system of bacteria, fish and plants, becomes established, the system can become almost self-sustaining with minimal effort.
There are many types of aquaponic kits and elaborate engineering plans for people to set up their very own; however, I like a simple approach to blending things into nature.
The kind of system I like doesn’t contain pipes, wires, containers of water or a complicated tubing and filtration system; it doesn’t even require a power source. Think about a small mountain lake or pond out in the middle of nowhere. It isn’t being cared for with chemicals and pow-er. How does it work?
Every landscape, soil type and resource type is different. There is no “one size fits all” when creating any micro ecosystem. Nevertheless, all we need to create a peaceful water ecosystem is a year-round creek or spring of any size, the nearby soil, rocks and plants, and a bit of elbow grease to lay it out and work everything into place. When built correctly, the native aquatic life will start moving in on its own.
It’s good to look at the natural landscaping, rock formations, flow of water, possibility of any flooding, and any other benefits or disadvantages of an area before deciding on a location. Finding a tranquil stream, cascading down the rocky hillside, shepherds my mind into the possibilities of a quite hide-a-way refuge.
I want my aquaponic system to be as natural as possible. Determining the percolation or drainage rates of an area can be done by completing a simple self-administered perc test. The rate of the stream flowing into the future pond must be equal to or greater than the absorption rate of the soil. The slope of the landscaping should be gradual enough that erosion is at a minimum while new plants get established, but sloped enough to ensure a good flow of water into the pooling area so it stays filled. Overflow systems need to be built into the design of the pond to prevent flooding and wash out. A pond liner should not be needed if a good location is found.
Because of seasonal highs and lows of water flow, I would not build the pond within the direct path of a stream. Just a side note: a small hole dug out in the stream can be helpful in persuading native fish to hang around while the main system is being constructed.
Watching how the water flows throughout the year is very beneficial when determining how close to build a pond. It is also a lot easier to build next to a stream; the water does not need to be diverted during the building process. Once the pond, overflow system, and other downstream features are completed, creating an inlet for the water to flow into the pond is fairly simple. Careful attention should be made to the flow rate and direction. An acute angle of flow to backfill the water may help keep excess debris out of the pond while allowing adequate water fill and fish traffic. Building inlets to miti- gate volume change, throughout droughts and floods, help preserve the integrity of the pond walls, features and bio organisms.
The floor and walls of the pond should have a lot of variation in depth and slope and, if possible, some natural overhangs. A shallow beach like area can help wildlife casually get a cool drink of water from your new ecosystem. Varying stones sizes and shapes, and even tree branches, can be used to create hiding places for fish and small wildlife. In zone 4-6, the pond should have valleys at least three feet deep to sustain fish throughout the winter. Colder areas should have deeper trenches.
Consider using nearby plant life. Plants growing around the construction area are already accustomed to growing in the same conditions so transplanting a few can easily bring life to the new build. Research the plants before digging them as there are some poisonous plants you don’t want to touch. Poison-hemlock “is acutely toxic to people and animals, with symptoms appearing 20 minutes to three hours after ingestion. All parts of the plant are poisonous and even the dead canes remain toxic for up to three years. The amount of toxin varies and tends to be higher in sunny areas.”
Don’t forget marginal plants. Plants that like growing in marshes or bogs help absorb excess nutrients on the shallow steps and ledges while their root system creates structural support of the walls and floor around them. Cattails and water irises, if already growing on the property, are free and can be relocated with little effort. What plants do you already have growing?
Algae can be problematic in still water ponds; however it is less likely to grow when there is a constant flow of fresh water. To help combat algae growth, have a lot of plants growing in the water. These plants take in excess nutrients, robbing them from the algae. Small water lilies help block sunlight, cutting off some of the algae’s food source. Water lilies also provide homes for aquatic life, such as frogs, and hiding places for fish. Don’t get large leaf lilies for a small pond, they can quickly take over and kill the other plant life.
With ample plant life, and once fish become established, algae should naturally be kept in check.
Now that the water ecosystem is set up, how can we use it for growing a garden?
Planting a garden below the pond, but to the side – think about flooding, can utilize the nutritionally rich fish water flowing downhill.
The ancient Egyptians developed a system of watering their crops called basin irrigation. Through a system of channels and walls they could control the water level in their fields. A similar but much smaller scale system of trenches throughout the garden, along with some flow control gates, can make watering the garden a breeze.
Some crops love water; watercress and lettuce are two examples. Setting up float beds within this system makes growing these types of plants easy; crops grown on rafts with holes that float on the water. Watercress is an aquatic or semi-aquatic perennial herb. Forty-six states in the United States list watercress as noxious and invasive. This means it is an easily grown and repeating food source and it does well being treated as a cut and come again crop. Growing watercress in float beds will help keep it from spreading out of control.
Landscaping around the new aquaponic area can easily be done with nearby resources. Large flat rocks or slate can make an aesthetic walkway around the water. Adding walkways and small path bridges throughout a garden like this can turn a “work” space into a place to relax.
Can’t you already hear the hypnotic gurgling of a mountain stream?