You’re probably thinking I’ve lost my mind at this point, but let me explain. Aquatic ecosystems have a lot of similarities to our bodies — we’re both a product of our diets. In fact, if you just look around, you’ll see similarities between lots of different ecosystems as they relate to food production and consumption.
The Human Body
Let’s start with the human body to get a baseline. Our bodies are living machines that are able to utilize outside resources such as food, water and oxygen to sustain us. After a series of internal biological processes, these resources allow us to grow, move, think and procreate similar to other animals; the thinking and reasoning piece, however, is unique to our species. Internally, we have specialized organs and tissues that can utilize the nutrients and energy produced from these nutrients for our day-to-day activities.
When we eat too much with low physical activity, our bodies will store the excess nutrients that have been processed for future use. This is an important adaptation, because we’ve already invested in the consumption and energy to process the food into a usable form. It would be wasteful to get rid of it, because we may need it in the future, and so it’s transformed into a valuable reservoir, which we call fat. A small amount of fat is actually important for our survival, but it can get out of control. When this happens, our bodies react negatively. Excess weight makes it more difficult for us to move around efficiently and puts an additional strain on our joints, lungs, heart, etc. These stressors will likely shorten our lifespan.
I don’t think any of you are reading this to learn about diets and exercise, so let’s transition into how this is similar to a pond.
Ponds are also living machines that require outside resources such as food, water and oxygen. And just like us, they rely on a host of other foreign organisms to survive. Food comes in the form of two sources, both external and internal. External food and nutrients are known as allochthonous materials. They’re comprised of anything that’s deposited into the water from an outside source, such as windblown leaf debris, organics that have been washed into the pond, fish food, etc. Autochthonous material is generated within the ecosystem and includes algae, aquatic vegetation, organic benthic sediments and more. Typically autochthonous material does not cause a lot of problems, because these compounds are growing from the nutrients already within the system. They’re recycled internally through photosynthesis and the process of decomposition.
Allochthonous material, on the other hand, can be thought of as overeating. The food and nutrients are coming in, but they’re not being used completely by the ecosystem, so it’s stored as a nutrient reserve. Similar to our bodies, a small amount of stored nutrients, organic sediments and fat are OK, but too much puts stress on the system. Healthy aquatic ecosystems will utilize the nutrient input as food for aquatic invertebrates, and the rest will be broken down by bacteria and fungi into simple compounds that will either stay locked up in the sediments or will be released into the water as soluble forms of food for a wide variety of primary producers (phytoplankton, string algae, aquatic plants, etc.). In aquatic ecosystems, this process is called eutrophication, which is a normal process that occurs slowly as organic compounds accumulate. This process can be sped up when fertilizer or other nutrients are washed into a pond and can lead to an algae bloom.
Go on a Diet
So, how do we keep the look and function of a young body or new water feature? We need to control the diet with plenty of exercise to consume any excess nutrients. Mechanical skimmer filters are one of the most important additions to a well-designed water feature, and if you have a limited budget, I would recommend this as your first purchase. The reason is simple; the skimmer will capture allochthonous materials from the surface of the pond, where it easily can be removed from the system. This simple step will help to control the available food in the ecosystem. This is like going on a restricted diet — you’ll start losing weight, because your body will utilize the stored food to keep your body functioning.
A mechanical skimmer requires a pump and piping to operate. The pump acts like the heart and blood vessels within our body, and its job is to circulate the water, just like our heart circulates our blood. The process of circulation delivers oxygen and nutrients throughout the ecosystem exactly like our circulatory system. Increasing the aerobic capacity in our bodies allows us to consume more nutrients while maintaining a healthy weight. Increasing the aerobic capacity of a pond will feed more oxygen to the microbiota, allowing them to degrade more organic compounds. This becomes more important when the bioload, or the amount of fish or other aquatic organisms, increases.
Oxygen, Oxygen, Oxygen!
This is an important piece of the puzzle, because without it, we suffocate. A lot of you may be thinking aerators when I say oxygen. While they do aerate the water, it’s not in the way you’re probably thinking. Aerators are a cost-effective way to move water up to the surface of the pond, where it comes into contact with the atmosphere, allowing for gas exchange. The actual amount of oxygen transfer that happens between the air bubble and water is very small because of the short contact time and surface area of the actual bubbles. A properly sized skimmer and pump can handle a typical backyard water garden.
A pond also needs a healthy biofilter, which is similar to our digestive system. The high surface area of the filter pads and biomedia is the perfect home for nitrifying bacteria that will efficiently reduce nitrogenous compounds into nitrite and nitrate. This also happens within our intestines, where the high surface area houses a unique mixture of microorganisms that break down complex proteins and carbohydrates into usable food.
If you’re an elite athlete and push your body to the limits of its function, you need to follow a clean diet and healthy exercise regimen. You’ll also probably take dietary supplements and probiotics to increase your level of performance. Beneficial bacteria, along with the proper mixture of water treatments, will increase the performance of your water feature to ensure optimal functioning.
Mind the Unknowns
This all sounds simple, but with any living system, there are a lot of unknowns that can completely throw off the entire system! Humans get sick despite taking good care of themselves because of viruses, bacterial infections, parasites, cancer and a variety of other stressors that will impact our performance, possibly leading to serious illness or death. Ponds are no different; you can do everything right but still struggle with poor water quality, algae blooms, sick fish and so on. This can be due to environmental factors that you’re not aware of, existing water quality parameters or new fish added to the populations.
I can say this with confidence, though: If you have a systematic way of creating your water features and you utilize the proper mixture of skimmers, biofilters, pumps and water treatments, your odds of success will increase exponentially, and you’ll be able to quickly diagnose a problem when it arises.
I hope you’re starting to see the parallels between the human body and a pond. We all have the ability to manage our living machines and control the outcome when we understand how all the pieces work seamlessly together.