The pond wouldn't be a closed ecosystem, since things can go in and out. The microorganisms you see would be a product of organisms outside* the pond. Life does not tend to occur spontaneously, as proved by Louis Pasteur.
There are many ways microorganisms can get into water.
For one thing, when the pond was built, the water was poured into a bed of soil. Soil is teeming with microorganisms such as bacteria. All they had to do was float into the water.
For another, the water itself was probably not sterilized beforehand, so chances are good that it had a number of microorganisms in it to start with.
Many microorganisms could also arrive in the pond by piggy-backing off other organisms such as insects. Larger animals which congregate at watering spots such as birds will leave microorganisms in the water with their droppings.
They heard a new subdivision was opening, contacted their real estate agents, and took out a mortgage loan. Most of them prefer Century 21, reasons unknown.
Comments
The pond wouldn't be a closed ecosystem, since things can go in and out. The microorganisms you see would be a product of organisms outside* the pond. Life does not tend to occur spontaneously, as proved by Louis Pasteur.
There are many ways microorganisms can get into water.
For one thing, when the pond was built, the water was poured into a bed of soil. Soil is teeming with microorganisms such as bacteria. All they had to do was float into the water.
For another, the water itself was probably not sterilized beforehand, so chances are good that it had a number of microorganisms in it to start with.
Many microorganisms could also arrive in the pond by piggy-backing off other organisms such as insects. Larger animals which congregate at watering spots such as birds will leave microorganisms in the water with their droppings.
They heard a new subdivision was opening, contacted their real estate agents, and took out a mortgage loan. Most of them prefer Century 21, reasons unknown.
From the soil. From animals. From plants, etc