What Organisms Can I Find in Dirty Ponds?

Dirty Misconception

• Often, when a pond appears dirty, it's actually a nutrient-rich environment. The floating scum on the surface of a pond is actually a filamentous algae. The algae grows underwater, producing bubbles of oxygen between its "tangles" and then floats to the surface, gathering in masses. There are hundreds of species of filamentous algae world-wide, in addition to numerous other algae varieties. An overgrowth of algae that depletes the water's oxygen supply and creates toxins, which is called an "algal bloom," can kill many forms of life, including fish, in large numbers.

Animals

• Most animals in a pond's environment can live in the waters as they become dirty, attracted to the food chains feeding on algae, insects and micro-organisms. Water birds, fish and reptiles such as frogs, toads and turtles are often seen in dirty ponds. Because fish obtain oxygen from the water and are unable to leave the pond, their death may indicate the severity of the pond's state.

Bacteria

• Some ponds may have hazardous bacteria such as eColi, however beneficial bacterias help maintain a healthy balance, regardless of how dirty the pond may appear. Nitrifying bacteria is a naturally occurring bacteria in soil that converts deadly ammonia created by fish and other organisms into nitrates as fertilizer for the pond's plant life.

Insects

• Water has a natural surface tension when it's undisturbed. This tension allows water striders to walk on the surface and pond snails to glide upside-down, and it provides young insects a place for metamorphosis from the nymph to adult stage of life. As water becomes dirtier, more insects are drawn to the water to feast on algae and microscopic animals.

Microscopic Animals

• Nematode worms, paramecium, tardigrades and other microscopic invertebrates can be found in pond water most anytime, however they prefer the water to have lots of vegetation debris and mud. Rotifers are multicelled animals the size of protazoa and cousin to the round-worm. There are approximately 2,000 species of rotifers, with a variety of physical differences such as one, two or no eyes and having different methods for eating.

Single-Cell Organisms

• Protozoans are microscopic single-cell organisms that include algae and fungi. Multiple species exist in any dirty pond, including the common paramecium that feeds on other microscopic organisms. The paramecium's predator is the didinium that stings its prey, paralyzing it, allowing the Didinium to catch organisms larger than itself. Scientists continue to discover new single-cell organisms in ponds. The Jan. 31, 2010 issue of the U.K.'s Metro announced the discovery of the loxodes rostrum. This organism survives by "milking" oxygen from tiny green algae that live inside it.