Naturalist's Notebook Blog

Naturalist's Notebook No. 1

Collect a Pond
by Don Kirk

One of the simplest and most enjoyable activities with freshwater is to choose a particular habitat in a pond or slow-moving stream and bring a portion of it home for study. Select a place that has a lot of variety, such as near the edge where aquatic vegetation is thick or emerging from the water (like cattails or arrowhead).

Don't try to duplicate a fast-moving stream in a home aquarium - all you will see is the mass mortality of the collected organisms!

The open water habitat is the easiest to collect, but is also the least interesting because the fewest organisms live there and are mostly microscopic.

All you need for collecting is a clean, three gallon plastic bucket, a four or five-inch wide aquarium fish net, a kitchen strainer with a handle, and a small shovel. A three or four-inch wide child’s toy shovel works well. If desired, the net handle may be extended by taping it to an old broom or rake handle. A sturdier handle can be made by using hose clamps instead of tape, easily obtained in many sizes at any auto parts or hardware store. Clean the bucket with plain water, no soap. If you can’t get the bucket clean enough, buy a new one.

Best for containing your pond sample is an inexpensive, five gallon or larger, all glass aquarium with a florescent light, or no light, and with a close-fitting cover. Do not put the aquarium in direct sunlight nor use an incandescent light over it, for too much heat will be generated. If a florescent light is not used, place the aquarium where it will receive good indirect light.

Do not attempt to collect a portion of the mud bottom for your tank, because you probably will never be able to really clear the water, even with a good filter. Instead, use plaster sand, also called utility sand, sold at lumber yards and sometimes at nurseries. The current price (April 2007) is around $3.20 for a 60-pound bag. This will provide you with plenty of extra sand you can share or use to set up future pond collections. However, if you wish to plant rooted aquatic plants, either collected or purchased, bagged sand is often washed too clean to provide needed nutrients for the plants.

Collecting river bank sand is the best option, although you will still have to wash some of the mud out of it. Just don’t wash it too clean. Also collect a couple of rocks from the creek or pond. Find one four or five inches high and another half that size.

Do not use extra fine sand. It will pack too hard for plant roots to grow properly. Pet shops rarely carry good sand for aquariums. Their “sand” is usually small gravel, often dyed many colors. It is a very poor material to put in your aquarium. While it may look pretty, it is too large for small bottom feeding creatures to forage in it and it has been washed so thoroughly it is useless for rooted plants.

Put about two inches of slightly muddy sand in your aquarium. Place the rocks to your satisfaction on the sand. Cover the sand and rocks with several folds of newspaper to keep the sand from being stirred up too much while pouring in water. The newspaper will float up with the rising water if the water is not poured too fast, and the bottom will remain relatively undisturbed. Ideally, all of the water should come from the exact area of the pond where you will collect, but that is a lot of work. Tap water will do nicely. Fill the tank with tap water and let it stand for a couple of days. By then all of the chlorine, if any, will have dispersed into the air.

Collect live material with care so as to not permanently damage or deplete a habitat. Never collect in parks or protected areas. If you know someone who has a pond or a creek on their property, ask them if you can gather some aquatic life for your aquarium. Collect one or two small rooted plants, digging carefully to prevent damage. Some rooted plants grow entirely underwater, while others send out floating leaves and flowers. Water lilies are good examples of the latter, but they grow much too large for the home aquarium. If there are no rooted or floating plants available you can buy a couple at a pet store or just do without. Don't deliberately collect algae (unless you are an algae-lover). You will get plenty anyway along with the other plants. You will also automatically collect a fairly large population of tiny animals with the plants, and that is okay - usually. Carry your collected plants home in a bucket or other container. Plant or float them in your aquarium and let it stand for several days, after which get your collecting equipment together and return to the pond.

Collect only a few animals -- 2 to 3 small fish, a few snails, and whatever else you may find. If no fish can be found, or if you are collecting on public land, two small goldfish from a pet store will do quite nicely. On public land it is best to leave all fish where you find them. While not essential, try to include some insect larvae and two or three, no more, adult aquatic insects. Look for diving beetles, for they are especially interesting. Avoid water striders, for they are quite active and soon tire of the surface of even a 20-gallon tank. Since they can fly, you might find them elsewhere in the house. Most of the aquatic beetles can fly too, but they usually will stay put in an aquarium. If aquatic snails are found, gather a couple of them.

Feed everything a good quality flake fish food, purchased at your local pet store. Also buy a small jar of shrimp pellets, or some other pelletized fish food that will sink to the bottom.

Put in only a small quantity of food each day. After a few days you can learn how much is being used daily and adjust your feeding. With both children and adults, I have found it hard to resist impulse to toss in vastly too much food. Only a little too much food and within hours, your tank is a foul smelling bacterial brew which you must totally clean out and start over.

Keep a daily or weekly log of the activities of the animals and plants - a sort of indoor field notebook. Note when they eat, and what or whom they eat. Don't worry if some eat each other, for that is probably what they do in the pond too! Observe and record any life cycles that may take place.

If you decide to go to other activities return everything you collected to the same pond. Absolutely do not release any purchased fish, plants, or any other aquatic life, such as snails or clams into public or private waterways. This is strictly illegal In public waterways such as creeks, rivers, lakes, and even swamps. Nearly all creeks on private property run onto other private or public land. Anything you put in will eventually make its way downstream. Often, an introduced non-native plant or animal will have no predator in the new area to help keep the alien’s population under control. As a result, the alien may out compete the local species for food and even cause their extinction. For example, an introduced foreign beetle may cause the disappearance of the native beetle and the plants upon which it feeds, giving rise to extensive ecological damage.

If you collected the “wild” organisms from a private pond, ask the owner if you can release both your collected and purchased items in their pond. Or, give them away to friends, or even ask the pet shop if you can return them, but don’t ask for or expect a refund.

If all this sounds like too much trouble there is another way to bring home a pond. You can simulate a pond or creek in your aquarium. Start by taking a notebook and pencil and go to the place you have selected. I like 3 inch by 5 inch spiral bound notebooks that will fit in my shirt pocket. You can find these in office supply stores, drugstores and even grocery stores. Also take your collecting equipment, even though you likely won’t make much use of it.

At the creek or pond, pick a place where it is easy to look down into the water. Make a list of what you see. You don’t need to know species names. Just list what you see as floating or rooted plants, emergent plants like cattails, fish, snails, insect larvae, aquatic beetles, and so on. Use your collecting equipment to look more closely at a fish or aquatic insect that seems overactive. With a little patience you probably won’t need to actually capture them. Compose yourself comfortably sitting or kneeling and wait. The aquatic life will calm down and begin to go about their business in a normal manner. Record their activities in your notebook.

Go home and set up your aquarium to resemble a creek or pond. When ready, buy goldfish or other suitable, cold-water fish, a few snails, and water plants simulating those you found in the “wild” location. Pet stores, tropical fish shops, and even some plant nurseries are good places to go. Since you won’t find any aquatic insects sold in a pet store, you will have to collect these. Aquatic insect adults and larvae are every bit as interesting and important as fish in this freshwater environment. When your aquarium is set up and running, go back to the wild location and collect a couple of aquatic insects, either larvae or adults.

Making a simulated pond will result in little, if any, disturbance to the natural habitat. Also, since everything, except the aquatic insects, are already used to living in an aquarium, the plants and fish are likely to do better than when collecting it all from nature.