Last summer, soon after the backyard pond expansion (to 1500 gallons) and adding new plants and fish, there was an infestation of anchor worms, lernia elegans, stringy looking parasites that attach under the scales of a fish and suck blood and produce eggs in an accelerating cycle. Soon, all the fish had anchor worms hanging off them and they looked sad, fins held close to the body and listless. The cure is to treat the pond with a product called dimilin, which interferes with the lernia�s ability to slough its shell as it grows. The dimilin also interferes with the same process in every other invertebrate that may be living in the water, including odonata (dragonfly and damselfly) nymphs. For that reason, it seemed best to avoid nuking the pond with dimilin since dragonflies had already deposited eggs and we were looking forward to the first generation of homegrown dragons in a few years.

It was then that the isolation/hospital tank was built. I lowered the water level in the main pond, caught most of the fish and moved them to the hospital tank. Next, I nuked the hospital tank with dimilin to kill the worms that were on the fish. The main pond was left low for several weeks. There were a couple of yoy goldfish, the frog and a couple of tadpoles left, along with all the plants. Garter snakes found the pond and enjoyed some good hunting while the water was low, cleaning out all the tadpoles and most of the young fish before we caught the slithery thieves and moved them a couple of blocks away to a neighbor�s garden. When it finally rained again that fall the pond filled and later still the goldfish, now cured of anchor worms, went back into the main pond a few at a time. Then winter set in.

This year there hasn�t been any sign of lernia. It�s puzzling what may have eliminated them from the environment since the main pond wasn�t nuked. My favorite theory is that the predatory nymphs from the dragons and damsels may have gobbled them up, or at least has kept them under control, in balance with the rest of the predator/prey invertebrates. The lernia may have gotten started in the first place because there weren�t any nymphs, because it was a new body of water and there wasn�t a base of predators to keep those parasites under control; the environment was out of balance. An Internet search for lernia produces plenty of hits, but nothing that describes their natural enemies or any biological control. Maybe water temperature had something to do with it, the winter-time drop may have been too much for them. It remains a mystery. In the wild, something maintains a balance and those kinds of parasites aren�t so much a problem.

The year West Nile virus attacked, that summer and fall it was common to find dead birds, mostly crows, some robins and blue jays, in random places where they had fallen from their perches and succumbed on the ground. By August, crows were not so common to see, even in trees that had always been regular roosts for large flocks.

West Nile is transmitted throught the bites of mosquitos, and mosquito control has become an issue. It was with this in mind that I scooped some mosquito fish from an ornamental pond in a nearby park and added them to the isolation/hospital tank. I didn�t know a thing about them except they were called mosquito fish and that they must eat mosquitos.

Mosquito fish look like guppies, act like guppies and reproduce like guppies (livebearers). They are intolerant of cold water and may not survive a midwestern winter. I don�t know this from experience, yet. If any survive through next spring, then my bad.

In April I collected the six individual fish, three females and three males (the females are larger and rounder). They have multiplied abundantly, astoundingly; there are too many to count now, but they easily number in the hundreds. The isolation tank is around 500 gallons. The mosquito larvae have disappeared. The backyard is as mosquito-free as we can remember. The isolation tank seems to be working as a magnet (still water) for breeding mosquitos and the little fish take care of the rest. The water has remained relatively clear and clean looking, and the little fish are thriving. All along, I have been tempted to add some to the main pond. What�s not to like about them? With their fecundity, they may make a good forage fish for the country pond, too.

In the isolation tank, the gambusia have done an efficient job of eliminating mosquito larvae. It is believed, however, that gambusia fry predate on many other things in addition to mosquitos and that they may in fact prefer other prey (and young fish) to mosquitos. They become a competitor for microorganisms with other predator species, fish and amphibians included. One website blames gambusia for a decline in a species of frog in California. Gambusia actually eat the tadpoles of a species of tiny frog in the highlands there. Anyway, forage may not be a good reason to introduce them to the country pond, and their appetite and fecundity make it unsuitable for the ornamental pond as well. If they survive a midwestern winter with no care, more power to them and next year the back yard will be mosquito free again. It may be that a �mosquito sink� is a way to trap and cut down on the mosquito population. But gambusia may be good for little else outside its natural range, and a detriment in other ways.

Alien species invade, natives suffer. The global village brings with it carp, northern snakehead, zebra mussels and others. Native varieties/species that are abundant now, that we take for granted, may decline from stress into heirloom varieties of tomorrow.

Bill Cody mentioned story ideas in another thread that may include bugs, part of the foundation that makes a successful, balanced aquatic environment. That aspect of pond management may have larger ramifications, including to the environment around the pond. Why does fertilization help? It fosters bloom, which supports invertebrates, which little fish prey on, which bigger fish prey on, etc. What are those bugs? Which ones do what? Who eats what? Those details will be fun. Bring it on, Bill, and thanks for describing the difference between damsels and dragons in my previous post.

Shawn; We harvested chardonelle grapes from a vineyard in Levasy Mo, that processed into 15 gallons of white wine, the best we�ve ever made. Last year was a stellar year for grapes in this part of the country. Good fruit makes good wine.
Pedro; let�s visit. I�m in KCK.
Others; thanks for reading and the feedback.
All; I hope my ruminations aren�t inappropriately long and that the on/off-topic nature isn�t too off-putting.