Beau July 10th, 2008
For the last few weeks I’ve noticed ripples in the pond on quiet days, usually near the shoreline. I look for fish quite often, and if it’s a bass or bluegill you can hear the “pop” or “smack” as they find an insect to dine on. The bullfrogs are calling now also with their slow “baarooom, baaroom” voices. And when two bullfrogs get together in a mating ritual, it’s like two splashy, flopping critters near the weeds.
But the ripples I’ve been seeing were not the same. The previous two years I stocked a few grass carp as well as koi to help control vegetation and algae in the pond. And years ago, a previous owner stocked a few of them as well. Whether it’s luck or the right combination of fish I don’t know, but thus far we have had no blooms of algae or emergent vegetation problems, and the pond has remained much more open and clear.
My suspicion is that the ripples I’m seeing along the water’s edge are the grass carp feeding. I’ve let the grass from the shoreline grow long enough to fall over into the water to some degree, and the critters around the pond seem to appreciate it. Every now and then I see ghostly shapes near the edge of the grass, but was not quite sure what it was. And I didn’t know for sure if the grass carp I stocked actually survived over the last two years.
But the other day I found out they not only survived, but are apparently thriving. Here’s picture of one of the ghostly shapes. See the darker fish in the shadow of the tree? It’s hard to tell size, but from the distance I took this picture, the fish is close to three feet long.
And then for the first time ever, I saw a small “school” of three grass carp near the surface and just happened to have the camera nearby. These are very large fish, easily 2-3 feet. They didn’t stay for long, and I haven’t seen them since. When I think I do see them and walk slowly near the pond’s edge to look, they vanish quickly.
It’s fascinating to think these have grown so large and overwintered on little to no vegetation, and with the surface of the pond frozen for weeks at a time. And it’s somewhat unnerving as well. These are the same species of nuisance fish that have escaped into many midwest rivers over the years. But these particular grass carp are triploid as well as being land-locked in the pond. Triploid meaning that they have three sets of chromosomes instead of the normal two, and cannot reproduce. (I always wonder about that, with the quote in mind from Jurassic Park that “nature finds a way”). However they do require rivers to breed successfully, so these fish won’t increase their population here. I was also careful not to put too many in our small body of water, because as you can tell they get very large, and are long-lived.
For now we seem to have a fortunate balance of fish with less vegetation, yet enough to maintain the fertility and biodiversity of the pond. There’s still healthy bluegill, bass, frog and turtle populations as well, so for now we’ll just see how things work out. We do fish occasionally, but I doubt we’ll hook one of these monsters. Then again, I wouldn’t know what to do with it anyway.