That's Not a Shad

Hundreds of hickory shad pushed their way upstream to spawn. I hovered on the edge of the current in a large eddy and stretched out into the stream to get as close to the school as possible without interrupting the procession.
The fish got used to me and allowed me to stay without leaving until I coughed, or cleared my leaky snorkel. They would swim from the hole when they heard the noise only to timidly return a few minutes later. I just hung out with the fish, a part of this eons old ritual of upstream migration, and enjoyed the privilege of witnessing this feat. There was an intensity of purpose with these fish. There wasn’t much that was going to keep them from their destination, and I absorbed as much of the view of their journey as I could.
The fish scattered and the pool became eerily still. There weren’t silver tubes struggling upstream in the hazy distance. There weren’t over bitten lower jaws characteristic of hickory shad, wiggling side to side in the current. There was an unexplained quiet in the pool and I thought I saw a large shadow pass just barely out of sight. If I were in the ocean I would have been thinking predator, the way the fish disappeared, as a shadow arrived. But this was a freshwater stream, and I figured my imagination was at work. The shad returned and I set back to experiencing this timeless journey.
Then it came up through the center of the pool against the current like the shad: a large Asian carp. The 2 foot long fish was twice as long and three times as wide as the shad. Asian carp were brought to North America to control algae and aquatic plant growth in aquaculture operations. They escaped captivity and are now considered an invasive species in most freshwater systems. They can alter habitats that results in the reduction of other species. They are herbivores and effectively out eat other fish. Billions of dollars are being spent on trying to keep them from entering the great lakes, and sometimes I wonder if it’s all folly. Once the genies out of the bottle, it’s pretty hard to put it back, especially when the genie is wet and slippery. Carp are considered invasive in the Chesapeake region and they root up submerged vegetation beds as they feed and reproduce. But still they are amazing fish to swim with. Shad spend their lives at sea and move into rivers and streams in spring to spawn. They are built with compact bodies and powerful caudal fins to make such a journey. Carp are more tubular and rotund, better built for lakes and slow moving water than this rapid. But this carp was able to move against the current with as much grace as the migrants, even though its body type is obviously not well suited for this environment, and I wonder what it was doing here, moving upstream with the sleek lined shad.