Sunday, April 15, 2012
Swimming With a Wall of Fish
The bottom of the pools looked grey from the bridge. But the grey patches moved. I knew the pools we full of shad. I walked fast, like a kid on a pool deck, down off the bridge, down the embankment to the shore. I suited up quickly. So fast that I almost forgot to zip my dry suit closed, waded into the river, and when I got close to the first pool, laid down in the two foot deep water.
Before I thought I should, I was surrounded by foot long fish, all moving in unison. I found a large rock, planted my feet on the upstream side and stretched out upstream into the current. The shad were jittery and each time I cleared water from my snorkel, each time a car drove over the bridge above me, or each time I got too sideways to the current and was thrown off the rock that kept me propped against the current, they scattered with panicked jerky movements. But soon they returned to their upstream quest and rhythmic almost mesmerizing undulations.
The few hundred fish strong school was made up of gizzard shad and smaller river herring, and it looked like each pool held about the same number. They all swam together and presented their sides to me to form a wall of fish. Swimming with this many fish is always a thrill. But the fact that many of the fish in this school were endangered American shad made the experience that much more special. To think that I was surrounded by possibly hundreds of a kind of animal that is at risk of dying off gave me hope that these fish would make it. I also felt honored to be witness to this incredible run, to possibly be one of the last humans to see such a sight. I have hope for the shad, but it is a guarded optimism. Their numbers started to drop in the 1800’s and we tried to reverse the trend even then, with little effect. We are good at destroying, not so good at restoring. It seemed the trend of declining American Shad populations reversed at Conowingo Dam a few years ago, and then another unexplained decline occurred, in a population that is already at historic lows. Turns out that the latest threat to the shad may be rockfish. Rockfish eat menhaden. However the menhaden fishery has been largely unregulated, and as many fish as possible were sucked from the Bay and converted to cosmetics and fertilizers. At the same time, one of the few fisheries success stories, rockfish, made a tremendous comeback after a moratorium on their take. Rockfish are top predators, and when there weren’t enough menhaden for the rockfish to eat, they switched to shad. Of course this isn’t the definite cause of the more recent shad decline, but to me it seems the most plausible.
As John Muir said, when we look at any one thing in universe, we find it hitched to everything else, and that certainly applies to the fish world. Our actions matter. As I swim with this wall of fish, I certainly feel that connection.