I came home to a nice river rolling at 12000 cfs and then a day later somewhere on the system we got hammered with rain and now it sits at 25,000. It nearly doubled in flows. What's interesting that before the added volume the water temperature was a nice 61 degrees now it's just under 65. Four degrees is a big difference, especially if the trend is a warming one.
This week is supposed to get hot so staying cooler longer is better for the fish. Striped bass, as with any fish, can get thermally stressed when temperatures rise and combined with the stress of being caught and fought. That increased metabolic stress leads to the build-up of lactic acid in the fishes muscles. Too much lactic acid less to lactic acidosis, which can be fatal for any living creature.
The dissolved oxygen (DO) in the river has been steady around 10 mg/L although it took a hit down to 9 with the increased temperature and off-colorless from the runoff in the water. Low oxygen levels and increased temperatures aren't good for river striped bass and that's why they prefer the shade (really), deep pools, near cool water discharges like tributaries, and at the head of runs, riffles, and falls.
You can see below what the water looks like just by studying the graph. Big and quick rains blowout, if you will, the river causing the turbidity to shoot up and shut things down. Before the rain it was at 3, then it shot up to 70. When I had my run in striped bass heaven a few weeks back it was a sustained 20-25. Sustained anything is good as the fish adjust to the increased flows and the visibility underwater. Shooting up quickly kind of shocks them and shuts them down. And any one event can send them packing down river and out into the ocean where they'll join their buds and act like "real" striped bass and begin the annual migration north and south each year. If some of them leave now I might have a shot at them in the Vineyard next week.
