River carp - where did they go?

[lungimsam]

Hello,

I fish a river in Maryland, USA that has carp you can see swimming around all summer long in the same area. The area I see them in is a 1/4 mile run.  However, for the last three weeks, they have vanished. Is there a reason for this movement, and where do they usually go when they leave a certain area? Haven't seen them since mid August. Only difference I see is the hydrilla exploded and grows to the top of the water now but in the usual bare runs, I don't see them swimming around anymore. They usually weigh 7-15 lbs.

It is the Patapsco river, in Baltimore County, MD. One end of the run is blocked by a dam, so they can go no further, the other end dumps into the port of Baltimore Harbor several miles later. It winds all they way down there. About 20 yards wide and goes from ankle shallow to 6' deep in some places. In the area I fish it is about 3-6' deep. There is no lake fed by this river as far as I can tell. At least not a deep enough side stream for their rotundity to travel. There are downed trees and Hydrilla vegetation.  Cannot understand where they would go or why. They cannot leave the river, except for going into the Baltimore Harbor.

[Golden Paws]

In the summer, Carp love to sunbathe and can be clearly visible. As the water starts to cool, they are more likely to be found closer to the bottom. I've seen this with chub in the UK and it amazes me how many can pack into a weed-bed or overhanging bush until you entice them out with loose feed.