This was the question at the Thursday Potomac River Fisheries Meeting last Thursday. Scientists from the Chesapeake Biological Lab (CBL) and Maryland DNR presented some interesting info. As one of your Maryland Commissioners in attendance - I am here to share some of what I learned.
The answer is may be one word - Polychaetes.
https://en.wikipedia.org/wiki/Polychaete
There is a time in May/June after the spawn that apparently rockfish count on, we know it as the May Worm hatch. After spawning, in the Chesapeake Bay tribs, rockfish rely on these for a much needed high protein diet. There are key to their survival and they will travel to get what they need.
At the same time their is a near total collapse of the benthic community (clams & worms) south of Solomons where these things live. Low dissolved oxygen is the culprit here. The centroid of rockfish aggregation is the mouth of the Choptank River and northward. That's the pattern the last several years. Start making sense...?
Other interesting facts:
Stomach samples in recent years include lots of worm AND clams in their spring diet. Yes clams. They too are are seeing a resurgence in the upper Bay. So how does a rockfish get a clam out of the mud? They have learned to follow cow nose rays who dig up the bottom exposing worms and clams. Cownose rays are key to their ability to feed. I tested this theory yesterday in the Patuxent River. We saw a pack of rays in shallow water, threw our lures in behind them, hooked up immediately with a couple fish.
The CBL scientist recently tagged 30 adult striped bass with the acoustic telementry technology I posted about a couple of times here. 21 of the fish exited the Bay through the Chesapeake Bay Tunnel. No surprise there. 9 of the fish went through the Chesapeake & Delaware Canal, a man made ditch. So what was theorized by some is absolutely true.
A bunch of juvenile rockfish were tagged in the Potomac River a few years ago. Guess where they went? To the Patuxent River! This shows a direct correlation between these two systems.
The Potomac River saw the smallest commercial catch of spot and summer flounder last year since keeping records in 1958.
More later...
The answer is may be one word - Polychaetes.
https://en.wikipedia.org/wiki/Polychaete
There is a time in May/June after the spawn that apparently rockfish count on, we know it as the May Worm hatch. After spawning, in the Chesapeake Bay tribs, rockfish rely on these for a much needed high protein diet. There are key to their survival and they will travel to get what they need.
At the same time their is a near total collapse of the benthic community (clams & worms) south of Solomons where these things live. Low dissolved oxygen is the culprit here. The centroid of rockfish aggregation is the mouth of the Choptank River and northward. That's the pattern the last several years. Start making sense...?
Other interesting facts:
Stomach samples in recent years include lots of worm AND clams in their spring diet. Yes clams. They too are are seeing a resurgence in the upper Bay. So how does a rockfish get a clam out of the mud? They have learned to follow cow nose rays who dig up the bottom exposing worms and clams. Cownose rays are key to their ability to feed. I tested this theory yesterday in the Patuxent River. We saw a pack of rays in shallow water, threw our lures in behind them, hooked up immediately with a couple fish.
The CBL scientist recently tagged 30 adult striped bass with the acoustic telementry technology I posted about a couple of times here. 21 of the fish exited the Bay through the Chesapeake Bay Tunnel. No surprise there. 9 of the fish went through the Chesapeake & Delaware Canal, a man made ditch. So what was theorized by some is absolutely true.
A bunch of juvenile rockfish were tagged in the Potomac River a few years ago. Guess where they went? To the Patuxent River! This shows a direct correlation between these two systems.
The Potomac River saw the smallest commercial catch of spot and summer flounder last year since keeping records in 1958.
More later...
