ryjohn - Good idea of checking the lower limit temperature of PK shrimp by putting them in the refrigerator or iced water and monitoring the correct temperature. I will try that for my PK shrimp next year. My strain of PK shrimp came from Lake Erie marshland. The northern population may have developed an adaptation to cooler winter waters than those shrimp in the southern states?
I'm curious what kind of catch density you had working those marshes. I use a finer mesh long-handled landing net here and best passes under the best weed matts here yield between 50 and 100 per swipe of the net. Average is probably more like 15-25 during Spring and early summer... it gets alot tougher this time of year, though.