How much does Salinity matter for Blue Crabs?

[jimaok]

I remember swimming at Old Silver beach in Falmouth with a diving mask in about 3 feet of water, and seeing dozens of blue crabs in the sand.  I would walk while looking down with the mask, and blue crab claws would reach up on both sides of my feet.  The crabs were actually under the sand.   This had to be July or August for me to be at the beach, and it was about 40 years ago.  

I have been looking for info thru the older posts, and there were a few that mentioned salinity levels.   One was about Swifts Beach, that it was too salty, and up the rivers in the brackish water was better.  Brackish waster is great for setting collapsible traps with floats, and checking them with Kayaks, or even dropping them off the sides of bridges.  but some of the beaches have decent access at night like Onset, Swifts, Hyannis, and I was going to hit those at night with a flashlight and dip net.    I will find out for sure this June, but whats the consensus on salinity levels?  (I will post how I do at the beaches when I go).

[jack1747]

"Blue crabs are found from the mouth of the Chesapeake Bay to tidal fresh areas. There are distinct differences in the ranges of males and females. During the summer months, males are found from freshwater to the polyhaline zone (waters with salinities of 18-30 ppt), although they occur in the greatest numbers in salinities of 3-15 ppt. Maximum numbers of females occur down Bay at salinities of 10 ppt to ocean salinities." https://www.bluecrab.info/lifecycle.html

Click on the little crab at the bottom on any page and the info section will open.  You will find almost all the info you want there.

[jack1747]

I modified your Subject Line before Rick could see it. 

[Wallco99]

LOL.