Hey, all! So, a quick question for anyone going out to the shorelines (and particularly marshes and muddy places) of the Gulf of Maine (north of Cape Cod all the way up to the Bay of Fundy) - can you be on the lookout for Blue Crabs? I ask as, I’m a marine biologist working out of UMB (and use iNat in my classes) and was doing some casual marsh work the other day and lo and behold, one of these beautiful savory swimmers showed up in one of my traps along the Rowley River in Mass. https://www.inaturalist.org/observations/53988878 - this is notable as they are starting to expand their range due to warming climate (see The Savory Swimmer Swims North - https://academic.oup.com/jcb/article/35/1/105/2547817 ) - and previously Cape Cod served as a barrier. They’ve been seen here since at least 2012 regularly, but only for folk who were REALLY looking for them, or in the occasional lobster trap. A reproductive female was found off of Nahant last year (can’t find the news article) which was HUGE as it means they’re not just moving up here in the summer warm months and then dying off, but rather that they are STAYING and thriving.
So, after seeing our guy yesterday (checked - it was a guy - I’m from Baltimore, so I know a wee bit about blue crabs as anyone from there should!), I looked on iNat, and aside from one shell in Wells from a molt, I didn’t see anything north of the Cape (well, except Nova Scotia - but that’s a whole different story about the Gulf Stream, and hence why I’m being specific to the Gulf of Maine only).
If any of you are going to the shore, throwing out crab traps for fun, fishing, or just poking around in muddy waters, please please please, try and look for these guys! It would be great to have iNat show us how far up they’ve come - and in future years see where they go!
Happy to talk more about this. See also https://www.northeastern.edu/ogl/blue-invaders/ and this great set of slides [pdf]