Last week on a transect survey at Lovell’s Island we found a shrimp in a tide pool. We took photos in the field and released the unknown, egg bearing shrimp.  Upon returning to the lab we tried to identify it from the photos, and we found it almost immediately: the European rock shrimp, Palaemon elegans.  It was a perfect match; the translucent body, the dark striping and the tell-tale orange and neon blue claws were all present.  Unfortunately, the European rock shrimp belongs in Europe.  It was an alien invasive.

Sure wish we hadn’t released it now… it was full of eggs.

The European rock shrimp is a fairly recent invasive,  first sighted on the East Coast in 2010  in Salem and Gloucester, MA.  However, this is the first time it has been sighted in the Boston Harbor.  To make sure  that it really was a European rock shrimp, we went back to Lovell’s Island to collect samples.

We didn’t think we would be successful: we had found one shrimp, in one tide pool, on one day. We were wrong.  We weren’t even finished unpacking our gear when Chris McIntyre, our resident shrimp expert, found one adult shrimp. And then another. Within a couple minutes we had several whirl bags and a Tupperware container full of twitching, wriggly, egg bearing shrimp that all looked exactly like the European rock shrimp.

Net full of babies

Rock Shrimp in a whirl bag

Wriggly tupperware

Since there was such an abundance of adults and babies (one sweep of a tide pool with a net caught over 20  baby shrimp) Chris decided to take the shrimp to U. Mass, to see which native fish would eat them. We brought a few back to the lab, preserved them in ethanol, and they promptly turned bright red.

Hopefully this discovery will help in the mitigation of the European rock shrimp, and stop it before it takes hold of the Boston Harbor Islands.