I live in Newfoundland, Canada. I'm fairly certain these guys might just be offspring of the run of the mill shrimp we can find here. The pictures are blurry, but they look like miniature shrimp. Thinking back now, there was some weird stuff hanging off of the plants in the little pools, which was most likely egg sacks for these guys.
I'm not going to put these guys in the tank with my betta, but I think I'll test them in a freshwater tank for a few days or so to see if they can thrive. If not, I'll just bring them back to where I found them.