They said it couldn’t be done, but this is an ecosphere inside a concavity slide, sealed with superglue, still standing after 4 months.

The orange guys here are Prorocentrum hoffmannianum, one of like, 5 large scale species remaining. There's one species of spiral shaped Cyanobacteria, two different diatom species, one small algal species, and a handful of miscellaneous bacterial guys that can't really be identified. That's it. It has experienced serious decline over the 4 months it's been sealed, there were at least 2 dozen species when it started. But, for something with well under a milliliter of liquid (by my guess, close to 100 microliters of water, but there is a large air bubble), and saltwater too, it's impressive the endurance of this ecosystem.