If you want to pick the project up again, I'm happy to help grab a sediment core anytime, Ian!

Delighted to share this with your students, Mark! Here is a link to a slightly higher resolution version. The white specks you see at beginning of the video are zooplankton feeding on the PSB (daphnia and copepods).
www.youtube.com/watch?v=Mm9y...

Yes! About a meter below the PSB you can catch the faint green/yellow color of the green sulfur bacteria. Just like the Winogradsky column in my window.