Hi Mr. Pittenger
What great questions! I need to do a little research on this one before I can answer. The research onboard the Healy was marine based but I am positive that I can find a scientist who knows about lichens.
I CAN comment on the ice algae aspect! The huge bloom that occurs in the Bering Sea starts in the ice with tiny diatoms (a phytoplankton). Sometimes the ice was stained dark rusty/greenish brown and had a thick layer right under the ice. The melting of the ice stabilizes the water column. The ice algae thrives in the ice melt and eats heartily of the nutrients in the water. The diatom population explosion feeds the consumers in the Bering Sea ecosystem.
But to get back to your first question, I will need to check back with some of my scientists to find the answers. Thank you so much for your interest. I will be back at school in two days. Hopefully I will have the answer by then.
warmly,
Mrs. P