Sarah experiments with temperature!

I've been playing around with exposing Gracilaria samples from our mudflat to hot and cold temperatures to find out the limits of what they can survive. I'm trying to figure out the best set of methods for doing this. So far, I've done 3 heat assays and 2 cold assays. For the heat assays, I've exposed samples to temperatures between 30-50 degrees Celsius (or 86-122 degrees Fahrenheit) for time periods of either fifteen or thirty minutes. From these experiments, we've found that samples exposed to temperatures of ~44 degrees C and above will die, samples exposed to temperatures of 30-34 degrees C are mostly okay, and samples exposed to temperatures in between these showed some variability. I attached a couple of graphs-the x axis has the temperatures and the y-axis shows the bleach index, which is basically a ranking of how bleached the samples are (5 means they're totally bleached and 0 means no bleaching).
For the cold assays, I've put samples in the freezer at -20 degrees C for varying periods of time, ranging from 5 minutes all the way up to 1 hour. I found during this experiment that the water that the samples were sitting in froze after just 10 minutes. I checked the samples a week after exposing them to the freezer and found that even the samples that had spent an entire hour in the freezer looked perfectly healthy-so this is a pretty tough seaweed! Next week, I'll keep some samples in the freezer for up to four hours to see if I can figure out how long it takes to freeze them to death!