What you had to do was first pull up the bag until you could not lift it any more, because the bag was completely filled with water (to the bursting at the seams point, nevermind that it doesn't have any seams except at the bottom). As soon as you could lift the water in the bags a centimeter or two above the level of the ocean water, you were certain that the bags were perfectly plumped out. Then you measured the distance between the height of the water in the bag and the 0 meter mark on the plastic. This told you the exact length of the bag (since we measured them out to be a perfect 10 meters plus the cone bottom which was traced out from a pattern). Thus, knowing the diameter of the plastic bags, we can now calculate the volume of water in the bags at the end of the experiment (which should be somewhere between 6000 and 7000 liters). And since we have only taken out perhaps 100 liters (maybe double this in some bags), we actually know the volume at the beginning of the experiment to at least within 5 or 10 %.
Tomorrow, after Richard has made a solo attempt to count the Bolinopsis remaining in his bags at the end of the experiment (which could be an interesting thing to do, but which everyone else thinks is a waste of time, seeing as how it has not been done at any point before the end of the nearly 3-week experiment and we certainly have seen the populations rise and fall and rise again, in some cases), we will kill the calcite bags. Then all there is left to do is tow in and dismantle the mesocosm raft structure, pack up, get our boxes and our precious frozen samples shipped of hither and yon, and then clean up and go home. It is certainly more than time.
Julia left us this morning. At mealtimes, the table is beginning to look desperately thin. It's got this definite And Then There Were None feel to it.
Aug 25 2012o- The first empty ring. *sniff*
lumpsucker fish that had taken a shine to the bottom of one of the big black mesocosm framework rings.