SESSION IV 197 DONALDSON: In the lagoons of the atolls the plankton comes up on the shore at night. It's carried in the surface layers, The waves bring it up on the chore, WARREN: And the circulation of the water in the atoll is downwind on the surface and when it reaches the other side then there's a return by the deeper currents, with considerable upwelling of cooler water on the upwind side. This is the deep circulation that you mentionec, DONALDSON:In part. WARREN; In part it leaks out into the ocean on the other side, DUNHAM: How deepis an atoll? too. DONALLSON: Most atolls are from 180 to 200 feet deep. Ina living atoll, this seems to be about the growth limit. They grow into the wind, toward the east, since the prevailing winds are from the east. CONARD: But you get lot of coral heads, don't you? DONALDSON: Yes, there are localized ones. Sut the coral heads are so spaced that they get food as it comes in with the currents. ROOT: Was the species of algae you mentioned a heavy purple seaweed with a strong iodine taste? DONALDSON: Yes. I'm hesitant because there are so manyalgae, If l recall correctly, there are some 170 species at Bikini alone, Many of them are various shades of purple and red. ROOT: These would be the high iodine concertrators? . DONALDSON: Yes, within this whole group of algae some species accumulate radionuclides much more specifically than others, and because of this lack of uniformity of concentration, guard against making a definitive statement, I think we must We cannot say all algae do this, all fish do that, or that all corals and plants do such and such. It's self-defeating to do this sort of thing, because you lose the understanding that can be gained by examining all uf the parameters,