Just a follow up on using seaweed for the prevention of radiation poisoning which Rodger asked about – this information may also be useful to anyone who is exposed to medical radiation either as imaging or treatment. Of course not eating any seaweeds from Japan in light of Greenpeace monitoring of fallout in seaweeds from Fukushima might be a sensible starting point! More recent research by Wood’s Hole Oceanographic Institution (WHOI)shows contamination of sea creatures 300 km off the coast of Japan and estimates another year or two for radiation to cross the Pacific http://www.livescience.com/19419-fukushima-radiation-pacific-ocean.html Radioactive caesium from the atomic bombs of the 1960’s and 1986 Chernobyl also continue to light up the oceans.
Now for the seaweed connection. Apart from being a good source of iodine which reduces uptake of radioactive iodine to the thyroid in a fallout situation, they are traditionally used to prepare miso soup which itself has other protective compounds. “Seaweeds are so effective that even the U.S. Atomic Energy Commission recommends that people consume two to three ounces of seaweeds a week (or 2 tbsp. of algin supplements a day) for maximum protection against radiation poisoning.” 
After the the second World War, western students of macrobiotics and Zen heard about Dr. Shinichiro Akizuki, then aged 29 and director of Saint Francis Hospital 1.4 kilometres from the epicentre in Nagasaki.
“On August 9, 1945, the atomic bomb was dropped on Nagasaki. It killed many thousands of people. The hospital I was in charge of at the time was located only one mile from the center of the blast. It was destroyed completely. My assistants and I helped many victims who suffered from the effects of the bomb. In my hospital there was a large stock of miso and tamari (the liquid that comes off the miso during the fermentation process and also used a condiment and soup stock). We also kept plenty of brown rice and wakame (a sea vegetable). So I fed my co-workers brown rice and miso soup. I remember that none of them suffered from the atomic radiation. I believe this is because they had been eating miso soup.
(Dr. Akizuki wrote about this further in How We Survived Nagasaki (London: Quartet Books, 1981)”>
He was able to contrast the state of his staff and patients with those of the University Hospital nearby which served meals of white rice, white flours and white sugar. The good doctor was adamant about avoiding sugar and included wholegrain rice and seaweed in the diet. His wife was also there at the time of the blast. Although they suffered bleeding gums and diarrhea at the time ( which can be mitigated by the vitamin C mentioned ) they survived without major radiation illness and he passed away in 2005. His wife was interviewed in 2006 by Dr. Furo, PhDDietary Practice of Hiroshima/Nagasaki Atomic Bomb survivors
I have finished my meagre supply of that ribbon type kelp that was Philips favourite, mixed with some store bought dulse flakes to make miso soup from dashi traditional japanese stock (which is just seaweed boiled in water!) You will need to use fresh not powdered miso. The recipe for soup and instructions to ferment your own miso, rather than purchasing supermarket japanese stock in the wake of Fukushima are in Sandor Katz’s “wild fermentation”
which has a lovely chapter on ‘seaweeds’ ( yes you can ferment these too!)
The red weed we saw at the beach which Philip doesn’t like to eat I think belongs to a class of coral-like seaweeds which are commercially ground up as mineral supplements for humans and animal feeds, and as fertiliser for acid soil correction. Beds of this off the coast of Ireland are called maerl.
Maintaining excellent body stores of minerals and trace elements is also good for preventing radiation damage and uptake of radioactive strontium from fallout.
Simple calcium and magnesium supplements in the ratio 800/300 mg for an adult (proportionally less for a child), will also block uptake of radioactive caesium, strontium, plutonium and uranium into cells by simple chemistry. This is a very cheap and reasonable dose to be taking every day simply as a dietary supplement even if you aren’t in a fallout zone.