Okay, maybe its time to clear some things.

1- "Even better, it does not bio-accumulate, because it's water".

Myth: First of all tritium is not water, is radioactive hydrogen. Hydrogen is a common piece in the metabolism of all living beings.

"The study showed that inorganic tritium accumulated differentially in mussel tissues in a dose-dependent manner, with the gut accumulating the highest amount of radioactivity, followed by the gill, mantle, muscle, foot and byssus thread".

-> Awadhesh, Dogra, Turner, Millward (2005) Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 586, 1: 47–57

-> Inomata T (1983). Accumulation and lethal effect of tritium (tritiated water) in Rhodopseudomonas spheroides. Under light-anaerobic and dark-aerobic conditions. Radiat Environ Biophys. 21(4):281-94.

-> Inomata T, Higuchi M. (1976) Incorporation of tritium into cell materials of Rhodopseudomonas spheroides from tritiated water in the medium under aerobic conditions. J Biochem. 80(3):569-78.

2- "Tritium is safe to drink if diluted".

True. But dangerous if eaten (and marine organisms can also pick up and reconcentrate again some substances). Japanese eat marine fishes, algae and clams all the time.

"Our results demonstrated that the dose calculation based on tissue-free-water tritium alone would under-estimate the radiation exposure of the human population exposed to tritiated food"

-> Komatsu, Okumura and Sakamoto (1990) Radiation dose to mouse liver cells from ingestion of tritiated food or water. Health Phys. 58(5):625-9.

3- "Tritium radioactivity is blocked just by a sheet of paper or by the skin"

Paper's blocking properties are not relevant under the sea. Human skin is not comparable to the structure or function of fish/crab/worm gills.

4- "Hundred kilos of tritium were released and nothing happened"

The fact is that hundred kilos of tritium where released and dozen of species of corals (and all its associated fauna) are missing still 50 years later from this area. This can be related with tritium or not, but "absence of evidence" can not be granted "as evidence of absence". Is a common rule in science. It only takes to briefly loose all its zooxanthellae to kill a 1000 years coral colony.

5- "Tritium don't have any efect in the marine organisms". "Nobody will be harmed"

Myth:

"Tritiated water delivering dose rates below 500 μGy h−1 was shown to be capable of inducing genetic damage in the haemocytes of edible mussels"

"Despite growing scientific, public and regulatory concern over the discharge of radioactive substances, no serious attempts have been made to develop a rationale to evaluate the impact of environmentally relevant radionuclides in the aquatic environment." ... "The study suggests that the generic dose limits recommended by the International Atomic Energy Agency for the protection of aquatic biota might not be applicable to all aquatic organisms".

-> Awadhesh, Dogra, Turner, Millward (2005) Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 586, 1: 47–57

New marine organisms are discovered every year. We just don't know the effect of tritium on most marine organisms, specially with critical groups like sea cucumbers (that process tons of silt and sand each year), sponges and filterer worms (millions of water liters processed), or coral zooxanthellae.

6- "Come on, its only four grams... what could be happen?"

Many things, this four grams could cause a serious damage to the credibility of the acuaculture japanese companies and to cultured shellfish, oysters and clams as source of reliable food for example. The value of total japanese aquaculture production in 2003 worth US$ 4 428 962 000 (source: FAO). Fish related economy is a 'no joke' affair for japanese employing a lot of people and moving big money each year so this would be also a political suicide probably.

The impact of tritium in fish eggs, alaskan cods, right whales or californian vaquita porpoises is totally unknown.

7- "Again, there's still no theory as to how tritium can do all this crazy stuff".

False: Tritium effects are similar to other typical carcinogenetic substances. On mice: abort of some mice embrios, increased mortality, bone marrow failure, resorbtion of gonadal tissue and developping of solid tumours. It depends on the dose.

"mice receiving a single intraperitoneal injection of tritiated water 7.4 x 10(8) Bq (20 mCi) died of bone marrow failure within 20 days".

-> Seyama, Yamamoto, Kinomura and Yokoro (1991) Carcinogenic effects of tritiated water (HTO) in mice: in comparison to those of neutrons and gamma-rays. J Radiat Res. 32 Suppl 2:132-42.

8- "The early 1960s (which saw peak tritium levels) are not known for a huge spike in inexplicable extinction events".

Myth (and not understanding how things really work in biology).

To prove extinction in marine organisms is notoriously difficult and in any case it takes 50 years to declare a species extinct. Therefore species extinct in 1960 are recognised as this by science in 2010, not in 1960.

And the fact also is that not enought research had be done. There is about 800 living hard corals providing support for 4.000 species of reef fishes, more than 50.000 species of marine molluscs, and 13.800 species only in the Class Polychaeta (a type of marine worms). Scientists estimate total number of different species inhabiting coral reefs between 2 and 9 millions. We are talking just of reef ecosystems here, there are also soft bottom ecosystems and epi/meso pelagic and abyssal plains. Most of the marine species are still undiscovered.

However, in years as recent as 2004 the World Conservation Union (IUCN) had conducted threat assessments of only 814 marine species (Baillie et al. 2004). The real situation of millions of species is unknown.