Here is a summary of the testing program drawn from various media reports
and interviews with Hokkaido government officials,
who also supplied some supporting charts:

SCOPE OF ONGOING TESTING PROGRAM AND RESULTS --

Over 85 different types of fish have been tested since March 24th (up to May 17th)
-- Testing has been conducted by 8 separate organizations including fisheries research institutes, semi-government organizations, citizen’s groups and a university.

-- 287 tests have been conducted so far in Tokyo (3 tests), Kanagawa (19 tests),
Chiba (46 tests), Ibaraki (152 tests), Miyagi (6 tests),
Fukushima (39 tests), Hokkaido (3), other (14).

-- One type of fish “Konago” (sand lance) has tested negatively since April 4th
in several areas including Ibaraki and Fukushima.
-- Since May 6th, the testing program has been conducted within a 300km radius from the Fukushima plant.
-- At least 14 tests have also been conducted in Hokkaido with no negative results.
-- The testing program includes weekly testing for common migratory fish ("Kaiyugyou"　回遊魚)
such as Saba (Pacific Mackeral), Iwashi (Sardines), Katsuo (Bonito), Tara (Cod) and Salmon.
(original data in Japanese available on request)

The wide scope of the testing -- both in terms of types of fish and the different organizations conducting the testing -- and finally the results, should put most people's minds at ease a little. But the case of the Konago is a concern. It is fished commercially and while a ban remains on fishing, fishermen will suffer.

It is also food for larger migratory fish, such as Saba (Pacific Mackeral). However no traces have been found in the Saba (Pacific Mackeral) in tests to date and levels of Caesium and Iodine have declined significantly in subsequent tests of Konago.

One concern in the media is that the fishermen (or Fishing Cooperatives) in each Prefecture -- not a higher authority -- select which fish to test.

Yet fishermen are precisely the people who suffer most from rumor and fear so you would think they were not the most reliable people to make the decision. However the fact that 85 different types of fish have been selected for testing shows that fishermen are committed to the testing program. The reality is that if the fisherman can't prove that his catch is safe, its not even going to make it to market.

Water releases

On 21 April, TEPCO estimated that 520 tons of radioactive water leaked into the sea before leaks in a pit in unit 2 were plugged, releasing 4,700 TBq of total water release (calculated by simple sum, which is inconsistent with the IAEA methodology for mixed nuclide releases[62]) (20,000 times facility's annual limit).[62][81] TEPCO's detailed estimates were 2,800 TBq of I-131, 940 TBq of Cs-134, 940 TBq of Cs-137.[62]

Another 300,000 tons of relatively less radioactive water had already been reported to have leaked or purposefully pumped into the sea to free room for storage of highly radioactively contaminated water.[82] TEPCO had attempted to contain contaminated water in the harbor near the plant by installing "curtains" to prevent outflow, but now believes this effort was unsuccessful.[82]

According to a report published in October 2011 by the French Institute for Radiological Protection and Nuclear Safety, between 21 March and mid-July around 2.7 × 1016 Bq of caesium-137 (about 8.4 kg) entered the ocean, about 82 percent having flowed into the sea before 8 April.[83]

This emission of radioactivity into the sea represents the most important individual emission of artificial radioactivity into the sea ever observed. However, the Fukushima coast has one of the world's strongest currents and these transported the contaminated waters far into the Pacific Ocean, thus causing a high dispersion of the radioactive elements.

The results of measurements of both the seawater and the coastal sediments lead to suppose that the consequences of the accident, for what concerns radioactivity, will be minor for marine life as of autumn 2011 (weak concentration of radioactivity in the water and limited accumulation in sediments).

On the other hand, significant pollution of sea water along the coast near the nuclear plan might persist, because of the continuing arrival of radioactive material transported towards the sea by surface water running over contaminated soil. Further, some coastal areas might have less favorable dilution or sedimentation characteristics than those observed so far.

Finally, the possible presence of other persistent radioactive substances, such as strontium-90 or plutonium, has not been sufficiently studied. Recent measurements show persistent contamination of some marine species (mostly fish) caught along the coast of Fukushima district. Organisms that filter water and fish at the top of the food chain are, over time, the most sensitive to caesium pollution. It is thus justified to maintain surveillance of marine life that is fished in the coastal waters off Fukushima.