The population and tax revenue in Tohoku's worst-hit coastal areas last March have plummeted since the natural disasters, a Kyodo News tally showed Tuesday, raising concerns that the shattered finances of these municipalities may hinder reconstruction efforts.

As of Feb. 1, the official overall population in 37 coastal municipalities in Iwate, Miyagi and Fukushima prefectures had dropped 2.22 percent, or 55,662 people, since March 1 last year to 2.45 million, according to the tally, which includes the roughly 18,000 lives believed lost in the disasters.

Among them, the municipalities of Rikuzentakata in Iwate Prefecture and Minamisanriku, Onagawa and Yamamoto in Miyagi Prefecture, which suffered some of the worst tsunami damage, saw their populations fall by 10 percent or more, the poll showed.

But the town of Otsuchi, Iwate Prefecture, one of the most devastated communities, logged the largest population drop, at 18.13 percent.

With many businesses forced to close down, Otsuchi's tax revenue also has shrunk by almost two-thirds, from about ¥1.1 billion to ¥400 million, and local officials said they fear a wide range of community services will be affected.

However, the true population drain is likely to be even larger, as many people are believed to have evacuated without reporting their change of address to the authorities and remain officially registered in their municipalities.

Of the 37 municipalities, the poll recorded slight population rises in Sendai and Rifu, both in Miyagi Prefecture.

Local officials largely attributed the increased numbers in Sendai, the prefectural capital and the base for coordinating Tohoku's reconstruction efforts, to an influx of evacuees from coastal areas in Miyagi and Fukushima prefectures, in the latter case mainly due to the nuclear crisis.