The article also mentioned the other effects of the tsunami: telephone poles, styrofoam, pieces of buildings, etc. were all still floating. Again, an accident, but it's hard to deny that it's preventable; at least one town was saved by a sea wall that was relatively inexpensive to build [1].
That said, overfishing is probably the worse problem since it's not tractable to enforce regulations (since police aren't on site to ensure that there isn't too much "extra" catch thrown back, etc.). At least it would be possible to mandate the construction of seawalls.
