Fisheye,
A recent peer-reviewed study done for Oceana concluded that there needs to be at least 20% observer coverage in a fishery in order to adequately monitor it. This percentage is needed in order to prevent what is called the "Observer Effect" (participants only playing by the rules while having an observer onboard).
That said observer coverage in the herring fishery peaked at about 13 percent a couple years ago. With the current funding there will only be about 2 to 3 percent coverage - no where near what is needed.
Best
Mike F.