There's quite a lot of confidence with regard to those types of sightings. Everyone's very attentive to the fact that there can be misidentifications. Often there are photographs that need to be seen by experts who can identify right whales or parts of right whales. We're quite certain that those are correct.
The opportunistic sightings refer to sightings of right whales that occur when there aren't dedicated surveys looking for right whales. Someone happens to see one and gets a good picture. It gets verified by somebody, and it gets included in the mapping program.