It does relate to North Atlantic right whale behaviour. As I understand it, North Atlantic right whales' vocalizing, their singing, is a behaviour that is not something they do all the time. While the presence of singing, the detection of singing, is a clear and positive confirmation of their presence, the absence of it is not confirmation of their absence. That is to say, in many instances whales can be present in an area and not be vocalizing. It's the nature of the North Atlantic right whale behaviour, so it is—
On September 27th, 2022. See this statement in context.