Brett Illingworth wrote:
Blue Groper were never a popular target for spearfishers in this state. We have competition records going back to the fifties which prove categorically that they were not a common catch in comps.... therefore not wiped out by spearfishers.
Than you have some reliable numbers, Brett. So, it looks like insisting that this fish was
"a popular target for spearfishers in the mid 1900s"
is groundless, based on assumptions rather than facts.
What about this one:
"Their (BG) numbers appear to be rebuilding in Victoria after heavy fishing in the 1960s and 70s."
http://vnpa.org.au/page/nature-conserva ... n-victoria??
You see, large species with high life expectancy like this species are more prone to local population depletion. However, some fish can be rare without any human pressure - could be a helluva reasons for that. For instance, green humphead parrotfish, the largest parrotfish is highly sought after by fishermen and in some areas declined because of overfishing. However, in the Northern Territory a harem of 11 individuals (1 male and 10 females) was recorded and reported only once - by me. This fish is not targeted at NT at all, but is very fussy to habitat requirement. Among 17 butterflyfishes of one of the NT marine parks only 6 were more or less common and 11 species were represented just by one individual in 3 years of intensive study.
What I read from your post indicates that Eastern Blue Grouper seems to be a species with very specific requirement to habitat.
Of course I agree with you saying that:
"
Just because you didn't see one on a survey once means nothing except that you weren't where the fish was. (were)."Spot on! as a biologist I was in such situations many times while searching for the animal: "wrong place, wrong time".
Certainly, I do trust your experience and extensive diving knowledge. However, I insist that all these clashes between alarmists-greenees-tree huggers and people with
"Ah, c'mon, everything is OK! with fish stocks!" have one serious reason: our knowledge on fish stocks and their dynamic is pathetic because of lack of interest, lack of funding, lack of human resources allocated for studies and survey. Eventually, decision makers instead of rigorous facts rely on campaigners, who rely on emotions, intuitions, their "dreams" and all this sort of crap.