North Australian FISH FINDER TM forums

Are fish shrinking? It says here that they are and they will ... https://onlinelibrary.wiley.com/doi/abs ... /gcb.12514

I've always put the reduction in 120s and 130s caught out of Shady Camp down to annual seasonal changes related to wet seasons. There seemed to be more 120s and 130s back in the gill net days.

Have poor wet seasons really affected the big-fish year classes that much, despite gill net removal?

Or are barra and other fish shrinking because of warmer waters?

So many variables, it's probably impossible to know, but it is interesting.

Not in Copeton.....

Too funny, should send that pic to the scientists who wrote the paper

Haven't read the above paper but think of it like this, if the record fish are the Andre the giants of the fish world ie. The naturally large individuals of a species and you take them out of the gene pool due to commercial fishing and catch and kill recreational fishing practices then you are effectively reducing the overall genetic ability of a species to become large, if this is coupled with overfishing of prey species then it is exacerbated from a lack of nutrition. A prime example of this is Alfred Glassels Black the long standing all tackle at 707.61 kg (1,560 lbs 0 oz)(The holy grail of billfishing btw) in 1953 in Cabo Blanco, Peru. Given the advances in tackle, boats, sonar and technique it is surprising that this record hasn't fallen until you take genetic degradation and into account. Although, it must be noted that perhaps potential record breakers have been released off Cairns if the stories are to be believed. There is also some solid research regarding gamefish size versus location also as when water gets cold the larger you are the less heat you loose because of surface area to weight ratios. Therefore it stands to reason that on the cold edge of their temperature range Gamefish tend to be larger and such fish are sometimes referred to as boundary riders. NZ Striped Marlin are an example of this.

Anyway I'm rambling now. Hope someone at least finds this interesting.
Cheers,
John.

Ok, just read the article so the boundary rider bit is their angle just in the inverse.

Yes John, be interesting to review all record dates to determine if it’s in decline. How would you overlay the catch n release factor and those captures that weren’t processed to record standards eg some of those Cairns billies?

Slightly off topic but picking up Matt’s comment;
If the annual commercial catch (reported) was 140 tonnes in Chambers Bay just prior to removal of the nets nominally there should be circa 600 tonnes of additional Barra in the ‘system’. Represented as meteries it would equate to 50,000 individuals. Clearly, they’re not all meteries but where are all the Barra?