Climate change effect?

[DougieK]

Nope.... Always check the SST maps first.

Yellowfin Tuna were once upon a time when the numbers were substantial a summer regular around the Prom and Phillip Island. The Bluefin were the same as they have been of recent years just more plentiful before commercial decimation worldwide. Kingfish over 20kg caught from Frankston pier in spring 60 years ago, fish over 60lb regularly leadlinned in the rip all 365 days of the year 60 years ago. It's all about mismanagement and the current management practices.

Holy poop we agree on something.

[re-tyred]

Environmental ‘loopholes’ and fish population dynamics: comparative pattern recognition with focus on El Niño effects in the Pacific
If you want to spend a week or two reading up on it, there is a huge resource here. Many other places too, just google fish stocks ENSO.

[DougieK]

Environmental ‘loopholes’ and fish population dynamics: comparative pattern recognition with focus on El Niño effects in the Pacific
If you want to spend a week or two reading up on it, there is a huge resource here. Many other places too, just google fish stocks ENSO.

I don't suppose you have a copy of it, the online mobs want $49 to access this.

The abstract sounds fascinating.

A process of comparative pattern recognition is undertaken for the purpose of garnering insights into the mechanisms underlying some currently puzzling conundrums in fishery resource ecology. These include (a) out‐of‐phase oscillations between anchovies and sardines, (b) the remarkable fish productivity of the Peru–Humboldt marine ecosystem, (c) sardine population increases in the eastern Pacific during El Niños, (d) basin‐wide synchronies in large‐amplitude abundance variations, (e) characteristic spawning of large tuna species in poorly productive areas, (f) contrary trends in Pacific tropical tuna abundance during the 1970s and early 1980s.

It is found that each of the items appears to become less enigmatic when the conceptual focus shifts from conventional trophodynamics to the idea that ‘loopholes’ in the fields of biological controls (i.e. of predators of early life stages), produced by poor ocean productivity or by disruptive environmental perturbations, may in fact lead to remarkable reproductive success. Implications include the following: (1) El Niño, rather than being an unmitigated disaster for Peruvian fisheries, may in the long run be a prime reason for the remarkable fishery productivity of the Peru–Humboldt large marine ecosystem. (2) Globally‐teleconnected climatic trends or shifts might produce globally‐coherent population expansions even when local environmental expressions may be quite different. (3) It may be unreasonable to expect any management methodologies to be able to keep the fish populations of highly climatically‐perturbed systems such as the Peruvian LME always at stable high levels; an alternative approach, for example, might be to take optimal advantage of the transient opportunities afforded by the high fish productivity of such inherently erratic systems.

[4liters]

Try emailing one of the authors and ask if they can forward you a copy.

They're usually pretty happy to hear from people who are interested in the work they're doing and have no stake in the journals that are restricting access to it.

[Sebb]

Yeah was gonna say interesting topic to read. But $49 ... Err...

[re-tyred]

Yeah sorry , there is a lot of similar info out there. I didn't notice the price tag on that one. I actually read most of what is in that one quite some time back when looking at stock assessment information. What it and many other studies show is that fish stocks and areas of habitat are closely linked to the long and short term oscillation in the Pacific. (ENSO) Many boom and bust cycles in the commercial fishing industry once thought to be caused by over fishing then under fishing after everyone went bust, were only partially due to the fishing pressure, but also had a strong influence by ENSO.
For example, in Australia the East Coast gemfish stocks supported a huge winter fishery on the NSW coast. About 1995 they failed and the fishery collapsed. Quotas were introduced and the fishery was expected to recover but it didn't. Now some 25 years later they are suddenly building up.
The very same has happened to tiger flathead at least 3 times since the 1930's. What is more interesting is this last year or two tiger flathead almost disappeared even though there are strict quotas. They are just starting to reappear according to the local commercial guys
Why I put it in this thread is that over our rather short lives we get a snap shot of what is "normal" during our early years and we think anything different is abnormal. Old geezers just roll their eyes and say oh yeah I remember back in, so and so, when that happened.
My formative years on the ocean took place in the late 60s and 70s Pelagic and many tropical species were often sighted in Bass Strait. At that time it was not uncommon to see patches of bait-fish stretching for miles and the birds in their thousands diving on them.
The appearance and disappearance of these things is what is being studied in these articles and it is likely linked to ENSO and the pacific decadal oscillations. That is my take on it anyway.

[re-tyred]

https://onlinelibrary.wiley.com/doi/abs ... IPZYzRXsps
see if this one works

[DougieK]

https://onlinelibrary.wiley.com/doi/abs ... IPZYzRXsps
see if this one works

Hahahahha that's the link i was looking at.


Do you want to give us the version of it that's not going to take me 40 hours of reading to figure out what all the words mean?

[4liters]

That just gets the abstract

[Sebb]

Is there a hard copy book of this or something similar?
I'm old school, I like reading hard copy books while commuting and before bed.