Rock And Chips
By Paul Homewood
There is a one more bit to that salmon study which explains an awful lot:
https://www.nature.com/articles/s41467-020-17726-z#article-info
We have had some discussion as to how hatchery salmon could have been competing against wild fish. The paper informs us that:
Across the Pacific Rim, ca. 5 billion hatchery salmon are released into the North Pacific each year where they add to already high abundances of wild pink, chum, and sockeye
Not only are millions of hatchery salmon released (don’t ask me why, I prefer rock salmon!), but evidently wild salmon are also highly abundant.
Not only that, but we also learn that:
We compared current size to a pre- 1990 baseline, but this captures only a small window of commercial salmon fisheries in Alaska, which started in the late 1800s. Size declines were observed long before 1990, and thus we expect that analyses over longer time series would likely reveal even more dramatic impacts.
Size declines have been going on long before AGW. It really does not take a genius to work out that the decline in salmon size has a lot more to do with fishing and other human activities than it does with weather.
FRIDAY FUNNY
OK, I know it’s not Friday, but I could not resist it!!
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NOT A LOT OF PEOPLE KNOW THAT 
Paul, you are a hero in a world of fools.
booo , terrible joke.
I heard a true story of an octopus that ate a farmed salmon and got ill. he hitched a ride on the back of a dolphin, ‘take me to the tentacle hospital and avoid that shark. promise?’
‘promise’
so the dolphin lied. swam up to the shark and said ‘here is that sick squid I owe you’
I’d never come across Rock Salmon until I worked in Kent for year. Thought I read somewhere that it couldn’t be called Rock Salmon now?
I was fairly sure that human intervention to boost number would be the cause. Doe raise the question have predator populations increased
We used to have it as kids in London, but you can’t get it up north – it’s all cod and haddock!
Last had it a few years ago in Devon
My local chippie is Surrey has rock. I keep meaning to try it as I can’t recall ever having it before.
You aren’t missing anything Gerry, it’s an inferior replacement for more expensive and desirable fish. As said below, Rock Salmon, Huss, whatever the local name, it’s a collective term for a variety of cartilaginous species you would usually throw back, makes up most of the by-catch carcasses I see on the beach, and I don’t pick it up and take it home for dinner! Even the gulls and crows aren’t that keen.
depends where you go up north … In many areas it is traditionally haddock or haddock.. and no cod
Rock Salmon is in fact shark, mainly spiny dogfish/mud shark or cat-sharks, the spiny dogfish is now an endangered species & on the red list due to over fishing.
We don’t allow faster than light neutrinos in here, said the bartender.
A neutrino walks into a bar.
🙂
It was pointed our many years ago (1972) that the American lobster grows faster and better to achieve a larger size and weight when the ambient water is warmer. From the Massachusetts Lobster Hatchery in Vineyard Haven…
“Stated very simply, warm water is the key. In standard sea temperatures of the northeast American coast, lobsters take between 7 and eleven years to reach one pound in weight. In his hatchery Hughes has cut this down to two years, and in some cases to a mere 18 months.”
This is, of course, contrary to the current lament that lobsters are moving northward into colder waters because of…you guessed it…climate change.
BBC news actually reported snow in SE Australia today. Of course the unusual nature of this ‘complex’ area of low pressure and Antarctic air was ‘unseasonable’ and made to sound unnatural and ‘rare’. The last completely irrelevant spoken words of the report – but it’s 34C in Darwin!
It’ll be interesting to see what the BBC and Met Office report about the UK summer 2020, because apart from the hot spell in August which if the 10 day forecast can be trusted will end up similar to Aug 1976 (Jul was the peak of the heat in 1976) will rate no higher than the top 50 of ~360 in the CET and be ~1.5C cooler than 1976 I reckon.
Still heading for a record yearly CET value though. 50/50?
We had snow in Brazil on French TV this morning
Won’t last, according to the BBC the place is in flames again this year!
https://www.bbc.co.uk/news/world-latin-america-53626544
Off topic but the relentless campaign to pretend that last week’s temperature in Death Valley is the highest ever recorded continues unabated.
Peter Stanford in todays Sunday Telegraph refers to “what is thought to be the Earth’s highest ever recorded temperature.”
Meanwhile Levison Wood in the Sunday Times calls temperature “perhaps the highest reliably recorded temperature ever.” And in case you skipped straight to the quiz page the News Quiz has the following teaser “Where did Death warm up to a record 54.4 °C?”
I’ve penned a response to both letter pages.
Countryfile : Tom Heap starts with an advertorial for electric cars
voice “you could charge up once a week and still have enough”
TH ” but we don’t have enough batteries, just one UK factory, the rest are imported
Here’s Ian from the Faraday Institution”
“they want £12bn invested in the UK battery industry”
Suddenly Tom is in Cornwall … surely by diesel
with blond female sciency voice
“the government is certainly excited”
Claim Cornish lithium brought up with geothermal will be carbon neutral
in 3-5 years”
Cornwall voice was Lucy Crane @Lucyvtcrane
claimed Cornwall will be producing UK batteries within 3-5 years
… I reckon you can forget 3 years.
The item seemed to be another GreenBlob advertorial at getting subsidy money for greendream projects.
A particular feature of some life histories is variability in time to maturity. A fish has to “decide” when to mature. In populations that are subject to intense harvests, there is selection pressure to mature earlier, at smaller sizes. This is entirely logical if you think about it. You can grow your body exponentially, but at some point you have to switch resources to reproduction. The longer you wait the bigger you are and the more fecund you are – but you run a constant risk of being killed before you get there. In some fish populations older age classes have been greatly reduced by fishing mortality and individuals are maturing as soon as they can.
When I visited the Lowestoft fish labs in the mid 80s, in one of their tanks they had a cod of vast dimensions called Boris. I am sure that today’s fishermen would be absolutely astonished to haul such a beast out of the deep.
I understand that fish moved on and got a job in politics . Still of vast dimensions and a face like a cod
“5 billion”: coo, that’s a lot. I’m so ignorant of the salmon biz that I have no idea why they release salmon into the Pacific.
I assume they breed far too many fish than they can hande, or sell
It is a deliberate release of young fish at the mouths of the spawning rivers. It replaces fish who perish in the river – the young suffer 90% predation travelling down the river after hatching. The fish that are released are of species that do not like to stay long in fresh water. So they head off to sea. One survey of salmon caught in open Alaskan waters showed that 34% of them originated from this restocking technique. Pacific salmon fishery has doubled in the last twenty years.
It is extremely unlikely that salmon would even notices changes in the food chain, resulting from climate change, because they will eat absolutely bloody anything that moves. They are top predators and so their principal competition is from other top predators
An element of conservation but mainly to feed tourism and commercial fishing.
The productivity of the ocean is closely linked to various decadal cycles, but regardless, if you have twice the number of fish in an ocean “the number of salmon in the Pacific Ocean is twice what it was 50 years ago”[2010] and “the north Pacific Ocean may be nearing the limit of its salmon-carrying capacity” they aren’t all going to be whoppers are they!
[Source: “Hatch 22” – get it!]
Yes, MrGN. There is a biological principal that an environment will tend to have all the life it can support. A mass balance. If there are more fish of a species, they should be expected to be smaller.
Stats for harvested and released – there is clearly NOT a problem with Ocean productivity related to any imagined climate change.
https://npafc.org/statistics/
Please be aware that these numbers have actually DECREASED since the 70’s and 80’s! All of the west coast states of California, Oregon and Washington have been decreasing their releases of hatchery origin fish. I can’t speak for Alaska or Canada but these other states are reducing or stopping hatcheries altogether.
Hatcheries were introduced to replace the fish lost due to overfishing and habitat destruction. There is too much politics and environmental red tape to go into all the details as to why but the bottom line is that they are reducing hatchery production in favor of wild origin fish. This has proven to be detrimental since the habitat has not recovered enough to support the amount of fish our society requires.
Hatcheries are a necessary evil and they are developing new and better ways to use them. They are starting to use broodstock fish now to spawn instead of only hatchery origin fish. They are doing a lot to improve in-stream conditions and estuarian environments for better survivability. However, reducing the number of salmon released from hatcheries is having an impact on a food source for Puget Sound orca whales.
There are many other issues to discuss here but it boils down to this:
Hatchery fish as getting smaller not because of climate change but because smaller fish are easier to spawn that larger fish. You are seeing these decreases mainly in hatchery Chinook salmon. Coho salmon sizes are still pretty much unchanged. The other species of salmon, Pink and Chum, are not highly produced in hatcheries in the three west coast states.
I can go on but I will leave it for another day.
When we buy smoked salmon it’s always Scottish. Would I be right to suspect that salmon in my fish pie might be from the Pacific? Can it be worth hauling salmon from there to here?