3 ms·

Warming waters cited as “key culprit” in mass die-off of Alaska snow crabs

30 points by makerofspoons 4y ago

11235813213455 4y ago
Most comments focused on overfishing in a previous thread https://news.ycombinator.com/item?id=33207372 https://news.ycombinator.com/item?id=33207372 But it's surely a combination of problems whose common source is the impact of 8 billion of humans, most of them with a lifestyle dramatically over polluting
- yrgulation 4y ago
  There’s a strong, committed, climate change denial crowd on here.
  - roguealpaca 4y ago
    It's overfishing that was enabled by melting sea ice the crabs had previously lived under during their mating season.
Mikeb85 4y ago
Do we actually know they died? And didn't just migrate? Also can we write off illegal Russian fishing? https://www.theepochtimes.com/alaskan-snow-crab-fishery-closed-as-canada-russia-report-bumper-harvests_4799352.html https://www.theepochtimes.com/alaskan-snow-crab-fishery-clos...
- nomel 4y ago
  It's really frustrating that the CBS articles don't have any links to the survey data, and now they're using a single person's factually stated claim, which doesn't appear to be based on any data. No numbers anywhere. It could definitely be true, but wow, this wouldn't pass a smell test in any professional environment I've worked in, but it's making national news. I'll be waiting for an org that's remotely related to scientific journalism, before believing anything. Related, it looks like adult males can move 8km/day [1]. If we had an idea of the area that was sampled, we could get a rough estimate for drop if it was from migration, alone. Also, they have a 20 year lifespans, so this couldn't just be from a single missed spawning season. 1. https://academic.oup.com/jcb/article/37/4/380/3869641 https://academic.oup.com/jcb/article/37/4/380/3869641
crashingintoyou 4y ago
I'll admit to having a soft spot for Russ George's work re: iron fertilization: https://russgeorge.net/2022/10/02/open-letter-to-academia-and-president-biden/ https://russgeorge.net/2022/10/02/open-letter-to-academia-an... It seems to have in earlier stage testing helped reinvigorate salmon populations in earlier testing around Alaska while simultaneously seeming like a cheap way to capture CO2. I wonder if something similar might also help here.
photochemsyn 4y ago
The way to understand this kind of story is to ignore the flood of recent news articles over the past few days, instead go to Google Scholar and enter something like: alaska snow crab history warming population size trends These problems don't just pop out of nowhere and as expected, there are a fair number of studies outlining the problem over the past decade. This one seems typical: (2020) Recent shifts in northern Bering Sea snow crab (Chionoecetes opilio) size structure and the potential role of climate-mediated range contraction, Fedewa et al. https://www.sciencedirect.com/science/article/pii/S0967064520301284 https://www.sciencedirect.com/science/article/pii/S096706452... > "These findings suggest that the spatial extent and average temperature of snow crab distribution are likely constrained by the availability of cold water habitat in the EBS, and dramatic declines in juvenile snow crab abundance observed in 2019 may be attributed to potential direct or indirect temperature effects on survival of highly stenothermic early benthic stages of snow crab. . . . While the increase in NBS mature male biomass may suggest the potential for a commercial fishery in more northern latitudes, concurrent declines in juvenile abundance suggest caution concerning the sustainability of the stock with continued warming." This all matches decades of data and theory pointing to more rapid warming in Arctic regions than almost anywhere else due to polewards atmospheric and ocean heat transport, from thinning and decreased area of Arctic sea ice to warming subsurface waters. Northward migration of cold-water crab populations (and decrease in size) is no surprise. A bit more worrying is the long-term destabilization of the Arctic seabed methane clathrates: https://www.hindawi.com/journals/jgr/2013/783969/ https://www.hindawi.com/journals/jgr/2013/783969/ Looks like the tipping point is now in the rear-view mirror, so get ready for the ride.
- toomuchtodo 4y ago
  > Looks like the tipping point is now in the rear-view mirror, so get ready for the ride. Over under odds of the Atlantic conveyor failing in the next 30 years? Thought Western Europe would be somewhat spared from climate change, seems like that’s not the case unfortunately. https://archive.ph/2021.12.15-033817/https://www.washingtonpost.com/climate-environment/2021/08/05/change-ocean-collapse-atlantic-meridional/ https://archive.ph/2021.12.15-033817/https://www.washingtonp...

30 points by makerofspoons 4y ago

Most comments focused on overfishing in a previous thread https://news.ycombinator.com/item?id=33207372 https://news.ycombinator.com/item?id=33207372 But it's surely a combination of problems whose common source is the impact of 8 billion of humans, most of them with a lifestyle dramatically over polluting

yrgulation 4y ago
There’s a strong, committed, climate change denial crowd on here.
- roguealpaca 4y ago
  It's overfishing that was enabled by melting sea ice the crabs had previously lived under during their mating season.

Mikeb85 4y ago

Do we actually know they died? And didn't just migrate? Also can we write off illegal Russian fishing? https://www.theepochtimes.com/alaskan-snow-crab-fishery-closed-as-canada-russia-report-bumper-harvests_4799352.html https://www.theepochtimes.com/alaskan-snow-crab-fishery-clos...

nomel 4y ago
It's really frustrating that the CBS articles don't have any links to the survey data, and now they're using a single person's factually stated claim, which doesn't appear to be based on any data. No numbers anywhere. It could definitely be true, but wow, this wouldn't pass a smell test in any professional environment I've worked in, but it's making national news. I'll be waiting for an org that's remotely related to scientific journalism, before believing anything. Related, it looks like adult males can move 8km/day [1]. If we had an idea of the area that was sampled, we could get a rough estimate for drop if it was from migration, alone. Also, they have a 20 year lifespans, so this couldn't just be from a single missed spawning season. 1. https://academic.oup.com/jcb/article/37/4/380/3869641 https://academic.oup.com/jcb/article/37/4/380/3869641

crashingintoyou 4y ago

I'll admit to having a soft spot for Russ George's work re: iron fertilization: https://russgeorge.net/2022/10/02/open-letter-to-academia-and-president-biden/ https://russgeorge.net/2022/10/02/open-letter-to-academia-an... It seems to have in earlier stage testing helped reinvigorate salmon populations in earlier testing around Alaska while simultaneously seeming like a cheap way to capture CO2. I wonder if something similar might also help here.

photochemsyn 4y ago

The way to understand this kind of story is to ignore the flood of recent news articles over the past few days, instead go to Google Scholar and enter something like: alaska snow crab history warming population size trends These problems don't just pop out of nowhere and as expected, there are a fair number of studies outlining the problem over the past decade. This one seems typical: (2020) Recent shifts in northern Bering Sea snow crab (Chionoecetes opilio) size structure and the potential role of climate-mediated range contraction, Fedewa et al. https://www.sciencedirect.com/science/article/pii/S0967064520301284 https://www.sciencedirect.com/science/article/pii/S096706452... > "These findings suggest that the spatial extent and average temperature of snow crab distribution are likely constrained by the availability of cold water habitat in the EBS, and dramatic declines in juvenile snow crab abundance observed in 2019 may be attributed to potential direct or indirect temperature effects on survival of highly stenothermic early benthic stages of snow crab. . . . While the increase in NBS mature male biomass may suggest the potential for a commercial fishery in more northern latitudes, concurrent declines in juvenile abundance suggest caution concerning the sustainability of the stock with continued warming." This all matches decades of data and theory pointing to more rapid warming in Arctic regions than almost anywhere else due to polewards atmospheric and ocean heat transport, from thinning and decreased area of Arctic sea ice to warming subsurface waters. Northward migration of cold-water crab populations (and decrease in size) is no surprise. A bit more worrying is the long-term destabilization of the Arctic seabed methane clathrates: https://www.hindawi.com/journals/jgr/2013/783969/ https://www.hindawi.com/journals/jgr/2013/783969/ Looks like the tipping point is now in the rear-view mirror, so get ready for the ride.

toomuchtodo 4y ago
> Looks like the tipping point is now in the rear-view mirror, so get ready for the ride. Over under odds of the Atlantic conveyor failing in the next 30 years? Thought Western Europe would be somewhat spared from climate change, seems like that’s not the case unfortunately. https://archive.ph/2021.12.15-033817/https://www.washingtonpost.com/climate-environment/2021/08/05/change-ocean-collapse-atlantic-meridional/ https://archive.ph/2021.12.15-033817/https://www.washingtonp...