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Marukai
Stranger

Registered: 08/14/11
Posts: 275
Last seen: 4 months, 12 days
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The 6th Great Extinction
#28374594 - 06/25/23 09:14 PM (6 months, 30 days ago) |
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I've been reading more and more and this mass extinction even that is currently ongoing. I'm not sure what to think. The world is crazy with no end in sight.
What do you all think of this 6th extinction event?
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sudly
Darwin's stagger

Registered: 01/05/15
Posts: 10,797
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Re: The 6th Great Extinction [Re: Marukai]
#28374663 - 06/25/23 11:19 PM (6 months, 30 days ago) |
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Yep, it'sa rollin on along alright. Other than meteor impacts and volcanoes, mass extinctions don't happen overnight, and the anthropocean is going to be holding onto a lot of different species.
I mean there's a limit to how many unique animals we can hunt or how much habitat we can remove before they can't repopulate effectively.
The orange roughy is a good example for the times of a fish vulnerable to exploitation.
This species was heavily targetted for its taste and fished as though it had the lifecycle of a typical fish. Eventually they realised they took upward of 27 years to reach maturity and could live to well over 100 years. Unsustainable fishing practices decimated their populations, and drag nets severely damaged the ecosystems that support them.
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In the mid-1970s Orange Roughy became one of New Zealand’s most profitable fisheries after large aggregations of the fish were discovered off its coast. Exports to the U.S. were booming, profits were soaring, and the total catch was significant. In 1989 alone, according to the Marine Stewardship Council, New Zealand’s Orange Roughy catch was a staggering 54,000 tonnes.
However, little was known about the Orange Roughy’s life cycle, leading to its collapse. Orange Roughy live at depths between 500 and 1000m under extreme pressure in frigid temperatures with little to no light. This reality makes the Orange Roughy more complicated to study today and even more so when the technology scientists had available was less developed. Scientists, however, did the best they could with the information they had. They assumed Orange Roughy had a similar life cycle to the shallower water fish they were more familiar with like cod and tilapia. These fish typically don’t live more than a few decades, mature early, and reproduce frequently, meaning they can support a high fishing intensity up to a point. With these assumptions in mind, it was thought the Orange Roughy could also handle a high catch rate.
A decade after the Orange Roughy fishing frenzy began, scientists discovered that its life cycle was not what they had thought. Orange Roughy turned out to live to over 200 years old, mature slowly and reproduce infrequently. Combined with the fact that they aggregate in huge numbers during spawning events (sometimes over 50m in height), they were extremely susceptible to overfishing. Many were simply caught before they had a chance to reproduce. This misunderstanding of their biology led to unintentionally fishing them at an unsustainable rate.
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The environment where the Orange Roughy live has also been impacted. They commonly live on underwater mountains covered in cold water corals that support a thriving ecosystem. When the large weighted nets used to catch Orange Roughy drag along the ocean geography, they take with them everything in their path, including the delicate corals. The damage incurred to this particular environment can take decades to recover, reducing the ecosystem it supports to a shadow of its former self.
https://www.themarinediaries.com/tmd-blog/the-story-of-the-orange-roughy-a-cautionary-tale-for-deep-sea-resource-extraction
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Orange Roughy can live for well over 100 years. The fish doesn't mature until 27 to 32 years of age. In Australia spawning aggregations form between mid-July and late August. These aggregations, which occur near the bottom, can be over 50 m in height.
Campaigners say a new assessment of orange roughy in New Zealand suggests that age could be much higher which could have implications for the ability for populations to recover after fishing.
New Zealand’s fisheries management assessed populations in one of its orange roughy fisheries and found that the age of breeding was “unexpectedly high” with only 50% of stocks spawning by 55 years old.
The age at which 95% of stocks were breeding was 73.3 years.
https://www.theguardian.com/environment/2022/jun/25/orange-roughy-campaigners-call-for-limit-to-trawling-of-species-after-breeding-age-of-73-revealed
-------------------- I am whatever Darwin needs me to be.
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redgreenvines
irregular verb


Registered: 04/08/04
Posts: 37,530
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Re: The 6th Great Extinction [Re: sudly]
#28374765 - 06/26/23 03:11 AM (6 months, 30 days ago) |
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wow, I used to love orange roughy. Stopped eating it 30 years ago, as I heard it was being overfished, but hey living to 100 means something worth studying a lot more.
perhaps we can learn something from them??
If I were making lab grown meat, I think I would want orange roughy stem cells to begin with.
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Moses_Davidson
Non-Prophet



Registered: 05/21/20
Posts: 613
Last seen: 3 months, 28 days
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I'm an environmentalist, but I think to call our current situation a "great extinction" is hubris regarding our own significance, and that one doesn't fully appreciate the scope and scale of the historical great extinctions. There have always been predators eating entire populations into oblivion.
-------------------- "In finance, everything that is agreeable is unsound and everything that is sound is disagreeable." --Sir Winston Churchill "The world may not only be stranger than we suppose, it may be stranger than we can suppose." J.B.S. Haldane "Truth is stranger than fiction, but it is because fiction is obliged to stick to possibilities; Truth isn't." Mark Twain
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redgreenvines
irregular verb


Registered: 04/08/04
Posts: 37,530
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It's not about us, it is already an ongoing extinction of hundreds of species, soon to be thousands, and probably ourselves as well.
not hubris
a clarion call to action, that is getting minimal response so far.
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Moses_Davidson
Non-Prophet



Registered: 05/21/20
Posts: 613
Last seen: 3 months, 28 days
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Quote:
redgreenvines said: It's not about us, it is already an ongoing extinction of hundreds of species, soon to be thousands, and probably ourselves as well.
not hubris
a clarion call to action, that is getting minimal response so far.
I'm doing my own small part, complete with bicycle, solar panels, and planting thousands of trees.
But in the scientific literature that I could find, there seems to be negligible reference to "The 6th Great Extinction". 2 obscure articles in off-brand journals with a whopping 15 citations between them both together.
-------------------- "In finance, everything that is agreeable is unsound and everything that is sound is disagreeable." --Sir Winston Churchill "The world may not only be stranger than we suppose, it may be stranger than we can suppose." J.B.S. Haldane "Truth is stranger than fiction, but it is because fiction is obliged to stick to possibilities; Truth isn't." Mark Twain
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sudly
Darwin's stagger

Registered: 01/05/15
Posts: 10,797
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Quote:
Moses_Davidson said: I'm an environmentalist, but I think to call our current situation a "great extinction" is hubris regarding our own significance, and that one doesn't fully appreciate the scope and scale of the historical great extinctions. There have always been predators eating entire populations into oblivion.
Doesn't matter if it's called a 'great' extinction or not, the amount of habitat loss and species loss is already building up, and in time more species will be lost. Species that without human intervention would have much healthier populations.
Ofcourse there are natural losses of species that happen, but dodos would have still been around if it weren't for us.
Hubris isn't a part of recognising humanities impact on the environment and population of species around us.
-------------------- I am whatever Darwin needs me to be.
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