# Climate change, extinctions, die offs, evolution, and biomass **URL:** \ **Category:** Factual Questions\ **Created:** [March 1, 2020, 1:25pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748 "2020-03-01T13:25:08Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [March 1, 2020, 1:25pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/1 "2020-03-01T13:25:08Z")
So if my understanding is correct, there are many, many fewer fish in the ocean than in the past, due to climate change, fishing practices, pollution, etc. If this is accurate, what happens to all that biomass? Much of it is removed from the ocean and processed into food for people, livestock, pets, etc, right? What happens after that? Does the ocean replace that biomass somehow, or is it gone for good? Also, how has pollution affected evolution? Are sea creatures evolving to either utilize plastics and other trash, or avoid being harmed by them? Is it happening too fast for evolution to catch up? ---
**Author:** ![pool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pool/32/4152_2.png) [@pool](https://boards.straightdope.com/u/pool)\ **Post date:** [March 1, 2020, 2:02pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/2 "2020-03-01T14:02:29Z")
I don’t know the answer but reading about the Permian-Triassic event the other day I was shocked to read that somewhere around 70% of land animals and 96% of all creatures in the sea went extinct. So I guess with all the extinction events that have happened it seems life and biomass have rebounded, granted we’re talking millions of years here. [https://en.m.wikipedia.org/wiki/Permian–Triassic\_extinction\_event](https://en.m.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event) All the articles I’ve been reading lately seems sea life are eating plastics and such that they are finding in the bellies of dead animals, not good. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 1, 2020, 2:10pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/3 "2020-03-01T14:10:02Z")
> [@iiandyiiii](#): > > So if my understanding is correct, there are many, many fewer fish in the ocean than in the past, due to climate change, fishing practices, pollution, etc. If this is accurate, what happens to all that biomass? Much of it is removed from the ocean and processed into food for people, livestock, pets, etc, right? What happens after that? Does the ocean replace that biomass somehow, or is it gone for good? Some of it resolves itself as an increase in biomass we don’t (usually) eat - like[jellyfish swarms](https://geographical.co.uk/nature/oceans/item/3374-rise-of-the-jellies) ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [March 1, 2020, 2:11pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/4 "2020-03-01T14:11:18Z")
As populations of fish decline populations of stuff that fish eat increase. When that imbalance puts survival pressure on the stuff that fish eat, they survive less robustly. So, the stuff that eats the dead bodies increases for a while. Then the chemistry of the ocean at various levels changes, and populations of things in those levels change as well. Certain critical elements of biomass are hard limits on how much living stuff can exist in the ocean. Oxygen is a big one, and as dead stuff accumulates that can cause large volumes of ocean to become far less productive of biomass. The ocean is moderately large, and it circulates in a moderately complex fashion. Fresh water melt from continental glaciers affects how much salt, and oxygen, and heat is added, mostly in the near polar regions, and the transport of those variation is a decades long system. (not entirely understood, by the way.) In addition, rivers flow into the sea from continents, bringing with them fairly large amounts of mineral and biological sediments which are deposited in deltas, and subsurface parts of continental shelves. The biological elements decompose over geologic time scales, leaving clathrates in varying degrees of stability buried on the continental shelves. The definition of “biomass” is a bit less uniform in description than fish populations. Is limestone a biomass? It was once. Oil? Coal? The facts are less uniformly measured than I would like, but total biomass is a variable in Earth’s history. The trends were generally millennial to epoch long trends until quite recently. Humans dig up stuff, set fires, and bury stuff more than any other species. I don’t know of any really reliable estimates of how much oxidation rates have increased during the last hundred thousand years, but it seems likely to have reached geologic proportions.’ My answer is “I don’t know.” A very unsatisfactory answer, even to me. ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [March 1, 2020, 2:23pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/5 "2020-03-01T14:23:40Z")
Ignorance fighting opportunity here. I thought all “mass” is already here. Organisms are built upon materials that they can acquire, and if you follow back to basic materials, it is all already present on Earth. No “new” mass is being created or removed - it’s just being recirculated (?). ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [March 1, 2020, 2:26pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/6 "2020-03-01T14:26:22Z")
To put fish biomass in context, the total biomass of all fish is less than that of marine crustaceans, which in turn is much less than that of diatoms and other phytoplankton. And the biomass of all marine life is dwarfed by that of land life (especially plants and fungi). Furthermore, IIUC, the biggest beneficiaries of man’s harvesting predator fish like tuna, are the forager fish those predators prey on. Nevertheless there has been some shift from fish to jellyfish, driven by environmental changes as well as over-harvesting of fish. Higher temperatures, higher acidity, and oxygen depletion all favor the “rugged” jellyfish over vertebrate fish. > [@](#): > > All around the world, jellyfish are behaving badly—reproducing in astonishing numbers and congregating where they’ve supposedly never been seen before. Jellyfish have halted seafloor diamond mining off the coast of Namibia [where the waters of the Benguela current now contain more jellyfish than fish] by gumming up sediment-removal systems. Jellies scarf so much food in the Caspian Sea they’re contributing to the commercial extinction of beluga sturgeon—the source of fine caviar. In 2007, mauve stinger jellyfish stung and asphyxiated more than 100,000 farmed salmon off the coast of Ireland as aquaculturists on a boat watched in horror. The jelly swarm reportedly was 35 feet deep and covered ten square miles. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [March 1, 2020, 2:41pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/7 "2020-03-01T14:41:37Z")
> [@snowthx](#): > > Ignorance fighting opportunity here. [. . .] No “new” mass is being created or removed - it’s just being recirculated (?). Biomass, although not uniformly defined, was never defined as “new” mass. New mass does arrive on Earth, but that isn’t a significant portion of the variable amount of biomass. Carbon Dioxide enters the atmosphere from plants, and volcanism, and a tiny fraction falls to Earth in meteors. It becomes a significant part of biomass after that. A very large percentage of the free Oxygen in our atmosphere comes from biological processes, and a tiny fraction from space. Nuclear synthesis products from the sun, and supernova ejections have also become parts of living things on Earth. At one time there was no biomass on Earth, now there is some. At some point that was “new biomass” and each and every atom of it, and all the other atoms were, at some time in the last few billion years “new” mass. Yours is a distinction without a difference. ---
**Author:** ![Trancephalic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trancephalic/32/380_2.png) [@Trancephalic](https://boards.straightdope.com/u/Trancephalic)\ **Post date:** [March 1, 2020, 3:34pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/8 "2020-03-01T15:34:38Z")
> [@iiandyiiii](#): > > Also, how has pollution affected evolution? Are sea creatures evolving to either utilize plastics and other trash, or avoid being harmed by them? Is it happening too fast for evolution to catch up? There has already been a plastic-eating bacteria discovered a few years ago. > **[Newly discovered bacteria can eat plastic bottles](https://phys.org/news/2016-03-newly-bacteria-plastic-bottles.html)** > > A team of Japanese scientists has found a species of bacteria that eats the type of plastic found in most disposable water bottles. ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [March 1, 2020, 4:07pm UTC](https://boards.straightdope.com/t/climate-change-extinctions-die-offs-evolution-and-biomass/848748/9 "2020-03-01T16:07:36Z")
> [@snowthx](#): > > Ignorance fighting opportunity here. I thought all “mass” is already here. Organisms are built upon materials that they can acquire, and if you follow back to basic materials, it is all already present on Earth. No “new” mass is being created or removed - it’s just being recirculated (?). Well, it can be sequestered such that it _doesn’t_ circulate on anything but the longest geological timescales - as limestone, for instance. So it’s no longer bio-available carbon.