# How many fish are in the ocean? **URL:** \ **Category:** Factual Questions\ **Created:** [December 5, 2002, 8:19pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760 "2002-12-05T20:19:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![empfsu1](https://avatars.discourse-cdn.com/v4/letter/e/db5fbb/32.png) [@empfsu1](https://boards.straightdope.com/u/empfsu1)\ **Post date:** [December 5, 2002, 8:19pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/1 "2002-12-05T20:19:02Z")
We are working on a project that has brought a very interesting question to our department…that even Jacque Custou’s son can’t accurately answer. How many fish are in the ocean? NOT SPECIES, but actual number of fish. Of course with fish dying & being born, there will never be a solid #, but an accurate estimate will do. ---
**Author:** ![JeffB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeffb/32/188_2.png) [@JeffB](https://boards.straightdope.com/u/JeffB)\ **Post date:** [December 5, 2002, 9:09pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/2 "2002-12-05T21:09:06Z")
There’s an infinite number, because no matter how many you count… …wait for it… …there’s always another fish in the sea. ---
**Author:** ![bryanmcc](https://avatars.discourse-cdn.com/v4/letter/b/eada6e/32.png) [@bryanmcc](https://boards.straightdope.com/u/bryanmcc)\ **Post date:** [December 5, 2002, 9:36pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/3 "2002-12-05T21:36:53Z")
There are 475,239,304,489 fish in the sea, as of…NOW. ---
**Author:** ![OfBlinkingThings](https://avatars.discourse-cdn.com/v4/letter/o/ebca7d/32.png) [@OfBlinkingThings](https://boards.straightdope.com/u/OfBlinkingThings)\ **Post date:** [December 5, 2002, 9:40pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/4 "2002-12-05T21:40:26Z")
My guess is a lot. More the 10 for sure. Maybe even more than 30. Thats a lot of fish! That is enough to feed 60 kind of hungry people. ---
**Author:** ![raz](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@raz](https://boards.straightdope.com/u/raz)\ **Post date:** [December 5, 2002, 9:40pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/5 "2002-12-05T21:40:46Z")
Nope. 475,239,304,491. You were a little off. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [December 5, 2002, 9:45pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/6 "2002-12-05T21:45:44Z")
Psssst! It’s Cousteau. Which ocean? ---
**Author:** ![OfBlinkingThings](https://avatars.discourse-cdn.com/v4/letter/o/ebca7d/32.png) [@OfBlinkingThings](https://boards.straightdope.com/u/OfBlinkingThings)\ **Post date:** [December 5, 2002, 10:01pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/7 "2002-12-05T22:01:14Z")
The one from Waterworld. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 5, 2002, 11:37pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/8 "2002-12-05T23:37:29Z")
I’m certain the information doesn’t exist on which to base anything resembling an _accurate_ estimate. As far as a ball park estimate, based on the net primary productivity of the oceans, the relationship of productivity to biomass, and the probable average size of an individual fish, I come up with: 100,000,000,000,000 individuals (100 trillion). But this could easily be off by several orders of magnitude, ---
**Author:** ![pseudotriton\_ruber\_ruber](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@pseudotriton\_ruber\_ruber](https://boards.straightdope.com/u/pseudotriton_ruber_ruber)\ **Post date:** [December 5, 2002, 11:49pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/9 "2002-12-05T23:49:12Z")
There’s one fish, two fish, red fish, blue fish…someone else take over for a while, okay? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 5, 2002, 11:53pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/10 "2002-12-05T23:53:46Z")
We don’t even know for sure how many different tyes of fish there are. The oceans are 3/4 of the earth and there are many unexplored places. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [December 6, 2002, 12:24am UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/11 "2002-12-06T00:24:30Z")
I work for the Monterey Bay Aquairum. If asked this, I would just say ‘alot’. ---
**Author:** ![Meatros](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Meatros](https://boards.straightdope.com/u/Meatros)\ **Post date:** [December 6, 2002, 12:29am UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/12 "2002-12-06T00:29:19Z")
Currently there are three. I know what you all are thinking…how could there be only three? To this I say; I’m willing to admit there might be four-five tops! ---
**Author:** ![bryanmcc](https://avatars.discourse-cdn.com/v4/letter/b/eada6e/32.png) [@bryanmcc](https://boards.straightdope.com/u/bryanmcc)\ **Post date:** [December 6, 2002, 2:17pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/13 "2002-12-06T14:17:55Z")
> [@](#): > > \*Originally posted by blink178 \* > \*\*Nope. 475,239,304,491. You were a little off. \*\* Oh damn, those three were hiding! ---
**Author:** ![Wallenstein](https://avatars.discourse-cdn.com/v4/letter/w/b5a626/32.png) [@Wallenstein](https://boards.straightdope.com/u/Wallenstein)\ **Post date:** [December 6, 2002, 2:25pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/14 "2002-12-06T14:25:16Z")
> [@](#): > > _Originally posted by blink178_ \*\*Nope. 475,239,304,491. You were a little off. \*\* > [@](#): > > \*Originally posted by bryanmcc \* > \*\*Oh damn, those three were hiding! \*\* Nah, they were stolen by **Meatros**. ---
**Author:** ![Celyn](https://avatars.discourse-cdn.com/v4/letter/c/9dc877/32.png) [@Celyn](https://boards.straightdope.com/u/Celyn)\ **Post date:** [December 6, 2002, 2:38pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/15 "2002-12-06T14:38:58Z")
OR, as the folk song puts the question “How many strawberries swim in the salt sea? How many fish swim in the forest?” Does that help at all? OK - I thought not. \ ---
**Author:** ![Meatros](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Meatros](https://boards.straightdope.com/u/Meatros)\ **Post date:** [December 6, 2002, 10:11pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/16 "2002-12-06T22:11:11Z")
> [@](#): > > \*Originally posted by e-logic \* > \*\*Nah, they were stolen by **Meatros**. \*\* **stolen** isn’t the right word e-logic…more like **digested** 😃 ---
**Author:** ![The\_Flying\_Dutchman](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@The\_Flying\_Dutchman](https://boards.straightdope.com/u/The_Flying_Dutchman)\ **Post date:** [December 6, 2002, 11:14pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/17 "2002-12-06T23:14:01Z")
> [@](#): > > \*Originally posted by Colibri \* > \*\*I’m certain the information doesn’t exist on which to base anything resembling an _accurate_ estimate. > > As far as a ball park estimate, based on the net primary productivity of the oceans, the relationship of productivity to biomass, and the probable average size of an individual fish, I come up with: > > 100,000,000,000,000 individuals (100 trillion). > > But this could easily be off by several orders of magnitude, \*\* You weren’t really bullshiting were you. That’s 1 x 1o^14. Based on an estimate that the weight of krill in the oceans is comparable to that of the human population, 7 x 10^9 total, weighing 7 x 10^4 grams each and a separate web source weighing each krill at 1 gram, I get a krill population of 4.9 x 10^14. If that is true, I’d be hard pressed to believe that we could get another order of magnitude out of that number based on the total population of all fish. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 6, 2002, 11:23pm UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/18 "2002-12-06T23:23:40Z")
> [@](#): > > \*Originally posted by grienspace \* > **You weren’t really bullshiting were you. That’s 1 x 1o^14.** No, I wasn’t. I did a few back of the envelope calculations based on the factors I cited and a few SWAGs. But some of my assumptions could be off and alter the results by several orders of magnitude, as I said. BTW, I am including larval fish in the total, not just adults. > [@](#): > > If that is true, I’d be hard pressed to believe that we could get another order of magnitude out of that number based on the total population of all fish. \*\* I don’t understand the point you are trying to make. What assumptions are you making about the relationship between numbers of krill and numbers of fish? ---
**Author:** ![The\_Flying\_Dutchman](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@The\_Flying\_Dutchman](https://boards.straightdope.com/u/The_Flying_Dutchman)\ **Post date:** [December 7, 2002, 12:24am UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/19 "2002-12-07T00:24:09Z")
Well I can’t think of any other fish that is any where near as populous and universal as zooplankton. To come up with 10 different fish for each krill that are higher in the food chain to get me another order of magnitude doesn’t seem likely to me. But I could be wrong. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [December 7, 2002, 1:31am UTC](https://boards.straightdope.com/t/how-many-fish-are-in-the-ocean/140760/20 "2002-12-07T01:31:24Z")
> [@](#): > > \*Originally posted by grienspace \* > \*\*Well I can’t think of any other fish that is any where near as populous and universal as zooplankton. To come up with 10 different fish for each krill that are higher in the food chain to get me another order of magnitude doesn’t seem likely to me. But I could be wrong. \*\* You seem to be assuming that krill are the only form of zooplankton. Krill are actually only a small part of the total zooplankton - many of which are copepods - and are relatively large in size. And many fish don’t eat zooplankton anyway, but phytoplankton. And besides that, many fish larvae - which are included in my estimate - are part of the zooplankton themselves. In other words, there is no reason to assume any relationship whatsoever between the numbers of krill and the numbers of fish in the ocean at large.