I am interested in knowing how much emptier (ideally in either number of fish or kg of biomass) the ocean is due to direct and intentional human activity such as fishing or artificially controlling ocean animals populations. Are there currently any data regarding this? Soft estimates are fine.

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    The question title is post-punk lyrics material. Commented Dec 12, 2017 at 22:03

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The Census of Marine Life concluded in 2010 that 90 percent of the large fish are gone, primarily because of overfishing. This includes many of the fish we love to eat, like Atlantic salmon, tuna, halibut, swordfish, Atlantic cod. If we don’t allow for proper recovery, these fish risk total extinction.

Novogratz, A. and Velings, M. (2014). The end of fish. In the Washington Post. Retrieved on Dec 5, 2017.

The index for all utilized fish species indicates a 50 per cent reduction in population numbers globally between 1970 and 2010.

WWF International. (2015). Living Blue Planet Report. Retrieved Dec 6, 2017.


Most of Canada’s commercial fish stocks are depleted. Since 1970, an estimated 52 per cent* of their biomass has disappeared.

Oceana Canada. (2017). Oceana Fishery Audit 2017. Retrieved on December 5, 2017.

  • Also see this short video from The Economist: youtube.com/watch?v=opIJXuvxD-g
    – Nic
    Commented Dec 6, 2017 at 0:53
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    This covers utilized fish species, and is a very good answer -- but can you include information on percentage of total fish species (e.g., including the ones humans never eat)?
    – Erica
    Commented Dec 7, 2017 at 17:57
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    Sorry, I don't have data on total fish species and I'm not even sure that it's collected at all. Generally the people collecting data on abundance of fish are working with fisheries, so data collection is mostly around utilized fish species.
    – Nic
    Commented Dec 7, 2017 at 18:44
  • I thought that would be the problem. Estimates for total ocean biomass are notoriously tricky, since they're so vast and relatively unexplored... just wanted to ask :) Thanks!
    – Erica
    Commented Dec 7, 2017 at 18:45

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