Thread by @DJShearwater

I am delighted to share our paper, published today in @nature, on baleen whale prey consumption and what it means for marine ecosystems. nature.com/articles/s4158… A thread 1/n

We used high-resolution #biologging tags, aerial #drones, and echosounders to estimate daily and annual prey consumption on daily and annual scales for the largest species in earth’s history. In brief, we found that whales eat more than previous work predicted. 2/n

(There are many possible reasons for this discrepancy. One reason is because most prior estimates were done using metabolic modeling of energy requirements of much smaller animals (dolphins and smaller) that were extrapolated to large whales, which have very different ecology.)

We were interested in using our findings to better understand ecosystem change over the last century. The Southern Ocean is of particular interest, where industrial whaling removed 80% of the large whales in only 60y (1910-1970). Blue whale populations were reduced by >99%. 3/n

Using our new estimates of prey consumption in past systems with over 1 million more whales, we conclude that the Southern Ocean must have been far more productive than at present. This is in general agreement with previously published findings. 4/n

How could an ecosystem with >1 million more huge krill predators (baleen whales) have supported hundreds of millions of tonnes of more krill (twice the biomass of krill today)? Behold, the power of poop. 5/n

Whales acted as mobile krill processing plants, digesting krill and dispersing the nutrients locked inside (e.g., iron) to the base of the food web (phytoplankton). These iron-starved phytoplankton are food for the krill. Whales manured their pastures, just as a farmer would 6/n

Whales supported more productive marine ecosystems. Rebuilding whale populations will have benefits on ecosystem health and function. In other words: We need a world with whales. 7/n

Also, go check out the necessarily bold News and Views covering the work. nature.com/articles/d4158… If anyone needs pdfs of the paper itself or the @NatureNV let me know and I will be happy to share 8/n

Couldn’t have done this without a terrific team, supporting organizations, and funders. Team includes: @mfczap @shirelkr @WhaleGough @jamesfahlbusch @KCBierlich @Paolo_Segre @dpnowacek @dioptrica @PyensonLab @btbel @elhazen @GoldbogenLab, as well as others not on Twitter 9/n

Orgs and funders include: @Stanford @HopkinsMarine @NOAAFisheries @MBNMS @NOAASBNMS @NOAA_CINMS @DukeEnvironment @DukeMarineLab @ucsc @NMNH @CascadiaRes @MandelaUni @NSF @USNavyResearch @NatGeoExplorers @WWF @ifawglobal and MAC3 Impact Philanthropies 10/n

Incredible art in the paper by @AlexBoersma_Art and Kylie Duthie; infographic with help of @DrStephBrodie. Speaking of cool visuals, we got the cover as a cherry on top! Overall, a pretty surreal experience. fin.