Krill component of the carbon pump was overestimated impacting e.g. climate models

We still know very little about climate and the natural global carbon cycle!

Thus, for this and other reasons, e.g. climate models and their forecasts are junk!

This study used only one instrument to observe krill in the vast oceans of our planet! A healthy dose of skepticism and doubt is advised!

Keep in mind: Global warming is a hoax and climate change is a religion! It is being used as a pretext by Big Government and the elite to interfere with our lives. It is among the greatest scams and scandals of at least the last 30 years!

From the editor's summary and abstract:

"Editor’s summary

Shrimp-like krill constitute the greatest biomass of any living animal: up to 379 million tonnes in the Southern Ocean. Dead krill and their feces sink and are assumed to export tens of millions of tons of carbon annually; however, these data are gleaned from patchy observations.

Smith et al. deployed a seafloor lander carrying an echosounder, camera, lights, and other equipment offshore of East Antarctica to provide consistent direct observational data, including difficult-to-obtain winter data, to feed into a carbon flux model. The year-long observations showed heterogeneous migratory behaviors by krill, including strong seasonal shifts. Migration means that recirculation of carbon can occur, so krill may make a smaller contribution to net carbon storage than what is found in current estimates. ..."

Abstract

INTRODUCTION

Antarctic krill (Euphausia superba) is among the most abundant animals on the planet (between 117 and 379 million tonnes). Krill play a vital role in the biological carbon pump—a biologically driven mechanism that sequesters carbon to the deep ocean—by consuming phytoplankton in the upper water column and producing fast-sinking fecal pellets which sink to the seafloor. Sinking particles, including carbon-rich fecal pellets, are vulnerable to degradation through fragmentation, reingestion, dissolution into the surrounding seawater, or bacterial remineralization. This means that not all of the material consumed by krill in the upper ocean is exported to deeper depths, and some of the consumed carbon is returned to the upper ocean. Vertical migration, a behavior common to krill and many zooplankton and fish species worldwide, is believed to increase the efficiency of the biological carbon pump by actively transporting particulate organic carbon consumed by organisms in the upper ocean directly into the mesopelagic zone (waters deeper than 200 m) with minimal degradation.

RATIONALE

...  A lack of observational data means that few global climate models include vertical migration as a mechanism for carbon export or models rely on broad assumptions with little exploration into seasonal variability. The exclusion of vertical migrations has been suggested to have considerable influence on the accuracy of carbon export estimates by global climate models. Using echosounder observations from a seafloor lander in East Antarctica coupled with a numerical model, we explore how observed patterns in vertically migrating krill contribute to the total particulate organic carbon flux across a full year.

RESULTS

An upward-looking echosounder positioned at 385-m depth on the continental shelf of Prydz Bay provided full water column high-resolution observations of krill density and depth every 7 min for a full year. Video camera footage captured Antarctic krill swarming around lights on the lander close to the seafloor with fecal pellets produced at depth. ...

CONCLUSION

Our observations show high seasonal variability in krill diel vertical migration patterns with almost no migration occurring into the mesopelagic during summer. Modeling results suggest that previous estimates of carbon injection by migrating krill, which are based on assumed rather than observed vertical migration behavior, have been overestimated and that the Antarctic krill migrant pump has a minor contribution to particulate organic carbon export. This contradicts established theories on the value of vertical migration to the biological carbon pump. However, increased attention is required to resolve changes to krill grazing behaviors and attenuation processes such as bacterial remineralization that are likely to affect carbon export and potentially influence the effect of vertical migration on the downward flux of carbon to deep waters."

In Science Journals | Science

Antarctic krill vertical migrations modulate seasonal carbon export (no public access)