Landschützer, P., Gruber, N. & Bakker, D. C. E. Decadal variations and trends of the global ocean carbon sink. Glob. Biogeochem. Cycles 30, 1396–1417 (2016).
Google Scholar
Gruber, N., Landschützer, P. & Lovenduski, N. S. The variable Southern Ocean carbon sink. Annu. Rev. Mar. Sci. 11, 159–186 (2019).
Google Scholar
Passow, U. & Carlson, C. A. The biological pump in a high CO2 world. Mar. Ecol. Prog. Ser. 470, 249–271 (2012).
Google Scholar
Henson, S. A., Sanders, R. & Madsen, E. Global patterns in efficiency of particulate organic carbon export and transfer to the deep ocean. Glob. Biogeochem. Cycles 26, GB1028 (2012).
Google Scholar
Eppley, R. W. & Peterson, B. J. Particulate organic matter flux and planktonic new production in the deep ocean. Nature 282, 677–680 (1979).
Google Scholar
Iversen, M. H., Nowald, N., Ploug, H., Jackson, G. A. & Fischer, G. High resolution profiles of vertical particulate organic matter export off Cape Blanc, Mauritania: degradation processes and ballasting effects. Deep Sea Res. Pt. I 57, 771–784 (2010).
Google Scholar
Steinberg, D. K. & Landry, M. R. Zooplankton and the ocean carbon cycle. Annu. Rev. Mar. Sci. 9, 413–444 (2017).
Google Scholar
Manno, C., Stowasser, G., Enderlein, P., Fielding, S. & Tarling, G. A. The contribution of zooplankton faecal pellets to deep-carbon transport in the Scotia Sea (Southern Ocean). Biogeosciences 12, 1955–1965 (2015).
Google Scholar
Archibald, K. M., Siegel, D. A. & Doney, S. C. Modeling the impact of zooplankton diel vertical migration on the carbon export flux of the biological pump. Glob. Biogeochem. Cycles 33, 181–199 (2019).
Google Scholar
Whitehouse, M. J. et al. Role of krill versus bottom-up factors in controlling phytoplankton biomass in the northern Antarctic waters of South Georgia. Mar. Ecol. Prog. Ser. 393, 69–82 (2009).
Google Scholar
Atkinson, A., Schmidt, K., Fielding, S., Kawaguchi, S. & Geissler, P. A. Variable food absorption by Antarctic krill: Relationships between diet, egestion rate and the composition and sinking rates of their fecal pellets. Deep Sea Res. 59–60, 147–158 (2012). Pt. II.
Google Scholar
Cavan, E. L. et al. The importance of Antarctic krill in biogeochemical cycles. Nat. Commun. 10, 4742 (2019).
Google Scholar
Belcher, A. et al. The potential role of Antarctic krill faecal pellets in efficient carbon export at the marginal ice zone of the South Orkney Islands in spring. Polar Biol. 40, 2001–2013 (2017).
Google Scholar
Belcher, A. et al. Krill faecal pellets drive hidden pulses of particulate organic carbon in the marginal ice zone. Nat. Commun. 10, 889 (2019).
Google Scholar
Gleiber, M. R., Steinberg, D. K. & Ducklow, H. W. Time series of vertical flux of zooplankton fecal pellets on the continental shelf of the western Antarctic Peninsula. Mar. Ecol. Prog. Ser. 471, 23–36 (2012).
Google Scholar
Belcher, A. et al. The role of particle associated microbes in remineralization of fecal pellets in the upper mesopelagic of the Scotia Sea, Antarctica. Limnol. Oceanogr. 61, 1049–1064 (2016).
Google Scholar
Siegel, V. & Watkins, J. L. Distribution, Biomass and Demography of Antarctic Krill, Euphausia Superba in Biology and Ecology of Antarctic Krill 21-100 (Springer International Publishing, Switzerland, 2016).
Cavan, E. L. et al. Attenuation of particulate organic carbon flux in the Scotia Sea, Southern Ocean, is controlled by zooplankton fecal pellets. Geophys. Res. Lett. 42, 821–830 (2015).
Google Scholar
Bathmann, U., Fischer, G., Müller, P. J. & Gerdes, D. Short-term variations in particulate matter sedimentation off Kapp Norvegia, Weddell Sea, Antarctica: relation to water mass advection, ice cover, plankton biomass and feeding activity. Polar Biol. 11, 185–195 (1991).
Ducklow, H. W. et al. Marine pelagic ecosystems: The West Antarctic Peninsula. Philos. Trans. R. Soc., B. 362, 67–94 (2007).
Clarke, A. et al. Climate change and the marine ecosystem of the western Antarctic Peninsula. Philos. Trans. R. Soc., B. 362, 149–166 (2007).
Vaughan, D. G. et al. Recent rapid regional climate warming on the Antarctic Peninsula. Clim. Change 60, 243–274 (2003).
Atkinson, A. et al. Krill (Euphausia superba) distribution contracts southward during rapid regional warming. Nat. Clim. Change 9, 142–147 (2019).
Google Scholar
Atkinson, A., Siegel, V., Pakhomov, E. & Rothery, P. Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature 432, 100–103 (2004).
Google Scholar
Bernard, K. S., Steinberg, D. K. & Schofield, O. M. E. Summertime grazing impact of the dominant macrozooplankton off the Western Antarctic Peninsula. Deep Sea Res. Pt. I 62, 111–122 (2012).
Pakhomov, E. A., Dubischar, C. D., Strass, V., Brichta, M. & Bathmann, U. V. The tunicate Salpa thompsoni ecology in the Southern Ocean. I. Distribution, biomass, demography and feeding ecophysiology. Mar. Biol. 149, 609–623 (2006).
Fischer, G. et al. Seasonal variability of particle flux in the Weddell Sea and its relation to ice cover. Nature 335, 426–428 (1988).
Google Scholar
Schmidt, K. & Atkinson, A. Feeding and Food Processing in Antarctic Krill (Euphausia superba Dana) in Biology and Ecology of Antarctic Krill 175-224 (Springer International Publishing, Switzerland, 2016).
Bone, Q., Carré, C. & Chang, P. Tunicate feeding filters. J. Mar. Biol. Assoc. 83, 907–919 (2003).
Pakhomov, E. A., Froneman, P. W. & Perissinotto, R. Salp/krill interactions in the Southern Ocean: spatial segregation and implications for the carbon flux. Deep Sea Res. 49, 1881–1907 (2002). Pt. II.
Google Scholar
Iversen, M. H. et al. Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean. Deep Sea Res. 138, 116–125 (2017). Pt. II.
Google Scholar
Loeb, V. et al. Effects of sea-ice extent and krill or salp dominance on the Antarctic food web. Nature 387, 897–900 (1997).
Google Scholar
Dubischar, C. D. & Bathmann, U. V. The occurrence of faecal material in relation to different pelagic systems in the Southern Ocean and its importance for vertical flux. Deep Sea Res. 49, 3229–3242 (2002). Pt. II.
Google Scholar
Manno, C. et al. Continuous moulting by Antarctic krill drives major pulses of carbon export in the north Scotia Sea, Southern Ocean. Nat. Commun. 11, 6051 (2020).
Google Scholar
Thiele, S., Fuchs, B. M., Amann, R. & Iversen, M. H. Colonization in the photic zone and subsequent changes during sinking determine bacterial community composition in marine snow. Appl. Environ. Microbiol. 81, 1463–1471 (2015).
Google Scholar
Pauli, N.-C. et al. Selective feeding in Southern Ocean key grazers—diet composition of krill and salps. Commun. Biol. 4, 1061 (2021).
Google Scholar
Siegel, V. Introducing Antarctic Krill Euphausia Superba Dana, 1850 in Biology and Ecology of Antarctic Krill 23-41 (Springer International Publishing, Switzerland, 2016).
Pakhomov, E. A. Salp/krill interactions in the eastern Atlantic sector of the Southern Ocean. Deep Sea Res. 51, 2645–2660 (2004). Pt. II.
Google Scholar
Phillips, B., Kremer, P. & Madin, L. P. Defecation by Salpa thompsoni and its contribution to vertical flux in the Southern Ocean. Mar. Biol. 156, 455–467 (2009).
Perissinotto, R. & Pakhomov, E. A. Contribution of salps to carbon flux of marginal ice zone of the Lazarev Sea, Southern Ocean. Mar. Biol. 131, 25–32 (1998).
Google Scholar
Iversen, M. H. & Ploug, H. Temperature effects on carbon-specific respiration rate and sinking velocity of diatom aggregates—potential implications for deep ocean export processes. Biogeosciences 10, 4073–4085 (2013).
Google Scholar
Ploug, H., Iversen, M. H. & Fischer, G. Ballast, sinking velocity, and apparent diffusivity within marine snow and zooplankton fecal pellets: Implications for substrate turnover by attached bacteria. Limnol. Oceanogr. 53, 1878–1886 (2008).
Google Scholar
Ploug, H., Iversen, M. H., Koski, M. & Buitenhuis, E. T. Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct measurements of ballasting by opal and calcite. Limnol. Oceanogr. 53, 469–476 (2008).
Google Scholar
Iversen, M. H. & Poulsen, L. K. Coprorhexy, coprophagy, and coprochaly in the copepods Calanus helgolandicus, Pseudocalanus elongatus, and Oithona similis. Mar. Ecol. Prog. Ser. 350, 79–89 (2007).
Google Scholar
Cavan, E. L., Kawaguchi, S. & Boyd, P. W. Implications for the mesopelagic microbial gardening hypothesis as determined by experimental fragmentation of Antarctic krill fecal pellets. Ecol. Evol. 11, 1023–1036 (2021).
Google Scholar
Briggs, N., Dall’Olmo, G. & Claustre, H. Major role of particle fragmentation in regulating biological sequestration of CO2 by the oceans. Science 367, 791–793 (2020).
Google Scholar
DeMott, W. R. Retention Efficiency, Perceptual Bias, and Active Choice As Mechanisms of Food Selection by Suspension-Feeding Zooplankton in Behavioural Mechanisms of Food Selection 569–594 (Springer, Berlin, Heidelberg, Germany, 1990).
Suh, H. L. & Nemoto, T. Morphology of the gastric mill in ten species of euphausiids. Mar. Biol. 97, 79–85 (1988).
Gauld, D. T. A peritrophic membrane in calanoid copepods. Nature 179, 325–326 (1957).
Google Scholar
Bruland, K. W. & Silver, M. W. Sinking rates of fecal pellets from gelatinous zooplankton (salps, pteropods, doliolids). Mar. Biol. 63, 295–300 (1981).
von Harbou, L. Trophodynamics of Salps in the Atlantic Southern Ocean. PhD thesis, University of Bremen, (2009).
Poulsen, L. K. & Iversen, M. H. Degradation of copepod fecal pellets: Key role of protozooplankton. Mar. Ecol. Prog. Ser. 367, 1–13 (2008).
Google Scholar
Böckmann, S. et al. Salp fecal pellets release more bioavailable iron to Southern Ocean phytoplankton than krill fecal pellets. Curr. Biol. 31, 2737–2746.e2733 (2021).
Google Scholar
Alcaraz, M. et al. Changes in the C, N, and P cycles by the predicted salps-krill shift in the Southern Ocean. Front. Mar. Sci. 1, 45 (2014).
Fielding, S., Watkins, J. L., Collins, M. A., Enderlein, P. & Venables, H. J. Acoustic determination of the distribution of fish and krill across the Scotia Sea in spring 2006, summer 2008 and autumn 2009. Deep Sea Res. 59-60, 173–188 (2012). Pt. II.
Google Scholar
Chiba, S., Horimoto, N., Satoh, R., Yamaguchi, Y. & Ishimaru, T. Macrozooplankton distribution around the Antarctic Divergence off Wilkes Land in the 1996 austral summer: With reference to high abundance of Salpa thompsoni. in: Proceedings of NIPR Symposium on Polar Biology, 33–50 (1998).
Henschke, N. & Pakhomov, E. A. Latitudinal variations in Salpa thompsoni reproductive fitness. Limnol. Oceanogr. 64, 575–584 (2018).
Google Scholar
Atkinson, A. et al. Oceanic circumpolar habitats of Antarctic krill. Mar. Ecol. Prog. Ser. 362, 1–23 (2008).
Google Scholar
Foxton, P. The Distribution and Life-History of Salpa thompsoni Foxton with Observations on a Related Species, Salpa gerlachei Foxton (Cambridge University Press, UK, Cambridge, 1966).
Meyer, B. et al. Successful ecosystem-based management of Antarctic krill should address uncertainties in krill recruitment, behaviour and ecological adaptation. Commun. Earth Environ. 1, 28 (2020).
Google Scholar
Atkinson, A., Siegel, V., Pakhomov, E. A., Jessopp, M. J. & Loeb, V. A re-appraisal of the total biomass and annual production of Antarctic krill. Deep Sea Res. Pt. I 56, 727–740 (2009).
Montes-Hugo, M. et al. Recent changes in phytoplankton communities associated with rapid regional climate change along the western Antarctic Peninsula. Science 323, 1470–1473 (2009).
Google Scholar
Fielding, S. et al. A Condensed History and Document of the Method Used by CCAMLR to Estimate Krill Biomass (B0) in 2010. (CCAMLR, 2016).
Chu, D., Foote, K. G. & Stanton, T. K. Further analysis of target strength measurements of Antarctic krill at 38 and 120 kHz: comparison with deformed cylinder model and inference of orientation distribution. J. Acoust. Soc. Am. 93, 2985–2988 (1993).
Google Scholar
McGehee, D. E., O’Driscoll, R. L. & Traykovski, L. V. M. Effects of orientation on acoustic scattering from Antarctic krill at 120 kHz. Deep Sea Res. 45, 1273–1294 (1998). Pt. II.
Google Scholar
Demer, D. A. & Conti, S. G. Reconciling theoretical versus empirical target strengths of krill: effects of phase variability on the distorted-wave Born approximation. ICES J. Mar. Sci. 60, 429–434 (2003).
Conti, S. G. & Demer, D. A. Improved parameterization of the SDWBA for estimating krill target strength. ICES J. Mar. Sci. 63, 928–935 (2006).
Calise, L. & Skaret, G. Sensitivity investigation of the SDWBA Antarctic krill target strength model to fatness, material contrasts and orientation. CCAMLR Sci. 18, 97–122 (2011).
Hewitt, R. P. et al. Biomass of Antarctic krill in the Scotia Sea in January/February 2000 and its use in revising an estimate of precautionary yield. Deep Sea Res. 51, 1215–1236 (2004). Pt. II.
Google Scholar
Flintrop, C. M. et al. Embedding and slicing of intact in situ collected marine snow. Limnol. Oceanogr. Methods 16, 339–355 (2018).
Markussen, T. N. et al. Tracks in the snow—advantage of combining optical methods to characterize marine particles and aggregates. Front. Mar. Sci. 7, 476 (2020).
Ploug, H. & Jorgensen, B. B. A net-jet flow system for mass transfer and microsensor studies of sinking aggregates. Mar. Ecol. Prog. Ser. 176, 279–290 (1999).
Google Scholar
Ploug, H., Terbrüggen, A., Kaufmann, A., Wolf-Gladrow, D. & Passow, U. A novel method to measure particle sinking velocity in vitro, and its comparison to three other in vitro methods. Limnol. Oceanogr. Methods 8, 386–393 (2010).
R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, Vienna, Austria, 2019).
ggplot2: Elegant Graphics for Data Analysis (Springer-Verlag New York, 2016).
Source: Ecology - nature.com
