1
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Schofield O, Cimino M, Doney S, Friedlaender A, Meredith M, Moffat C, Stammerjohn S, Van Mooy B, Steinberg D. Antarctic pelagic ecosystems on a warming planet. Trends Ecol Evol 2024:S0169-5347(24)00200-3. [PMID: 39266440 DOI: 10.1016/j.tree.2024.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 08/09/2024] [Accepted: 08/12/2024] [Indexed: 09/14/2024]
Abstract
High-latitude pelagic marine ecosystems are vulnerable to climate change because of the intertwining of sea/continental ice dynamics, physics, biogeochemistry, and food-web structure. Data from the West Antarctic Peninsula allow us to assess how ice influences marine food webs by modulating solar inputs to the ocean, inhibiting wind mixing, altering the freshwater balance and ocean stability, and providing a physical substrate for organisms. State changes are linked to an increase in storm forcing and changing distribution of ocean heat. Changes ripple through the plankton, shifting the magnitude of primary production and its community composition, altering the abundance of krill and other prey essential for marine mammals and seabirds. These climate-driven changes in the food web are being exacerbated by human activity.
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Affiliation(s)
- Oscar Schofield
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA.
| | - Megan Cimino
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Scott Doney
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA
| | | | | | - Carlos Moffat
- School of Marine Science and Policy, University of Delaware, Newark, DE, USA
| | - Sharon Stammerjohn
- Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, USA
| | | | - Deborah Steinberg
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, VA, USA
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2
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Savoca MS, Kumar M, Sylvester Z, Czapanskiy MF, Meyer B, Goldbogen JA, Brooks CM. Whale recovery and the emerging human-wildlife conflict over Antarctic krill. Nat Commun 2024; 15:7708. [PMID: 39256348 PMCID: PMC11387826 DOI: 10.1038/s41467-024-51954-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 08/20/2024] [Indexed: 09/12/2024] Open
Abstract
The Southern Ocean ecosystem has undergone extensive changes in the past two centuries driven by industrial sealing and whaling, climate change and commercial fishing. However, following the end of commercial whaling, some populations of whales in this region are recovering. Baleen whales are reliant on Antarctic krill, which is also the largest Southern Ocean fishery. Since 1993, krill catch has increased fourfold, buoyed by nutritional supplement and aquaculture industries. In this Perspective, we approximate baleen whale consumption of Antarctic krill before and after whaling to examine if the ecosystem can support both humans and whales as krill predators. Our back-of-the-envelope calculations suggest that current krill biomass cannot support both an expanding krill fishery and the recovery of whale populations to pre-whaling sizes, highlighting an emerging human-wildlife conflict. We then provide recommendations for enhancing sustainability in this region by reducing encounters with whales and bolstering the krill population.
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Affiliation(s)
- Matthew S Savoca
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
| | - Mehr Kumar
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Zephyr Sylvester
- Department of Environmental Studies, University of Colorado, Boulder, Boulder, CO, USA
| | - Max F Czapanskiy
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Bettina Meyer
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
| | - Jeremy A Goldbogen
- Department of Oceans, Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Cassandra M Brooks
- Department of Environmental Studies, University of Colorado, Boulder, Boulder, CO, USA
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3
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Manno C, Carlig E, Falco PP, Castagno P, Budillon G. Life strategy of Antarctic silverfish promote large carbon export in Terra Nova Bay, Ross Sea. Commun Biol 2024; 7:450. [PMID: 38605093 PMCID: PMC11009349 DOI: 10.1038/s42003-024-06122-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 03/28/2024] [Indexed: 04/13/2024] Open
Abstract
Antarctic silverfish Pleuragramma antarcticum is the most abundant pelagic fish in the High Antarctic shelf waters of the Southern Ocean, where it plays a pivotal role in the trophic web as the major link between lower and higher trophic levels. Despite the ecological importance of this species, knowledge about its role in the biogeochemical cycle is poor. We determine the seasonal contribution of Antarctic silverfish to carbon flux in terms of faeces and eggs, from samples collected in the Ross Sea. We find that eggs and faeces production generate a flux accounting for 41% of annual POC flux and that the variability of this flux is modulated by spawning strategy. This study shows the important role of this organism as a vector for carbon flux. Since Antarctic silverfish are strongly dependent on sea-ice, they might be especially sensitive to climatic changes. Our results suggest that a potential decrease in the biomass of this organism is likely to impact marine biogeochemical cycles, and this should be factored in when assessing Southern Ocean carbon budget.
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Affiliation(s)
- Clara Manno
- British Antarctic Survey, Natural Environment Research Council, NERC, Cambridge, UK.
| | - Erica Carlig
- National Research Council (CNR) of Italy, Institute for the study of the Anthropic impacts and the Sustainability of the marine environment (IAS), Genoa, Italy
| | - Pier Paolo Falco
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Pasquale Castagno
- Department of Mathematics and Computer Sciences, Physical Sciences and Earth Sciences (MIFT), University of Messina, Messina, Italy
| | - Giorgio Budillon
- Department of Science and Technology, University of Naples "Parthenope", Naples, Italy
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4
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Möller L, Vainshtein Y, Meyer B, Neidhardt J, Eren AM, Sohn K, Rabus R. Rich microbial and depolymerising diversity in Antarctic krill gut. Microbiol Spectr 2024; 12:e0403523. [PMID: 38466097 PMCID: PMC10986584 DOI: 10.1128/spectrum.04035-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 02/13/2024] [Indexed: 03/12/2024] Open
Abstract
With almost a quadrillion individuals, the Antarctic krill processes five million tons of organic carbon every day during austral summer. This high carbon flux requires a broad range of hydrolytic enzymes to decompose the diverse food-derived biopolymers. While krill itself possesses numerous such enzymes, it is unclear, to what extent the endogenous microbiota contribute to the hydrolytic potential of the gut environment. Here we applied amplicon sequencing, shotgun metagenomics, cultivation, and physiological assays to characterize the krill gut microbiota. The broad bacterial diversity (273 families, 919 genera, and 2,309 species) also included a complex potentially anaerobic sub-community. Plate-based assays with 198 isolated pure cultures revealed widespread capacities to utilize lipids (e.g., tributyrin), followed by proteins (casein) and to a lesser extent by polysaccharides (e.g., alginate and chitin). While most isolates affiliated with the genera Pseudoalteromonas and Psychrobacter, also Rubritalea spp. (Verrucomicrobia) were observed. The krill gut microbiota growing on marine broth agar plates possess 13,012 predicted hydrolyses; 15-fold more than previously predicted from a transcriptome-proteome compendium of krill. Cultivation-independent and -dependent approaches indicated members of the families Flavobacteriaceae and Pseudoalteromonadaceae to dominate the capacities for lipid/protein hydrolysis and to provide a plethora of carbohydrate-active enzymes, sulfatases, and laminarin- or porphyrin-depolymerizing hydrolases. Notably, also the potential to hydrolyze plastics such as polyethylene terephthalate and polylactatide was observed, affiliating mostly with Moraxellaceae. Overall, this study shows extensive microbial diversity in the krill gut, and suggests that the microbiota likely play a significant role in the nutrient acquisition of the krill by enriching its hydrolytic enzyme repertoire.IMPORTANCEThe Antarctic krill (Euphausia superba) is a keystone species of the Antarctic marine food web, connecting the productivity of phyto- and zooplankton with the nutrition of the higher trophic levels. Accordingly, krill significantly contributes to biomass turnover, requiring the decomposition of seasonally varying plankton-derived biopolymers. This study highlights the likely role of the krill gut microbiota in this ecosystem function by revealing the great number of diverse hydrolases that microbes contribute to the krill gut environment. The here resolved repertoire of hydrolytic enzymes could contribute to the overall nutritional resilience of krill and to the general organic matter cycling under changing environmental conditions in the Antarctic sea water. Furthermore, the krill gut microbiome could serve as a valuable resource of cold-adapted hydrolytic enzymes for diverse biotechnological applications.
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Affiliation(s)
- Lars Möller
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Yevhen Vainshtein
- In Vitro Diagnostics, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany
| | - Bettina Meyer
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University Oldenburg (HIFMB), Oldenburg, Germany
- Biosciences, Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - John Neidhardt
- Department of Human Medicine, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - A. Murat Eren
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University Oldenburg (HIFMB), Oldenburg, Germany
- HIFMB-MPG Bridging Group for Marine Genomics, Max Planck Institute for Marine Microbiology, Bremen, Germany
- Alfred Wegener Institute (AWI), Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany
| | - Kai Sohn
- In Vitro Diagnostics, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany
| | - Ralf Rabus
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
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5
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Rowlands E, Galloway T, Cole M, Lewis C, Hacker C, Peck VL, Thorpe S, Blackbird S, Wolff GA, Manno C. Scoping intergenerational effects of nanoplastic on the lipid reserves of Antarctic krill embryos. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 261:106591. [PMID: 37329636 DOI: 10.1016/j.aquatox.2023.106591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/05/2023] [Accepted: 05/24/2023] [Indexed: 06/19/2023]
Abstract
Antarctic krill (Euphausia superba) plays a central role in the Antarctic marine food web and biogeochemical cycles and has been identified as a species that is potentially vulnerable to plastic pollution. While plastic pollution has been acknowledged as a potential threat to Southern Ocean marine ecosystems, the effect of nanoplastics (<1000 nm) is poorly understood. Deleterious impacts of nanoplastic are predicted to be higher than that of larger plastics, due to their small size which enables their permeation of cell membranes and potentially provokes toxicity. Here, we investigated the intergenerational impact of exposing Antarctic krill to nanoplastics. We focused on whether embryonic energy resources were affected when gravid female krill were exposed to nanoplastic by determining lipid and fatty acid compositions of embryos produced in incubation. Embryos were collected from females who had spawned under three different exposure treatments (control, nanoplastic, nanoplastic + algae). Embryos collected from each maternal treatment were incubated for a further 6 days under three nanoplastic exposure treatments (control, low concentration nanoplastic, and high concentration nanoplastic). Nanoplastic additions to seawater did not impact lipid metabolism (total lipid or fatty acid composition) across the maternal or direct embryo treatments, and no interactive effects were observed. The provision of a food source during maternal exposure to nanoplastic had a positive effect on key fatty acids identified as important during embryogenesis, including higher total polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) when compared to the control and nanoplastic treatments. Whilst the short exposure time was ample for lipids from maternally digested algae to be incorporated into embryos, we discuss why the nanoplastic-fatty acid relationship may be more complex. Our study is the first to scope intergeneration effects of nanoplastic on Antarctic krill lipid and fatty acid reserves. From this, we suggest directions for future research including long term exposures, multi-stressor scenarios and exploring other critical energy reserves such as proteins.
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Affiliation(s)
- Emily Rowlands
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom.
| | - Tamara Galloway
- Biosciences, Faculty of Health and Life Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Matthew Cole
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, United Kingdom
| | - Ceri Lewis
- Biosciences, Faculty of Health and Life Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Christian Hacker
- Biosciences, Faculty of Health and Life Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - Victoria L Peck
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom
| | - Sally Thorpe
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom
| | - Sabena Blackbird
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Jane Herdman Building, 4 Brownlow Street, Liverpool L69 3GP, United Kingdom
| | - George A Wolff
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Jane Herdman Building, 4 Brownlow Street, Liverpool L69 3GP, United Kingdom
| | - Clara Manno
- British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom.
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6
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Trinh R, Ducklow HW, Steinberg DK, Fraser WR. Krill body size drives particulate organic carbon export in West Antarctica. Nature 2023; 618:526-530. [PMID: 37316721 DOI: 10.1038/s41586-023-06041-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/31/2023] [Indexed: 06/16/2023]
Abstract
The export of carbon from the ocean surface and storage in the ocean interior is important in the modulation of global climate1-4. The West Antarctic Peninsula experiences some of the largest summer particulate organic carbon (POC) export rates, and one of the fastest warming rates, in the world5,6. To understand how warming may alter carbon storage, it is necessary to first determine the patterns and ecological drivers of POC export7,8. Here we show that Antarctic krill (Euphausia superba) body size and life-history cycle, as opposed to their overall biomass or regional environmental factors, exert the dominant control on the POC flux. We measured POC fluxes over 21 years, the longest record in the Southern Ocean, and found a significant 5-year periodicity in the annual POC flux, which oscillated in synchrony with krill body size, peaking when the krill population was composed predominately of large individuals. Krill body size alters the POC flux through the production and export of size-varying faecal pellets9, which dominate the total flux. Decreases in winter sea ice10, an essential habitat for krill, are causing shifts in the krill population11, which may alter these export patterns of faecal pellets, leading to changes in ocean carbon storage.
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Affiliation(s)
- Rebecca Trinh
- Deparment of Earth and Environmental Sciences, Columbia University, New York, NY, USA.
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.
| | - Hugh W Ducklow
- Deparment of Earth and Environmental Sciences, Columbia University, New York, NY, USA
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, VA, USA
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7
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Pearson HC, Savoca MS, Costa DP, Lomas MW, Molina R, Pershing AJ, Smith CR, Villaseñor-Derbez JC, Wing SR, Roman J. Whales in the carbon cycle: can recovery remove carbon dioxide? Trends Ecol Evol 2023; 38:238-249. [PMID: 36528413 DOI: 10.1016/j.tree.2022.10.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 10/04/2022] [Accepted: 10/31/2022] [Indexed: 12/23/2022]
Abstract
The great whales (baleen and sperm whales), through their massive size and wide distribution, influence ecosystem and carbon dynamics. Whales directly store carbon in their biomass and contribute to carbon export through sinking carcasses. Whale excreta may stimulate phytoplankton growth and capture atmospheric CO2; such indirect pathways represent the greatest potential for whale-carbon sequestration but are poorly understood. We quantify the carbon values of whales while recognizing the numerous ecosystem, cultural, and moral motivations to protect them. We also propose a framework to quantify the economic value of whale carbon as populations change over time. Finally, we suggest research to address key unknowns (e.g., bioavailability of whale-derived nutrients to phytoplankton, species- and region-specific variability in whale carbon contributions).
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Affiliation(s)
- Heidi C Pearson
- Department of Natural Sciences, University of Alaska Southeast, Juneau, AK, USA.
| | - Matthew S Savoca
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Daniel P Costa
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Michael W Lomas
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Renato Molina
- Rosenstiel School of Marine, Atmospheric, and Earth Science and Miami Herbert Business School, University of Miami, Miami, FL, USA
| | | | - Craig R Smith
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Juan Carlos Villaseñor-Derbez
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA; Bren School of Environmental Science & Management, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Stephen R Wing
- Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Joe Roman
- Gund Institute for Environment, University of Vermont, Burlington, VT, USA
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8
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Wilkie Johnston L, Bergami E, Rowlands E, Manno C. Organic or junk food? Microplastic contamination in Antarctic krill and salps. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221421. [PMID: 36998765 PMCID: PMC10049761 DOI: 10.1098/rsos.221421] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
Microplastics (MP) have been reported in Southern Ocean (SO), where they are likely to encounter Antarctic zooplankton and enter pelagic food webs. Here we assess the presence of MP within Antarctic krill (Euphausia superba) and salps (Salpa thompsoni) and quantify their abundance and type by micro-Fourier transform infrared microscopy. MP were found in both species, with fibres being more abundant than fragments (krill: 56.25% and salps: 22.32% of the total MP). Polymer identification indicated MP originated from both local and distant sources. Our findings prove how in situ MP ingestion from these organisms is a real and ongoing process in the SO. MP amount was higher in krill (2.13 ± 0.26 MP ind-1) than salps (1.38 ± 0.42 MP ind-1), while MP size extracted from krill (130 ± 30 µm) was significantly lower than MP size from salps (330 ± 50 µm). We suggest that differences between abundance and size of MP ingested by these two species may be related to their food strategies, their ability to fragment MP as well as different human pressures within the collection areas of the study region. First comparative field-based evidence of MP in both krill and salps, two emblematic zooplankton species of the SO marine ecosystems, underlines that Antarctic marine ecosystems may be particularly sensitive to plastic pollution.
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Affiliation(s)
- Laura Wilkie Johnston
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
- University of St Andrews, St Andrews, Scotland KY16 9AJ, UK
| | - Elisa Bergami
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Giuseppe Campi 213/D, Modena, Italy
| | - Emily Rowlands
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Clara Manno
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK
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9
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Décima M, Stukel MR, Nodder SD, Gutiérrez-Rodríguez A, Selph KE, Dos Santos AL, Safi K, Kelly TB, Deans F, Morales SE, Baltar F, Latasa M, Gorbunov MY, Pinkerton M. Salp blooms drive strong increases in passive carbon export in the Southern Ocean. Nat Commun 2023; 14:425. [PMID: 36732522 PMCID: PMC9894854 DOI: 10.1038/s41467-022-35204-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 11/23/2022] [Indexed: 02/04/2023] Open
Abstract
The Southern Ocean contributes substantially to the global biological carbon pump (BCP). Salps in the Southern Ocean, in particular Salpa thompsoni, are important grazers that produce large, fast-sinking fecal pellets. Here, we quantify the salp bloom impacts on microbial dynamics and the BCP, by contrasting locations differing in salp bloom presence/absence. Salp blooms coincide with phytoplankton dominated by diatoms or prymnesiophytes, depending on water mass characteristics. Their grazing is comparable to microzooplankton during their early bloom, resulting in a decrease of ~1/3 of primary production, and negative phytoplankton rates of change are associated with all salp locations. Particle export in salp waters is always higher, ranging 2- to 8- fold (average 5-fold), compared to non-salp locations, exporting up to 46% of primary production out of the euphotic zone. BCP efficiency increases from 5 to 28% in salp areas, which is among the highest recorded in the global ocean.
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Affiliation(s)
- Moira Décima
- National Institute of Water and Atmospheric Research (NIWA), Hataitai, Wellington, 6021, New Zealand. .,Scripps Institution of Oceanography, University of California at San Diego, San Diego, CA, 92093, USA.
| | - Michael R Stukel
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, 32304, USA.,Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, 32310, USA
| | - Scott D Nodder
- National Institute of Water and Atmospheric Research (NIWA), Hataitai, Wellington, 6021, New Zealand
| | - Andrés Gutiérrez-Rodríguez
- National Institute of Water and Atmospheric Research (NIWA), Hataitai, Wellington, 6021, New Zealand.,Instituto Español de Oceanografía, Centro Oceanográfico de Gijón, Avenida Príncipe de Asturias, 70 bis, 33212, Gijón, Spain
| | - Karen E Selph
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA
| | - Adriana Lopes Dos Santos
- Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Karl Safi
- National Institute of Water and Atmospheric Research, P.O. Box 11-115, Hamilton, New Zealand
| | - Thomas B Kelly
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, 32304, USA.,College of Fisheries and Ocean Sciences, University of Alaska, Fairbanks, AK, 99775, USA
| | - Fenella Deans
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Sergio E Morales
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Federico Baltar
- Department of Functional & Evolutionary Ecology, University of Vienna, Vienna, 1090, Austria
| | - Mikel Latasa
- Instituto Español de Oceanografía, Centro Oceanográfico de Gijón, Avenida Príncipe de Asturias, 70 bis, 33212, Gijón, Spain
| | - Maxim Y Gorbunov
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Matt Pinkerton
- National Institute of Water and Atmospheric Research (NIWA), Hataitai, Wellington, 6021, New Zealand
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10
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Durfort A, Mariani G, Tulloch V, Savoca MS, Troussellier M, Mouillot D. Recovery of carbon benefits by overharvested baleen whale populations is threatened by climate change. Proc Biol Sci 2022; 289:20220375. [PMID: 36321488 PMCID: PMC9627705 DOI: 10.1098/rspb.2022.0375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 10/10/2022] [Indexed: 12/03/2022] Open
Abstract
Despite the importance of marine megafauna on ecosystem functioning, their contribution to the oceanic carbon cycle is still poorly known. Here, we explored the role of baleen whales in the biological carbon pump across the southern hemisphere based on the historical and forecasted abundance of five baleen whale species. We modelled whale-mediated carbon sequestration through the sinking of their carcasses after natural death. We provide the first temporal dynamics of this carbon pump from 1890 to 2100, considering both the effects of exploitation and climate change on whale populations. We reveal that at their pre-exploitation abundance, the five species of southern whales could sequester 4.0 × 105 tonnes of carbon per year (tC yr-1). This estimate dropped to 0.6 × 105 tC yr-1 by 1972 following commercial whaling. However, with the projected restoration of whale populations under a RCP8.5 climate scenario, the sequestration would reach 1.7 × 105 tC yr-1 by 2100, while without climate change, recovered whale populations could sequester nearly twice as much (3.2 × 105 tC yr-1) by 2100. This highlights the persistence of whaling damages on whale populations and associated services as well as the predicted harmful impacts of climate change on whale ecosystem services.
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Affiliation(s)
- Anaëlle Durfort
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Gaël Mariani
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Vivitskaia Tulloch
- Department of Forest and Conservation Science, University of British Columbia, Vancouver, BC, Canada
| | | | | | - David Mouillot
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
- Institut Universitaire de France, 75231, Paris, France
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11
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Johnston NM, Murphy EJ, Atkinson A, Constable AJ, Cotté C, Cox M, Daly KL, Driscoll R, Flores H, Halfter S, Henschke N, Hill SL, Höfer J, Hunt BPV, Kawaguchi S, Lindsay D, Liszka C, Loeb V, Manno C, Meyer B, Pakhomov EA, Pinkerton MH, Reiss CS, Richerson K, Jr. WOS, Steinberg DK, Swadling KM, Tarling GA, Thorpe SE, Veytia D, Ward P, Weldrick CK, Yang G. Status, Change, and Futures of Zooplankton in the Southern Ocean. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.624692] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the Southern Ocean, several zooplankton taxonomic groups, euphausiids, copepods, salps and pteropods, are notable because of their biomass and abundance and their roles in maintaining food webs and ecosystem structure and function, including the provision of globally important ecosystem services. These groups are consumers of microbes, primary and secondary producers, and are prey for fishes, cephalopods, seabirds, and marine mammals. In providing the link between microbes, primary production, and higher trophic levels these taxa influence energy flows, biological production and biomass, biogeochemical cycles, carbon flux and food web interactions thereby modulating the structure and functioning of ecosystems. Additionally, Antarctic krill (Euphausia superba) and various fish species are harvested by international fisheries. Global and local drivers of change are expected to affect the dynamics of key zooplankton species, which may have potentially profound and wide-ranging implications for Southern Ocean ecosystems and the services they provide. Here we assess the current understanding of the dominant metazoan zooplankton within the Southern Ocean, including Antarctic krill and other key euphausiid, copepod, salp and pteropod species. We provide a systematic overview of observed and potential future responses of these taxa to a changing Southern Ocean and the functional relationships by which drivers may impact them. To support future ecosystem assessments and conservation and management strategies, we also identify priorities for Southern Ocean zooplankton research.
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12
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Shin Y, Midgley GF, Archer ERM, Arneth A, Barnes DKA, Chan L, Hashimoto S, Hoegh‐Guldberg O, Insarov G, Leadley P, Levin LA, Ngo HT, Pandit R, Pires APF, Pörtner H, Rogers AD, Scholes RJ, Settele J, Smith P. Actions to halt biodiversity loss generally benefit the climate. GLOBAL CHANGE BIOLOGY 2022; 28:2846-2874. [PMID: 35098619 PMCID: PMC9303674 DOI: 10.1111/gcb.16109] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 05/04/2023]
Abstract
The two most urgent and interlinked environmental challenges humanity faces are climate change and biodiversity loss. We are entering a pivotal decade for both the international biodiversity and climate change agendas with the sharpening of ambitious strategies and targets by the Convention on Biological Diversity and the United Nations Framework Convention on Climate Change. Within their respective Conventions, the biodiversity and climate interlinked challenges have largely been addressed separately. There is evidence that conservation actions that halt, slow or reverse biodiversity loss can simultaneously slow anthropogenic mediated climate change significantly. This review highlights conservation actions which have the largest potential for mitigation of climate change. We note that conservation actions have mainly synergistic benefits and few antagonistic trade-offs with climate change mitigation. Specifically, we identify direct co-benefits in 14 out of the 21 action targets of the draft post-2020 global biodiversity framework of the Convention on Biological Diversity, notwithstanding the many indirect links that can also support both biodiversity conservation and climate change mitigation. These relationships are context and scale-dependent; therefore, we showcase examples of local biodiversity conservation actions that can be incentivized, guided and prioritized by global objectives and targets. The close interlinkages between biodiversity, climate change mitigation, other nature's contributions to people and good quality of life are seldom as integrated as they should be in management and policy. This review aims to re-emphasize the vital relationships between biodiversity conservation actions and climate change mitigation in a timely manner, in support to major Conferences of Parties that are about to negotiate strategic frameworks and international goals for the decades to come.
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Affiliation(s)
| | - Guy F. Midgley
- School for Climate Studies, Department of Botany and ZoologyStellenbosch UniversityStellenboschSouth Africa
| | - Emma R. M. Archer
- Department of GeographyGeo‐Informatics and MeteorologyUniversity of PretoriaHatfield, PretoriaSouth Africa
| | - Almut Arneth
- Atmospheric Environmental ResearchKarlsruhe Institute of Technology (KIT)Garmisch‐PartenkirchenGermany
| | | | - Lena Chan
- International Biodiversity Conservation DivisionNational Parks BoardSingaporeSingapore
| | | | - Ove Hoegh‐Guldberg
- School of Biological Sciences and ARC Centre of Excellence for Coral Reef StudiesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Gregory Insarov
- Institute of Geography of the Russian Academy for SciencesMoscowRussia
| | - Paul Leadley
- Laboratoire d’Ecologie Systématique EvolutionUniversité Paris‐Saclay, CNRS, AgroParisTechOrsayFrance
| | - Lisa A. Levin
- Center for Marine Biodiversity and Conservation and Integrative Oceanography DivisionScripps Institution of OceanographyUniversity of CaliforniaSan DiegoCaliforniaUSA
| | - Hien T. Ngo
- Office of Climate Change, Biodiversity and Environment, Food and Agriculture Organization of the United NationsRomeItaly
- Intergovernmental Science‐Policy Platform on Biodiversity and Ecosystem Services (IPBES)BonnGermany
| | - Ram Pandit
- Centre for Environmental Economics and PolicyUWA School of Agriculture and EnvironmentThe University of Western AustraliaCrawleyWestern AustraliaAustralia
- Global Center for Food, Land and Water ResourcesResearch Faculty of AgricultureHokkaido UniversitySapporoHokkaidoJapan
| | - Aliny P. F. Pires
- Department of Ecology – IBRAGRio de Janeiro State University (UERJ)Rio de JaneiroBrazil
| | - Hans‐Otto Pörtner
- Alfred Wegener Institute for Polar and Marine ResearchBremerhavenGermany
| | | | - Robert J. Scholes
- Global Change InstituteUniversity of the WitwatersrandJohannesburgSouth Africa
| | - Josef Settele
- Department of Conservation Biology and Social‐Ecological SystemsHelmholtz Centre for Environmental Research—UFZHalleGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Pete Smith
- Institute of Biological and Environmental SciencesUniversity of AberdeenAberdeenUK
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13
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Pauli NC, Flintrop CM, Konrad C, Pakhomov EA, Swoboda S, Koch F, Wang XL, Zhang JC, Brierley AS, Bernasconi M, Meyer B, Iversen MH. Krill and salp faecal pellets contribute equally to the carbon flux at the Antarctic Peninsula. Nat Commun 2021; 12:7168. [PMID: 34887407 PMCID: PMC8660819 DOI: 10.1038/s41467-021-27436-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 11/15/2021] [Indexed: 11/09/2022] Open
Abstract
Krill and salps are important for carbon flux in the Southern Ocean, but the extent of their contribution and the consequences of shifts in dominance from krill to salps remain unclear. We present a direct comparison of the contribution of krill and salp faecal pellets (FP) to vertical carbon flux at the Antarctic Peninsula using a combination of sediment traps, FP production, carbon content, microbial degradation, and krill and salp abundances. Salps produce 4-fold more FP carbon than krill, but the FP from both species contribute equally to the carbon flux at 300 m, accounting for 75% of total carbon. Krill FP are exported to 72% to 300 m, while 80% of salp FP are retained in the mixed layer due to fragmentation. Thus, declining krill abundances could lead to decreased carbon flux, indicating that the Antarctic Peninsula could become a less efficient carbon sink for anthropogenic CO2 in future.
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Affiliation(s)
- Nora-Charlotte Pauli
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26111, Oldenburg, Germany. .,Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Clara M. Flintrop
- grid.10894.340000 0001 1033 7684Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany ,grid.7704.40000 0001 2297 4381MARUM and University of Bremen, Leobener Str. 8, 28359 Bremen, Germany
| | - Christian Konrad
- grid.10894.340000 0001 1033 7684Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany ,grid.7704.40000 0001 2297 4381MARUM and University of Bremen, Leobener Str. 8, 28359 Bremen, Germany
| | - Evgeny A. Pakhomov
- grid.17091.3e0000 0001 2288 9830Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, 2207 Main Mall, Vancouver, British Columbia V6T 1Z4 Canada ,grid.17091.3e0000 0001 2288 9830Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall, Vancouver, British Columbia V6T 1Z4 Canada ,grid.484717.9Hakai Institute, PO Box 25039, Campbell River, British Columbia V9W 0B7 Canada
| | - Steffen Swoboda
- grid.7704.40000 0001 2297 4381MARUM and University of Bremen, Leobener Str. 8, 28359 Bremen, Germany
| | - Florian Koch
- grid.10894.340000 0001 1033 7684Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Xin-Liang Wang
- grid.43308.3c0000 0000 9413 3760Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, 266071 China
| | - Ji-Chang Zhang
- grid.43308.3c0000 0000 9413 3760Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, 266071 China
| | - Andrew S. Brierley
- grid.11914.3c0000 0001 0721 1626Pelagic Ecology Research Group, Gatty Marine Laboratory, Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, Fife KY16 8LB UK
| | - Matteo Bernasconi
- grid.11914.3c0000 0001 0721 1626Pelagic Ecology Research Group, Gatty Marine Laboratory, Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, Fife KY16 8LB UK
| | - Bettina Meyer
- Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26111, Oldenburg, Germany. .,Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany. .,Helmholtz Institute for Functional Marine Biodiversity (HIFMB), Ammerländer Heerstraße 231, 26129, Oldenburg, Germany.
| | - Morten H. Iversen
- grid.10894.340000 0001 1033 7684Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany ,grid.7704.40000 0001 2297 4381MARUM and University of Bremen, Leobener Str. 8, 28359 Bremen, Germany
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14
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Selective feeding in Southern Ocean key grazers-diet composition of krill and salps. Commun Biol 2021; 4:1061. [PMID: 34508174 PMCID: PMC8433442 DOI: 10.1038/s42003-021-02581-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 08/24/2021] [Indexed: 02/08/2023] Open
Abstract
Over the past decades, two key grazers in the Southern Ocean (SO), krill and salps, have experienced drastic changes in their distribution and abundance, leading to increasing overlap of their habitats. Both species occupy different ecological niches and long-term shifts in their distributions are expected to have cascading effects on the SO ecosystem. However, studies directly comparing krill and salps are lacking. Here, we provide a direct comparison of the diet and fecal pellet composition of krill and salps using 18S metabarcoding and fatty acid markers. Neither species' diet reflected the composition of the plankton community, suggesting that in contrast to the accepted paradigm, not only krill but also salps are selective feeders. Moreover, we found that krill and salps had broadly similar diets, potentially enhancing the competition between both species. This could be augmented by salps' ability to rapidly reproduce in favorable conditions, posing further risks to krill populations.
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15
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Kane MK, Atkinson A, Menden-Deuer S. Lowered cameras reveal hidden behaviors of Antarctic krill. Curr Biol 2021; 31:R237-R238. [PMID: 33689718 DOI: 10.1016/j.cub.2021.01.091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Antarctic krill (Euphausia superba, hereafter 'krill') exemplify the methodological challenges of studying small, mobile, aggregating pelagic organisms.1 Krill are a central species in the Southern Ocean food web, provide important biogeochemical functions and support a valuable commercial fishery.2 Most of what we know about krill has been derived from acoustic surveys and net samples, the former being essential for estimating krill biomass and catch limits. However, understanding krill behavior, particularly in the poorly-studied autumn-winter seasons, is key for management and conservation. Here, we used seasonal video observations collected with a profiling camera system of krill along the Western Antarctic Peninsula to reveal krill vertical distribution, aggregation density and individual behaviors that have remained hidden from traditional sampling methods.3.
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Affiliation(s)
- Mary K Kane
- Plymouth Marine Laboratory, 1 Prospect Place, Plymouth, Devon PL1 3DH, UK; Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA.
| | - Angus Atkinson
- Plymouth Marine Laboratory, 1 Prospect Place, Plymouth, Devon PL1 3DH, UK
| | - Susanne Menden-Deuer
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA
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16
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Le Mézo PK, Galbraith ED. The fecal iron pump: Global impact of animals on the iron stoichiometry of marine sinking particles. LIMNOLOGY AND OCEANOGRAPHY 2021; 66:201-213. [PMID: 33664531 PMCID: PMC7891356 DOI: 10.1002/lno.11597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 03/16/2020] [Accepted: 08/20/2020] [Indexed: 06/12/2023]
Abstract
The impact of marine animals on the iron (Fe) cycle has mostly been considered in terms of their role in supplying dissolved Fe to phytoplankton at the ocean surface. However, little attention has been paid to how the transformation of ingested food into fecal matter by animals alters the relative Fe-richness of particles, which could have consequences for Fe cycling in the water column and for the food quality of suspended and sinking particles. Here, we compile observations to show that the Fe to carbon (C) ratio (Fe:C) of fecal pellets of various marine animals is consistently enriched compared to their food, often by more than an order of magnitude. We explain this consistent enrichment by the low assimilation rates that have been measured for Fe in animals, together with the respiratory conversion of dietary organic C to excreted dissolved inorganic C. Furthermore, we calculate that this enrichment should cause animal fecal matter to constitute a major fraction of the global sinking flux of biogenic Fe, a component of the marine iron cycle that has been previously unappreciated. We also estimate that this fecal iron pump provides an important source of Fe to marine animals via coprophagy, particularly in the mesopelagic, given that fecal matter Fe:C can be many-fold higher than the Fe:C of local phytoplankton. Our results imply that the fecal iron pump is important both for global Fe cycling and for the iron nutrition of pelagic and mesopelagic communities.
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Affiliation(s)
- Priscilla K. Le Mézo
- Institut de Ciència i Tecnologia Ambientals (ICTA)Universitat Autonoma de Barcelona (UAB)BarcelonaSpain
- Laboratoire de Météorologie Dynamique (LMD) / Institut Pierre Simon LaplaceCNRS, Ecole Normale Supérieure, Université PSL, Ecole Polytechnique, Sorbonne UniversitéParisFrance
| | - Eric D. Galbraith
- Institut de Ciència i Tecnologia Ambientals (ICTA)Universitat Autonoma de Barcelona (UAB)BarcelonaSpain
- Catalan Institution for Research and Advanced Studies (ICREA)BarcelonaSpain
- Earth and Planetary SciencesMcGill UniversityMontrealQuebecCanada
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17
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Cavan EL, Kawaguchi S, Boyd PW. Implications for the mesopelagic microbial gardening hypothesis as determined by experimental fragmentation of Antarctic krill fecal pellets. Ecol Evol 2021; 11:1023-1036. [PMID: 33520184 PMCID: PMC7820144 DOI: 10.1002/ece3.7119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 11/08/2020] [Accepted: 11/12/2020] [Indexed: 11/26/2022] Open
Abstract
Detritivores need to upgrade their food to increase its nutritional value. One method is to fragment detritus promoting the colonization of nutrient-rich microbes, which consumers then ingest along with the detritus; so-called microbial gardening. Observations and numerical models of the detritus-dominated ocean mesopelagic zone have suggested microbial gardening by zooplankton is a fundamental process in the ocean carbon cycle leading to increased respiration of carbon-rich detritus. However, no experimental evidence exists to demonstrate that microbial respiration rates are higher on recently fragmented sinking detrital particles.Using aquaria-reared Antarctic krill fecal pellets, we showed fragmentation increased microbial particulate organic carbon (POC) turnover by 1.9×, but only on brown fecal pellets, formed from the consumption of other pellets. Microbial POC turnover on un- and fragmented green fecal pellets, formed from consuming fresh phytoplankton, was equal. Thus, POC content, fragmentation, and potentially nutritional value together drive POC turnover rates.Mesopelagic microbial gardening could be a risky strategy, as the dominant detrital food source is settling particles; even though fragmentation decreases particle size and sinking rate, it is unlikely that an organism would remain with the particle long enough to nutritionally benefit from attached microbes. We propose "communal gardening" occurs whereby additional mesopelagic organisms nearby or below the site of fragmentation consume the particle and the colonized microbes.To determine how fragmentation impacts the remineralization of sinking carbon-rich detritus and to parameterize microbial gardening in mesopelagic carbon models, three key metrics from further controlled experiments and observations are needed; how particle composition (here, pellet color/krill diet) impacts the response of microbes to the fragmentation of particles; the nutritional benefit to zooplankton from ingesting microbes after fragmentation along with identification of which essential nutrients are being targeted; how both these factors vary between physical (shear) and biological particle fragmentation.
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Affiliation(s)
- Emma L. Cavan
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaBattery PointTASAustralia
- Department of Life Sciences, Silwood Park CampusImperial College LondonAscotUK
| | - So Kawaguchi
- Australian Antarctic DivisionKingstonTASAustralia
| | - Philip W. Boyd
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaBattery PointTASAustralia
- Antarctic Climate and Ecosystems CRCUniversity of TasmaniaBattery PointTASAustralia
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18
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Continuous moulting by Antarctic krill drives major pulses of carbon export in the north Scotia Sea, Southern Ocean. Nat Commun 2020; 11:6051. [PMID: 33247126 PMCID: PMC7699634 DOI: 10.1038/s41467-020-19956-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 11/04/2020] [Indexed: 12/02/2022] Open
Abstract
Antarctic krill play an important role in biogeochemical cycles and can potentially generate high-particulate organic carbon (POC) fluxes to the deep ocean. They also have an unusual trait of moulting continuously throughout their life-cycle. We determine the krill seasonal contribution to POC flux in terms of faecal pellets (FP), exuviae and carcasses from sediment trap samples collected in the Southern Ocean. We found that krill moulting generated an exuviae flux of similar order to that of FP, together accounting for 87% of an annual POC flux (22.8 g m−2 y−1). Using an inverse modelling approach, we determined the krill population size necessary to generate this flux peaked at 261 g m−2. This study shows the important role of krill exuviae as a vector for POC flux. Since krill moulting cycle depends on temperature, our results highlight the sensitivity of POC flux to rapid regional environmental change. Antarctic krill are known to be important to the carbon cycle, but the exact contribution is not known. Here the authors show that krill moulting is a major vector of carbon export in the Southern Ocean, together with krill faecal pellets accounting for almost 90% of annual particulate organic carbon flux.
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19
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Bergami E, Manno C, Cappello S, Vannuccini ML, Corsi I. Nanoplastics affect moulting and faecal pellet sinking in Antarctic krill (Euphausia superba) juveniles. ENVIRONMENT INTERNATIONAL 2020; 143:105999. [PMID: 32763632 DOI: 10.1016/j.envint.2020.105999] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
Plastic debris has been identified as a potential threat to Antarctic marine ecosystems, however, the impact of nanoplastics (<1 μm) is currently unexplored. Antarctic krill (Euphausia superba) is a keystone species of Southern Ocean pelagic ecosystems, which plays a central role in the Antarctic food webs and carbon (C) cycle. Krill has been shown to rapidly fragment microplastic beads through the digestive system, releasing nanoplastics with unknown toxicological effects. Here we exposed krill juveniles to carboxylic (COOH, anionic) and amino- (NH2, cationic) polystyrene nanoparticles (PS NPs) and we investigated lethal and sub-lethal endpoints after 48 h. The analysis of PS NP suspensions in Antarctic sea water (SW) media showed that PS-COOH formed large agglomerates (1043 ± 121 nm), while PS-NH2 kept their nominal size (56.8 ± 3 nm) during the exposure time. After 48 h, no mortality was found but increase in exuviae production (12.6 ± 1.3%) and reduced swimming activity were observed in juveniles exposed to PS-NH2. The microbial community composition in SW supports the release of krill moults upon PS NP exposure and stimulates further research on the pivotal role of krill in shaping Southern Ocean bacterial assemblages. The presence of fluorescent signal in krill faecal pellets (FPs) confirmed the waterborne ingestion and egestion of PS-COOH at 48 h of exposure. Changes in FP structure and properties were also associated to the incorporation of PS NPs regardless of their surface charge. The effects of PS NPs on krill FP properties were compared to Control 0 h as a reference for full FPs (plastic vs food) and Control 48 h as a reference for more empty-like FPs (plastic vs lack of food). Exposure to PS NPs led to a FP sinking rate comparable to Control 48 h, but significantly lower than Control 0 h (58.40 ± 23.60 m/d and 51.23 ± 28.60 m/d for PS-COOH and PS-NH2; 168.80 ± 74.58 m/d for Control 0 h). Considering the important role played by krill in the food web and C export in the Southern Ocean, the present study provides cues about the potential impact of nanoplastics on Antarctic pelagic ecosystems and their biogeochemical cycles.
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Affiliation(s)
- E Bergami
- Department of Physical, Earth and Environmental Sciences (DSFTA), University of Siena, Siena 53100, Italy.
| | - C Manno
- British Antarctic Survey (BAS), Natural Environment Research Council, Cambridge CB3 0ET, UK
| | - S Cappello
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council, Messina 98121, Italy
| | - M L Vannuccini
- Department of Physical, Earth and Environmental Sciences (DSFTA), University of Siena, Siena 53100, Italy
| | - I Corsi
- Department of Physical, Earth and Environmental Sciences (DSFTA), University of Siena, Siena 53100, Italy
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20
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Southern Ocean carbon export efficiency in relation to temperature and primary productivity. Sci Rep 2020; 10:13494. [PMID: 32778681 PMCID: PMC7417578 DOI: 10.1038/s41598-020-70417-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 07/29/2020] [Indexed: 11/29/2022] Open
Abstract
Satellite remote sensing and numerical models are widely used to estimate large-scale variations in ocean carbon export, but the relationship between export efficiency (e-ratio) of sinking organic carbon out of the surface ocean and its drivers remains poorly understood, especially in the Southern Ocean. Here, we assess the effects of temperature and primary productivity on e-ratio by combining particulate organic carbon export flux from in situ measurements during 1997–2013, environmental parameters from satellite products, and outputs from ocean biogeochemical models in the Southern Ocean. Results show that “High Productivity Low E-ratio” (HPLE) is a common phenomenon in the Subantarctic Zone and the Polar Frontal Zone, but not the Antarctic Zone. The e-ratio shows little dependence on temperature below 6 °C. Our results support the hypothesis that the HPLE phenomenon is due to the large contribution of non-sinking organic carbon. Both temperature and ballast minerals play less important roles in controlling e-ratio than ecosystem structure at low temperatures. These findings suggest that non-sinking organic carbon, ecosystem structure, and region-specific parameterizations of e-ratio are key factors to quantify the carbon export in the Southern Ocean.
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21
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Rogers AD, Frinault BAV, Barnes DKA, Bindoff NL, Downie R, Ducklow HW, Friedlaender AS, Hart T, Hill SL, Hofmann EE, Linse K, McMahon CR, Murphy EJ, Pakhomov EA, Reygondeau G, Staniland IJ, Wolf-Gladrow DA, Wright RM. Antarctic Futures: An Assessment of Climate-Driven Changes in Ecosystem Structure, Function, and Service Provisioning in the Southern Ocean. ANNUAL REVIEW OF MARINE SCIENCE 2020; 12:87-120. [PMID: 31337252 DOI: 10.1146/annurev-marine-010419-011028] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this article, we analyze the impacts of climate change on Antarctic marine ecosystems. Observations demonstrate large-scale changes in the physical variables and circulation of the Southern Ocean driven by warming, stratospheric ozone depletion, and a positive Southern Annular Mode. Alterations in the physical environment are driving change through all levels of Antarctic marine food webs, which differ regionally. The distributions of key species, such as Antarctic krill, are also changing. Differential responses among predators reflect differences in species ecology. The impacts of climate change on Antarctic biodiversity will likely vary for different communities and depend on species range. Coastal communities and those of sub-Antarctic islands, especially range-restricted endemic communities, will likely suffer the greatest negative consequences of climate change. Simultaneously, ecosystem services in the Southern Ocean will likely increase. Such decoupling of ecosystem services and endemic species will require consideration in the management of human activities such as fishing in Antarctic marine ecosystems.
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Affiliation(s)
- A D Rogers
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
- REV Ocean, 1366 Lysaker, Norway
| | - B A V Frinault
- School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, United Kingdom
| | - D K A Barnes
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - N L Bindoff
- Antarctic Climate and Ecosystems Cooperative Research Centre and CSIRO Oceans and Atmospheres, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - R Downie
- WWF, Living Planet Centre, Surrey GU21 4LL, United Kingdom
| | - H W Ducklow
- Lamont-Doherty Earth Observatory and Department of Earth and Environmental Sciences, Columbia University, Palisades, New York 10964-8000, USA
| | - A S Friedlaender
- Institute for Marine Sciences, University of California, Santa Cruz, California 95060, USA
| | - T Hart
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
| | - S L Hill
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - E E Hofmann
- Center for Coastal Physical Oceanography, Old Dominion University, Norfolk, Virginia 23508, USA
| | - K Linse
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - C R McMahon
- Integrated Marine Observing System Animal Tracking Facility, Sydney Institute of Marine Science, Sydney, New South Wales 2088, Australia
| | - E J Murphy
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - E A Pakhomov
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Aquatic Ecosystems Research Lab, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - G Reygondeau
- Aquatic Ecosystems Research Lab, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - I J Staniland
- British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, United Kingdom
| | - D A Wolf-Gladrow
- Alfred-Wegener-Institut Helmholtz Zentrum für Polar- und Meeresforschung (AWI), 27570 Bremerhaven, Germany
| | - R M Wright
- Tyndall Centre, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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Cavan EL, Belcher A, Atkinson A, Hill SL, Kawaguchi S, McCormack S, Meyer B, Nicol S, Ratnarajah L, Schmidt K, Steinberg DK, Tarling GA, Boyd PW. The importance of Antarctic krill in biogeochemical cycles. Nat Commun 2019; 10:4742. [PMID: 31628346 PMCID: PMC6800442 DOI: 10.1038/s41467-019-12668-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/25/2019] [Indexed: 02/02/2023] Open
Abstract
Antarctic krill (Euphausia superba) are swarming, oceanic crustaceans, up to two inches long, and best known as prey for whales and penguins - but they have another important role. With their large size, high biomass and daily vertical migrations they transport and transform essential nutrients, stimulate primary productivity and influence the carbon sink. Antarctic krill are also fished by the Southern Ocean's largest fishery. Yet how krill fishing impacts nutrient fertilisation and the carbon sink in the Southern Ocean is poorly understood. Our synthesis shows fishery management should consider the influential biogeochemical role of both adult and larval Antarctic krill.
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Affiliation(s)
- E L Cavan
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia.
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.
| | - A Belcher
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Rd, Cambridge, CB3 0ET, UK
| | - A Atkinson
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - S L Hill
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Rd, Cambridge, CB3 0ET, UK
| | - S Kawaguchi
- Australian Antarctic Division, Kingston, TAS, Australia
| | - S McCormack
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, TAS, Australia
| | - B Meyer
- Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111, Oldenburg, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg, Ammerländer Heerstrasse 231, Oldenburg, 26129, Germany
| | - S Nicol
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - L Ratnarajah
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - K Schmidt
- School of Geography, Earth and Environmental Science, University of Plymouth, Plymouth, UK
| | - D K Steinberg
- Virginia Institute of Marine Science, College of William & Mary, Williamsburg, VA, USA
| | - G A Tarling
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Rd, Cambridge, CB3 0ET, UK
| | - P W Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, TAS, Australia
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