Ocean Carbon & Biogeochemistry
Studying marine ecosystems and biogeochemical cycles in the face of environmental change
  • Home
  • About OCB
    • About Us
    • Scientific Breadth
      • Biological Pump
      • Changing Marine Ecosystems
      • Changing Ocean Chemistry
      • Estuarine and Coastal Carbon Fluxes
      • Ocean Carbon Uptake and Storage
      • Ocean Observatories
    • Code of Conduct
    • Get Involved
    • Project Office
    • Scientific Steering Committee
    • OCB committees
      • Ocean-Atmosphere Interaction
      • Ocean Time-series
      • US Biogeochemical-Argo
  • Activities
    • Summer Workshop
    • OCB Webinars
    • Guidelines for OCB Workshops & Activities
    • Topical Workshops
      • CMIP6 Models Workshop
      • Coastal BGS Obs with Fisheries
      • C-saw extreme events workshop
      • Expansion of BGC-Argo and Profiling Floats
      • Fish, fisheries and carbon
      • Future BioGeoSCAPES program
      • GO-BCG Scoping Workshop
      • Lateral Carbon Flux in Tidal Wetlands
      • Leaky Deltas Workshop – Spring 2025
      • Marine CDR Workshop
      • Ocean Nucleic Acids ‘Omics
      • Pathways Connecting Climate Changes to the Deep Ocean
    • Small Group Activities
      • Aquatic Continuum OCB-NACP Focus Group
      • Arctic-COLORS Data Synthesis
      • BECS Benthic Ecosystem and Carbon Synthesis WG
      • Carbon Isotopes in the Ocean Workshop
      • CMIP6 WG
      • Filling the gaps air–sea carbon fluxes WG
      • Fish Carbon WG
      • Meta-eukomics WG
      • mCDR
      • Metaproteomic Intercomparison
      • Mixotrophs & Mixotrophy WG
      • N-Fixation WG
      • Ocean Carbonate System Intercomparison Forum
      • Ocean Carbon Uptake WG
      • OOI BGC sensor WG
      • Operational Phytoplankton Observations WG
      • Phytoplankton Taxonomy WG
    • Other Workshops
    • Science Planning
      • Coastal CARbon Synthesis (CCARS)
      • North Atlantic-Arctic
    • Ocean Acidification PI Meetings
    • Training Activities
      • PACE Hackweek 2025
      • PACE Hackweek 2024
      • PACE Training Activity 2022
  • Science Support
    • Data management and archival
    • Early Career
    • Funding Sources
    • Jobs & Postdocs
    • Meeting List
    • OCB Topical Websites
      • Ocean Fertilization
      • Trace gases
      • US IIOE-2
    • Outreach & Education
    • Promoting your science
    • Student Opportunities
    • OCB Activity Proposal Solicitations
      • Guidelines for OCB Workshops & Activities
    • Travel Support
  • Publications
    • OCB Workshop Reports
    • Science Planning and Policy
    • Newsletter Archive
  • Science Highlights
  • News

Archive for zooplankton – Page 2

Water clarity impacts temperature and biogeochemistry in Chesapeake Bay

Posted by mmaheigan 
· Thursday, December 3rd, 2020 

Estuarine water clarity is determined by suspended materials in the water, including colored dissolved organic matter, phytoplankton, sediment, and detritus. These constituents directly affect temperature because when water is opaque, sunlight heats only the shallowest layers near the surface, but when water is clear, sunlight can penetrate deeper, warming the waters below the surface. Despite the importance of accurately predicting temperature variability, many numerical modeling studies do not adequately parameterize this fundamental relationship between water clarity and temperature.

In a recent study published in Estuaries and Coasts, the authors quantified the impact of a more realistic representation of water clarity in a hydrodynamic-biogeochemical model of the Chesapeake Bay by comparing two simulations: (1) water clarity is constant in space and time for the calculation of solar heating vs. (2) water clarity varies with modeled concentrations of light-attenuating materials. In the variable water clarity simulation (2), the water is more opaque, particularly in the northern region of the Bay. During the spring and summer months, the lower water clarity in the northern Bay is associated with warmer surface temperatures and colder bottom temperatures. Warmer surface temperatures encourage phytoplankton growth and nutrient uptake near the head of the Bay, thus fewer nutrients are transported downstream. These conditions are exacerbated during high-river flow years, when differences in temperature, nutrients, phytoplankton, and zooplankton extend further seaward.

Figure 1: Top row: Difference in the light attenuation coefficient for shortwave heating, kh[m-1] (variable minus constant light attenuation simulation). June, July, and August average for (A) 2001, (B) average of 2001-2005, and (C) 2003; difference in bottom temperatures [oC] (variable minus constant). Bottom row: Difference in June, July, and August average bottom temperature for (D) 2001, (E) average of 2001-2005, and (F) 2003. Data for 2001 are representative of low river discharge, and 2003 are representative high river discharge years.

This work demonstrates that a constant light attenuation scheme for heating calculations in coupled hydrodynamic-biogeochemical models underestimates temperature variability, both temporally and spatially. This is an important finding for researchers who use models to predict future temperature variability and associated impacts on biogeochemistry and species habitability.

 

Authors:
Grace E. Kim (NASA, Goddard Space Flight Center)
Pierre St-Laurent (VIMS, William & Mary)
Marjorie A.M. Friedrichs (VIMS, William & Mary)
Antonio Mannino (NASA, Goddard Space Flight Center)

Austral summer vertical migration patterns in Antarctic zooplankton

Posted by mmaheigan 
· Thursday, October 15th, 2020 

Sunrise and sunset are the main cues driving zooplankton diel vertical migration (DVM) throughout the world’s oceans. These marine animals balance the trade-off between feeding in surface waters at night and avoiding predation during the day at depth. Near-constant daylight during polar summer was assumed to dampen these daily migrations. In a recent paper published in Deep-Sea Research I, authors assessed austral summer DVM patterns for 15 taxa over a 9-year period. Despite up to 22 hours of sunlight, a diverse array of zooplankton – including copepods, krill, pteropods, and salps – continued DVM.

Figure caption: Mean day (orange) and night (blue) abundance of (A) the salp Salpa thompsoni, (B) the krill species Thysanoessa macrura, (C) the pteropod Limacina helicina, and (D) chaetognaths sampled at discrete depth intervals from 0-500m. Horizontal dashed lines indicate weighted mean depth (WMD). N:D is the night to day abundance ratio for 0-150 m. Error bars indicate one standard error. Sample size n = 12 to 22. Photos by Larry Madin, Miram Gleiber, and Kharis Schrage.

The Palmer Antarctica Long-Term Ecological Research (LTER) Program conducted this study using a MOCNESS (Multiple Opening/Closing Net and Environmental Sensing System) to collect depth-stratified samples west of the Antarctic Peninsula. The depth range of migrations during austral summer varied across taxa and with daylength and phytoplankton biomass and distribution. While most taxa continued some form of DVM, others (e.g., carnivores and detritivores) remained most abundant in the mesopelagic zone, regardless of photoperiod, which likely impacted the attenuation of vertical carbon flux. Given the observed differences in vertical distribution and migration behavior across taxa, ongoing changes in Antarctic zooplankton assemblages will likely impact carbon export pathways. More regional, taxon-specific studies such as this are needed to inform efforts to model zooplankton contributions to the biological carbon pump.

 

Authors:
John Conroy (VIMS, William & Mary)
Deborah Steinberg (VIMS, William & Mary)
Patricia Thibodeau (VIMS, William & Mary; currently University of Rhode Island)
Oscar Schofield (Rutgers University)

Turning a spotlight on grazing

Posted by mmaheigan 
· Thursday, July 23rd, 2020 

Microscopic plankton in the surface ocean make planet Earth habitable by generating oxygen and forming the basis of marine food webs, yielding harvestable protein. For over 100 years, oceanographers have tried to ascertain the physical, chemical, and biological processes governing phytoplankton blooms. Zooplankton grazing of phytoplankton is the single largest loss process for primary production, but empirical grazing data are sparse and thus poorly constrained in modeling frameworks, including assessments of global elemental cycles, cross-ecosystem comparisons, and predictive efforts anticipating future ocean ecosystem function. As sunlight decays exponentially with depth, upper-ocean mixing creates dynamic light environments with predictable effects on phytoplankton growth but unknown consequences for grazing.

Figure caption: Rates (d−1) of phytoplankton growth (μ), grazing mortality (g), and biomass accumulation (r) under four mixed layer scenarios simulated using light as a proxy of (a) sustained deep mixing, (b) rapid shoaling, (c) sustained shallow mixing, and (d) rapid mixed layer deepening. Error bars represent one standard deviation of the mean of duplicate experiments. Grazing was measured but not detected in the sustained deep mixing and rapid shoaling conditions, denoted with x.

Using data from a spring cruise in the North Atlantic, authors of a recent study published in Limnology & Oceanography compared the influences of microzooplankton predation and fluctuations in light availability—representative of a mixing water column—on phytoplankton standing stock. Data from at-sea incubations and light manipulation experiments provide evidence that phytoplankton’s instantaneous and zooplankton’s delayed responses to light fluctuations are key modulators of the balance between phytoplankton growth and grazing rates (Figure 1). These results suggest that light is a potential, remotely retrievable predictor of when and where in the ocean zooplankton grazing may represent an important loss term of phytoplankton production. If broadly verified, this approach could be used to systematically assess sparsely measured grazing across spatial and temporal gradients in representative regions of the ocean. Such data will be essential for enhancing our predictive capacity of ocean food web function, global biogeochemical cycles and the many derived processes, including fisheries production and the flow of carbon through the oceans.

Authors:
Françoise Morison (University of Rhode Island)
Gayantonia Franzè (University of Rhode Island, currently Institute of Marine Research, Norway)
Elizabeth Harvey (University of Georgia, currently University of New Hampshire)
Susanne Menden-Deuer (University of Rhode Island)

 

Modern OMZ copepod dynamics provide analog for future oceans

Posted by mmaheigan 
· Thursday, July 23rd, 2020 

Global warming increases ocean deoxygenation and expands the oxygen minimum zone (OMZ), which has implications for major zooplankton groups like copepods. Reduced oxygen levels may impact individual copepod species abundance, vertical distribution, and life history strategy, which is likely to perturb intricate oceanic food webs and export processes. In a study recently published in Biogeosciences, authors conducted vertically-stratified day and night MOCNESS tows (0-1000 m) during four cruises (2007-2017) in the Eastern Tropical North Pacific, sampling hydrography and copepod distributions in four locations with different water column oxygen profiles and OMZ intensity (i.e. lowest oxygen concentration and its vertical extent in a profile). Each copepod species exhibited a different vertical distribution strategy and physiology associated with oxygen profile variability. The study identified sets of species that (1) changed their vertical distributions and maximum abundance depth associated with the depth and intensity of the OMZ and its oxycline inflection points, (2) shifted their diapause depth, (3) adjusted their diel vertical migration, especially the nighttime upper depth, or (4) expanded or contracted their depth range within the mixed layer and upper part of the thermocline in association with the thickness of the aerobic epipelagic zone (habitat compression concept) (Figure 1). Distribution depths for some species shifted by 10’s to 100’s of meters in different situations, which also had metabolic (and carbon flow) implications because temperature decreased with depth.  This observed present-day variability may provide an important window into how future marine ecosystems will respond to deoxygenation.

Figure caption: Schematic diagram showing how future OMZ expansion may affect zooplankton distributions, based on present-day responses to OMZ variability. The dashed line indicates diel vertical migration (DVM) and highlights the shoaling of the nighttime depth as the aerobic habitat is compressed. The lower oxycline community and the diapause layer for some species, associated with a specific oxygen concentration, may deepen as the OMZ expands.

 

Authors:
Karen F. Wishner (University of Rhode Island)
Brad Seibel (University of South Florida)
Dawn Outram (University of Rhode Island)

Tiny, but effective: Gelatinous zooplankton and the ocean biological carbon pump

Posted by mmaheigan 
· Wednesday, March 25th, 2020 

Barely visible to the naked eye, gelatinous zooplankton play important roles in marine food webs. Cnidaria, Ctenophora, and Urochordata are omnipresent and provide important food sources for many more highly developed marine organisms. These small, nearly transparent organisms also transport large quantities of “jelly-carbon” from the upper ocean to depth. A recent study in Global Biogeochemical Cycles focused on quantifying the gelatinous zooplankton contribution to the ocean carbon cycle.

Figure 1. Processes and pathways or gelatinous carbon transfer to the deep ocean.

Using >90,000 data points (1934 to 2011) from the Jellyfish Database Initiative (JeDI), the authors compiled global estimates of jellyfish biomass, production, vertical migration, and jelly carbon transfer efficiency. Despite their small biomass relative to the total mass of organisms living in the upper ocean, their rapid, highly efficient sinking makes them a globally significant source of organic carbon for deep-ocean ecosystems, with 43-48% of their upper ocean production reaching 2000 m, which translates into 0.016 Pg C yr-1.

Figure 2. Mass deposition event of jellyfish at 3500 m in the Arabian Sea (Billett et al. 2006).

Sediment trap data have suggested that carbon transport associated with large, episodic gelatinous blooms in localized open ocean and continental shelf regions could often exceed phytodetrital sources, in particular instances. These mass deposition events and their contributions to deep carbon export must be taken into account in models to better characterize marine ecosystems and reduce uncertainties in our understanding of the ocean’s role in the global carbon cycle.

Links:

Jellyfish Database Initiative http://jedi.nceas.ucsb.edu, http://jedi.nceas.ucsb.edu-dmo.org/dataset/526852 )

 

Authors:
Mario Lebrato (Christian‐Albrechts‐University Kiel and Bazaruto Center for Scientific Studies, Mozambique)
Markus Pahlow (GEOMAR)
Jessica R. Frost (South Florida Water Management District)
Marie Küter (Christian‐Albrechts‐University Kiel)
Pedro de Jesus Mendes (Marine and Environmental Scientific and Technological Solutions, Germany)
Juan‐Carlos Molinero (GEOMAR)
Andreas Oschlies (GEOMAR)

Krillin’ it with poop: Highlighting the importance of Antarctic krill in ocean carbon and nutrient cycling

Posted by mmaheigan 
· Tuesday, February 4th, 2020 

Scientists have long known the role of Antarctic krill (Euphausia superba) in Southern Ocean ecosystems. Evidence is gathering about krill’s biogeochemical importance through releasing millions of faecal pellets in swarms and stimulating primary production through nutrient excretion. Here, we explore and synthesise the known impacts that this highly abundant and rather large species has on the environment. Krill exemplify how metazoa can play a dominant role in shaping ocean biogeochemistry, thus providing additional motivation for protecting certain harvested species.

Figure 1: The ecological roles of krill in Southern Ocean biogeochemical cycles, including releasing faecal pellets, excreting nutrients whilst grazing, and larval krill migrating throughout the water column, shedding exoskeletons, and feeding on the seabed.

A review published in Nature Communications uncovers at least 13 possible pathways by which Antarctic krill either influence the carbon sink or release fertilizing nutrients (Figure 1). Their large size (up to 7 cm) and swarming nature (millions of krill aggregate) enable krill to strongly impact ocean biogeochemistry. Swarms release large numbers of faecal pellets, overwhelming detritivores and resulting in a large sink of faecal carbon. Krill may physically mix nutrients from the deep ocean and become a decades-long carbon store in whale biomass. Antarctic krill larvae, which live near the sea-ice, undergo deeper diel vertical migrations compared to adult Antarctic krill (400 m vs. 200 m), so any carbon respired or faecal pellets released by larvae could remain in the deep ocean longer than those released by adult krill at a shallower depth; the larval krill contribution to carbon export has not been quantified. Furthermore, it is currently unknown how many krill larvae are removed from the Antarctic krill fishery as by-catch. Perhaps the biggest challenge in constraining the role of krill (adult and larvae) in biogeochemical cycles is our limited capacity to quantify the abundance and biomass of Antarctic krill, since shipboard sampling methods (nets or acoustics) have limited spatial and temporal coverage. Ultimately, the Southern Ocean is an important physical AND biological sink of carbon, and we must consider the role krill and other animals have in this cycle.

Figure 2: Processes in the biological carbon pump including the sinking of dead phytoplankton aggregates, zooplankton, krill and fish faecal pellets and dead animals. Microbial remineralisation is depicted through the return of particulate organic carbon to dissolved organic carbon (DOC) and eventually carbon dioxide.

Authors:
Emma Cavan (Imperial College London and University of Tasmania)
Anna Belcher (British Antarctic Survey)
Angus Atkinson (Plymouth Marine Laboratory)
Simeon Hill (British Antarctic Survey)
So Kawaguchi (Australian Antarctic Division)
Stacey McCormack (University of Tasmania)
Bettina Meyer (Alfred Wegener Institute for Polar and Marine Research and University of Oldenburg)
Stephen Nicol (University of Tasmania)
Lavenia Ratnarajah (University of Liverpool)
Katrin Schmidt (University of Plymouth)
Deborah Steinberg (Virginia Institute of Marine Science)
Geraint Tarling (British Antarctic Survey)
Philip Boyd (University of Tasmania and Antarctic Climate and Ecosystems Cooperative Research Centre)

Zooplankton-fueled carbon export is changing in the North Atlantic Ocean

Posted by mmaheigan 
· Monday, June 10th, 2019 

Zooplankton-mediated carbon export is an important, but variable and relatively unconstrained part of the biological carbon pump—the processes that fix atmospheric carbon dioxide in organic material and transport it from the upper sunlit ocean to depth. Changes in the biological pump impact the climate system, but are challenging to quantify because such analyses require spatially and temporally explicit information about biological, chemical, and physical properties of the ocean, where empirical observations are in short supply.

A recent study in Nature, Ecology and Evolution focused on copepods in the northern half of the North Atlantic Ocean, where the Continuous Plankton Recorder (CPR) time series program has documented surface plankton abundance and taxonomic composition for nearly six decades. Copepods transport carbon passively by producing sinking fecal pellets while feeding near the sea surface, and actively via daily and seasonal migrations to deeper waters where carbon is released through respiration, defecation, and mortality. Using allometry, metabolic theory, and an optimal behavior model, the authors examined patterns of passive and active carbon transport from 1960 to 2014 and sensitivity of carbon export to different model inputs.

Figure caption: Spatial distribution and change, from 1960 to 2014, of modeled copepod-mediated carbon flux: top left – mean passive carbon flux (sinking fecal pellets), bottom left – change in passive carbon flux, top right – mean active carbon flux (respiration plus fecal pellets produced during diel vertical migration), bottom right – change in active carbon flux.

The authors observed that from southern Iceland to the Gulf of Maine, copepod-mediated carbon transport has increased over the last six decades, with the highest rates around 30 mgC m-2 y-1 each decade for passive flux, and 4 mgC m-2 y-1 each decade for active flux. Meanwhile, it has decreased across much of the more temperate central northern North Atlantic with highest rates around 69 mgC m-2 y-1 each decade for passive flux and 8 mgC m-2 y-1 each decade for active flux. This pattern is largely driven by changes in copepod population distributions and community structure, specifically the distributions of large and abundant species (e.g. Calanus spp.). These results suggest that shifts in species distributions driven by a changing global climate are already impacting ecosystem function across the northern North Atlantic Ocean. These shifts are not latitudinally uniform, thus highlighting the complexity of marine ecosystems. This study demonstrates the importance of these sustained plankton measurements and how plankton-mediated carbon fluxes can be mechanistically implemented in next-generation biogeochemical models.

Authors:
Philipp Brun (Technical University of Denmark and Swiss Federal Research Institute)
Karen Stamieszkin (University of Maine, Bigelow Lab and Virginia Institute of Marine Science)
Andre W. Visser (Technical University of Denmark)
Priscilla Licandro (Sir Alister Hardy Foundation for Ocean Science, Plymouth Marine Laboratory, and Stazione Zoologica Anton Dohrn, Italy)
Mark R. Payne (Technical University of Denmark)
Thomas Kiørboe (Technical University of Denmark)

 

Also see OCB2019 plenary session: The effect of size on ocean processes (allometry) and implications for export (Thursday, June 27, 2019)

Zooplankton vertical migrations represent a significant source of carbon export in the ocean

Posted by mmaheigan 
· Friday, March 15th, 2019 

Huge numbers of tiny marine animals, known as zooplankton, migrate between the surface ocean and the twilight zone (200 – 1,000 m below the surface) everyday; it is the largest migration event anywhere on the planet. How much carbon do these animals transport with them and how much do they leave behind sequestered in the deep ocean? In a recent publication in Global Biogeochemical Cycles, Archibald et al. (2019) used a simple model to estimate the magnitude of carbon flux into the twilight zone from zooplankton vertical migrations and observed that it was a significant contributor to carbon export on a global scale. The study also revealed strong regional patterns in migration-mediated carbon flux, with the greatest impact on export occurring at subtropical latitudes (Figure 1).

Figure 1. Percent increase in the modeled carbon export flux out of the surface ocean as a result of zooplankton vertical migrations.

Migrating zooplankton also consume significant amounts of oxygen at depth, generating a local maximum in the oxygen utilization profile at depth within the migration layer. By including the effect of the metabolism of migrating zooplankton, the model is able to produce a more detailed picture of oxygen utilization over the twilight zone. The model in this study effectively simulates the complex phenomenon of zooplankton vertical migrations, providing a simple framework that will allow researchers to investigate how this key component of the global carbon cycle might change under future climatic conditions. For example, if increased stratification leads to a greater representation of small cells in phytoplankton communities, then zooplankton migration-mediated carbon export is expected to make up a proportionally larger fraction of the total carbon export flux.

Authors:
Kevin M. Archibald (Woods Hole Oceanographic Institution and Massachusetts Institute of Technology)
David A. Siegel (University of California, Santa Barbara)
Scott C. Doney (University of Virginia)

Artificial light from sampling platforms changes zooplankton behavior

Posted by mmaheigan 
· Monday, November 26th, 2018 

When designing sampling we make generally accepted assumptions that what we collect is representative of what is “normal” or naturally occurring at the place, time, and depth of collection. However, a recent study in Science Advances revealed that this might not be true. During round-the-clock shipboard sampling, lights used at night can actually be a form of pollution that disrupts the diel cycle of zooplankton vertical migration.

Effect of light pollution on krill from a ship (left), diel vertical migration in natural dark conditions (middle) and effect of moonlight (right). Figure by Malin Daase (UiT).

Using a Autonomous Surface Vehicle the authors documented zooplankton behavioral patterns of light avoidance never previously seen. The study compared results from high Arctic polar night (unpolluted light environment for an extended time), to near ship samples. During months of near constant darkness in the Arctic, there was still a diel vertical migration of zooplankton limited to the upper 30 m of the water column and centered around the local sun noon. Contrasting the results from light-polluted and unpolluted areas, the authors observed that the vast majority of the pelagic community exhibit a strong light-escape response in the presence of artificial light (both ship light and even headlamps from researchers in open boats). This effect was observed down to 100 m depth and 190 m from the ship. These results suggest that artificial light from traditional sampling platforms may bias studies of zooplankton abundance and diel migration within the upper 100 m. These findings underscore the need for alternative sampling methods such as autonomous platforms, particularly in dim-light conditions, to collect more accurate and representative physical and biological data for ecological studies. In addition to research cruises and sampling, anthropogenic light pollution from predicted increases in shipping, oil and gas exploration, and light-fishing are anticipated to impact the diel rhythms of zooplankton behavior all around the globe.

Authors:
Jørgen Berge (Norwegian University of Technology and Science; UiT The Arctic University of Norway)
Martin Ludvigsen (Norwegian University of Technology and Science; University Centre in Svalbard)
Maxime Geoffroy (UiT The Arctic University of Norway, Memorial University of Newfoundland)
Jonathan H. Cohen (University of Delaware)
Pedro R. De La Torre (Norwegian University of Technology and Science)
Stein M. Nornes (Norwegian University of Technology and Science)
Hanumant Singh (Northeastern University)
Asgeir J. Sørensen (Norwegian University of Technology and Science)
Malin Daase (Norwegian University of Technology and Science)
Geir Johnsen (Norwegian University of Technology and Science; Norwegian University of Technology and Science)

Lasers shed light on giant larvacean filtration impact on the ocean’s biological pump

Posted by mmaheigan 
· Thursday, January 4th, 2018 

To accurately assess the impacts of climate change, we need to understand how atmospheric carbon is transported from surface waters to the deep sea. Grazers and filter feeders drive the ocean’s biological pump as they remove and sequester carbon at various rates. This pump extends down into the midwater realm, the largest habitat on earth. Giant larvaceans are fascinating and enigmatic occupants of the upper 400 m of the water column, where they build complex filtering structures out of mucus that can reach diameters greater than 1 m in longest dimension (Figure 1A). Because of the fragility of these structures, direct measurements of filtration rates require us to study them in situ. We developed DeepPIV, an ROV-deployable instrument (Figure 1B) to directly measure fluid motion and filtration rates in situ (Figure 1C).

Figure 1. (A) Traditional view of a giant larvacean illuminated by white ROV lights. (B) DeepPIV instrument is seen attached to Monterey Bay Aquarium Research Institute’s (MBARI) MiniROV. (C) DeepPIV-illuminated interior view of a giant larvacean house, where particle motion in ambient seawater serves as a proxy for fluid motion. White arrows in (A) and (C) indicate larvacean head/trunk; white arrow in (B) indicates DeepPIV.

The filtration rates we measured for giant larvaceans are far greater than for any other zooplankton filter feeder. When combined with abundance data from a 22-year time series, the grazing impact of giant larvaceans indicates that within 13 days, they can filter the total volume of water within their habitable depth range (~100-300 m; based on maximum abundance and measured filtration rates). Our results reveal that the contribution of giant larvaceans to vertical carbon flux is much greater than previously thought. Small larvaceans, which are present in the water column in even larger quantities than giant larvaceans, may also have a measurable impact on carbon fluxes. New technologies such as DeepPIV are yielding more quantitative observations of midwater filter feeders, which is improving our understanding of the roles that deep-water biota play in the long-term removal of carbon from the atmosphere.

Read the full journal article: http://advances.sciencemag.org/content/3/5/e1602374.full

Authors: (All at MBARI)
Kakani Katija
Rob E. Sherlock
Alana D. Sherman
Bruce H. Robison

« Previous Page
Next Page »

Filter by Keyword

abundance acidification additionality advection africa air-sea air-sea interactions algae alkalinity allometry ammonium AMO AMOC anoxic Antarctic Antarctica anthro impacts anthropogenic carbon anthropogenic impacts appendicularia aquaculture aquatic continuum aragonite saturation arctic Argo argon arsenic artificial seawater AT Atlantic atmospheric CO2 atmospheric nitrogen deposition authigenic carbonates autonomous platforms AUVs bacteria bathypelagic BATS BCG Argo benthic bgc argo bio-go-ship bio-optical bioavailability biogeochemical cycles biogeochemical models biogeochemistry Biological Essential Ocean Variables biological pump biophysics bloom blue carbon bottom water boundary layer buffer capacity C14 CaCO3 calcification calcite carbon carbon-climate feedback carbon-sulfur coupling carbonate carbonate system carbon budget carbon cycle carbon dioxide carbon export carbon fluxes carbon sequestration carbon storage Caribbean CCA CCS changing marine chemistry changing marine ecosystems changing marine environments changing ocean chemistry chemical oceanographic data chemical speciation chemoautotroph chesapeake bay chl a chlorophyll circulation clouds CO2 CO3 coastal and estuarine coastal darkening coastal ocean cobalt Coccolithophores commercial community composition competition conservation cooling effect copepod copepods coral reefs CTD currents cyclone daily cycles data data access data assimilation database data management data product Data standards DCM dead zone decadal trends decomposers decomposition deep convection deep ocean deep sea coral denitrification deoxygenation depth diatoms DIC diel migration diffusion dimethylsulfide dinoflagellate dinoflagellates discrete measurements distribution DOC DOM domoic acid DOP dust DVM ecology economics ecosystem management ecosystems eddy Education EEZ Ekman transport emissions ENSO enzyme equatorial current equatorial regions ESM estuarine and coastal carbon fluxes estuary euphotic zone eutrophication evolution export export fluxes export production extreme events faecal pellets fecal pellets filter feeders filtration rates fire fish Fish carbon fisheries fishing floats fluid dynamics fluorescence food webs forage fish forams freshening freshwater frontal zone functional role future oceans gelatinous zooplankton geochemistry geoengineering geologic time GEOTRACES glaciers gliders global carbon budget global ocean global warming go-ship grazing greenhouse gas greenhouse gases Greenland ground truthing groundwater Gulf of Maine Gulf of Mexico Gulf Stream gyre harmful algal bloom high latitude human food human impact human well-being hurricane hydrogen hydrothermal hypoxia ice age ice cores ice cover industrial onset inland waters in situ inverse circulation ions iron iron fertilization iron limitation isotopes jellies katabatic winds kelvin waves krill kuroshio lab vs field land-ocean continuum larvaceans lateral transport LGM lidar ligands light light attenuation lipids low nutrient machine learning mangroves marine carbon cycle marine heatwave marine particles marine snowfall marshes mCDR mechanisms Mediterranean meltwater mesopelagic mesoscale mesoscale processes metagenome metals methane methods microbes microlayer microorganisms microplankton microscale microzooplankton midwater mitigation mixed layer mixed layers mixing mixotrophs mixotrophy model modeling model validation mode water molecular diffusion MPT MRV multi-decade n2o NAAMES NCP nearshore net community production net primary productivity new ocean state new technology Niskin bottle nitrate nitrogen nitrogen cycle nitrogen fixation nitrous oxide north atlantic north pacific North Sea NPP nuclear war nutricline nutrient budget nutrient cycles nutrient cycling nutrient limitation nutrients OA observations ocean-atmosphere ocean acidification ocean acidification data ocean alkalinity enhancement ocean carbon storage and uptake ocean carbon uptake and storage ocean color ocean modeling ocean observatories ocean warming ODZ oligotrophic omics OMZ open ocean optics organic particles oscillation outwelling overturning circulation oxygen pacific paleoceanography PAR parameter optimization parasite particle flux particles partnerships pCO2 PDO peat pelagic PETM pH phenology phosphate phosphorus photosynthesis physical processes physiology phytoplankton PIC piezophilic piezotolerant plankton POC polar polar regions policy pollutants precipitation predation predator-prey prediction pressure primary productivity Prochlorococcus productivity prokaryotes proteins pteropods pycnocline radioisotopes remineralization remote sensing repeat hydrography residence time resource management respiration resuspension rivers rocky shore Rossby waves Ross Sea ROV salinity salt marsh satellite scale seafloor seagrass sea ice sea level rise seasonal seasonality seasonal patterns seasonal trends sea spray seawater collection seaweed secchi sediments sensors sequestration shelf ocean shelf system shells ship-based observations shorelines siderophore silica silicate silicon cycle sinking sinking particles size SOCCOM soil carbon southern ocean south pacific spatial covariations speciation SST state estimation stoichiometry subduction submesoscale subpolar subtropical sulfate surf surface surface ocean Synechococcus technology teleconnections temperate temperature temporal covariations thermocline thermodynamics thermohaline thorium tidal time-series time of emergence titration top predators total alkalinity trace elements trace metals trait-based transfer efficiency transient features trawling Tris trophic transfer tropical turbulence twilight zone upper ocean upper water column upwelling US CLIVAR validation velocity gradient ventilation vertical flux vertical migration vertical transport warming water clarity water mass water quality waves weathering western boundary currents wetlands winter mixing zooplankton

Copyright © 2025 - OCB Project Office, Woods Hole Oceanographic Institution, 266 Woods Hole Rd, MS #25, Woods Hole, MA 02543 USA Phone: 508-289-2838  •  Fax: 508-457-2193  •  Email: ocb_news@us-ocb.org

link to nsflink to noaalink to WHOI

Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). The OCB Project Office is housed at the Woods Hole Oceanographic Institution.