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Robert H Condon - One of the best experts on this subject based on the ideXlab platform.
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Gelatinous Zooplankton‐Mediated Carbon Flows in the Global Oceans: A Data‐Driven Modeling Study
Global Biogeochemical Cycles, 2020Co-Authors: Jessica Y. Luo, Robert H Condon, Carlos M Duarte, Kylie A Pitt, Cathy H Lucas, Charles A. Stock, Robert K CowenAbstract:Among marine organisms, Gelatinous Zooplankton (GZ; cnidarians, ctenophores, and pelagic tunicates) are unique in their energetic efficiency, as the Gelatinous body plan allows them to process and assimilate high proportions of oceanic carbon. Upon death, their body shape facilitates rapid sinking through the water column, resulting in carcass depositions on the seafloor (“jelly‐falls”). GZ are thought to be important components of the biological pump, but their overall contribution to global carbon fluxes remains unknown. Using a data‐driven, three‐dimensional, carbon cycle model resolved to a 1° global grid, with a Monte Carlo uncertainty analysis, we estimate that GZ consumed 7.9–13 Pg C y−1 in phytoplankton and Zooplankton, resulting in a net production of 3.9–5.8 Pg C y−1 in the upper ocean (top 200 m), with the largest fluxes from pelagic tunicates. Non‐predation mortality (carcasses) comprised 25% of GZ production, and combined with the much greater fecal matter flux, total GZ particulate organic carbon (POC) export at 100 m was 1.6–5.2 Pg C y−1, equivalent to 32–40% of the global POC export. The fast sinking GZ export resulted in a high transfer efficiency (Teff) of 38–62% to 1,000 m and 25–40% to the seafloor. Finally, jelly‐falls at depths >50 m are likely unaccounted for in current POC flux estimates and could increase benthic POC flux by 8–35%. The significant magnitude of and distinct sinking properties of GZ fluxes support a critical yet underrecognized role of GZ carcasses and fecal matter to the biological pump and air‐sea carbon balance.
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Gelatinous Zooplankton mediated carbon flows in the global oceans a data driven modeling study
Global Biogeochemical Cycles, 2020Co-Authors: Jessica Y. Luo, Robert H Condon, Carlos M Duarte, Kylie A Pitt, Cathy H Lucas, Charles A. Stock, Robert K CowenAbstract:Among marine organisms, Gelatinous Zooplankton (GZ; cnidarians, ctenophores, and pelagic tunicates) are unique in their energetic efficiency, as the Gelatinous body plan allows them to process and assimilate high proportions of oceanic carbon. Upon death, their body shape facilitates rapid sinking through the water column, resulting in carcass depositions on the seafloor (“jelly‐falls”). GZ are thought to be important components of the biological pump, but their overall contribution to global carbon fluxes remains unknown. Using a data‐driven, three‐dimensional, carbon cycle model resolved to a 1° global grid, with a Monte Carlo uncertainty analysis, we estimate that GZ consumed 7.9–13 Pg C y−1 in phytoplankton and Zooplankton, resulting in a net production of 3.9–5.8 Pg C y−1 in the upper ocean (top 200 m), with the largest fluxes from pelagic tunicates. Non‐predation mortality (carcasses) comprised 25% of GZ production, and combined with the much greater fecal matter flux, total GZ particulate organic carbon (POC) export at 100 m was 1.6–5.2 Pg C y−1, equivalent to 32–40% of the global POC export. The fast sinking GZ export resulted in a high transfer efficiency (Teff) of 38–62% to 1,000 m and 25–40% to the seafloor. Finally, jelly‐falls at depths >50 m are likely unaccounted for in current POC flux estimates and could increase benthic POC flux by 8–35%. The significant magnitude of and distinct sinking properties of GZ fluxes support a critical yet underrecognized role of GZ carcasses and fecal matter to the biological pump and air‐sea carbon balance.
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Gelatinous Zooplankton biomass in the global oceans: geographic variation and environmental drivers
Global Ecology and Biogeography, 2014Co-Authors: Cathy H Lucas, Robert H Condon, William M Graham, Carlos M Duarte, Kylie A Pitt, Kelly L Robinson, Daniel O.b. Jones, Catherine J. Hollyhead, Mark Schildhauer, James RegetzAbstract:Aim: Scientific debate regarding the future trends, and subsequent ecological, biogeochemical and societal impacts, of Gelatinous Zooplankton (GZ) in a changing ocean is hampered by lack of a global baseline and an understanding of the causes of biogeographic patterns. We address this by using a new global database of GZ records to test hypotheses relating to environmental drivers of biogeographic variation in the multidecadal baseline of epipelagic GZ biomass in the world's oceans. Location: Global oceans. Methods: Over 476,000 global GZ data and metadata items were assembled from a variety of published and unpublished sources. From this, a total of 91,765 quantitative abundance data items from 1934 to 2011 were converted to carbon biomass using published biometric equations and species-specific average sizes. Total GZ, Cnidaria, Ctenophora and Chordata (Thaliacea) biomass was mapped into 5° grid cells and environmental drivers of geographic variation were tested using spatial linear models. Results: We present JeDI (the Jellyfish Database Initiative), a publically accessible database available at http://jedi.nceas.ucsb.edu. We show that: (1) GZ are present throughout the world's oceans; (2) the global geometric mean and standard deviation of total Gelatinous biomass is 0.53 ± 16.16 mg C m−3, corresponding to a global biomass of 38.3 Tg C in the mixed layer of the ocean; (3) biomass of all Gelatinous phyla is greatest in the subtropical and boreal Northern Hemisphere; and (4) within the North Atlantic, dissolved oxygen, apparent oxygen utilization and sea surface temperature are the principal drivers of biomass distribution. Main conclusions: JeDI is a unique global dataset of GZ taxa which will provide a benchmark against which future observations can be compared and shifting baselines assessed. The presence of GZ throughout the world's oceans and across the complete global spectrum of environmental variables indicates that evolution has delivered a range of species able to adapt to all available ecological niches.
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questioning the rise of Gelatinous Zooplankton in the world s oceans
BioScience, 2012Co-Authors: Robert H Condon, William M Graham, Carlos M Duarte, Kylie A Pitt, Cathy H Lucas, Steven H D Haddock, Kelly R Sutherland, Kelly L Robinson, Michael N Dawson, Mary Beth DeckerAbstract:During the past several decades, high numbers of Gelatinous Zooplankton species have been reported in many estuarine and coastal ecosystems. Coupled with media-driven public perception, a paradigm has evolved in which the global ocean ecosystems are thought to he heading toward being dominated by “nuisance” jellyfish. We question this current paradigm by presenting a broad overview of Gelatinous Zooplankton in a historical context to develop the hypothesis that population changes reflect the human-mediated alteration of global ocean ecosystems. To this end, we synthesize information related to the evolutionary context of contemporary Gelatinous Zooplankton blooms, the human frame of reference for changes in Gelatinous Zooplankton populations, and whether sufficient data are available to have established the paradigm. We conclude that the current paradigm in which it is believed that there has been a global increase in Gelatinous Zooplankton is unsubstantiated, and we develop a strategy for addressing the critical questions about long-term, human-related changes in the sea as they relate to Gelatinous Zooplankton blooms.
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production of dissolved organic matter and inorganic nutrients by Gelatinous Zooplankton in the york river estuary chesapeake bay
Journal of Plankton Research, 2010Co-Authors: Robert H Condon, Deborah K. Steinberg, Deborah A BronkAbstract:Large "blooms" of ctenophores (Mnemiopsis leidyi) and scyphomedusae (Chrysaora quinquecirrha) occur throughout the York River, a sub-estuary of Chesapeake Bay. These Gelatinous Zooplankton blooms can influence carbon (C) and nutrient cycling through excretion of dissolved organic matter (DOM), and inorganic nitrogen (N) and phosphorus (P). We measured dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP), ammonium (NH + 4 ) and phosphate (PO 3- 4 ) released by M. leidyi and C. quinquecirrha in the laboratory and estimated their contribution to in situ DOC and inorganic pools. Both species released high amounts of DOC compared with DON and DOP DOM released by Mnemiopsis was C-rich with higher DOC:DON (29:1) compared with the Redfield ratio (6.6C:1N). Daily turnover of DOC and DON in ctenophores was high (25.2% of body C and 18.3% of body N), likely due to mucus production. In contrast, individual Chrysaora released DOC and DON similar to Redfield stoichiometry, but daily turnover of these compounds was low (<3% of body C and N). Both species released dissolved N and P in inorganic form but also released sizeable quantities of DON (21 and 35% of total dissolved nitrogen, TDN, for ctenophores and medusae, respectively) and DOP (34 and 46% of TDP). Most of the DOC in the York River came from Mnemiopsis populations during summer (May-July). While their contribution to bulk DOC pools was low (<1% day -1 ctenophore populations released higher amounts of DOC to labile pools (18-29% day -1 ). Contributions to NH + 4 and PO 3- 4 pools were highest at times when the York River was N-limited (5.8N:1P). Despite their potential to release phytoplankton from nutrient limitation, N excretion from Gelatinous Zooplankton supported <4% of primary production. Because net NH + 4 released by Mnemiopsis populations exceeded standing concentrations, we hypothesize an alternative DIN sink whereby bacterioplankton supplement uptake of DOM released by Gelatinous Zooplankton with inorganic N and P to satisfy intracellular elemental requirements.
Deborah A Bronk - One of the best experts on this subject based on the ideXlab platform.
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production of dissolved organic matter and inorganic nutrients by Gelatinous Zooplankton in the york river estuary chesapeake bay
Journal of Plankton Research, 2010Co-Authors: Robert H Condon, Deborah K. Steinberg, Deborah A BronkAbstract:Large "blooms" of ctenophores (Mnemiopsis leidyi) and scyphomedusae (Chrysaora quinquecirrha) occur throughout the York River, a sub-estuary of Chesapeake Bay. These Gelatinous Zooplankton blooms can influence carbon (C) and nutrient cycling through excretion of dissolved organic matter (DOM), and inorganic nitrogen (N) and phosphorus (P). We measured dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP), ammonium (NH + 4 ) and phosphate (PO 3- 4 ) released by M. leidyi and C. quinquecirrha in the laboratory and estimated their contribution to in situ DOC and inorganic pools. Both species released high amounts of DOC compared with DON and DOP DOM released by Mnemiopsis was C-rich with higher DOC:DON (29:1) compared with the Redfield ratio (6.6C:1N). Daily turnover of DOC and DON in ctenophores was high (25.2% of body C and 18.3% of body N), likely due to mucus production. In contrast, individual Chrysaora released DOC and DON similar to Redfield stoichiometry, but daily turnover of these compounds was low (<3% of body C and N). Both species released dissolved N and P in inorganic form but also released sizeable quantities of DON (21 and 35% of total dissolved nitrogen, TDN, for ctenophores and medusae, respectively) and DOP (34 and 46% of TDP). Most of the DOC in the York River came from Mnemiopsis populations during summer (May-July). While their contribution to bulk DOC pools was low (<1% day -1 ctenophore populations released higher amounts of DOC to labile pools (18-29% day -1 ). Contributions to NH + 4 and PO 3- 4 pools were highest at times when the York River was N-limited (5.8N:1P). Despite their potential to release phytoplankton from nutrient limitation, N excretion from Gelatinous Zooplankton supported <4% of primary production. Because net NH + 4 released by Mnemiopsis populations exceeded standing concentrations, we hypothesize an alternative DIN sink whereby bacterioplankton supplement uptake of DOM released by Gelatinous Zooplankton with inorganic N and P to satisfy intracellular elemental requirements.
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Production of dissolved organic matter and inorganic nutrients by Gelatinous Zooplankton in the York River estuary, Chesapeake Bay
Journal of Plankton Research, 2009Co-Authors: Robert H Condon, Deborah K. Steinberg, Deborah A BronkAbstract:Large "blooms" of ctenophores (Mnemiopsis leidyi) and scyphomedusae (Chrysaora quinquecirrha) occur throughout the York River, a sub-estuary of Chesapeake Bay. These Gelatinous Zooplankton blooms can influence carbon (C) and nutrient cycling through excretion of dissolved organic matter (DOM), and inorganic nitrogen (N) and phosphorus (P). We measured dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP), ammonium (NH + 4 ) and phosphate (PO 3- 4 ) released by M. leidyi and C. quinquecirrha in the laboratory and estimated their contribution to in situ DOC and inorganic pools. Both species released high amounts of DOC compared with DON and DOP DOM released by Mnemiopsis was C-rich with higher DOC:DON (29:1) compared with the Redfield ratio (6.6C:1N). Daily turnover of DOC and DON in ctenophores was high (25.2% of body C and 18.3% of body N), likely due to mucus production. In contrast, individual Chrysaora released DOC and DON similar to Redfield stoichiometry, but daily turnover of these compounds was low (
Steven H D Haddock - One of the best experts on this subject based on the ideXlab platform.
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New symbiotic associations of hyperiid amphipods (Peracarida) with Gelatinous Zooplankton in deep waters off California
Journal of the Marine Biological Association of the United Kingdom, 2014Co-Authors: Rebeca Gasca, Rebecca Hoover, Steven H D HaddockAbstract:Hyperiid amphipods are holoplanktonic marine crustaceans that are known as temporary symbionts of different groups of Gelatinous Zooplankton. The nature and dynamics of these associations are still poorly understood, particularly in deep waters. The mesopelagic and deep-living planktonic fauna off Monterey Bay, California (down to 4000 m) was surveyed using a remotely operated submersible (ROV) and blue-water diving (BWD) between September 2005 and January 2008. In this work we report our observations on a total of 51 symbiotic associations observedin situ(not from Zooplankton samples), between hyperiid amphipods and various taxa of Gelatinous Zooplankton. We present the first information on the symbiotic relations of the hyperiidVibilia caeca, and we provide data of 34 previously unknown symbiotic associations. The host range was expanded for several widely distributed hyperiid species. These findings suggest that the symbiotic associations between hyperiid amphipods and Gelatinous Zooplankton in deep waters deserve further study worldwide.
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questioning the rise of Gelatinous Zooplankton in the world s oceans
BioScience, 2012Co-Authors: Robert H Condon, William M Graham, Carlos M Duarte, Kylie A Pitt, Cathy H Lucas, Steven H D Haddock, Kelly R Sutherland, Kelly L Robinson, Michael N Dawson, Mary Beth DeckerAbstract:During the past several decades, high numbers of Gelatinous Zooplankton species have been reported in many estuarine and coastal ecosystems. Coupled with media-driven public perception, a paradigm has evolved in which the global ocean ecosystems are thought to he heading toward being dominated by “nuisance” jellyfish. We question this current paradigm by presenting a broad overview of Gelatinous Zooplankton in a historical context to develop the hypothesis that population changes reflect the human-mediated alteration of global ocean ecosystems. To this end, we synthesize information related to the evolutionary context of contemporary Gelatinous Zooplankton blooms, the human frame of reference for changes in Gelatinous Zooplankton populations, and whether sufficient data are available to have established the paradigm. We conclude that the current paradigm in which it is believed that there has been a global increase in Gelatinous Zooplankton is unsubstantiated, and we develop a strategy for addressing the critical questions about long-term, human-related changes in the sea as they relate to Gelatinous Zooplankton blooms.
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Symbiotic associations between crustaceans and Gelatinous Zooplankton in deep and surface waters off California
Marine Biology, 2007Co-Authors: Rebeca Gasca, Eduardo Suárez-morales, Steven H D HaddockAbstract:Using a remotely operated submersible (ROV) in the sea off Monterey, California, we collected deep-living Zooplankton and observed their associations with crustacean symbionts. Little is known about the nature of these symbioses. Among the most interesting findings was the description of a previously unknown modality of symbiosis of the deep-living copepod Pseudolubbockia dilatata Sars. It was recorded within the subumbrellar cavity of three specimens of the bathypelagic hydromedusa Aegina citrea Eschscholtz at depths of 606–1,098 m. One of these medusae hosted a mating pair of adult copepods along with the remains of their molts corresponding to copepodid stages CV of the female and CII, CIII, CIV, and CV of the male; another medusa had an adult female, and molts of a female CV and of male CIII, CIV and CV copepodids. Our data indicate that the medusae were occupied first by an early male copepodid, and then the female joined as a CV. The presence of an adult female alone with its CV molt in a third medusa suggests that females invade the host regardless of the presence of the male in it. The medusa represents a protected environment for these copepods during vulnerable stages or processes (molting and mating). We also observed 13 new associations between hyperiid amphipods and Gelatinous Zooplankton at different depths. These involve four new records among members of the Infraorder Physosomata, for which only six other associations were known, and five species of amphipods and six hosts among the Gelatinous Zooplankton not previously recorded as symbionts. Data are provided on three families of Hyperiidea for which symbiotic associations were hitherto unknown. The ROV represents a valuable tool for the observation and sampling of these associations, whose existence has been known for a long time, but which are still poorly understood.
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Bioluminescence spectra of shallow and deep-sea Gelatinous Zooplankton: ctenophores, medusae and siphonophores
Marine Biology, 1999Co-Authors: Steven H D Haddock, James F. CaseAbstract:We have examined the variability and potential adaptive significance of the wavelengths of light produced by Gelatinous Zooplankton. Bioluminescence spectra were measured from 100 species of planktonic cnidarians and ctenophores collected between 1 and 3500 m depth. Species averages of maximal wavelengths for all groups ranged from 440 to 506 nm. Ctenophores (41 species) had characteristically longer wavelengths than medusae (34 species), and the wavelengths from siphonophores (25 species) had a bimodal distribution across species. Four species each produced two different wavelengths of light, and in the siphonophore Abylopsistetragona these differences were associated with specific body regions. Light from deep-dwelling species had significantly shorter wavelengths than light from shallow species in both ctenophores (p = 0.010) and medusae (p = 0.009). Although light production in these organisms was limited to the blue-green wavelengths, it appears that within this range, colors are well-adapted to the particular environment which the species inhabit.
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Associations between Gelatinous Zooplankton and hyperiid amphipods (Crustacea: Peracarida) in the Gulf of California
Coelenterate Biology 2003, 1Co-Authors: Rebeca Gasca, Steven H D HaddockAbstract:Hyperiid amphipods are pelagic crustaceans that live associated with Gelatinous Zooplankton including medusae, ctenophores, siphonophores, and salps. Standard plankton sampling disrupts natural associations, so the most reliable way to determine an association is through direct observation of the organisms in their environment. The planktonic fauna of the Gulf of California dwelling between 10 and 3000 m was surveyed using SCUBA diving and a remotely operated submersible (ROV) during March 2003. Here we report our observations on a total of 14 symbiotic associations found between the hyperiid amphipods and various taxa of Gelatinous Zooplankton. We found parental care behavior in a group of amphipods (Oxycephalidae) in which this phenomenon has not been previously reported. For two hyperiid species, Euthamneus rostratus and Vibilia australis, we present the first information on their symbiotic relations. Additional hosts were discovered for other well-known and widely distributed hyperiid species (i.e. Brachyscelus crusculum, Hyperoche medusarum). Photographic evidence of some of these interactions is included in this contribution. This is the first survey of these relationships in the Gulf of California, and many aspects of the ecology and biology of these symbioses remain to be studied.
Marsh J. Youngbluth - One of the best experts on this subject based on the ideXlab platform.
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Distribution and trophic links of Gelatinous Zooplankton on Dogger Bank, North Sea
Marine Biology, 2012Co-Authors: Jessica R. Frost, Anneke Denda, Charles A. Jacoby, Rolf Koppelmann, Morten Holtegaard Nielsen, Marsh J. YoungbluthAbstract:The ecology of small, Gelatinous Zooplankton is not integrated into management of Dogger Bank (54° 00′ N, 3° 25′ E to 55° 35′ N, 2° 20′ E). In pursuit of this goal, Gelatinous Zooplankton and their potential prey were sampled along a transect across the bank on June 10–16, 2007. Eleven species of small medusae and ctenophores were collected, with six abundant taxa occurring in greater numbers below the thermocline and in the shallower, southeastern portion of the bank. There were no statistically significant diel changes in distribution. In contrast, potential prey were distributed more evenly across the bank and throughout the water column. Isotopic analyses revealed that Gelatinous Zooplankton fed on both smaller (100–300 μm) and larger (>300 μm) mesoZooplankton, but also potentially on each other. These ecological insights suggest that small medusae and ctenophores should be integrated into sustainable management of Dogger Bank.
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Distribution and trophic links of Gelatinous Zooplankton on Dogger Bank, North Sea
Marine Biology, 2012Co-Authors: Jessica R. Frost, Anneke Denda, Charles A. Jacoby, Rolf Koppelmann, Morten Holtegaard Nielsen, Clive J. Fox, Marsh J. YoungbluthAbstract:The ecology of small, Gelatinous Zooplankton is not integrated into management of Dogger Bank (54° 00′ N, 3° 25′ E to 55° 35′ N, 2° 20′ E). In pursuit of this goal, Gelatinous Zooplankton and their potential prey were sampled along a transect across the bank on June 10–16, 2007. Eleven species of small medusae and ctenophores were collected, with six abundant taxa occurring in greater numbers below the thermocline and in the shallower, southeastern portion of the bank. There were no statistically significant diel changes in distribution. In contrast, potential prey were distributed more evenly across the bank and throughout the water column. Isotopic analyses revealed that Gelatinous Zooplankton fed on both smaller (100–300 μm) and larger (>300 μm) mesoZooplankton, but also potentially on each other. These ecological insights suggest that small medusae and ctenophores should be integrated into sustainable management of Dogger Bank.
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Vertical distribution and relative abundance of Gelatinous Zooplankton, in situ observations near the Mid-Atlantic Ridge
Deep-sea Research Part Ii-topical Studies in Oceanography, 2007Co-Authors: Marsh J. Youngbluth, Aino Hosia, T. Sørnes, Lars StemmannAbstract:Abstract Fourteen dives were conducted with the ROVs Aglantha and Bathysaurus to depths of 2335 m along the Mid-Atlantic Ridge ( 42 ∘ 52 ′ – 53 ∘ 17 ′ N ) . The most frequently observed Gelatinous fauna in order of overall abundance included medusae, ctenophores, siphonophores, appendicularians, and tunicates. All of these animals, except the tunicates, occurred throughout the water column. Their relative abundances differed with depth and location. Identification to species was limited to easily recognized fauna because relatively few Gelatinous animals were collected. Each group of Gelatinous Zooplankton tended to be most numerous in a region just south of the Charlie-Gibbs Fracture Zone. Medusae (mainly Aeginura grimaldii) were the most frequently encountered animals (up to 25 individuals per 100 m 3 ). On a vertical scale their abundance peaked from 550 to 800 m and these maxima were consistently within the SAIW and NACWe. In the NACW their densities were notably lower (up 2 individuals per 100 m 3 ) and the majority of the population was deeper, ranging from 800 to 1050 m. Ctenophores (mainly Bathocyroe fosteri) were most prominent (as many as 27 individuals per 100 m 3 ) in a zone from 300 to 600 m in the NACWe. Appendicularians (primarily oikopleurids) had a broader vertical distribution in all water masses, mainly from 450 to 1000 m. Up to 12 houses per 100 m 3 were noted in the NACWe, and these estimates are considered to be very conservative. Sorties near the sea floor (as deep as 2100 m) indicated these detritivores were a prominent component (up to 5 houses per 100 m 3 ) of the epibenthic macroZooplankton. Siphonophores (mostly calycophorans) reached densities of about 14 colonies per 100 m 3 in the NACWe and occurred mainly from 300 to 600 m, at most locations. Tunicates (salps and doliolids) were patchy in their distribution and infrequently observed. Salps were numerous (up to 3 solitary individuals per 100 m 3 ) at only one location (sta. 50) near the surface. Deep-living doliolids (up to 1 individual per 100 m 3 ) appeared from 400 to 500 m at this site and occasionally within the same depth range at most of the other stations.
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Vertical distribution (0–1000 m) of Gelatinous Zooplankton and particulate matter (60ìm
2007Co-Authors: Lars Stemmann, Aino Hosia, Marsh J. Youngbluth, Henrik Søiland, Marc Picheral, Gabriel GorskyAbstract:The vertical distribution (0-1000 m depth) of macroZooplankton along the northern portion of the Mid-Atlantic Ridge (59°58N, 25°53W to 41°29N, 28°19W) was investigated during the MARECO program (June and July 2004) using the Underwater Video Profiler (UVP). Twelve relatively large (> 1 cm) groups were selected from the recorded images: sarcodines (with two sub-groups), crustaceans (excluding copepods), chaetognaths, ctenophores (with two sub-groups cydippids and lobates), siphonophores, medusae (with three subgroups Aeginura grimaldii, Aglantha spp. and all other medusae), appendicularians, and thaliaceans. The numerically dominant groups over the whole area were crustaceans (26%), medusae (20%) and appendicularians (17%). The Gelatinous fauna were consistently most numerous between 400-900 m. Appendicularians, ctenophores and A. grimaldii occurred mostly below 300 m (maximum concentrations of 75, 58, and 30 individuals 100m-3, respectively). The macroZooplankton community below 200 m varied with the spatial distribution of the four regions defined by the temperature and salinity profiles. The results suggest that the Sub-Polar Front restricts the mixing of macroZooplankton communities down to 1000 m depth. The observed relationship between appendicularians and biovolume and size of particles is investigated in the four oceanic regions. Keywords: Gelatinous Zooplankton, mesopelagic Zooplankton, Sub Polar Front, North Atlantic, Underwater Video Profiler, MARECO .
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vertical distribution 0 1000 m of Gelatinous Zooplankton and particulate matter 60im 5mm along the mid atlantic ridge in the north atlantic potential impact of appendicularians on particle aggregation
11 s., 2007Co-Authors: Lars Stemmann, Aino Hosia, Marsh J. Youngbluth, Henrik Søiland, Marc Picheral, Gabriel GorskyAbstract:The vertical distribution (0-1000 m depth) of macroZooplankton along the northern portion of the Mid-Atlantic Ridge (59°58N, 25°53W to 41°29N, 28°19W) was investigated during the MARECO program (June and July 2004) using the Underwater Video Profiler (UVP). Twelve relatively large (> 1 cm) groups were selected from the recorded images: sarcodines (with two sub-groups), crustaceans (excluding copepods), chaetognaths, ctenophores (with two sub-groups cydippids and lobates), siphonophores, medusae (with three subgroups Aeginura grimaldii, Aglantha spp. and all other medusae), appendicularians, and thaliaceans. The numerically dominant groups over the whole area were crustaceans (26%), medusae (20%) and appendicularians (17%). The Gelatinous fauna were consistently most numerous between 400-900 m. Appendicularians, ctenophores and A. grimaldii occurred mostly below 300 m (maximum concentrations of 75, 58, and 30 individuals 100m-3, respectively). The macroZooplankton community below 200 m varied with the spatial distribution of the four regions defined by the temperature and salinity profiles. The results suggest that the Sub-Polar Front restricts the mixing of macroZooplankton communities down to 1000 m depth. The observed relationship between appendicularians and biovolume and size of particles is investigated in the four oceanic regions. Keywords: Gelatinous Zooplankton, mesopelagic Zooplankton, Sub Polar Front, North Atlantic, Underwater Video Profiler, MARECO .
Robert K Cowen - One of the best experts on this subject based on the ideXlab platform.
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Gelatinous Zooplankton‐Mediated Carbon Flows in the Global Oceans: A Data‐Driven Modeling Study
Global Biogeochemical Cycles, 2020Co-Authors: Jessica Y. Luo, Robert H Condon, Carlos M Duarte, Kylie A Pitt, Cathy H Lucas, Charles A. Stock, Robert K CowenAbstract:Among marine organisms, Gelatinous Zooplankton (GZ; cnidarians, ctenophores, and pelagic tunicates) are unique in their energetic efficiency, as the Gelatinous body plan allows them to process and assimilate high proportions of oceanic carbon. Upon death, their body shape facilitates rapid sinking through the water column, resulting in carcass depositions on the seafloor (“jelly‐falls”). GZ are thought to be important components of the biological pump, but their overall contribution to global carbon fluxes remains unknown. Using a data‐driven, three‐dimensional, carbon cycle model resolved to a 1° global grid, with a Monte Carlo uncertainty analysis, we estimate that GZ consumed 7.9–13 Pg C y−1 in phytoplankton and Zooplankton, resulting in a net production of 3.9–5.8 Pg C y−1 in the upper ocean (top 200 m), with the largest fluxes from pelagic tunicates. Non‐predation mortality (carcasses) comprised 25% of GZ production, and combined with the much greater fecal matter flux, total GZ particulate organic carbon (POC) export at 100 m was 1.6–5.2 Pg C y−1, equivalent to 32–40% of the global POC export. The fast sinking GZ export resulted in a high transfer efficiency (Teff) of 38–62% to 1,000 m and 25–40% to the seafloor. Finally, jelly‐falls at depths >50 m are likely unaccounted for in current POC flux estimates and could increase benthic POC flux by 8–35%. The significant magnitude of and distinct sinking properties of GZ fluxes support a critical yet underrecognized role of GZ carcasses and fecal matter to the biological pump and air‐sea carbon balance.
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Gelatinous Zooplankton mediated carbon flows in the global oceans a data driven modeling study
Global Biogeochemical Cycles, 2020Co-Authors: Jessica Y. Luo, Robert H Condon, Carlos M Duarte, Kylie A Pitt, Cathy H Lucas, Charles A. Stock, Robert K CowenAbstract:Among marine organisms, Gelatinous Zooplankton (GZ; cnidarians, ctenophores, and pelagic tunicates) are unique in their energetic efficiency, as the Gelatinous body plan allows them to process and assimilate high proportions of oceanic carbon. Upon death, their body shape facilitates rapid sinking through the water column, resulting in carcass depositions on the seafloor (“jelly‐falls”). GZ are thought to be important components of the biological pump, but their overall contribution to global carbon fluxes remains unknown. Using a data‐driven, three‐dimensional, carbon cycle model resolved to a 1° global grid, with a Monte Carlo uncertainty analysis, we estimate that GZ consumed 7.9–13 Pg C y−1 in phytoplankton and Zooplankton, resulting in a net production of 3.9–5.8 Pg C y−1 in the upper ocean (top 200 m), with the largest fluxes from pelagic tunicates. Non‐predation mortality (carcasses) comprised 25% of GZ production, and combined with the much greater fecal matter flux, total GZ particulate organic carbon (POC) export at 100 m was 1.6–5.2 Pg C y−1, equivalent to 32–40% of the global POC export. The fast sinking GZ export resulted in a high transfer efficiency (Teff) of 38–62% to 1,000 m and 25–40% to the seafloor. Finally, jelly‐falls at depths >50 m are likely unaccounted for in current POC flux estimates and could increase benthic POC flux by 8–35%. The significant magnitude of and distinct sinking properties of GZ fluxes support a critical yet underrecognized role of GZ carcasses and fecal matter to the biological pump and air‐sea carbon balance.
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Associations between lobster phyllosoma and Gelatinous Zooplankton in relation to oceanographic properties in the northern Gulf of Mexico
Fisheries Oceanography, 2017Co-Authors: Adam T Greer, Robert K Cowen, Christian Briseño-avena, Alison L. Deary, Frank J. Hernandez, William M GrahamAbstract:Lobster phyllosoma are known to associate with large cnidarian medusae; however, direct quantitative observations are difficult because Gelatinous Zooplankton are extremely fragile, and the phyllosoma easily detach from their host when sampled by plankton nets. We provide the first large scale quantitative information of the distribution of this association using an in situ imaging system, with synoptic measurements of water column properties. All phyllosoma were identified as slipper lobsters (Scyllarus chacei) and were associated with previously unreported “hosts” such as small hydromedusae, doliolids, and siphonophores in the northern Gulf of Mexico. Along the shelf, phyllosoma were more likely to be present at greater depths and higher salinities. Approximately 30% of the 347 lobster phyllosoma imaged were attached to at least one Gelatinous organism, and salinity and depth were positively related to the probability of attachment on 30 October, but did not show a significant relationship for the other days of sampling. Many of the phyllosoma were larger than the Gelatinous organisms to which they were attached, and some Gelatinous Zooplankton showed damage likely from feeding by the phyllosoma. In this coastal environment, Gelatinous Zooplankton tended to be more abundant in the same offshore region where phyllosoma occurred, so these Gelatinous “hosts” may provide a steady food supply in the more oligotrophic waters on the outer shelf. Similar complex interactions among Zooplankton may influence the life histories of other species, hindering our ability to forecast ecosystem level processes until the population level consequences of species interactions are fully understood.
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relationships between phytoplankton thin layers and the fine scale vertical distributions of two trophic levels of Zooplankton
Journal of Plankton Research, 2013Co-Authors: Adam T Greer, Robert K Cowen, Jeff C Sevadjian, Cedric M Guigand, Margaret A. Mcmanus, Amanda H V TimmermanAbstract:Thin layers of phytoplankton are well documented, common features in coastal areas globally, but little is known about the relationships of these layers to higher trophic levels. We deployed the In Situ Ichthyoplankton Imaging System (ISIIS) to simultaneously quantify the three trophic levels of plankton, including phytoplankton, primary consumers (copepods and appendicularians) and secondary consumers (Gelatinous Zooplankton). Over a 2-week sampling period, phytoplankton thin layers, primarily composed of Pseudo-nitzschia spp., were common on two of the five sampling days. Imagery showed copepods aggregating in zones of lower chlorophyll-a fluorescence, while appendicularians were more common at greater depths and higher chlorophylla levels. All Gelatinous Zooplankton generally increased in abundance with depth. Bolinopsis spp. ctenophores underwent a ‘bloom,’ and they were the only species observed to aggregate within phytoplankton thin layers. The vertical separation between copepods, phytoplankton and Gelatinous Zooplankton suggests that copepods may use the surface waters as a predation refuge, only performing short migrations into favorable feeding zones where Gelatinous predators are much more abundant. Thin layers containing dense diatom aggregates obstruct light reaching deeper waters (.10 m), which may allow Gelatinous Zooplankton to avoid visual predation as well as improve the effectiveness of contact predation with copepod prey.