Robert H. Condon

University of North Carolina Wilmington

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Kylie A. Pitt

Griffith University

Cathy H. Lucas

National Oceanography Centre

Carlos M. Duarte

King Abdullah University of Science and Technology

Kelly L. Robinson

University of Louisiana at Lafayette

Mario Lebrato

Kiel University

William M. Graham

Dauphin Island Sea Lab

Jennifer E. Purcell

Western Washington University

Daniel O. B. Jones

National Oceanography Centre

Kelly R. Sutherland

University of Oregon

Hermes Mianzán

National University of Mar del Plata

Cooperative Institutions

Institut de Ciències del Mar

Centre National de la Recherche Scientifique

National Oceanography Centre

University of Southampton

Consejo Superior de Investigaciones Científicas

Griffith University

Institut Català de Ciències del Clima

University of California, Santa Barbara

Dauphin Island Sea Lab

Woods Hole Oceanographic Institution

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Questioning the Rise of Gelatinous Zooplankton in the World's Oceans

BioScience (2012)

Robert H. Condon William M. Graham Carlos M. Duarte Kylie A. Pitt Cathy H. Lucas

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 be 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.

Gelatinous zooplankton

Marine ecosystem

Historical Ecology

10.1525/bio.2012.62.2.9

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Citations (314)

Commensal associations between the hyperiid amphipod,themisto australis,and the scyphozoan jellyfish,Cyanea capillata

Marine and Freshwater Behaviour and Physiology (1999)

Robert H. Condon Mark D. Norman

Click to increase image sizeClick to decrease image sizeKey words: Commensalismscyphomedusaehyperiid amphipodsfeeding strategies Themisto australis Cyanea capillata

10.1080/10236249909379054

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Citations (13)

Production of dissolved organic matter and inorganic nutrients by gelatinous zooplankton in the York River estuary, Chesapeake Bay

Journal of Plankton Research (2009)

Robert H. Condon Deborah K. Steinberg Deborah A. Bronk

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 (NH4+) and phosphate (PO43−) 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 NH4+ and PO43− 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 NH4+ 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.

Redfield ratio

Gelatinous zooplankton

10.1093/plankt/fbp109

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Citations (51)

Jelly-falls historic and recent observations: a review to drive future research directions

Hydrobiologia (2012)

Mario Lebrato Kylie A. Pitt Andrew K. Sweetman Daniel O. B. Jones Joan Enric Cartes

Gelatinous zooplankton

Marine ecosystem

Spring bloom

10.1007/s10750-012-1046-8

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Citations (96)

Influence of jellyfish blooms on carbon, nitrogen and phosphorus cycling and plankton production

Springer eBooks (2008)

Kylie A. Pitt David T. Welsh Robert H. Condon

Bacterioplankton

Nutrient cycle

10.1007/978-1-4020-9749-2_10

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Citations (12)

Exploring the paradigm of a global expansion in jellyfish blooms: implications for biogeochemical cycles and food webs in a changing ocean

Robert H. Condon Kylie A. Pitt Carlos M. Duarte William M. Graham Cathy H. Lucas

Biogeochemical Cycle

Source

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What's in a jellyfish? Proximate and elemental composition and biometric relationships for use in biogeochemical studies

Ecology (2011)

Cathy H. Lucas Kylie A. Pitt Jennifer E. Purcell Mario Lebrato Robert H. Condon

Many marine organisms have gelatinous bodies, but the trait is most common in the medusae (phylum Cnidaria), ctenophores (phylum Ctenophora), and the pelagic tunicates (phylum Chordata, class Thaliacea). Although there are taxonomic and trophic differences between the thaliaceans and the other two closely related phyla, the collective term "jellyfish" has been used within the framework of this article. Because of the apparent increase in bloom events, jellyfish are receiving greater attention from the wider marine science community. Questions being posed include: (1) what is the role of jellyfish in pelagic food webs in a changing environment, and (2) what is the role of jellyfish in large-scale biogeochemical processes such as the biological carbon pump? In order to answer such questions, fundamental data on body composition and biomass are required. The purpose of this data set was to compile proximate and elemental body composition and length–mass and mass–mass regressions for jellyfish (i.e., medusae, siphonophores, ctenophores, salps, doliolids, and pyrosomes) to serve as a baseline data set informing studies on biogeochemical cycling, food web dynamics, and ecosystem modeling, as well as physiology. Using mainly published data from 1932 to 2010, we have assembled three data sets: (1) body composition (wet, dry, and ash-free dry mass, C, N, P as a percentage of wet and dry mass, and C:N), (2) length–mass biometric equations, and (3) mass–mass biometric equations. The data sets represent a total of 102 species from six classes (20 Thaliacea, 2 Cubozoa, 33 Hydrozoa, 26 Scyphozoa, 17 Tentaculata, 4 Nuda) in three phyla. Where it exists, we have included supplementary data on location, salinity, whole animal or tissue type, measured size range, and where appropriate, the regression type with values of sample size, correlation coefficients (r, r2) and level of significance for the relationship. In addition to the raw unpublished data, we have provided summary tables of mean (±SD) body composition for the main taxonomic groups. The complete data sets corresponding to abstracts published in the Data Papers section of the journal are published electronically in Ecological Archives at 〈http://esapubs.org/archive〉. (The accession number for each Data Paper is given directly beneath the title.)

Scyphozoa

Biogeochemical Cycle

Hydrozoa

Gelatinous zooplankton

Aurelia aurita

10.1890/11-0302.1

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Citations (74)

Bloom and Bust: Why Do Blooms of Jellyfish Collapse?

Springer eBooks (2013)

Kylie A. Pitt Ariella Chelsky Budarf Joanna G. Browne Robert H. Condon

Bloom

10.1007/978-94-007-7015-7_4

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Recurrent jellyfish blooms are a consequence of global oscillations

Proceedings of the National Academy of Sciences (2012)

Robert H. Condon Carlos M. Duarte Kylie A. Pitt Kelly L. Robinson Cathy H. Lucas

A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.

Scyphozoa

10.1073/pnas.1210920110

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Citations (449)

Dataset for Gelatinous zooplankton-mediated carbon flows in the global oceans: A data-driven modeling study

Zenodo (CERN European Organization for Nuclear Research) (2020)

Jessica Y. Luo Robert H. Condon Charles A. Stock Carlos M. Duarte Cathy H. Lucas

Gridded dataset of gelatinous zooplankton (GZ) biomass (mg C m^-3) and numeric density (individuals m^-3), time-averaged, in a 1-degree grid. Data are separated by phyla: Cnidaria, Ctenophora, and Chordata (pelagic tunicates). Original data compiled as part of the Jellyfish Database Initiative Project (JeDI; Condon et al. 2015, doi:10.1575/1912/7191) and converted to carbon biomass units for Lucas et al. 2014. Cnidarian additions to this dataset include records from the northern California Current (Brodeur et al., 2014) and Gulf of Mexico (Robinson et al., 2015). Chordata additions include salps from the Bermuda Atlantic Time Series (BATS; Stone & Steinberg, 2014), Western Antarctic Peninsula (WAP; Steinberg et al., 2015), and Southern Ocean, from KRILLBASE (Atkinson et al., 2017). Note that we excluded the KRILLBASE records from the WAP region that to prevent double-counting. See Methods in Luo et al. (2020) for details on biometric conversions to carbon biomass. Data were averaged by time (season, then year), and then within each 1-degree grid cell. Code for the model using this dataset is available at: https://github.com/jessluo/gz_biogeochem_pub Luo, Jessica Y., Condon, R. H., Stock, C. A., Duarte, C. M., Lucas, C. H., Pitt, K. A., & Cowen, R. K. (2020). Gelatinous zooplankton‐mediated carbon flows in the global oceans: A data‐driven modeling study. Global Biogeochemical Cycles, 34, e2020GB006704. https://doi.org/10.1029/2020GB006704

Gelatinous zooplankton

10.5281/zenodo.3891704

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