Publications

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 &amp; 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 <strong>Luo, Jessica Y.</strong>, Condon, R. H., Stock, C. A., Duarte, C. M., Lucas, C. H., Pitt, K. A., &amp; Cowen, R. K. (2020). Gelatinous zooplankton‐mediated carbon flows in the global oceans: A data‐driven modeling study. <em>Global Biogeochemical Cycles</em>, 34, e2020GB006704. https://doi.org/10.1029/2020GB006704

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 &amp; 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 <strong>Luo, Jessica Y.</strong>, Condon, R. H., Stock, C. A., Duarte, C. M., Lucas, C. H., Pitt, K. A., &amp; Cowen, R. K. (2020). Gelatinous zooplankton‐mediated carbon flows in the global oceans: A data‐driven modeling study. <em>Global Biogeochemical Cycles</em>, 34, e2020GB006704. https://doi.org/10.1029/2020GB006704

Our recent finding that dilution limits dissolved organic carbon (DOC) utilization in the deep ocean has been criticized based on the common misconception that lability equates to rapid and complete utilization. Even when considering the redefinition of recalcitrant DOC recently proposed by Jiao et al., the dilution hypothesis best explains our experimental observations.

The Mediterranean Sea is a two-basin system, with the boundary zone restricted to the Strait of Sicily and the narrow Strait of Messina. Two main population groups are recognized in the Mediterranean endemic seagrass Posidonia oceanica, corresponding to the Western and the Eastern basins. To address the nature of the East–West cleavage in P. oceanica, the main aims of this study were: (i) to define the genetic structure within the potential contact zone (i.e. the Strait of Sicily) and clarify the extent of gene flow between the two population groups, and (ii) to investigate the role of present water circulation patterns vs. past evolutionary events on the observed genetic pattern. To achieve these goals, we utilized SSR markers and we simulated, with respect to current regime, the possible present-day dispersal pattern of Posidonia floating fruits using 28-day numerical Lagrangian trajectories. The results obtained confirm the presence of the two main population groups, without any indices of reproductive isolation, with the break zone located at the level of the Southern tip of Calabria. The populations in the Strait of Sicily showed higher affinity with Western than with Eastern populations. This pattern of genetic structure probably reflects historical avenues of recolonization from relict glacial areas and past vicariance events, but seems to persist as a result of the low connectivity among populations via marine currents, as suggested by our dispersal simulation analysis.

In coastal areas around the world, the dominant primary producers are benthic macrophytes, including seagrasses and macroalgae, that provide habitat structure and food for diverse and abundant populations and communities, and drive ecosystem processes. Seagrass meadows and macroalgal forests are economically central to coastal human communities, particularly in the developing world, contributing to fisheries yield, storm protection, blue carbon storage, and important cultural values. These services are threatened worldwide by human activities, with substantial areas of seagrass and kelp forests lost over the last half-century. Tracking status and trends in marine macrophyte cover and quality is an emerging priority for ocean and coastal management, but doing so has been challenged by limited coordination across the numerous efforts to monitor macrophytes, which vary widely in goals, methodologies, scales, capacity, governance approaches, and data availability. Here, we present a consensus assessment and recommendations on the current state of and opportunities for advancing global marine macrophyte observations, integrating contributions from a community of researchers with broad geographic and disciplinary expertise. The time is ripe to harmonize marine macrophyte observations by building on existing networks and identifying a core set of common metrics and approaches in sampling design, field measurements, taxonomy, governance, capacity building, and data management. A global macrophyte observation community would then be facilitated by ensuring rigorous documentation, archiving and open-access sharing of protocols and resources at all stages of workflow, from field surveys to data management, and provision of open-access data. Realizing these recommendations will produce more effective, efficient, and responsive observing, a more accurate global picture of change in macrophyte systems, and stronger international capacity for sustaining observations.