Culhane Emmett

No Thumbnail Available
Last Name
Culhane
First Name
Emmett
ORCID
0000-0002-2787-7414

Filters

2022 - 2023 2
2
2
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • Article
    Plankton imagery data inform satellite-based estimates of diatom carbon
    (American Geophysical Union, 2022-06-18) Chase, Alison P. ; Boss, Emmanuel S. ; Haëntjens, Nils ; Culhane, Emmett ; Roesler, Collin S. ; Karp-Boss, Lee
    Estimating the biomass of phytoplankton communities via remote sensing is a key requirement for understanding global ocean ecosystems. Of particular interest is the carbon associated with diatoms given their unequivocal ecological and biogeochemical roles. Satellite-based algorithms often rely on accessory pigment proxies to define diatom biomass, despite a lack of validation against independent diatom biomass measurements. We used imaging-in-flow cytometry to quantify diatom carbon in the western North Atlantic, and compared results to those obtained from accessory pigment-based approximations. Based on this analysis, we offer a new empirical formula to estimate diatom carbon concentrations from chlorophyll a. Additionally, we developed a neural network model in which we integrated chlorophyll a and environmental information to estimate diatom carbon distributions in the western North Atlantic. The potential for improving satellite-based diatom carbon estimates by integrating environmental information into a model, compared to models that are based solely on chlorophyll a, is discussed.
  • Article
    A shallow scattering layer structures the energy seascape of an open ocean predator
    (American Association for the Advancement of Science, 2023-10-04) Arostegui, Martin C. ; Muhling, Barbara A. ; Culhane, Emmett ; Dewar, Heidi ; Koch, Stephanie S. ; Braun, Camrin D.
    Large predators frequent the open ocean where subsurface light drives visually based trophic interactions. However, we lack knowledge on how predators achieve energy balance in the unproductive open ocean where prey biomass is minimal in well-lit surface waters but high in dim midwaters in the form of scattering layers. We use an interdisciplinary approach to assess how the bioenergetics of scattering layer forays by a model predator vary across biomes. We show that the mean metabolic cost rate of daytime deep foraging dives to scattering layers decreases as much as 26% from coastal to pelagic biomes. The more favorable energetics offshore are enabled by the addition of a shallow scattering layer that, if not present, would otherwise necessitate costlier dives to deeper layers. The unprecedented importance of this shallow scattering layer challenges assumptions that the globally ubiquitous primary deep scattering layer constitutes the only mesopelagic resource regularly targeted by apex predators.