Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Related Datasets
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Samples were collected during daylight from the R/V Atlantis (AGOR-25) along the Newport Hydrographic (NH) Line at station “NH5” (N 44° 39.084’, W 125° 7.151’) on July 22nd as well as along the Trinidad Head (TR) Line at stations “TR1” (N 41° 3.467, W 124° 16.016) and “TR3” (N 41° 3.448, W 124° 26.7) on July 17th and 19th, respectively.

Doliolids were sampled using a modified coupled Multiple Opening and Closing Net and Environmental Sensing System (MOCNESS). Doliolids were rinsed three times with 0.2 µm filtered seawater to remove unattached microbes, collected in a 1-mL sterile bead-beater tube containing 0.55- and 0.25-mm beads, and then frozen at -80 °C.

Seawater and doliolid samples were lysed by beadbeating with 0.55 mm and 0.25 mm sterile glass beads at 30 Hz for 2 min after addition of lysis buffer, freeze-fractured three times, incubated with Proteinase K (VWR Chemicals, Solon, OH) at 20 mg/mL for 1 h at 55 ˚C, and incubated with RNase A at 100 mg/mL for 10 min at 65˚C. The primer pair 515F‐Y/806R was chosen to amplify the 16S rRNA V4 hypervariable region. Reactions were performed with 0.5-2 ng of DNA using the QuantaBio 5Prime HotMasterMix (Qiagen Beverly, MA USA). The Agilent High Sensitivity Kit in the Bioanalyzer (Agilent Technologies, Waldbronn, Germany) confirmed amplicon size. Triplicate reactions from each sample were pooled and paired-end sequenced with Illumina MiSeq v.3 (Illumina, San Diego, CA). Raw sequence data are available in the Sequence Read Archive Project # PRJNA1055560.

* Converted file to flat file format for improved interoperability
* Adjusted parameter names to comply with database requirements
* Split lat/lon column into their own columns
* Converted dates to ISO format

NSF Award Abstract:
The oceans are dominated by microscopic plants and animals (microorganisms) that are at the base of the food web and drive energy and carbon cycles on global scales. Soft jellylike animals called gelatinous grazers specialize in feeding on microorganisms using nets made out of mucus. Gelatinous grazers are abundant in the ocean and have high feeding rates on microorganisms so could have a very strong influence on the abundance and diversity of microorganisms and could change how oceanic food webs are currently understood. However, gelatinous grazers are very fragile and patchy in their distributions so it has been difficult to determine the magnitude and dynamics of these important predator-prey relationships on a meaningful scale using traditional approaches, thus they have typically been disregarded in food web studies. Learning more about the predator-prey relationship between gelatinous grazers and microorganisms will improve understanding of the structure, mechanics, and dynamics of the ocean's food web, which is a critical economic and ecosystem resource on Earth. This project is determining grazing rates by gelatinous animals on microbes to inform food web models. The project also trains students to communicate, disseminate, and interpret scientific findings. These broader impacts goals will be attained through partnerships at the University of Oregon (Applied Scientific Communication) and Portland State University (Advanced Technical Writing), training of 1 PhD student, 2 undergraduates, and 4 science communication interns, and development of a week-long workshop and establish student mentorship relationships towards production of communication products.

The project integrates laboratory and oceanographic approaches to address several specific aspects of the predator-prey relationship between gelatinous grazers and ocean microorganisms. Five distinct types of gelatinous grazers, each with different feeding morphologies and life history, will be studied in an oceanographic setting with an abundant and diverse natural microbial population. These target organisms include pelagic tunicates (salps, appendicularians, doliolods and pyrosomes) and thecosome pteropods. The approach quantifies: 1) grazing rates in the natural ocean environment, 2) particle selectivity with a focus on size and shape and, 3) the morphological and hydrodynamic properties of feeding that underlie the measured grazing rates and particle selection. The project uses a variety of techniques including sampling via SCUBA diving, laboratory experiments, high speed/high resolution videography, flow cytometry, and DNA sequencing techniques.