Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

The primary data file for this dataset, "897682_particle_speed.csv", contains the raw data. The supplemental file, "897682_particle_speed_averages_and_maximums.csv", contains the maximum speed and average speed for each video, as well as the population mean maximum speeds. The videos are attached as Supplemental Files (there is one .zip folder for each temperature treatment).

All experimental animals were obtained from the appendicularian culture facility at the Sars Centre for Marine Molecular Biology in Bergen, Norway in December 2015. Oikopleura dioica were filmed individually following Gemmell et al. (2014). Images were recorded using an Edgertronic high-speed camera (1280 × 1024-pixel resolution, 500 frames per second) with brightfield illumination from a fiber optic light source, or a Photron FastCam Mini Ux100 (1280x1024, 125-1000 frames per second) with darkfield illumination from a tilting mirror base. The filming vessel was positioned on a manually adjustable stage between the light source and the camera. A long working-distance microscope objective (4x or 40x) was mounted to an adjustable-height optics clamp positioned between the filming vessel and the camera. Videos were converted to image stacks in QuickTime Pro. Day 1 animals were filmed in a 50-milliliter glass cuvette in treatments comprising 3 temperatures: 5° Celsius, 15° Celsius, and 25° Celsius.

Data Processing:
Particle tracking to estimate inlet flow speeds were measured in ImageJ. Flow speeds were determined by manual particle tracking, with distance over time obtained from the first and last of 10 frames. An average and maximum of 5 particle speeds were recorded for all individuals.

BCO-DMO Processing:
- separated the original data file into two resources: one with the averages and maximums (summary statistics) and one with the raw data;
- renamed fields for both resources to comply with BCO-DMO naming conventions;
- bundled the videos into 3 .zip files (see Supplemental Files).

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.