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Using Size Fractionation to Determine Whether the SCTLD Pathogen is Bacterial, Viral or Other

Project Lead(s): Valerie Paul, Blake Ushijima, Kelly Pitts, Tessa Vekich and Jay Houk
Commencement Date: August 2, 2020

This project aimed to determine what might be causing SCTLD – a bacterium, virus, or something else – by filtering microbes found on diseased corals into various sizes and determining which size caused SCTLD lesions. When healthy great star corals were exposed to water filtered to contain bacteria, they developed the disease, suggesting bacteria can cause SCTLD in certain species.

In addition to the report authors, Valerie Paul, Blake Ushijima, Kelly Pitts, Tessa Vekich and Jay Houk contributed to the experimental setup, monitoring and data collection. Smithsonian Marine Station provided the healthy corals for mesocosm inoculation and all the coral-housing facilities for the size-fractionation experiments. Collaborative support was essential in the collection of diseased corals: from aren Neely, Kevin Macaulay, and Michelle Dobler in November 2020 and from Cynthia Lewis, Bill Ferrell, Joshua Farmer and the Keys Marine Laboratory team in March 2021. Coral fragments for the filter treatments were provided by Coral Restoration Foundation for the October 2019 pilot (Project ID CRF-2019-011) and November 2020 experiment (Project ID CRF-2020-004), and by Mote Marine Laboratory for the March 2021 experiment. This study leveraged support from the USGS Natural Hazards and Ecosystems Mission Areas. Healthy and diseased corals were collected under permits FKNMS-2017-128-A2 and FKNMS-2019-160 to Valerie Paul.

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

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