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    • Structure from motion images collected during marine debris surveys at coral reef sites entangled with derelict fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands in 2018 and 2021

    Metadata Updated: October 19, 2024

    The photographs described in this dataset were collected using a Structure from Motion (SfM) approach during in-water marine debris swim surveys conducted by snorkelers in search of derelict fishing nets. Surveys were conducted by the NOAA Fisheries, Ecosystem Sciences Division (ESD) at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands (NWHI). Initial surveys occurred from September 24 - October 3, 2018 during an ESD-led marine debris removal mission aboard the NOAA Ship Oscar Elton Sette, and follow-up surveys occurred from September 13-14, 2021 on a joint mission with non-profit organization Papahanaumokuakea Marine Debris Project aboard the M/V IMUA.

    During the 2018 mission, only a subset of marine debris surveys resulted in a SfM survey. Fishing nets were located during swim surveys and selected for SfM if the net was interacting with coral or hard substrate, the depth of the net was within ~1- 4 m of the surface, and the area of the net fit within the 9 sq. meter SFM survey plot. During a SFM survey, a permanent 3 x 3 m plot was established around the center of the fishing net, and the net was photographed using a back and forth swim pattern ("before" photos) for later processing using a SfM approach. The net was then removed and the same area was photographed again in the same way ("after" photos). A nearby (>50 m distant) paired control site was also photographed using the same method ("control" photos).

    During the 2021 mission, relocation of all paired sites where "after" and "control" photos were taken in 2018 was attempted; if found, the permanent 3 x 3m plot was reimaged using the same SfM approach. Only a subset of 2018 sites were successfully relocated in 2021 (12 "after" sites, 8 "control" sites), and five new nearby "control" sites had to be established to fulfill the paired study design.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date October 3, 2024
    Metadata Created Date October 19, 2024
    Metadata Updated Date October 19, 2024
    Reference Date(s) April 28, 2020 (creation), May 5, 2022 (revision), 2022 (publication)
    Frequency Of Update notPlanned

    Metadata Source

    Harvested from NMFS PIFSC

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Date October 3, 2024
    Metadata Created Date October 19, 2024
    Metadata Updated Date October 19, 2024
    Reference Date(s) April 28, 2020 (creation), May 5, 2022 (revision), 2022 (publication)
    Responsible Party (Point of Contact, Custodian)
    Contact Email
    Guid gov.noaa.nmfs.inport:59423
    Access Constraints Cite As: Pacific Islands Fisheries Science Center, [Date of Access]: Structure from motion images collected during marine debris surveys at coral reef sites entangled with derelict fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands in 2018 and 2021 [Data Date Range], https://www.fisheries.noaa.gov/inport/item/59423., Use Constraints: These marine debris survey data act as a proxy for area surveyed and have not been screened for accuracy based on environmental conditions or GPS accuracy. NOAA can not be held liable for use of these data in a manner other than for perusal of preliminary marine debris data for scientific research on coral reef ecosystems. When using this data, please credit the NOAA Fisheries, Ecosystem Sciences Division. Suggested citation: Ecosystem Sciences Division, Pacific Islands Fisheries Science Center, 2022: Structure from motion images collected during marine debris surveys at coral reef sites entangled with derelict fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands in 2018 and 2021, https://www.fisheries.noaa.gov/inport/item/59423., Distribution Liability: While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.
    Bbox East Long -175.7880926
    Bbox North Lat 27.89404863
    Bbox South Lat 27.82745706
    Bbox West Long -175.8211335
    Coupled Resource
    Frequency Of Update notPlanned
    Harvest Object Id d7404312-58f1-4e2f-ad2e-aa2eb1fba242
    Harvest Source Id c0beac72-5f43-4455-8c33-1b345fbc2dfe
    Harvest Source Title NMFS PIFSC
    Licence NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
    Lineage Marine debris removal has been conducted by the Pacific Islands Fisheries Science Center's Ecosystem Sciences Division at the atolls, reefs and islands of Northwestern Hawaiian Islands since 1996. Standardized data collection has been implemented since 1999. Swim surveys are typically used in the comparatively high-relief and patchy lagoonal reef habitats. Survey areas are chosen based on regional reef morphology and past accumulation records. At each Structure from Motion (SfM) data collection site, a permanent 3 x 3 m plot was established around the center of the net. SfM images were taken underwater before and after net removal. The same method was also used at the paired control sites. Sites were relocated and reimaged in 2021.
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-175.8211335, 27.82745706], [-175.7880926, 27.82745706], [-175.7880926, 27.89404863], [-175.8211335, 27.89404863], [-175.8211335, 27.82745706]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2018-09-24
    Temporal Extent End 2018-10-03

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