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Dataset Overview | National Centers for Environmental Information (NCEI)

Benthic cover derived from 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 from 2021-09-13 to 2021-09-14 (NCEI Accession 0253462)

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The benthic cover and fishing-net related data described in this dataset are derived from the GIS analysis of benthic orthophotos. Source imagery was collected by snorkelers using a Structure from Motion (SfM) approach from at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands (NWHI). This data was collected from September 13-14, 2021 as part of a joint marine debris removal mission with the NOAA Fisheries, Ecosystem Sciences Division (ESD) and non-profit organization Papahānaumokuākea Marine Debris Project aboard the charter vessel M/V IMUA.

This 2021 benthic cover dataset follows a 2018 benthic cover dataset from SfM surveys of net-impacted and paired control sites; sites were revisited in 2021 to compare the benthic composition of net-impacted sites to control sites three years after net removal. Only a subset of 2018 sites were successfully relocated in 2021, therefore new paired control sites were also included.

The photographs from each site were processed using Agisoft Metashape software to generate orthomosaic images that were analyzed in ArcGIS for benthic cover using a random point approach. For net-impacted sites, twenty random points were assigned to each orthophoto within the shapefile of the 2018 net polygon overlaid in the appropriate area. For control sites, the net shapefile from 2018 was overlaid in the center of the image and 20 random points were assigned within that polygon. For all sites, each point was classified into one of six benthic categories: algae, sand, bare substrate, coral, sponge, or crustose coralline algae (CCA). The annotated points for each site were converted to percent cover for each benthic category.
  • Cite as: NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division (2022). Benthic cover derived from 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 from 2021-09-13 to 2021-09-14 (NCEI Accession 0253462). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0253462. Accessed [date].
gov.noaa.nodc:0253462
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Distributor NOAA National Centers for Environmental Information
+1-301-713-3277
NCEI.Info@noaa.gov
Dataset Point of Contact NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Time Period 2021-09-13 to 2021-09-14
Spatial Bounding Box Coordinates
West: -175.817246
East: -175.7902661
South: 27.82745706
North: 27.89114188
Spatial Coverage Map
General Documentation
Associated Resources
  • Benthic cover and other related datasets derived from Structure-from-Motion (SfM) imagery of coral reef ecosystems in Pacific Islands Regions
    • NCEI Collection
      Navigate directly to the URL for data access and direct download.
  • Ecosystem Sciences Division, Pacific Islands Fisheries Science Center (2020). Benthic cover derived from 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 from 2018-09-24 to 2018-10-03 (NCEI Accession 0209247). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0209247.
  • Pacific Islands Fisheries Science Center, 2022: Benthic cover derived from 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 from missions in 2018 and 2021, https://www.fisheries.noaa.gov/inport/item/59172.
  • Successful application of a novel technique to quantify negative impacts of derelict fishing nets on Northwestern Hawaiian Island reefs
  • Integrating structure-from-motion photogrammetry with geospatial software as a novel technique for quantifying 3D ecological characteristics of coral reefs
  • Derelict fishing gear in the Northwestern Hawaiian Islands: diving surveys and debris removal in 1999 confirm threat to coral reef ecosystems
  • Processing Photomosaic Imagery of Coral Reefs Using Structure-from-Motion Standard Operating Procedures
  • 2018 Marine Debris Removal and Assessment in the Northwestern Hawaiian Islands
  • Parent ID (indicates this dataset is related to other data):
    • gov.noaa.nodc:PIFSC-SfM-DerivedData
Publication Dates
  • publication: 2022-05-12
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Complete - production of the data has been completed
Historical archive - data has been stored in an offline storage facility
Data Update Frequency As needed
Supplemental Information
Submission Package ID: 4KDA2E

Note: The dataset abstract references source imagery. These images were not included with this submission.
Purpose The purpose of the Structure from Motion (SfM) surveys at Pearl and Hermes Atoll is to understand how derelict fishing nets alter the benthic community composition of the reef, how these impacts last over time once the net is removed, and if the benthic community can recover over time. This study leveraged SfM, an emerging photogrammetry technique, to allow efficient data collection alongside marine debris survey and removal efforts. The Papahānaumokuākea Marine National Monument (PMNM) includes the 1200 nautical mile chain of atolls and islets known as the Northwestern Hawaiian Islands (NWHI) that are geographically positioned as a repository for marine debris. Marine debris circulates within the North Pacific Subtropical Gyre until it encounters the atolls of the NWHI. The Ecosystem Sciences Division (ESD) at NOAA Fisheries has conducted both ship- and shore-based missions in the NWHI to survey for and remove derelict fishing gear and many other types of marine debris. Exploratory and opportunistic efforts began in 1996 that evolved into ~annual cruises.
Use Limitations
  • accessLevel: Public
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Dataset Citation
  • Cite as: NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division (2022). Benthic cover derived from 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 from 2021-09-13 to 2021-09-14 (NCEI Accession 0253462). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0253462. Accessed [date].
Cited Authors
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Acknowledgments
  • Related Funding Agency: NOAA Marine Debris Program
Theme keywords NODC DATA TYPES THESAURUS NODC OBSERVATION TYPES THESAURUS WMO_CategoryCode
  • oceanography
CoRIS Discovery Thesaurus
  • Numeric Data Sets > Benthic
CoRIS Theme Thesaurus
  • EARTH SCIENCE > Biosphere > Aquatic Habitat > Benthic Habitat
  • EARTH SCIENCE > Biosphere > Aquatic Habitat > Reef Habitat
  • EARTH SCIENCE > Biosphere > Vegetation > Algae > Algal Cover
  • EARTH SCIENCE > Biosphere > Vegetation > Algae > Crustose Coralline Algae
  • EARTH SCIENCE > Biosphere > Vegetation > Algae > Fleshy Macroalgae
  • EARTH SCIENCE > Biosphere > Vegetation > Algae > Turf Algae
  • EARTH SCIENCE > Biosphere > Zoology > Corals
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Damage Assessment > Marine Debris
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Photographic Analysis
  • EARTH SCIENCE > Biosphere > Zoology > Sponges
  • EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Hard Seafloor Substrate
  • EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs
  • EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology
  • EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology > Coral Cover
  • EARTH SCIENCE > Oceans > Marine Biology > Coral
Global Change Master Directory (GCMD) Science Keywords
Data Center keywords NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS Contributing Data Centers
  • CRED
  • CREP
  • Coral Reef Ecosystem Division
  • Coral Reef Ecosystem Program
  • ESD
  • Ecosystem Sciences Division
  • PIFSC
  • Pacific Islands Fisheries Science Center
Global Change Master Directory (GCMD) Data Center Keywords
Platform keywords Provider Platform Names
  • M/V IMUA
Instrument keywords NODC INSTRUMENT TYPES THESAURUS Provider Instruments
  • Dive Computer
Place keywords NODC SEA AREA NAMES THESAURUS CoRIS Place Thesaurus
  • COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Northwestern Hawaiian Islands (28N178W0000)
  • COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Pearl and Hermes Reef (27N176W0001)
  • OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands (28N178W0000)
  • OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands > Pearl and Hermes Reef (27N176W0001)
Global Change Master Directory (GCMD) Location Keywords Provider Place Names
  • Papahanaumokuakea Marine National Monument
Project keywords NODC PROJECT NAMES THESAURUS Provider Project Names
  • Papahanaumokuakea Marine Debris Project
Keywords NCEI ACCESSION NUMBER
Use Constraints
  • Cite as: NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division (2022). Benthic cover derived from 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 from 2021-09-13 to 2021-09-14 (NCEI Accession 0253462). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0253462. Accessed [date].
Access Constraints
  • Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
Fees
  • In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Processing Steps
  • 2022-05-12T21:28:45Z - NCEI Accession 0253462 v1.1 was published.
Output Datasets
Lineage information for: dataset
Processing Steps
  • Parameter or Variable: REEF AND/OR BOTTOM REGIME - PERCENT COVER (calculated); Units: percent; Observation Category: derived products; Sampling Instrument: photograph; Sampling and Analyzing Method: Orthomosaics from net-impacted sites and paired controls were assessed for benthic cover using ArcMap 10.6.1. For each impact site, a shapefile of the net boundary delineated by Suka et al. in 2020 was overlaid and repositioned on the recent orthophotos to align with the original location of the derelict net. For control sites, the same boundary shapefile was overlaid in the center of the orthophoto. The benthic cover at each control and impact site site was assessed from 20 random points placed within the net boundary shapefile of each orthophoto. The benthic feature under each point was then classified into one of six benthic categories: algae (grouping turf and macroalgae), sand, bare, coral, sponge, and crustose coralline algae (CCA) and then converted to percent cover for the site.; Data Quality Method: Representativeness: The data set derived from the image analysis is as good as the mosaic image itself; points that fell within areas of low contrast, shadow, obstruction, or blur were discarded. Accuracy: Prior to conducting surveys, researchers are trained to identify benthic taxa. Both classroom and field training were completed for all researchers (experienced and inexperienced alike) before any surveys were conducted. This training ensures that all analysis is conducted consistently by all analysts..
  • Parameter or Variable: DEPTH - BOTTOM (measured); Units: meter; Observation Category: in situ; Sampling Instrument: Dive Computer; Sampling and Analyzing Method: The minimum and maximum depths of each site were measured using a wrist mounted depth gauge and placing it on the benthos at the shallowest and deepest areas of each site. Average depth was calculated by averaging the minimum and maximum depths, in meters.; Data Quality Method: Average depth of sites ranged from 1.2 - 3.5 meters..
Acquisition Information (collection)
Instrument
  • photograph
Last Modified: 2023-02-06T13:44:10Z
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