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Structure from motion images collected at control sites during marine debris surveys of coral reefs entangled with fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands from 2018-09-24 to 2018-10-03 (NCEI Accession 0210740)

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The “control site” 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) from September 24 to October 3, 2018 at Pearl and Hermes Atoll during an ESD-led marine debris mission to the Northwestern Hawaiian Islands (NWHI) aboard NOAA Ship Oscar Elton Sette. The lagoon at Pearl and Hermes was surveyed equally across the spatial gradient, from locations where derelict fishing nets are common to locations where derelict fishing nets have never been observed. 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.

A complete SfM survey is comprised of three sets of images. Two sets were taken at each net-impact site. A final set—the “control site” photographs—was taken at a paired “control” site that was selected ≥50 m away from the net-impact site. During a SFM survey at the “control” sites, a permanent 3 x 3 m survey plot was established and photographed using a back and forth swim pattern for later processing using a SfM approach.
  • Cite as: Ecosystem Sciences Division, Pacific Islands Fisheries Science Center (2020). Structure from motion images collected at control sites during marine debris surveys of coral reefs entangled with fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands from 2018-09-24 to 2018-10-03 (NCEI Accession 0210740). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0210740. Accessed [date].
gov.noaa.nodc:0210740
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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 2018-09-24 to 2018-10-03
Spatial Bounding Box Coordinates
West: -175.8211335
East: -175.7880926
South: 27.82745706
North: 27.89404863
Spatial Coverage Map
General Documentation
Associated Resources
  • Structure from motion images collected during marine debris surveys at coral reef sites entangled with fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands from 2018/09/24 to 2018/10/03
    • NCEI Collection
      Navigate directly to the URL for data access and direct download.
  • 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.
  • Successful application of a novel technique to quantify negative impacts of derelict fishing nets on Northwestern Hawaiian Island reefs
  • 2018 Marine Debris Removal and Assessment in the Northwestern Hawaiian Islands
  • Processing Photomosaic Imagery of Coral Reefs Using Structure-from-Motion Standard Operating Procedures
    • Parent ID (indicates this dataset is related to other data):
    • gov.noaa.nodc:PIFSC-SfM-Images-HI
Publication Dates
  • publication: 2020-06-17
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: DDDDY5
Purpose 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. The collected photographs were processed using a structure from motion (SfM) approach to create orthophotos and analyzed in GIS for benthic cover. The purpose of the Structure from Motion (SfM) surveys at Pearl and Hermes Atoll is to understand whether derelict fishing nets significantly alter the benthic community composition of the reef. In addition, we investigated how net size and fouling level may vary the severity of this impact. This study leveraged SfM, an emerging photogrammetry technique, to allow efficient data collection alongside marine debris survey and removal efforts.
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  • 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: Ecosystem Sciences Division, Pacific Islands Fisheries Science Center (2020). Structure from motion images collected at control sites during marine debris surveys of coral reefs entangled with fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands from 2018-09-24 to 2018-10-03 (NCEI Accession 0210740). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0210740. Accessed [date].
Cited Authors
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Theme keywords NODC DATA TYPES THESAURUS NODC OBSERVATION TYPES THESAURUS WMO_CategoryCode
  • oceanography
CoRIS Discovery Thesaurus
  • Visual Images > Habitats
CoRIS Theme Thesaurus
  • EARTH SCIENCE > Biosphere > Aquatic Habitat > Benthic Habitat
  • EARTH SCIENCE > Biosphere > Aquatic Habitat > Reef Habitat
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Damage Assessment > Marine Debris
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Benthos Analysis
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > In Situ Biological
  • EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Photographic Analysis
  • EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs
  • EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology > Benthic biology
  • EARTH SCIENCE > Oceans > Marine Biology > Coral Communities
Data Center keywords NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS Global Change Master Directory (GCMD) Data Center Keywords
Platform keywords NODC PLATFORM NAMES THESAURUS Global Change Master Directory (GCMD) Platform Keywords ICES/SeaDataNet Ship Codes
Instrument keywords NODC INSTRUMENT TYPES THESAURUS Global Change Master Directory (GCMD) Instrument Keywords
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
Project keywords NODC PROJECT NAMES THESAURUS
Keywords NCEI ACCESSION NUMBER
Use Constraints
  • Cite as: Ecosystem Sciences Division, Pacific Islands Fisheries Science Center (2020). Structure from motion images collected at control sites during marine debris surveys of coral reefs entangled with fishing nets at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands from 2018-09-24 to 2018-10-03 (NCEI Accession 0210740). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://www.ncei.noaa.gov/archive/accession/0210740. 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.
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Lineage information for: dataset
Processing Steps
  • 2020-06-17T02:49:05Z - NCEI Accession 0210740 v1.1 was published.
Output Datasets
Lineage information for: dataset
Processing Steps
  • Parameter or Variable: images (measured); Units: unitless; Observation Category: in situ; Sampling Instrument: camera; Sampling and Analyzing Method: Derelict fishing nets tend to accumulate in certain locations inside Pearl and Hermes lagoon creating a spatial gradient from where net impacts are common, to locations where nets have never been observed. To the extent possible, the lagoon was surveyed equally across this gradient of high to low fishing net prevalence. The prevalence gradient was determined by plotting the location of each fishing net found during marine debris missions between 2006 and 2014 onto a 30 m x 30 m grid of hard substrate reef areas within the lagoon. Each grid cell was then characterized by the number of surveys and fishing nets that occurred within each cell. Five spatial zones were defined from the fishing net prevalence. A minimum of three fishing nets were surveyed in each of the five zones using a Structure from Motion (SfM) approach if the net also fit within the additional selection criteria (≥ 75% hard substrate and ~1-4 m depths, and fit within the 9 m2 survey plot). The swim survey method was developed for surveys in lagoonal, reticulated reef areas. During swim surveys, two or more divers swam across reefs to search for fishing nets while being directed by personnel in small boats to follow pre-planned routes and were coordinated for maximum visual area covered. Survey areas and routes were chosen based on regional reef morphology and past accumulation records. A complete SfM survey is comprised of three sets of images. Two sets were taken at each net-impact site, one series “before” and one series “after” the fishing net was removed from the reef. A final set was taken at a paired “control” site that was selected ≥50 m away from the net-impact site within the same zone (for independence). At each SfM “control” site, a permanent 3 x 3 m plot was established by securing zip ties to the reef at each corner of the plot and taking a GPS location at the center. Depth measurements were recorded at each corner of the plot. SfM images were collected underwater by snorkeling over the plot in a crosshatch pattern 1 m above the substrate to achieve image overlap of at least 60% (~580 images per site). JPEG images were collected using a Nikon SL2 digital camera in an underwater housing.; Data Quality Method: Prior to conducting surveys, the SfM image collector was trained to swim in a crosshatch pattern to collect imagery with 60-80% overlap. Both classroom and field training were completed before any surveys were conducted. This training ensures that all SfM marine debris image collection was conducted consistently during the mission. A single experienced researcher was designated to collect all the Structure from Motion imagery and set up the plots. The images were collected by swimming a crosshatch pattern rather than a single pass to ensure no gaps occurred in the image collection. A paired control site was selected for each net within the same zone (≥ 50 m away from net-impact site for independence). Four control sites were deemed unusable as they did not meet the study design requirements for matching spatial zone or habitat type (i.e., ≥ 75% hard substrate). In these cases, an existing control site within the same zone was used as a paired control. In total, 20 net-impact sites and 16 control sites were surveyed. The same method of image collection was used at each surveyed site. Each image set was evaluated for image quality. Images deemed unsatisfactory due to poor resolution, poor lighting, extraneous objects (e.g., dive fins), or blur were removed from the image set..
Acquisition Information (collection)
Instrument
  • camera
Platform
  • NOAA Ship Oscar Elton Sette
Last Modified: 2024-02-21T13:44:27Z
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