CRED Fish Biomass Estimates at Tutuila Island, 2008

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What does this data set describe?

Title: CRED Fish Biomass Estimates at Tutuila Island, 2008
Abstract:
Fish biomass data were collected using a Towed Optical Assessment Device (TOAD), an underwater sled equipped with an underwater digital video camera and lights. Data were collected at American Samoa, Tutuila Island to support Benthic Habitat Mapping efforts.
Supplemental_Information:
Tutuila is the largest of seven islands in American Samoa at 142.3 sq. km. Volcanic in origin, it reaches a height of 653m at Matafao Peak. Tutuila is centered at 14.30 degrees N, 169.75 degrees W, has 101.3 km of coastline and an estimated 36.2 sq. km of reef area. The port of Pago Pago is a collapsed crater and is one of the largest natural ports in the Pacific. Pago Pago contains a tuna cannery which is a hub of a large purse-seining tuna fishing fleet. The cannery outputs large amounts of nutrients as byproduct into the waters of Pago Pago harbor. The human population of Tutuila in 1990 was 45,043. It is considered a high island and contributes significant nutrient and sediment runoff to coastal waters. Tutuila's waters are protected by the 0.7 sq. km Fagatele Bay National Marine Sanctuary, as well as by the National Park of American Samoa, which covers the north-central part of the island and approximately 5 sq. km of coastline.

Optical validation data were collected using the Tethered Optical Assessment Device (TOAD), a sled equipped with underwater video camera and lights. These data are used to provide fish count and biomass maps where benthic habitat classification has been completed. Camera sled deployments were conducted during daylight hours, usually between 0600 and 1700. The duration of each tow varied but averaged about 40 minutes of bottom time at a given location. The camera sled was deployed from the starboard gunwhale of the Bonavista II. At each station the TOAD was lowered slowly to the bottom by the deck crew. The operator monitored a live video feed from the camera and began recording data on the video tape recorder. When the camera reached bottom the deck crew was notified by radio to stop lowering. The vessel then began a course of a predetermined heading maintaining a speed of approximately 1 knot for the remainder of the survey. The operator continued to monitor the vehicle and provided commands to raise or lower it to keep the camera just above the bottom.

Equipment Description: The TOAD was deployed from the starboard gunwhale of the vessel. The TOAD sled body used for the 2008 data collection is constructed from a shortened Phantom ROV body with a tail piece added for stability. It is equipped with a Deep Sea Power and Light Multi SeaCam 2060 color video camera, two 500 W DeepSea Power and Light Multi-SeaLite model 1050 underwater lights, a sonar altimeter to detect the height of the camera above the seafloor, a pair of parallel lasers to determine the size/scale of viewed objects, a compass to determine the sled heading and orientation, and a depth (pressure) sensor. The video signal from the sled is send via a coaxial conductor within a 200 m long and 127 mm diameter umbilical cable to a topside control unit. All TOAD surface components were located below deck in the V berth of the vessel within an equipment rack secured to the benches.

Data Files: Video data were recorded on a video tape recorder. The position of the camera sled was recorded using Hypack Max version 6.2b survey software. File naming convention: Each tow is given a name consisting of a 3-letter designator for the island area followed by two-digit year and three-digit tow number. For example, during BV0801 (Bonavista II's 1st cruise in calendar year 2008) the first tow was called TUT08001. Video tape labels and paper log forms are annotated with the tow name. Data files recorded in Hypack software followed their CHS filename format consisting of the year, the first two letters of the platform name, the Julian date, and the hour and minute in which the file was started. For example, a file collected on July 18, 2005 (Julian date 199) aboard the Hi'ialakai starting at time 1935 would be 2005HI1991935. Time Correlation: All times are based on UTC. Three clocks were manually synchronized prior to starting data collection; the clock in the video character generator that was used to annotate the video tape, in the video cassette recorder, and in the computer running the Hypack Max software. These clocks were set to UTC at the beginning of each day's operations.

Name & address of person collecting data:

John Rooney NOAA IRC NMFS/PIFSC/CRED 1845 WASP Blvd., Building 176 Honolulu, HI 96818

Resource Description: Digital video imagery that is geo-referenced to navigation files.

  1. How might this data set be cited?
    Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), 20090930, CRED Fish Biomass Estimates at Tutuila Island, 2008.

    Online Links:

    Other_Citation_Details:
    Format: Video imagery, track line navigation files, and log sheets
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -170.92
    East_Bounding_Coordinate: -170.49
    North_Bounding_Coordinate: -14.20
    South_Bounding_Coordinate: -14.38
  3. What does it look like?
    http://www.soest.hawaii.edu/pibhmc/amsamoa_images/tut_toad_mf_445.jpg (JPEG)
    Tutuila, American Samoa: TOAD Tows and Multibeam Bathymetry
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 15-Feb-2008
    Ending_Date: 25-Feb-2008
    Currentness_Reference: ground condition
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0001. Longitudes are given to the nearest 0.0001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: No correction
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
  2. Who also contributed to the data set?
    Benthic Habitat Mapping Group, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Oceanic and Atmospheric Administration (NOAA)
  3. To whom should users address questions about the data?
    Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
    Attn: John Rooney
    NOAA IRC
    Honolulu, HI

    808 725-5360 (voice)
    808 725-5429 (FAX)
    nmfs.pic.credinfo@noaa.gov
    Contact_Instructions: e-mail preferred

Why was the data set created?

These data will provide optical observations that will be correlated with bathymetry and acoustic backscatter imagery to create a fish biomass map of Tutuila Island. Refer to supplemental information for description of instrument and survey.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 01-Sep-2009 (process 1 of 1)
    After a tow was completed the video tape data was reviewed by spot checking the master and backup tape to verify that data were recorded. Navigation data were copied from the acquisition computer to the data archive. A metadata extractor (gloFilter.py, version 3/06) was run to summarize the navigation data and test for errors. If errors were detected they were corrected or flagged as appropriate and a new data file was made. This file's header was updated to document what type of processing occurred. A metadata file was recorded in the data archive in the same location as the navigation data. Processed navigation data were then read into ArcView 3.2 shapefiles using an ArcView Avenue script named TOAD.Import.Playback, version 9/25/01, written by Ronald Hoeke. TOAD video were classified for benthic habitat type to create Optical Validation maps to interpret acoustically derived data layers. These classified points were imported into a Microsoft Access 2003 database. All fish present during 15 second intervals before and after these positions were recorded and identified. Using LW coefficients derived from fishbase.org and size estimates from video, total biomass was calculated for a given point. An area of 0.0012 hectares per point observation was assumed based on average distances traveled between points as well as average width of field of view. A table with position, island, biomass(tonnes/hectare), and number of fish was exported from MS Access into ArcGis v9.3. This file was exported as a shapefile. A column with biomass data was symbolized using layer file MF_Biomass.lyr to create Fish Biomass Estimates map.
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    Hypack Max includes a window for manual entry of the length of camera sled cable paid out, a utility to enter horizontal and vertical offsets between the GPS antenna and sheave over which the camera sled cable passes, and a built-in caternary function. Using these data, Hypack Max automatically estimates the camera sled's position. Analysis of tow data indicate that horizontal positional uncertainty associated with the location of the camera sled recorded in Hypack is plus or minus 13 m.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Complete
  5. How consistent are the relationships among the observations, including topology?
    Unspecified

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as the source of this information.
  1. Who distributes the data set? (Distributor 1 of 1)
    Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
    Attn: John Rooney
    NOAA IRC
    Honolulu, HI

    808 725-5360 (voice)
    808 725-5429 (FAX)
    nmfs.pic.credinfo@noaa.gov
    Contact_Instructions: e-mail preferred
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 29-Mar-2020
Last Reviewed: 02-Dec-2009
Metadata author:
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
NOAA IRC
Honolulu, HI

808 725-5360 (voice)
808 725-5429 (FAX)
nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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