Recovery of Queen Conch in the U. S. Virgin Islands

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Frequently anticipated questions:

What does this data set describe?

Title: Recovery of Queen Conch in the U. S. Virgin Islands
The queen conch is an important cultural component and an extremely valuable coral reef fishery resource throughout the Caribbean, historically second only to the spiny lobster. Comparisons of past studies with current densities from these areas continue to show that queen conch populations are depletd although we may be seeing small signs of increase. This data set investigates the population status of queen conch around St. John, U.S. Virgin Islands, through mark and recapture, habitat availability and utilization, sonic tracking, and seasonal migration studies to provide needed information for improved management.
  1. How should this data set be cited?

    Doerr, Jennifer, Unknown, Recovery of Queen Conch in the U. S. Virgin Islands.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -64.794
    East_Bounding_Coordinate: -64.661
    North_Bounding_Coordinate: 18.388
    South_Bounding_Coordinate: 18.286

  3. What does it look like? (JPEG)
    All Tag Locations All Bays - Information from mark and recapture and habitat studies.

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: May-2005
    Ending_Date: Sep-2010
    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 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.

  7. How does the data set describe geographic features?

    Temp = temperature in degrees Celsius; D.O. = dissolved oxygen in mg/L; depth = water depth in meters; sal = salinity in parts per thousand; shell length = total length of each conch measured in millimeters; lip = lip thickness of each conch measured in millimeters.
    Entity_and_Attribute_Detail_Citation: NOAA/NMFS/SEFSC/Galveston Laboratory/Fishery Ecology Branch

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?

  3. To whom should users address questions about the data?

    Jennifer Doerr
    NOAA/NMFS/SEFSC/Galveston Laboratory/Fishery Ecology Branch
    Research Fishery Biologist
    4700 Avenue U, Building 302
    Galveston, TX 77551

    409-766-3705 (voice)

    Hours_of_Service: 8:00-4:30

Why was the data set created?

The intent of this project is to investigate possible causes of the lack of recovery of queen conch, particularly juvenile, populations around St. John.

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: Not complete (process 1 of 1)
    Three field expeditions per year were completed beginning in May 2005 and ending in September 2010, each lasting from 10-14 days. During each sampling period, we haphazardly surveyed each bay for the presence of queen conch. The majority of these surveys were conducted by snorkel, but occasional SCUBA surveys were completed. At each conch's location we measured dissolved oxygen, salinity, depth, water temperature, air temperature, and wind speed. Spatial coordinates were collected using a portable wide area augmentation system-enabled global positioning system (WAAS GPS) unit. Siphonal (shell) length and lip thickness were measured with vernier calipers. Upon initial capture each conch was tagged with a uniquely numbered disk or T-bar anchor tag by drilling a small hole adjacent to the lip of the shell and injecting the tag through the hole. A small drop of super glue secured the tag in place until the conch deposited new material permanently integrating the tag into the shell. High resolution determination of habitat type at each conch's location was completed by centering a 1-m2 quadrat over the conch and visually identifying all benthic organisms contained within the quadrat. Vemco model VR2 omnidirectional hydrophone receivers were deployed throughout each study site such that an array of overlapping detection zones was created corresponding with changes in benthic habitat structure. Range tests were performed at each location on several occasions until a maximum range of tag detection was established. Locations were tested and adjusted accordingly to ensure adequate overlap in zones between neighboring receivers. Hydrophones were mounted on steel tie-down anchors, sunk approximately 1 m into the sediment such that the receiver base rested just above the sediment surface. Receivers were secured to the anchor with a combination of cable ties, hose clamps, and a padlock to minimize the possibility of equipment loss from vandalism or natural events. During the course of the project, we deployed 12 hydrophones in Fish Bay, 4 in No Name Bay, 5 in Brown Bay, and 5 in Coral Bay. HOBO temperature loggers (Onset Computer Corp.) were deployed at each hydrophone location, as well as several surface locations throughout each bay. Prior to deploying acoustic tags, varying sizes and maturity categories of queen conch were selected to effectively represent the composition of the population at large. Individuals matching the chosen size classes were randomly captured and tagged with Vemco V7-4L-R64K acoustic transmitters (20.5 mm length, 7 mm diameter) with a time interval of 60-180 seconds and an average life expectancy of 220 days. Tags were cemented using Liquid Roc 700 Acrylic Twin Tube epoxy (MKT Fastening, LLC) onto the highest portion of the spire where signal transmission was least likely to be obstructed. After the epoxy had cured (10-15 minutes) conch were returned to their exact location, marked previously by a fluorescent flag. On each field trip data files were downloaded from the receivers using an underwater cable. Temperature loggers were downloaded by temporarily removing them from the anchors, downloading, and replacing them in their previous location. After 12 months of continuous deployment receivers were removed from their anchors, cleaned, and batteries replaced to ensure no gaps in data collection. Data files were converted to MS Excel spreadsheets and transferred into ArcView 9.1. Spatial locations of tagged conch were overlayed onto categorized NOAA benthic habitat maps (NOAA/NCCOS Biogeography Program) to examine distributions through habitat types. Movement patterns and position estimates for queen conch with acoustic tags were interpreted from locational data collected on capture/recapture and detection patterns in hydrophone data.

  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?

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    These data consist of multiple tagging locations of queen conch in several bays around St. John. Also included is habitat use, movement and migration information from visual surveys and long-term acoustic tracking, and environmental data such as temperature and salinity.

  5. How consistent are the relationships among the observations, including topology?

    Not applicable.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

The National Marine Fisheries Service (NMFS) does not approve, recommend, or endorse any proprietary product or proprietary material contained in this data set. The NMFS Galveston Laboratory Fishery Ecology Branch compiled these data sets in order to develop a scientific basis for refining essential fish habitat designations for future amendments to fishery management plans. NMFS is not responsible for any uses of these data sets beyond those for which they were intended, and NMFS makes no claims regarding the accuracy of any data provided by agencies or individuals outside NMFS.
Use_Constraints: See Access Constraints.

  1. Who distributes the data set? (Distributor 1 of 1)

    Jennifer Doerr
    NOAA/NMFS/SEFSC/Galveston Laboratory/Fishery Ecology Branch
    Research Fishery Biologist
    4700 Avenue U, Building 302
    Galveston, TX 77551

    409-766-3705 (voice)

    Hours_of_Service: 8:00-4:30
  2. What's the catalog number I need to order this data set?

    Map Files

  3. What legal disclaimers am I supposed to read?

    While every effort has been made to ensure that these data are accurate and reliable within the limits of the currrent 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.

  4. How can I download or order the data?

Who wrote the metadata?

Last modified: 24-Jan-2017
Last Reviewed: 21-Jun-2012
Metadata author:
Jennifer Doerr
NOAA/NMFS/SEFSC/Galveston Laboratory/Fishery Ecology Branch
Research Fishery Biologist
4700 Avenue U, Building 302
Galveston, TX 77551

409-766-3705 (voice)

Hours_of_Service: 8:00-4:30
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.13 on Thu Oct 19 09:47:18 2017