Coral cores collected in Dry Tortugas National Park, Florida, U.S.A.: Photographs and X-rays

Field photographs of the coral colonies, in the ocean environment where they lived, were taken underwater at a depth of approximately 1 to 3 meters using an Olympus C-5050Z zoom camera enclosed in an Olympus underwater housing. The photographs were taken in-situ, then subsequently color corrected using Adobe Photoshop CC 2015 version 17.0.1 to adjust for the truncated underwater light regime. The in-situ field photographs of the corals are included in the data release download file, DRTO_coral_cores_field_photographs.zip. Once the six coral cores were extracted from the field, they were transported back to the SPCMSC core lab in St. Petersburg, FL.

In the lab, the coral cores were sectioned along the primary growth axis into 4-millimeter-thick slabs using a lapidary saw with a carbide-tipped blade. Multiple slabs (designated by numbers) were taken from each coral-core section (designated by letters) because corallite walls tend to meander over time and having replicate slabs increases the chance of obtaining a continuous path for geochemical sampling. When necessary, the cores were slabbed at an angle to follow the main axis of growth. The resulting slabs were cleaned in deionized milli-Q water using a Branson Sonifer 450 sonication device and air dried before storage. None of the slabs was treated with bleach or any oxidizing chemicals. Photographs of the coral slabs in their core boxes are included in the data release download file, DRTO_coral_cores_slab_photographs.zip.

X-radiographs (X-rays) of each coral slab were taken at the USGS St. Petersburg Coastal and Marine Science Center (SPCMSC) in St. Petersburg, FL. The coral slabs were placed on a phosphor plate and X-rayed at 55 kilovolts and 2.5 milli-Ampere-seconds (mAs). The distance between the plate and the X-ray source was 79 centimeters (cm). The plate was scanned on an iCR3600+ scanner at 254 dots per inch (dpi) resolution (10 pixels per millimeter), processed on iCRco, Inc. software, and adjusted for contrast and brightness using Adobe Photoshop CC 2015 version 17.0.1. The x-ray images of the corals are included in the data release download file, DRTO_coral_cores_xrays.zip.

The coral core field photograph locations were collected using a Garmin GPSMAP 78SC handheld Global Positioning System (GPS) and written into field notebooks. EXchangeable Image File format (EXIF) headers were initially populated during data collection by the camera’s imaging software but were subsequently updated by USGS staff to include additional core-related details. A Python version 2.7.3 script (UpdatePhotoEXIFv2.py, WHCMSC script) was run to incorporate the GPS locations, along with additional information, into the appropriate locations in the EXIF header of each full-resolution JPEG image. The Python script used ExifTool (version 10.25) to write the information to the image headers. The following tags were populated in the JPEG image headers. Information is duplicated in some tags. This was done because different software packages access different tags.
GPS tags: The values populated are unique for each image and based on the information exported from the handheld GPS.

GPSLatitudeRef
GPSLatitude
GPSLongitudeRef
GPSLongitude
GPSTimeStamp
GSPDateStamp

JPEG tags: The tag is listed along with the information used to populate it - which is the same for every image taken with a particular camera. The following information is based on the Olympus C-5050Z camera.

comment: Photo collected in May 2012 from the Dry Tortugas, Florida during field activity 12CBC03 (http://cmgds.marine.usgs.gov/fan_info.php?fan=12CBC03). Published as USGS data release DOI:10.5066/F7V69GQ2.

EXIF tags: The tag is listed along with the information used to populate it - which is the same for every image.

ImageDescription: Underwater photograph of in-situ coral collected from Dry Tortugas National Park, Florida during survey 12CBC03.

Artist: Ilsa Kuffner
Copyright: Public Domain - please credit U.S. Geological Survey

IPTC tags: The tag is listed along with the information used to populate it - which is the same for every image.

Credit: U.S. Geological Survey
Contact: gs-g-spcmsc_data_inquiries@usgs.gov
Keywords: Dry Tortugas National Park, Florida, Florida Keys, 12CBC03, coral, Siderastrea siderea, Orbicella faveolata, sea-surface temperature, USGS
CopyrightNotice: Public Domain - please credit U.S. Geological Survey
Caption-Abstract: Underwater photograph of in-situ coral collected from Dry Tortugas National Park, Florida during survey 12CBC03.

XMP tags: The tag is listed along with the information used to populate it - which is the same for every image.

Caption: Underwater photograph of in-situ coral collected from Dry Tortugas National Park, Florida during survey 12CBC03.

To extract the information from the image headers using ExifTool, the following command can be used (tested with ExifTool version 10.25):

exiftool.exe -csv -f -filename -GPSTimeStamp -GPSLongitude -GPSLatitude -n -Artist -Credit -comment -keywords -Caption -Copyright -CopyrightNotice -Caption-Abstract -ImageDescription photos/*.jpg > out.csv

The -csv flag writes the information out in a comma-delimited format. The -n option formats the latitude and longitude as signed decimal degrees.