Images of corals, sponges, and fishes from the 2019 Midwater Asseessment and Conservation Engineering Program Survey (NCEI Accession 0305766)

Collected during the biennial Alaska Fisheries Science Center's (AFSC) Gulf of Alaska (GOA) bottom trawl survey, this image data set was used for deep sea coral and sponge identification and annotation. Each transect was 15 minutes long with a vessel speed close to 1 knot. The lowered stereo camera system (LSC) was kept within 1 m of the bottom during the transect. The start of each transect was haphazardly chosen. Most transects took place at night. The LSC system consisted of two parallel-mounted machine-vision cameras spaced approximately 30 cm apart in underwater housings connected via ethernet cables to a computer in a separate underwater housing enclosed in a protective aluminum cage. A monochromatic/color camera pair was used with image resolution. The monochromatic camera (Point Grey, BFLY-PGE_50S5M) collected images at 5.01 megapixels, and the color camera (Point Grey, BFLY-PGE_50S5C) collected images at 5.01 megapixels. Four high intensity strobe LED illuminators provided lighting and were activated at the surface when the camera unit entered the water and deactivated at the end of the deployment when the unit returned to a depth of approximately 10 m. Each strobe was constructed of two Cree CXB3590 arrays capable of producing 25,000 lumens at 200 W. Synchronous images were recorded at a frequency of one image per second. Images for each transect are organized into folders with a Haul number and the images from the two cameras on the tow sled are in their own respective folders.