Dataset: Megafaunal presence recorded from AUV Sentry phototransects conducted at sites across the Costa Rica margin from R/V Atlantis cruises AT37-13, AT42-03 in 2017 and 2018

Location:  Pacific coast of Costa Rica

Sampling and analytical procedures:

AUV Sentry was deployed on two R/V Atlantis cruises in May-June 2017 and October-November 2018 off the Pacific coast of Costa Rica to capture seafloor images of predetermined transects along with their associated coordinates and environmental conditions. Visual assessment of each photo was undertaken, and biogenic habitat forming species presence was recorded, as well as carbonate rock presence for sessile species attachment.

Photos were processed visually at Temple University, PA, USA. The "proc" format of the photos were analyzed "color corrected and smoothed color TIFF photos" (see https://ndsf.whoi.edu/sentry/using-sentry/data-products/).

Instruments:
The AUV houses several sensors, including a Seapoint optical backscatter sensor for turbidity, an Anderaa optode 4330 dissolved oxygen sensor, and a Seabird SBE49 CTD probe for salinity, temperature and depth monitoring. Finally, a NOAA PMEL oxidation-reduction potential (ORP) probe was attached to the AUV as a proxy measure for methane seepage