DOI: 10.5285/7fb2f0c1-413c-4cd6-84ab-a504bf431290
title: Organisms identified from OFOBS images from PS118 Profiles 6_9 (Weddell Sea) and 69 (Powell Basin), April - May 2019

description: This dataset contains the object ID, morphotaxonomic name, and approximate size (in mm) of over 70,000 organisms identified from select Ocean Floor Observation and Bathymetry System (OFOBS) images from the cruise PS118 to the Weddell Sea from April - May 2019. Images were collected for assessing epibenthic megafauna communities and establishing temporal baselines for future studies.

This work has been supported by Natural Environment Research Council (NERC) Independent Research Fellowship NE/S014756/1, awarded to EM. TK is funded by a Cambridge International and Newnham College Scholarship, administered by Cambridge Trust. RW and HG are funded by UK Research and Innovation (UKRI) Future Leaders Fellowship MR/ W01002X/1 "The past, present and future of unique cold-water benthic (seafloor) ecosystems in the Southern Ocean" awarded to RW. HG is also funded by BIOPOLE, funded by the NERC, under National Capability Science Multi-Centre award scheme (NC-SM2).
description: OFOBS Data was collected on the AWI Polarstern cruise PS118 from April-May 2019 in order to assess epibenthic megafauna communities and establishing temporal baselines for comparison with future studies. OFOBS photos contain latitude, longitude, and the water depth at which the photo was taken. Each photograph had three laser dots placed in an equilateral triangle (50 cm sides) near the center of the photograph.
We annotated two profiles: Profile 69_1 (Powell Basin, approx. 2000 m water depth) and Profile_6_9 (Weddell Sea, approx. 420m water depth), as these two profiles provided the maximum variation in substrate and water depth for this cruise. Photo annotations were made on Inkscape. We scaled each photo using the laser dots and used a sample box of 1.5m x 1.5 m for annotations for the Powell Basin, and 2 m x 1.5 m for the Weddell Sea. We identified, at least to class, often to genus and species levels, every macrobenthic organism visible in the photographs. Bounding boxes were ellipses.
Images can be downloaded from PANGAEA.
Annotations are found in the two csv files: "OFOBS_annotations_Powell_Basin.csv", "OFOBS_annotations_Weddell_Sea.csv". 
The headers in these files refer to:
Morphotaxa - the best possible ID name for the observed individual
Ids - an object ID assigned by Inkscape when annotating
rx - the length of the ellipse (mm)
ry - the width of the ellipse (mm)
Area - the area of the ellipse (mm2), calculated using (0.5rx)*(0.5ry)*pi
Image - the filename of the annotated image. These images can be downloaded from PANGAEA.
These annotations were then condensed into site-by-taxa matrices in R. These can be found in the two further CSV files: "Abundance_Powell_Basin.csv", "Abundance_Weddell_Sea.csv".
The headers in these files refer to:
Image - the filename of the image.
encrustor_percentage (%) - an estimate of area coverage of the substrate by organisms - they are likely hard parts that settle on/are attached to the seafloor - they may be disarticulated/broken portions of stylasterids, lace corals, cup corals, or urchin spines, i.e., impossible to ascertain provenance. 
Other columns - morphotaxa observed.
description: Inkscape Version 1.1
R
description: Annotations are made to the lowest taxonomic level possible based on the resolution of the seabed photographs.