ALBERT

Description: The data involves annotations with the MBARI VARS annotation software of pelagic HD video transects obtained by the pelagic in situ observations system PELAGIOS. PELAGIOS is a newly developed towed camera system for deep-sea biological exploration and performance of video transects for diversity and distribution data. The data was collected in 2015 during cruise MSM49 on R/V MARIA S. MERIAN, from 20 to 950 m, during day (187 minutes) and night (292 minutes) transects on the northwestern slope of Senghor Seamount (17°14.2'N, 22°00.7'W; bottom depth of approximately 1000 m). The annotated organisms include fishes, crustaceans and gelatinous zooplankton. One file includes the transect length at each depth at day or night and another file has all individual annotated taxa observed at a particular depth at day or night. The Figure 4 is made with this data. A third file involves the data we used to make Figure 3 which is the comparison between the observations of Poeobius observed in PELAGIOS and UVP5 to calculate sample volume.

Description: Pelagic observations were collected via horizontal video transects using the pelagic in situ observation system PELAGIOS from 50-1000 m during MSM49. The collected video was annotated using the video and annotation reference system (VARS) developed by the Monterey Bay Aquarium Research Institute. In total more than 40 hours of video were collected and annotated, and 43 taxonomic groups were annotated, mostly consisting of gelatinous zooplankton.

Description: Net catches of cephalopods were obtained during the cruises POS320/2 (March 2005), MSM49 (November/December 2015) and WH383 (March/April 2015) off Cabo Verde at a total of 18 stations at depths between 0 and 1000 m. Cephalopods were caught during POS320/2 with either a Isaacs-Kidd midwater trawl (IKMT) with a 6 m2 net opening, 4 mm mesh size equipped with a flowmeter, a Hydro-Bios Multinet Maxi with a 0.5 m2 net opening and 500 µm mesh size between the surface and 250 m water depth, or an 80 feet bottom trawl. Net sampling during MSM49 was conducted with two types of multiple opening/closing nets (MOCNESS) and an IKMT. The smaller MOCNESS had a net opening of 1 m2 opening (three nets with a mesh size of 2 mm and six nets with a mesh size of 335 μm) and the larger MOCNESS a net opening of 10 m2 opening (five nets, mesh size: 1.5 mm) and were deployed between the surface to 1000 m. The IKMT had a net opening of 7 m2 and ended in a cod end of 500 µm mesh size. It was deployed to a maximum depth of 500 m. During WH383 a pelagic trawl ('Aalnetz', Engel Netze, Bremerhaven, Germany) with a mouth opening of 16 x 30 m, length of 150 m including multiple opening-closing device, 260 meshes by 180 cm stretched mesh size at the front, a cod end 20 mm stretched mesh-opening and a 1.8 mm inlet sewn into last 1 m of cod end was used with a multisampler (Construction Services AS, Bergen, Norway) allowing depth-stratified sampling. During WH383 three strata (mean vertical extension of ca. 40 m) were trawled mostly during night and one time during daytime at depths between 30 and 700 m in horizontal tows for 30 minutes per stratum with a mean speed of three knots (2.8-3.3 kn). During this cruise, night trawls took place at 22:00 local time, and the day-time trawl at 12:00 local time. Onboard, cephalopods were identified morphologically to the lowest taxonomic level possible (species, genus or family), and whole specimens were preserved in formalin as voucher.