Abstract:
This dataset contains a summary of the spatial distribution of reef fish in the Florida Middle Grounds (FMG). Fish density and total number, as well as habitat classification, were obtained with towed-camera observations (C-BASS). The C-BASS towed camera system was deployed at the Florida Middle Grounds, which was used to image four overlapping transects. Over ten hours of video were recorded along with a total of 70.6 km. This coverage targeted higher relief areas and was oriented to pass near the four, previously installed hydrophones. The original fish counts were binned into 15-second intervals during analysis, and these values were later converted to density estimates by calculating the average field of view and length of transect covered per bin. These were then geo-referenced by estimating the temporal layback of the towed C-BASS system relative to the ship using the amount of tow line out and C-BASS’s recorded operation depth. Fish egg collection, active-acoustic transects, and passive acoustic data, also part of this experiment, are found in related datasets under GRIIDC Unique Dataset Identifiers (UDIs): F2.x836.000:0004 (doi: 10.7266/n7-gyg9-yz64), F2.x836.000:0005 (doi: 10.7266/n7-axjv-t334), and F2.x836.000:0006 (doi: 10.7266/n7-8r9q-8f26).
Suggested Citation:
Murawski, Steven, and Sarah Grasty. 2021. Towed-camera (C-BASS) observations of fish density and habitat in the Florida Middle Grounds from 2017-07-13 to 2017-07-14. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-n5p5-c621
Data Parameters and Units:
The data are contained in two Excel spreadsheet, made up of two worksheets for the fish density data and the habitat data.
Density Data: Time (UTC, [HH:MM:SS]), Date [M/DD/YYYY], Area_Code [FMG_SHELF], Transect ID [4-place alphanumeric code], Camera [Blackfly], Video (minute-long video recording, sequential and starting at 0), Area.Covered.SOG.m2 [m^2], CBASS.depth [m], Approx.CBASS.lat [decimal degrees N], Approx.CBASS.long [decimal degrees E], species, density.n_m2 (number density), number (total number), NOTES.
Habitat Data: Date [M/DD/YYYY[, Area.Code [FMG_SHELF], Transect. [4-place alphanumeric code], Time.UTC (UTC, [HH:MM:SS}, Video (minute-long video recording, sequential and starting at 0), Time.Video (15-second bin of 1-minute long recording, [0:15:45], Physiographic.Setting, Induration, %.Cover.Primary [%], Hardbottom.Primary.Level.I, HB.Primary.Level.II, HB.Primary.Level.III, Hard.bottom.Secondary..Level.I, HB.Secondary..Level.II, HB.Secondary..Level.III. Soft.Bottom.Level.I.Primary, SB.Primary..Level.II, SB.Primary..Level.III, Soft.Bottom.Secondary..Level.I, SB.Secondary..Level.II, SB.Secondary..Level.III, Debris_Extent, Debris_Origin, Biologic.Component.Primary.Level.I, BC.Primary.Level.II, BC.Primary.Level.III, Biological.Component.Secondary.Level.1, BC.Secondary.Level.II, BC.Secondary.Level.III, Notes.
Methods:
The habitat classification followed NOAA's Coastal and Marine Ecological Classification Standard for the Geoform, Substrate, and Biological Components (the Water Column Component is not addressed). The geographic position for samples acquired after 11:40 on 2017-07-14 was reconstructed after data acquisition and are there of lesser quality than the positions of the earlier data.
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