IMIS - Marine Onderzoeksgroepen

Additionally, in every station another oblique haul was performed using a Bongo net with 90 cm diameter aperture and a mesh size of 750 µm diameter. The Bongo nets were towed at depth integrated double oblique hauls at 2 knots from surface to 10 m above bottom or to 200 m at deeper stations. All plankton samples were preserved in 4% borax buffered formaldehyde prepared using seawater and subsequently sorted and analyzed for decapod larvae. The biovolume was determined by displacement volume method (Harris et al., 2000: https://wgze.net/methodology-manual/).

Sampling Methods

All plankton samples were preserved in 4% borax buffered formaldehyde prepared using seawater and subsequently sorted and analyzed for decapod larvae. The biovolume was determined by displacement volume method (Harris et al., 2000: https://wgze.net/methodology-manual/).

Method step description:

1. The LHPR was used in 16 stations to collect information on the water column distribution of the species. It was towed at 4 knots on oblique hauls from the surface to near the seabed or around 400 m at the deeper stations. Samples were collected at 25 m depth intervals. Mesh aperture of the collecting net and filtering gauze for all the hauls was 280 µm. A Bongo net with 60 cm diameter aperture and a mesh size of 335 µm was used in all the other stations. Additionally, in every station another oblique haul was performed using a Bongo net with 90 cm diameter aperture and a mesh size of 750 µm diameter. The Bongo nets were towed at depth integrated double oblique hauls at 2 knots from surface to 10 m above bottom or to 200 m at deeper stations.