Microsetella norvegica at station Svartnes, Balsfjord, Norway in June 2017 and June 2018 (sampled with a GoFlow bottle)

Study Extent

All samples were collected at the same station. Both in 2017 and 2018, the station was sampled twice and during each of the in total 4 sampling days, zooplankton water samples were collected at 6 depths (0, 10, 20, 50, 90, 120 m).

Sampling

To enumerate different developmental stages of Microsetella norvegica in June 2017 and June 2018, a 30 L GoFlow bottle was in each year successively deployed to 6 water depth (surface, 10, 20, 50, 90, 120 m) on two different days. The collected water was brought on board. From each GoFlow bottle cast, 20 L water were gently emptied via a silicone tube. The water sample was concentrated onto a 20 μm meshed sieve and transferred to a PVC bottle for later counts of Microsetella norvegica. These zooplankton samples were preserved with buffered formaldehyde at 4 % final concentration.

Method steps

1. Zooplankton enumeration was generally done according to the procedures described in Postel et al. (2000., Biomass and abundance, p. 83-192. In R. Harris, J. Lenz, M. Huntley, P. Wiebe and H. R. Skjoldal (eds.), ICES Zooplankton Methodology Manual. Academic Press.) and Kwasniewski et al. (2010, doi: 10.1016/j.pocean.2010.06.004).
2. Only a sub-sample was identified and counted. A box splitter was used to divide the GoFlo samples into two halves, and then only 1 half was examined in its entirety due to the low zooplankton concentrations. Copepodite life stages CI-CV of M. norvegica were identified at higher magnification using the Olympus light microscope model BX50, the other indentification was mostly done in a Olympus model SZX7 stereomicroscope.

1. Microsetella norvegica
   rank: species

Svartnes, Balsfjorden, Norway (190 m bottom depth)