ZooImage training set, northern Baltic zooplankton

A small training set for ZooImage program: scanned zooplankton images, grouped into taxonomic / functional groups. The zooplankton have been collected as part of the COMBINE monitoring programme in the open sea areas of the Gulf of Finland.

An article based on the data is published and can be found at https://doi.org/10.1016/j.ecolind.2016.05.036

Data processing steps: sampling

Description: The samples were collected in August from the surface layer,
during regular monitoring cruises on R/V Aranda from the Gulf
of Finland, northern Baltic Sea, using a vertically towed
100 micro-m mesh sized WP-2 closing plankton net (Hydrobios, Kiel,
Germany). Samples were preserved immediately after collection
with 4% formaldehyde solution (Harris et al., 2000) until analysis
in the laboratory.

Data processing steps: processing

Description: Before scanning, samples were dyed overnight
using eosin to enhance contrast (Harris et al., 2000) and applied
thinly, so that the zooplankton individuals were mostly separate
from each other on a clear, transparent plastic tray (the lid of a
PCR plate). Sixteen samples were scanned two at the time using an
Epson PerfectionV750 scanner at 2800 dpi resolution,meaning that
the length of 1 mm includes approximately 110 pixels in the image.
The pictures (examples in Fig. 2) were scanned as colour pictures
and analysed using colour picture algorithm. For the training set,
81 subsamples were scanned, and a total of 1446 scanned images
(zooplankton individuals and inanimate objects) of were included.