Table 2.

FORCIS database main table and primary key description.

FORCIS table	Description
Sites Primary key: ‘site_id’ Number of variables: 7	Each site is characterized only by its location (longitude and latitude coordinates). Associated information are water depth and ocean basin. The unique identifier or primary key (‘site_id’) could be either sourced from the original publication/study (e.g. PECH_B), or generated by the database managers (e.g. MedSeaCruise_St1).
Profiles Primary key: ‘profile_id’ Foreign key (s): ‘site_id’ Number of variables: 15	For the net data, profiles are distinguished by their time of collection and location as well. Overall, profile_id’s have the same coordinates, and different times of sampling were incremented. For the sediment trap data, the profile_id is incremented when the deployment has changed. The date, depth range of each profile, availability of the environmental data including ambient seawater chemistry, and profile season are also included in the table profiles.
Casts Primary key: ‘cast_id’ Foreign key (s): ‘site_id’ and ‘profile_id’ Number of variables: 8	Provides information regarding the casts, the sampling device name, depth range of a cast, mesh size, and net opening of the plankton tow.
Samples Primary key: ‘sample_id’ Foreign key (s): ‘site_id’, ‘profile_id’ and ‘cast_id’ Number of variables: 22	Each sample in this table is characterized by its depth range, volume of water filtered (for net data), coordinates, segment length (for CPR data), date of sampling, and in situ temperature and salinity.
Subsamples Primary key: ‘subsample_id’ Foreign key (s): ‘site_id’, ‘profile_id’, ‘cast_id’ and ‘sample_id’ Number of variables: 15	One sample could be divided into different subsamples (‘subsample_id’) based on their subsample_size_fraction_min, subsample_size_fraction_max or/and subsample_living_or_dead. Other information is also reported in this table such as: subsample_count_type, subsample_sieved_or_measured, subsample_storage_type, and subsample_splitting_type.
Counts Identifier: species_name Foreign key (s): ‘site_id’, ‘profile_id’, ‘cast_id’, ‘sample_id’ and ‘subsample_id’	The table contains counts per species or total number of species for each subsample. A count value is made unique by its subsample_id and the species name.
Publications Primary key: ‘ref_id’ Number of variables: 2	The publications table covers all references of publications and studies published or unpublished from where the data were sourced. A ref_id was assigned to each reference and listed in this table.
Species Number of variables: 3	The different species’ original names were kept in the FORCIS database as they were given by the data contributor or in publication/manuscript and listed in the table species. This species names list was formatted according to 2 levels of taxonomy: level 1 “validated taxonomy” and level 2 “lumped taxonomy”.
Sampling_devices Number of variables: 3	There are only four main sampling device types comprising this table, which are: net (plankton tow), CPR, sediment traps, and pump.
Count_type Number of variables: 2	Count data in FORCIS are reported in different units: raw as number of individuals, absolute (ind/m3), relative (%) and fluxes (ind/m2/day). The binned data were also included in the FORCIS database as a range of values (raw as number of individuals, absolute (ind/m3), relative (%) or fluxes (ind/m2/day)).