Table 3. List of variables assessed in the derivation of the best fitting Generalised Linear Model (GLM).

Variables		Abbreviation	Descriptor
Dependant variable	count	count	number of particles per sample
Environmental data	sea surface temperature	SST	in °C
	sea surface salinity	SSS	in %
	wind speed	WS	in metres per second
	wind direction	WD	in degrees
	distance to shore	DS	in km
Vessel information	boat speed	BS	in knots
Sample information	volume filtered	VOL	in litres
	sample length	SL	in km
Sample method	method	method	1. underway system
			2. manta net