Council Regulation (EU) 2018/120Show full title

ANNEX 21-03/B GUIDELINES FOR ESTIMATING THE GREEN WEIGHT OF KRILL CAUGHT

a Individual haul when using a conventional trawl, or integrated over a six-hour period when using the continuous fishing system.
b Individual haul when using a conventional trawl, or a two-hour period when using the continuous fishing system.
Method	Equation (kg)	Parameter
		Description	Type	Estimation method	Unit
Holding tank volume	W * L * H * ρ * 1 000	W = tank width	Constant	Measure at the start of fishing	m
		L = tank length	Constant	Measure at the start of fishing	m
		ρ = volume-to-mass conversion factor	Variable	Volume-to-mass conversion	kg/litre
		H = depth of krill in tank	Haul-specific	Direct observation	m
Flow metera	V * Fkrill * ρ	V = volume of krill and water combined	Haula-specific	Direct observation	litre
		Fkrill = fraction of krill in the sample	Haula-specific	Flow meter volume correction	—
		ρ = volume-to-mass conversion factor	Variable	Volume-to-mass conversion	kg/litre
Flow meterb	(V * ρ) – M	V = volume of krill paste	Haula-specific	Direct observation	litre
		M = amount of water added to the process, converted to mass	Haula-specific	Direct observation	kg
		ρ = density of krill paste	Variable	Direct observation	kg/litre
Flow scale	M * (1 – F)	M = mass of krill and water combined	Haulb-specific	Direct observation	kg
		F = fraction of water in the sample	Variable	Flow scale mass correction	—
Plate tray	(M – Mtray) * N	Mtray = mass of empty tray	Constant	Direct observation prior to fishing	kg
		M = mean mass of krill and tray combined	Variable	Direct observation, prior to freezing with water drained	kg
		N = number of trays	Haul-specific	Direct observation	—
Meal conversion	Mmeal * MCF	Mmeal = mass of meal produced	Haul-specific	Direct observation	kg
		MCF = meal conversion factor	Variable	Meal to whole krill conversion	—
Codend volume	W * H * L * ρ * π/4 * 1 000	W = codend width	Constant	Measure at the start of fishing	m
		H = codend height	Constant	Measure at the start of fishing	m
		ρ = volume-to-mass conversion factor	Variable	Volume-to-mass conversion	kg/litre
		L = codend length	Haul-specific	Direct observation	m
Other	Please specify

Observation steps and frequency U.K.

a A new period will commence when the vessel moves to a new subarea or division.
b Individual haul when using a conventional trawl, or integrated over a six-hour period when using the continuous fishing system.
Holding tank volume
At the start of fishing	Measure the width and length of the holding tank (if the tank is not rectangular in shape, then additional measurements may be required; precision ± 0,05 m)
Every montha	Estimate the volume-to-mass conversion derived from the drained mass of krill in a known volume (e.g. 10 litres) taken from the holding tank
Every haul	Measure the depth of krill in the tank (if krill are held in the tank between hauls, then measure the difference in depth; precision ± 0,1 m)
	Estimate the green weight of krill caught (using equation)
Flow metera
Prior to fishing	Ensure that the flow meter is measuring whole krill (i.e. prior to processing)
More than once per montha	Estimate the volume-to-mass conversion (ρ) derived from the drained mass of krill in a known volume (e.g. 10 litres) taken from the flow meter
Every haulb	Obtain a sample from the flow meter and:
	measure the volume (e.g. 10 litres) of krill and water combined
	estimate the flow meter volume correction derived from the drained volume of krill
	Estimate the green weight of krill caught (using equation)
Flow meterb
Prior to fishing	Ensure that both flow meters (one for the krill product and one for the water added) are calibrated (i.e. show the same, correct reading)
Every weeka	Estimate the density (ρ) of the krill product (ground krill paste) by measuring the mass of a known volume of krill product (e.g. 10 litres) taken from the corresponding flow meter
Every haulb	Read both flow meters, and calculate the total volumes of the krill product (ground krill paste) and that of the water added; density of the water is assumed to be 1 kg/litre
	Estimate the green weight of krill caught (using equation)
Flow scale
Prior to fishing	Ensure that the flow scale is measuring whole krill (i.e. prior to processing)
Every haulb	Obtain a sample from the flow scale and:
	measure the mass of krill and water combined
	estimate the flow scale mass correction derived from the drained mass of krill
	Estimate the green weight of krill caught (using equation)
Plate tray
Prior to fishing	Measure the mass of the tray (if trays vary in design, then measure the mass of each type; precision ±0,1 kg)
Every haul	Measure the mass of krill and tray combined (precision ± 0,1 kg)
	Count the number of trays used (if trays vary in design, then count the number of trays of each type)
	Estimate the green weight of krill caught (using equation)
Meal conversion
Every montha	Estimate the meal to whole krill conversion by processing 1 000 to 5 000 kg (drained mass) of whole krill
Every haul	Measure the mass of meal produced
	Estimate the green weight of krill caught (using equation)
Codend volume
At the start of fishing	Measure the width and height of the codend (precision ± 0,1 m)
Every montha	Estimate the volume-to-mass conversion derived from the drained mass of krill in a known volume (e.g. 10 litres) taken from the codend
Every haul	Measure the length of codend containing krill (precision ± 0,1 m)
	Estimate the green weight of krill caught (using equation)