Table 3. Euphausia superba.

Sampling season	Overall model statistics		Model terms
			Environmental variables	Linear estimate	df	p
Summer	AIC	9.6	Ice thickness	−0.2096		<0.01
	Expl. deviance	94.6%	ATC(MLD)	−2.2845		<0.01
			s(Ice coverage)		3.0	<0.01
			s(MLD)		3.0	<0.01
Autumn	AIC	35.7	Temperature (MLD)	2.0715		<0.01
	Expl. deviance	70.8%	s(salinity 0–200 m)		2.2	0.03
Winter	AIC	59.2	Depth	0.0007		0.01
	Expl. deviance	72.2%	MLDs(temperature (MLD))	0.0261	2.9	0.010.01

Parameters for optimal models relating the density of postlarval krill to environmental variables in summer (2007/2008), autumn (2004) and winter (2006). ATC: attenuation; df: estimated degrees of freedom of smoother; MLD: mixed layer depth; s: Cubic Splines smoother.