Model-supported estimation of mortality rates in Baltic cod (Gadus morhua callarias L.) larvae: the varying impact of 'critical periods'

Table 1 Cod larval mortality rates:

	May 1988 Time interval between surveys: 5.66 days;				August 1991 Time interval between surveys: 5.92 days;
survey	1	2	1	2	1	2	1	2
stage	Egg IV	L 5	L 5–7	L 8	Egg IV	L 5	L 5–7	L 8
age [days] ^*	14.09	19.35	22.35	28.35	13.51	19.72	21.72	27.72
dt age	5.26		6.00		6.21		6.00
n/m² _obs	0.98	0.21	2.43	1.50	0.66	0.52	1.97	0.33
n/m²/d_obs	0.39	0.10	0.41	0.25	0.27	0.26	0.33	0.06
n/m²/d_adj		0.11		0.25		0.26		0.06
M [1/d]	0.2359		0.0804		0.0078		0.2972
M [%/d]	21.02		7.73		0.78		25.71
n/m²/d_corr	-	0.12	-	0.26	-	0.27	-	0.07
M [1/d]_corr	0.2226		0.0729		0.0008		0.2547
M [%/d]_corr	19.95		7.03		0.08		22.49

^*:at mean ambient egg incubation temperatures of 5.75°C in May 1998 and 5.87°C in August 1991. Observed (_obs) and adjusted (_adj) abundance (n/m²) and daily production (n/m²/d) of different developmental stages inside the 80 m depth contour line, as well as resulting mortaliy rates (M) with and without correction for transport (_corr) for May 1988 and August 1991.

ISSN: 1472-6785