Population estimates

The parameters used for the assessments of the Greenland Sea hooded seals were.


Table 3.3.3.3.10. Estimates of proportions of mature females (p) at ages 2–11.

Age	2	3	4	5	6	7	8	9	10	11
p	0.05	0.27	0.54	0.75	0.87	0.93	0.97	0.98	0.99	1.00

Table 3.3.3.3.11. Survey estimates of Greenland Sea hooded seal pup production.

Year	Estimate	c.v.
1997	24 000	0.28
2005	15 200	0.25
2007	15 370	0.11

The prior distributions for M₁₊, M₀, and F (Table 3.3.3.3.12) are as in ICES (2006b). The mean of the prior for M₀ was taken to be approximately three times that of M₁₊. The model runs shown in Figure 3.3.3.3.3 seem to indicate a substantial decrease in population abundance from the late 1940s and up to the early 1980s. In the most recent two decades, the population size appears to have been relatively stable at a low level, but the current trajectory is uncertain. Using a prior value of M₁₊ of 0.11 (CV = 0.45), a 2007 abundance of 66890 (CV = 0.13) is obtained for age 1+ seals while the estimated number of pups is 15490 (CV = 0.10), combining to a total of 82380 animals (CV = 0.11).


Table 3.3.3.3.12. Status of hooded seals in the Greenland Sea in 2007. The column “Model Estimate” shows the estimated parameters (point estimate and standard deviations), while the column “Prior” shows the prior distributions placed on parameters.

Parameter	Model Estimate		Prior
	Est.	C.V	Mean	C.V
M1+	0.157	0.22	0.11	0.46
M0	0.334	0.15	0.33	0.15
F	0.869	0.11	0.88	0.11
N1+(2007)	66 890	8 645
N0(2007)	15 490	1 528	15 370	1 675