Cohort life tables for a population of the soft-shell clam, Mya arenaria L., in the White Sea

Table 2 Life table of Mya arenaria in the White Sea (low intertidal zone, the Lebyazhya bight)

Year of observation	Age (years)	N _x	l _x	d _x	q _x	L _x	T _x	e _x
1989	1	2,156.0	1.000	0.4787	0.48	0.761	2.889	2.89
1990	2	1,124.0	0.521	0.0955	0.18	0.474	2.128	4.08
1991	3	918.0	0.426	0.1503	0.35	0.351	1.655	3.89
1992	4	594.0	0.276	0.0181	0.07	0.266	1.304	4.73
1993	5	555.0	0.257	0.0255	0.10	0.245	1.038	4.03
1994	6	500.0	0.232	0.0390	0.17	0.212	0.793	3.42
1995	7	417.0	0.193	0.0733	0.38	0.157	0.580	3.00
1996	8	259.0	0.120	0.0290	0.24	0.106	0.424	3.53
1997	9	196.4	0.091	0.0401	0.44	0.071	0.318	3.49
1998	10	110.0	0.051	0.0056	0.11	0.048	0.247	4.84
1999	11	98.0	0.045	0.0061	0.13	0.042	0.199	4.37
2000	12	84.8	0.039	0.0100	0.25	0.034	0.156	3.97
2001	13	63.2	0.029	0.0022	0.08	0.028	0.122	4.16
2002	14	58.4	0.027	0.0020	0.08	0.026	0.094	3.46
2003	15	54.0	0.025	0.0171	0.68	0.017	0.068	2.70
2004	16	17.2	0.008	0.0004	0.05	0.008	0.051	6.41
2005^a	17	16.3^a	0.008	0.0005	0.06	0.007	0.043	5.73
2006	18	15.3	0.007	0.0004	0.06	0.007	0.036	5.08
2007	19	14.4	0.007	0.0004	0.06	0.006	0.029	4.36
2008	20	13.5	0.006	0.0005	0.07	0.006	0.023	3.62
2009^a	21	12.5^a	0.006	0.0004	0.07	0.006	0.017	2.87
2010	22	11.6	0.005	0.0004	0.07	0.005	0.011	2.05
2011	23	10.8	0.005	0.0028	0.56	0.004	0.006	1.17
2012	24	4.8	0.002	0.0011	0.50	0.002	0.002	1.00
2013	25	2.4	0.001	–	–	0.001	0.001	0.50

^aIn these years, no observations were made, data on the number of Mya arenaria from the 1988 cohort were obtained by averaging the mollusc number in the previous and subsequent years. The other notation conventions are given in the text

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