River- and Sex-Specific Annual Survival Rates of Mature Anadromous Alewife (Alosa pseudoharengus)

Table 1

Year, river, location (river kilometer, rkm) relative to river mouth (rkm 0), period and the number (n) of alewife (Alosa pseudoharengus) tagged, or recaptured following one or more years at large, during 2013–2021 tagging sessions. The number of returning individuals detected (returnees) with RFID biotelemetry arrays in the LaPlanche (LP), La Coupe (LC), Missaquash (MS), and Tantramar (TM) rivers are presented for 2014–2019 and 2021. Fieldwork was suspended in 2020 due to COVID-19 restrictions.

Years	Rivers	Tagging (rkm)	Tagging periods	n tagged	n recaptures	n returnees
2013	LC	14	10–27 May	406	—	—
2013	LP	9	3–27 May	376	—	—
2013	MS	5	8–27 May	416	—	—
2013	TM	19	1–19 Jun	191	—	—
2014	LC	14	18–28 May	283	5	161
2014	LP	9	18–31 May	477	0	100
2014	MS	5	29 May–5 Jun	361	1	92
2015	LC	12	20 May–4 Jun	379	4	167
2015	LP	5	21 May–10 Jun	649	2	104
2015	MS	5	22–28 May	242	0	130
2016	LC	12	30 Apr–6 Jun	414	3	181
2016	LP	2, 5	1 May–7 Jun	594	1	290
2016	MS	5	24 Apr–8 Jun	635	1	101
2017	LC	12	17 May–12 Jun	313	1	35
2017	LP	2	5 May–2 Jun	436	0	369
2017	MS	5	8–31 May	752	1	184
2018	LC	12	16–23 May	200	1	81
2018	LP	2	27 Apr–23 May	199	2	300
2018	MS	5	24 Apr–16 May	401	3	270
2018	TM	19	4–24 May	394	0	30^†
2019	LC	12, 3	17 May–6 Jun	203	2	25
2019	LP	2	5–29 May	204	0	152
2019	MS	5	1 May–4 Jun	386	3	166
2019	TM	19	9 May–25 Jun	359	0	22^‡
2021	LC	3	7 May–17 Jun	216	1	68
2021	MS	5	4–29 May	388	0	81
2021	TM	19	7 May–16 Jun	337	0	11^§
2013–2021			24 Apr–25 Jun	10,211	31	3,120

^†Returnees were tagged in the LC (n = 6), LP (n = 11) and MS (n = 13) rivers during 2014–2017. ^‡Returnees were tagged in the TM during 2018 (n = 18) and in the LP (n = 1) and MS (n = 3) rivers during 2017 and 2018. ^§Returnees were tagged in the TM (n = 11) during 2018 and 2019.