Improved Estimates of Escapement, Survival and Exploitation for Nicomen Slough Coho

Currently, Coho escapement to the Lower Fraser River (LFC) MU is an important requirement of FRAM but is estimated with unknown and substantial uncertainty. Low recoveries of CWTs (coded-wire tags) from the current hatchery indicator stock (Inch Creek) have resulted in imprecise estimates of survival, exploitation, and escapement for the MU. The continuation of this proposed project would augment the Inch Creek CWT releases into Nicomen Slough by tagging Coho that are already clipped and released into Norrish Creek (a tributary of Nicomen Slough). This nearly doubles the CWTs available to sample and will increase the precision of our escapement estimates to Nicomen Slough and also improve survival and exploitation rates for the LFC MU. Additionally, the analysis from this project can be used to estimate the total escapement of LFC when the results from this project are used in conjunction with the results from a new sampling fishery conducted above the confluence of the Fraser River Arms and below Pitt River, Chilliwack Coho PIT tag mark-recapture, and a project estimating Lillooet Coho escapement. This proposal includes estimation of Nicomen Slough Coho escapement in 2021 when the first CWT Norrish Coho (first brood year 2018) return as adults.