The Northern Boundary Annex to the Canada/U.S. Pacific Salmon Treaty (PST) agreement, past (1985, 1999, and 2009) and present (2019) agreements, requires detailed accounting of the harvests for Nass and Skeena Sockeye Salmon (Oncorhynchus nerka) stocks. The PST stipulates an annual harvest share of Nass River Sockeye for the Alaskan Tree Point fishery, and harvest limitations for Nass and Skeena River Sockeye stocks in the Alaska Noyes Island fishery. Each year, the Pacific Salmon Commission’s Northern Boundary Technical Committee (NBTC) provide the catch, escapement, and total run size estimates for the regional Sockeye stocks required to implement the 1999, 2009, and 2019 PST provisions through an annual northern boundary run reconstruction modelling process developed bilaterally in the mid 1990’s. The modelling process provides bilaterally agreed data on catch, escapement, and stock composition for five modelled Sockeye stocks including the Skeena River, Nass River, Stikine River, McDonald Lake, and US other stocks in Southeast Alaska originating in the northern boundary area with reconstructed runs conducted from 1982 to 2008.

LGL Limited was contracted by Fisheries and Oceans Canada (2009–2014, 2019–2021) and Pacific Salmon Commission (2015–2018) to assist the Northern Boundary Technical Committee (NBTC) in run reconstruction modelling and assessments for Sockeye Salmon returning from 2009 to 2021 as part of the Northern Boundary Annexes to the 1999, 2009, and 2019 Canada/US Salmon Treaty agreements.