Tag Archives: Weir counts

Babine River Sockeye Migration and Predation Assessment

Lake Babine Nation Fisheries (LBNF) plans to work with Fisheries and Oceans Canada (DFO) to continue the investigation of the behaviour and ecology of Babine River sockeye fry. The proposed project is composed of four relatively discrete components which include:

  1. early life history behaviour and migration;
  2. extent and rate of predation on juvenile sockeye;
  3. egg-to-fry and fry-to-smolt survival, frequency of occurrence of disease and parasites and condition as a function of length and weight; and
  4. presence and behaviour of sockeye fry rearing in downstream slow water habitats to obtain evidence of a riverine juvenile sockeye ecotype.

Other observed adverse effects that may affect sockeye fry survival and overall sockeye production will be documented. These studies are intended to address the diminished abundance of Late Run Upper and Lower Babine River sockeye in their juvenile freshwater environment.

 

 

Boundary Area Coho Escapement

The Hugh Smith Lake coho salmon population is substantially exploited by mixed-stock fisheries in both the U.S. and Canada and is, therefore, a key indicator stock used to monitor total adult abundance and escapements, and the pattern and intensity of exploitation by these fisheries on populations in the northern boundary area. It is the only system in the southern portion of Southeast Alaska where a total count (with back-up mark-recapture estimate) of coho salmon escapement has been routinely collected since 1982. Its location 70 km southeast of Ketchikan makes it a particularly strategic indicator stock for boundary area fisheries. It has also been one of three key indicator stocks used to measure the overall abundance of wild coho salmon available to the Alaska troll fishery and to measure the exploitation rate by the fishery.
Escapement projections are made from both the cumulative weir count and estimation models based on recovery of coded-wire tags to provide real-time information for management of fisheries for escapement. Peak helicopter survey counts at other Boundary Area streams provide an index with greater coverage that complements higher resolution assessment at Hugh Smith Lake.

 

Hugh Smith Lake Coho Smolt Enumeration and Marking

The Hugh Smith Lake coho salmon population is substantially exploited by mixed-stock fisheries in both the U.S. and Canada and is, therefore, a key indicator stock used to monitor total adult abundance and escapements, and the pattern and intensity of exploitation by these fisheries on populations in the northern Boundary Area. Its location 70 km southeast of Ketchikan makes it a particularly strategic indicator stock for boundary area fisheries. It has also been one of three key coded-wire tagged indicator stocks used to measure the exploitation rate by the Alaska troll fishery and to estimate the overall abundance of wild coho salmon available to the fishery. Timely escapement projections are made from both the cumulative weir count and estimation models based on recovery of coded-wire tags to provide real-time information for management of fisheries for escapement goals.
The Hugh Smith Lake coho salmon population has been the only long-term, continuously operated wild coho indicator stock project in the northern boundary area, with a record of catch, escapement, smolt production, marine survival, and age composition estimates dating from 1982. The proposal would continue to fund operation of a smolt weir to enumerate and coded-wire tag coho salmon smolts emigrating from Hugh Smith Lake to generate total population estimates, including total smolt production, marine survival, exploitation rate, and catch by area, time, and gear type. Coho smolt estimates and tag recovery rates in the Southeast Alaska troll fishery will be used to generate inseason estimates of marine survival and total adult abundance for fishery management. Estimates of brood year smolt production and adult return by age class will be used to evaluate and refine the biological escapement goal. Counts and samples of sockeye salmon smolts are also obtained at the smolt weir and have been used to evaluate escapement goals and effectiveness of sockeye salmon stock enhancement efforts. The proposed project will continue a core stock assessment program needed to manage fisheries for coho salmon in the northern Boundary Area.

Alsek Sockeye Run Reconstruction

Weir counts have been made on the Klukshu River, part of the Alsek River system, by the Department of Fisheries and Oceans (DFO) in co-operation with the Champagne-Aishihik First Nation, since 1976. A mark-and-recapture program ran from 2000 to 2004, and in 2005 and 2006, the Alsek sockeye population was estimated using tissue sample and catch information from the commercial sockeye fishery in Dry Bay as well as the weir counts. By recommendation by the Northern Fund Committee in 2008, a statistically valid sampling strategy that would provide the foundation for reconstructing sockeye and Chinook returns to the Alsek River was completed. Based on this model, it was proposed that funding be provided to analyze sockeye tissue samples collected in the commercial sockeye fishery in Dry Bay (up to 750 per season), to reconstruct the Alsek sockeye runs as described in Gazey’s analysis.

 

 

Alsek Chinook Run Reconstruction

Since 1976, weir counts have been made on the Klukshu River, part of the Alsek River system, by the Department of Fisheries and Oceans (DFO) in co-operation with the Champagne-Aishihik First Nation. In 2007, the weir counts at Klukshu, in conjunction with Chinook catches from the test fishery at Dry Bay, were used to estimate the Alsek Chinook population. The results were encouraging, and by recommendation by the Northern Fund Committee in 2008, a statistically valid sampling strategy that would provide the foundation for reconstructing the Chinook return to the Alsek River was completed. Based on this model, it was proposed that funding be provided to analyze Chinook tissue samples collected in the commercial sockeye fishery in Dry Bay (up to 500 per season), to reconstruct the Alsek Chinook runs as described in Gazey’s analysis. The project was carried out successfully in 2014, but there has not been enough fish in 2015 and 2016.

N14-I32 Alsek Chinook Run Reconstruction 2014

NF-2014-I-32 Huebschwerlen