All posts by Angus Mackay

Mark Recovery Program Coded Wire Tag Sampling, Dissection and Reporting

This project is one component of the Coast Wide CWT System which includes fully integrated CWT tagging, sampling, lab operations, analyses and data exchange along the entire west coast of North America with a high level of coordination and cooperation among the coastal states and Canada across many political jurisdictions. The funding supports fishery CWT sampling from Commercial, First Nations economic, and recreational fisheries in BC that encounter Chinook indicator stocks, as well as head lab operations and the management of resulting data.

CWT data is essential in annual analyses in deriving Canadian and US allotments of chinook total allowable catch, assessing compliance under the PST, calculating fisheries and stock specific statistics (i.e. exploitation rates, survival rates, maturation rates), monitoring trends in marine survival, assessing fishing impacts, forecasting pre-fishery ocean stock abundances, and evaluating the effectiveness of hatchery production and experimental programs. CWT data is also important for assessing stock status, forecasting stock abundance, and monitoring trends in regional survival patterns for climate change investigations and ecosystem-based assessments. Long-term time series of CWT data is key information to discern variations in salmon abundance resulting from variations in ocean survival and human-induced impacts.

 

Juan de Fuca Strait Chum Sampling Program. Year 1 of 4

The Chum Technical Committee (TCChum), in consideration of the requirements of the latest version of Annex IV, Chapter 6 (Chum Annex) of the Pacific Salmon Treaty, has determined that a significant amount of stock assessment work should be undertaken by the parties, in order to provide the level of information necessary for the successful implementation of the Annex. Part of implementing the strategic plan (Figure 1), the TCChum submitted various proposals over the last few years to target key components of the plan. In 2014 the first phase of the Chum Genetic and Environmental Management model (ChumGEM) was initiated to develop a run reconstruction model for Southern BC and Washington Chum salmon.

Through the initial work on ChumGEM, it was very apparent that the diversion of chum salmon stocks through the southern route (Strait of Juan de Fuca) was a significant gap in our information needed to populate the model. Currently the model structure is available to incorporate this information, but we are making assumptions on the migration pathways that require investigation and validation through this project.

The Southern Panel has identified the establishment of a chum sampling program for the Strait of Juan de Fuca as a top research priority for the next call for proposals through the Southern Endowment Fund for 2016.

Strait of Juan de Fuca Sampling Program:

With the goal of stock reconstruction for Southern BC and Washington Chum salmon, one significant data gap is the diversion of chum populations through the Southern Route via Juan de Fuca Strait. This project will work towards addressing that data gap by sampling this migration route in both US and Canadian waters to determine:

  • The spatial and temporal stock composition of chum salmon migrating through the Southern Diversion route,
  • Provide sampling platform for stock identification, migration rate studies etc.
  • Develop time series of Catch per Unit effort data to pair with the Johnstone Strait Test Fishery to determine diversion rate of various chum populations.

This multi-year program will be broken into 2 phases. Phase 1 will involve assessing the feasibility of a structured sampling program (2016) in Juan de Fuca Strait (Canadian Area 20 and US Area 5). This will involve chartering a Purse Seine vessel to fish 4 days/week starting the 1st week of October for 5 weeks. Catch per Unit Effort information will be collected as well as biological samples for stock identification purposes. All fish will be released except for the 400 samples/week (a total of 2,000 chum) that will be collected during the program. Phase 2, dependent upon the 1st year of the program, will expand the sampling program to include a tagging component to evaluate the migration rates of chum salmon via migration route which is a key parameter in the reconstruction model (2017-2019).

 

 

Nahlin Chinook Escapement Enumeration

This proposal involves enumeration of the escapement of Chinook salmon to the Nahlin River using sonar technology and analysis of GSI data from in-river fisheries, for 2016-18. Based on GSI and aerial survey data, the Nahlin River (into which both the Dudidontu River and Tseta Creek drain) is the second most important Chinook tributary in the Taku River drainage, supporting approximately one third of the total annual return. An accurate escapement figure for approximately one third of the drainage will be of considerable value on its own. However, this will be enhanced by coupling the count with GSI data from the lower Taku river, thereby permitting a ratio-based estimate of Chinook abundance drainage-wide for comparison with estimates currently generated using other methodologies.

Kuthai Lake Sockeye Review & Access Improvement Assessment

This project began with an investigation into why Kuthai Lake sockeye escapement has dramatically declined and remains low. The focus will be upon evaluating migration access for the Kuthai stock, along with estimating relative abundance and stock proportions for Kuthai and co-migrating early run main-stem sockeye.

In the later stages, this project will involve two field surveys which will inform the development of design and cost estimates for improving sockeye migration access to Kuthai Lake. The results of which strongly indicate that access to the lake is particularly restricted in the lower reach of the Silver Salmon River.

The primary objective of this project is to focus on increasing the abundance of fish stocks by opening freshwater habitat to salmon spawning and rearing. In specific instances, it will be possible and appropriate to rehabilitate previously productive habitat that has been degraded as a result of human or natural activity.

Nass Chinook Mark-Recapture Project

Since 2009, the Pacific Salmon Commission (PSC) Chinook Technical Committee (CTC) has established a 15% coefficient of variation (CV) as an acceptable level of uncertainty for estimating Chinook Salmon populations that are used in managing US and Canadian Chinook Salmon fisheries. We are requesting funding support from the PSC Northern Fund to continue the Upper Nass Chinook Salmon mark-recapture (MR) program initiated in 2009 in order to achieve the PSC CTC data standard. Past funding from the PSC to the Nisga’a Fisheries and Wildlife Department (NFWD) supported increased marking and recovery efforts for generating accurate estimates of abundance for the Upper Nass Chinook Salmon aggregate population, meeting the CV data standard in six of the seven years that funding was provided. Overall, the Nass Chinook Salmon program has achieved the CV data standard in 15 of 24 (63%) years since the start of the Nisga’a Fisheries Program in 1992. The main factor determining CV has been the number of marked Chinook Salmon recovered at terminal spawning areas in the Upper Nass River. Achieving an adequate number of marked recoveries has required two conditions to be met: (1) a sufficient number of Chinook Salmon are marked (>1250) at the fishwheels and (2) sufficient effort is made on the spawning grounds for recovering marks such that >50 marks are recovered. Results from the past funded studies have indicated that these requirements can be met, even in low return years, by marking adult Chinook Salmon at both fishwheel marking locations (Gitwinksihlkw and Grease Harbour), examining fish throughout the run at Meziadin Fishway and the Kwinageese videocounting weir, and conducting carcass surveys at Damdochax Creek. These three Upper Nass spawning systems represent on average 39% of the aggregate spawning stock based on stock composition estimates and are geographically separated to be representative of all stocks that spawn above the marking sites.
The primary purposes of the proposed project are to: (1) continue to augment marking and recovery efforts, (2) improve methods for generating accurate and precise MR escapement estimates for the Upper Nass River Chinook Salmon aggregate stock, and (3) achieve unbiased population estimates that meet the PSC CTC data standard (CV – 15%).

Increased Chinook Salmon Stock Coded-Wire Tagging to Improve the Quality of Chinook Indicator Stock Analyses

We propose to maintain increased coded-wire tagging (CWT) for nine Chinook indicator stocks in B.C. that contribute to Northern and Southern Boundary Area fisheries. This proposal will fund incremental tagging beyond the base level provided by the Canadian Department of Fisheries and Oceans (DFO) in order to meet standards derived by the PSC CWT work group to account for survival rate, fishery sampling rate, exploitation rate, and an 80% probability of attaining a minimum standard of observed CWT recoveries. This work has been funded through the Pacific Salmon Treaty (PST) Coded Wire Tag Improvement Fund from 2009-2013, and the PSC Northern Endowment Fund and as a Very High Priority Chinook project in 2014-2016. This project proposes to maintain the increased tagging rates on the highest priority indicator stocks through to 2018, until which time CWTs will be the primary fishery assessment tool for Chinook salmon. This proposal addresses several priorities for implementation of the PST and will improve the ability to better manage the Chinook stocks and fisheries of relevance to the PST.

This proposal is for stocks providing the majority of benefits, based on total fishing mortality distribution, to Northern and Southern Boundary Area fisheries. This proposal addresses nine stock groups represented by CWT indicator programs on Robertson (WCVI), Quinsam (Upper Georgia Strait), Lower Shuswap and Nicola (Fraser Early), Atnarko (Central Coast), Kitsumkalum (North Coast), Harrison and Chilliwack (Fraser Late), and Cowichan (lower Georgia Strait) populations. When these stocks are healthy and abundant they can be large contributors to Southeast Alaska (SEAK), Northern British Columbia (NBC) and West Coast Vancouver Island (WCVI) fisheries.

 

 

Little Tahltan River Chinook Assessment

Historically, Little Tahltan River Chinook have been a major contributor to the overall Stikine production, but have declined in recent years, both in abundance and relative contribution to the total Stikine Chinook run. This project would be a preliminary investigation into why the Little Tahltan River Chinook escapement has declined and remains low. The scope of the project would be focused upon evaluating environmental conditions that may possibly be affecting spawning and incubation habitats. A field survey would be conducted in order assess or monitor habitat factors that may have influenced the decline or be limiting productivity.

 

Nakina Creel Survey

The main intent of this project is to augment information for the Taku Chinook mark/re-capture program. This additional effort, in the form of a creel survey will focus on collecting Chinook samples from the lower Nakina River during the Canadian sport fishery. As a secondary objective, on-site information relating to harvest would be collected, and the feasibility of a future alternative methodology to estimate such will also be explored.

 

Coldwater River Adult Coho Enumeration

With increasing pressure to ease fisheries restraints on Interior Fraser River (IFR) Coho, a new emphasis must be placed on better exploitation rate (ER) estimates. There is limited hatchery capacity for coho coded wire tag (CWT) smolt production in the IFR and that capacity is currently split between two systems in the Thompson River complex whereby the Coldwater and Eagle Rivers both receive approximately 60,000 smolts per year. The works proposed here will strengthen the current Coldwater CWT indicator stream assessment.The Coldwater River coho program has been an indicator for IFR coho since 1987 and also benefits from the Nicola Tribal Association’s (NTA) Aboriginal Fisheries Strategy (AFS) enumeration activities including area under the curve (AUC), DIDSON operations, and carcass recovery. Current Coldwater indicator program involves a system escapement estimate using AUC and DIDSON technology. Carcass recovery is used to determine adipose fin clip (AFC) and sex ratios. We propose to enhance the existing program to obtain greater certainty around both the escapement estimate and AFC ratios of IFR coho in the Coldwater River thereby providing greater certainty around the CWT ER of IFR coho.

 

Klukshu Chinook and Sockeye Escapement Enumeration

Continuation of the Klukshu weir is identified as a priority in the Pacific Salmon Commission Transboundary Panel Strategic Salmon Plan (March 2009). The weir monitors Chinook and Sockeye escapement to an important Alsek River sub-drainage. When coupled with GSI it permits estimation of escapement drainage-wide. It is the primary tool for identifying whether or not Klukshu and Alsek river escapement goals have been achieved.