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This paper identifes reference points for Dungeness Crab in Crab Management Areas I and J in British Columbia. We estimated an Upper Stock Reference (USR = 0.456 female standardized CPUE) and a Limit Reference Point (LRP = 0.228 female standardized CPUE), as described in A Fishery Decision-Making Framework Incorporating the Precautionary Approach (DFO 2009) also known as DFO's Precautionary Approach (PA) policy. These reference points will inform the assessment of stock status of Dungeness Crab in Crab Management Areas (CMAs) I and J. Candidate reference points were estimated using three methodologies: a data-driven empirical method, a model-based method which estimates the stock-recruitment relationship, and a simulation model-based method. We recommend applying the empirically-based methodology for determining reference points for the Dungeness Crab in CMAs I and J as they are more interpretable than the simulation model-based reference points, and are more estimable than the stock-recruitment reference points. Subsequent research can use this framework to develop reference points for Dungeness Crab in other CMAs. [ABSTRACT FROM AUTHOR]

This paper presents an assessment modeling framework that integrates all available fishery monitoring and survey data into a Spatially Implicit Statistical Catch-At-Length (SISCAL) operating model for Northwest Atlantic Fishery Organization (NAFO) Subareas 0+1 (offshore) Greenland Halibut (GH-0+1). The model is subsequently used to provide both an assessment of stock status and productivity as well as a closed loop simulation framework for evaluating GH-0+1 feedback harvest strategies. The SISCAL model fit reasonably well to GH-0+1 data, as determined by standard goodness of fit metrics, although some sensitivities and data issues were noted. The retrospective behaviour of the model was also within reason. Simulationevaluation self-tests also showed that the model was unlikely to be biased over a large number of simulated data sets. After model testing, SISCAL was used to condition a closed-loop simulation framework for testing GH-0+1 management procedures against performance metrics based on NAFO precautionary approach fishery management policy. As an illustrative example, we defined an adaptive model/index-based management procedure that set total allowable catches on a biennial basis, using decision rule parameters that were updated via simulated SISCAL stock assessments every 6 years. Simulated SISCAL stock assessments were fit to historical and simulated catch and biological data from six commercial fleets, differing by nation and gear type, and stock indices and length compositions from three fishery independent surveys. The three surveys included two existing offshore (NAFO Divisions 0A1CD) and inshore (NAFO Divisions 1A to F) research vessel surveys, as well as an additional proposed survey that will begin in 2022 and was assumed to encounter small fish in inshore waters of Divisions 0A and 0B. For comparison, a non-adaptive index-based method was also tested, where decision rule parameters are based off the initial SISCAL model for the entire simulation. The adaptive procedure performed well, keeping biomass above the limit reference point of = 0.3BMSY in all simulations, and avoiding the limit fishing mortality rate Flim = FMSY with high probability. In contrast, the non-adaptive procedure ended up slightly overfishing the GH-0+1 stock, with biomass appearing to continue declining past the end of the simulation. Moreover, the non-adaptive procedure had a roughly neutral probability of exceeding Flim, making it unacceptable under NAFO policy. We close with recommendations for future work to expand this framework to a full management strategy evaluation, enabling the development of a full harvest strategy for the GH-0+1 fishery consistent with fishery management policy. [ABSTRACT FROM AUTHOR]

Fisheries and Oceans Canada (DFO) is developing a precautionary approach (PA) framework for the management of the Atlantic Salmon recreational fisheries for DFO Gulf Region rivers. A DFO Fisheries Management-led working group (DFO-WG) convened over the previous year to discuss and develop candidate harvest decision rules (HDRs) for the Atlantic Salmon recreational fishery using the Miramichi River as a case study. The candidate HDRs for the recreational fishery are evaluated for compliance to the PA policy and supporting science advice. The candidate HDRs specify management measures for different levels of abundance prior to recreational fisheries rather than being specific about exploitation rates. There is insufficient information to determine the extent to which the described management measures will change the exploitation rates and losses due to fishing. Using historical exploitation rates and assumed catch and release mortality rates from the Miramichi River, the management measures in the candidate HDRs are translated into the proportion of the total eggs lost from recreational fishing. The losses for similar management measures are higher in the Northwest Miramichi compared to the Southwest Miramichi because of differing biological characteristics and seasonal catch profiles between the two rivers. Several elements of the candidate HDRs, such as adjusting losses for three status zones and maximum losses being less than the removal rate reference, comply with the PA policy. Other elements of the candidate HDRs may not comply with the PA policy, subject to interpretation. One key element is the interpretation of the PA statements that removals be kept to the lowest level possible and no tolerance for preventable decline when the stock is in the critical zone. Both candidate rules would allow a directed catch and release recreational fishery when the abundance is in the critical zone; directed fisheries would only be closed if the abundance before fishing was < 15% or < 25% of the Limit Reference Point (LRP), dependent on the rule. The losses from a catch and release fishery in the critical zone would be approx. 1% of the eggs prior to the fishery but could be as high as 4 to 7% if the season-adjusted catch and release mortality rate was in the range of 16 to 25% as indicated from a wider meta-analysis of studies and mean water temperatures in the Miramichi, rather than 3% mortality rate that has been used to date. The implementation of the candidate HDRs requires a forecast of expected abundance prior to the fishery. The performance of the candidate HDRs and compliance to the PA policy will need to be reevaluated to take account of the uncertainties and biases of the forecast model and the decision making process. [ABSTRACT FROM AUTHOR]

The status of the northern contingent of Atlantic mackerel (Scomber scombrus) in the Northwest Atlantic is assessed every two years using an age-structured stock assessment model. This document presents the background information, data, and methods used to calculate the main stock status indicators for mackerel which form the basis of advice given to the Fisheries and Aquaculture Management Branch of Fisheries and Oceans Canada (DFO) in the setting of Total Allowable Catch (TAC). The present stock assessment took place on the 25-26 of February and March 3rd of 2021 and provides advice for the 2021-2022 fishing seasons. The main results of this assessment indicated that in 2020, the spawning stock biomass (SSB) of mackerel was estimated to be at an all-time low and in the Critical Zone, as per DFO's Precautionary Approach (PA), since 2011. Recruitment of age 1 fish was estimated to be near record lows in recent years and the age structure of the stock was severely truncated. The fishing mortality rate (F) was also above the reference point. Short-term projections indicated that the probability of the SSB leaving the Critical Zone by 2023 varied from 29%-37% (TAC = 10 000 t) to 51%-58% (TAC = 0 t) depending on the assumptions of future recruitment. [ABSTRACT FROM AUTHOR]

The Striped Bass (Morone saxatilis) population of the southern Gulf of St. Lawrence, the most northern spawning population of the species distribution in eastern North America, is widely distributed in estuaries and coastal waters of the southern Gulf of St. Lawrence from the north shore of the Gaspe Peninsula in Quebec to the northern tip of Cape Breton Island, Nova Scotia. For purposes of assessment and development of fisheries reference points, the southern Gulf Striped Bass population distribution comprises the Gulf of St. Lawrence region. Following on the sustained rebuilding of the spawner abundances from the lows of the late 1990s to the current high abundances that exceed 300 thousand spawners, DFO Gulf Ecosystems and Fisheries Management requested the development of fisheries based reference points that conform to the Precautionary Approach (PA) to guide further management decisions on the development of the Striped Bass fisheries. The extensive information on the abundance and biological characteristics of the Striped Bass population of the southern Gulf of St. Lawrence is presented. An age structured population model is used to estimate stock and recruitment parameters and associated mortality rates at age based on assessed abundances of spawners for the years 1996 to 2019. Equilibrium modelling is used to define candidate Limit Reference Point (LRP), Upper Stock Reference (USR), and removal rate references that would conform to the Precautionary Approach. Despite model uncertainties, a LRP value of just over 330 thousand spawners is consistent with one of the population model results as well as with the history of the management decisions for re-opening of fisheries access since 2013. The USR value of 720 thousand spawners would represent a healthy condition for this population, based on the assessed spawner abundances to 2019 and on the potential productive capacity of this population. A number of knowledge gaps and uncertainties remain. The most important assessment and management gap is the incomplete to non-existent catch statistics for any of the Striped Bass fisheries in the southern Gulf of St. Lawrence, including Indigenous Food Social and Ceremonial fisheries and the larger recreational fisheries. In the absence of these catch and harvest data, it is not possible to provide fisheries management advice in terms of total allowable catches nor can the status of the population relative to removal rates be assessed. Striped Bass is a predator of other valued anadromous fisheries species in the southern Gulf of St. Lawrence. The reference points presented are derived based on optimizing value functions specific to Striped Bass. No multi-species reference points or management options are discussed. [ABSTRACT FROM AUTHOR]

Canada's Fisheries Act was revised on June 21, 2019, resulting in new Considerations and Fish Stocks provisions (FSP) that relate to the management of fisheries. The FSP (Section 6) contains new terminology: 1) a requirement to implement measures to maintain major fish stocks "at or above the level necessary to promote the sustainability of the stock" (s 6.1(1)); and 2) if those management measures are unfeasible due to cultural or socio-economic impacts, to maintain stocks above the limit reference point or LRP (s 6.1(2)), which is a biological threshold to serious harm. Definitions of sustainability recognize both time and the need for equitable access to benefits across generations of resource users. Most jurisdictions recognize multiple axes of sustainability including ecological, socio-economic and institutional axes, but prioritize them differently. Consideration of all axes is necessary to operationalize fisheries management to support sustainable use, and science alone cannot advise on all of them. A pragmatic definition of sustainability in fisheries is that it is the process that conveys the ability to maintain a specified level of practical and effective use of a fisheries resource over the long term, where practical and effective reflects value-based measureable objectives related to biological, socio-economic and cultural outcomes. In the same vein, a level necessary to promote sustainability of the stock can be defined as "a threshold representing a specified level of practical and effective resource use over the long term." In the absence of clearly-defined value-based objectives for resource use or tolerance for risk to the stock, the threshold cannot be defined more specifically. Thresholds and other levels fulfilling s 6.1(1) or s 6.1(2) differ with respect to trade-offs among biological, socio-economic, and/or cultural objectives but both sections imply the stock be maintained above the LRP. Limits, other thresholds and target reference points play important roles in constraining which stock states are considered sustainable internationally. Review of Canada's PA Policy suggests that fisheries sustainability could be evaluated, in part, by considering whether stock status exceeds the LRP and whether fishing mortality is less than the removal reference rate. The question of sustainability can also be assessed by evaluating whether management measures are expected to perform acceptably with respect to stated limits and targets over specified time frames. The multiple axes of sustainability imply there is a role for multiple sectors in defining and promoting stock and fisheries sustainability. The Science Sector sets LRPs, evaluates stock status against reference points, and may contribute by evaluating other elements of the ecological axis of sustainability such as age or size composition of the stock, habitat, trophic level and other ecosystem considerations in relation to objectives. Setting targets, other thresholds, time frames and determining acceptable risks are value-based choices and cannot be established via scientific means alone. All Sectors may benefit from Departmental guidance as to how s 6.1(1) and s 6.1(2) differ in implementation, particularly with respect to the use of PA Policy reference points in management objectives, and implications for management measures including harvest control rules. [ABSTRACT FROM AUTHOR]

The Precautionary Approach (PA) is a general philosophy to managing threats of serious or irreversible harm where there is scientific uncertainty. An implementation of this approach, in the form of the PA Framework, serves as a foundation for the establishment of Limit Reference Points (LRPs), below which productivity is sufficiently impaired to cause serious harm to a fishery. Fisheries and Oceans Canada (DFO) has committed to implementing a PA Framework (DFO 2006) in the management of the Northern (Pandalus borealis) and Striped (P. montagui) shrimp fisheries located in Hudson Strait and Ungava Bay (Western Assessment Zone; WAZ). To support these efforts, this document provides directions for establishing of LRPs and suggests the Upper Stock Reference Points (USRs) for these stocks. This document also discusses updated LRPs and suggests USRs for the Northern and Striped Shrimp fisheries in Davis Strait (Eastern Assessment Zone; EAZ). Two approaches to establishing the LRPs are considered herein: 30% and 40% of the geometric mean of female spawning stock biomass (SSB). In the WAZ, based on a 6-year time series, new LRPs based on a 30% scenario were calculated as 3,100 and 9,200 t for Northern Shrimp and Striped Shrimp, respectively. The 40% scenario in the WAZ would result in new LRPs of 4,100 and 12,300 t for Northern Shrimp and Striped Shrimp, respectively. New proposed USRs in the WAZ, based on a 6-year time series and calculated at 80% of the geometric mean of SSB, would be 8,200 and 24,600 t for Northern Shrimp and Striped Shrimp, respectively. Similarly in the EAZ, two scenarios for calculating updated LRPs were also considered (i.e., 30% and 40% of the geometric mean of SSB). Based on a longer, 11-year time series, updated LRPs based on a 30% scenario were calculated as 11,800 t (increase from 6,800 t) and 2,300 t (no change) for Northern Shrimp and Striped Shrimp, respectively. The 40% scenario in the EAZ would result in updated LRPs of 15,800 t (increase from 6,800 t) and 3,100 t (increase from 2,300 t) for Northern Shrimp and Striped Shrimp, respectively. The updated USRs, based on 80% of geometric mean of SSB, in the EAZ are proposed at 31,600 t (increase from 18,200 t) for Northern Shrimp and 6,100 t (no change) for Striped Shrimp. The updated reference points for the EAZ reflect a longer time series (11 years versus 3 years as previously explored) and expanded spatial coverage to reflect current assessment extent. The intent of this document is to serve as a source of supporting information to provide advice to DFO Resource Management, consistent with the Department's PA Framework in support of the sustainable management of these fisheries. [ABSTRACT FROM AUTHOR]