A5045229202- Marine and fisheries research
- Fish Ecology and Management Studies
- Marine Bivalve and Aquaculture Studies
- Coral and Marine Ecosystems Studies
- Oceanographic and Atmospheric Processes
- Wildlife Ecology and Conservation
- Genetic and phenotypic traits in livestock
- Hydrology and Watershed Management Studies
- Avian ecology and behavior
- Aquaculture Nutrition and Growth
- Marine Ecology and Invasive Species
- Fish Biology and Ecology Studies
- Statistical Methods and Bayesian Inference
- Coastal wetland ecosystem dynamics
- Hydrology and Sediment Transport Processes
- Turtle Biology and Conservation
- Aquatic Invertebrate Ecology and Behavior
University of British Columbia
2011-2024
Fisheries and Oceans Canada
2018-2020
The majority of global fish stocks lack adequate data to evaluate stock status using conventional assessment methods. This poses a challenge for the sustainable management these stocks. Recent requirements set scientifically based catch limits in several countries, and growing consumer demand sustainably managed have spurred an emerging field methods estimating overfishing thresholds setting with limited data. Using strategy evaluation framework we quantified performance number data-limited...
Qualitative risk assessment frameworks, such as the Productivity Susceptibility Analysis (PSA), have been developed to rapidly evaluate risks of fishing marine populations and prioritize management research among species. Despite being applied over 1,000 fish populations, an ongoing debate about most appropriate method convert biological fishery characteristics into overall measure risk, assumptions predictive capacity these approaches not evaluated. Several interpretations PSA were mapped a...
Using a management strategy evaluation approach, we compare range of new and established procedures (MPs) for setting catch-limits in fisheries. Performance is evaluated with respect to fish life history type, level stock depletion, data quality, autocorrelation recruitment strength. We quantify the robustness each MP various observation processes. Methods using observations absolute biomass or depletion offer best overall performance this consistent across types, qualities, levels. Simple...
Abstract A simulation‐based approach known as management strategy evaluation ( MSE ) is increasingly used by resource managers to identify procedures that are robust uncertainties in system dynamics. The majority of global fish populations data limited and there large uncertainty over their population exploitation Data‐Limited Methods Toolkit (DLMtool) an R package allows for rapid flexible specification. consolidates a number existing data‐limited testing new approaches. DLMtool has...
The first relatively complete landscape-scale social–ecological system (SES) model of a recreational fishery was developed and ground-truthed with independent angling effort data. Based on the British Columbia multistock for rainbow trout (Oncorynchus mykiss), includes hundreds individual lake fisheries, thousands anglers, originating from tens communities, connected by complex road trail networks, all distributed over landscape approximately half million square kilometres. approach is...
Abstract Fisheries managers are in need of quantitative tools to inform decisions regarding selection robust management practices, prioritising research gaps and stocks focus on, particularly where there limited resources or data. To support these decisions, the use Management Strategy Evaluation (MSE), that is, closed loop simulation‐testing procedures, is widely regarded as best practice. However, applying MSE time‐ computationally intensive, requires highly skilled expertise processes for...
We develop and test spatial population dynamics models that estimate age-dependent offshore movement of fish populations from fishery data. Spatially aggregated produced biased estimates maximum sustainable yield (MSY) reference points when were simulated. Spatial provided relatively unbiased MSY regardless whether demonstrate by using conventional data are disaggregated spatially, it is possible to with age obtain more accurate management points. The new fitted for Gulf Mexico red grouper...
Abstract Potential users of the model proposed by Froese et al. (2018) should be aware several issues. First, method to calculate equilibrium numbers-at-length is incomplete and leads negatively biased estimates fishing mortality. Second, inadequate simulation testing fails reveal that highly sensitive assumptions conditions population average asymptotic length (L∞) can approximated largest observed size (Lmax). Finally, relies on assumption ratio natural mortality (M) von Bertalanffy growth...
We formulate and simulation-test a spatial surplus production model that provides basis with which to undertake multispecies, multi-area, stock assessment. Movement between areas is parameterized using simple gravity includes "residency" parameter determines the degree of mixing among areas. The deliberately in order (1) accommodate nontarget species typically have fewer available data (2) minimize computational demand enable simulation evaluation management strategies. Using this model, we...
Specifying annual catch limits for artisanal fisheries, low economic value stocks, or bycatch species is problematic due to data limitations. Many empirical management procedures (MPs) have been developed that provide advice based on achieving a stable historical target (i.e., instead of maximum sustainable yield). However, thorough comparison derived yield streams between MPs and stock assessment models has not explored. We first evaluate trade-offs in conservation metrics data-limited...
Abstract Common uncertainties in stock assessment relate to parameters or assumptions that strongly determine both the estimates of quantities management interest (e.g. depletion) and related reference points biomass at maximum sustainable yield). The risks associated with these are often presented managers form decision tables. However, a formal evaluation from misspecifying an model over time‐horizons spanning multiple cycles requires closed‐loop simulation. There were two aims this study:...
Rebuilding depleted fish populations is a priority of modern fisheries management. In the U.S., strong statutory mandates extend to both goals and process by which stocks are be rebuilt. However, National Standard Guidelines that govern implementation Magnuson-Stevens Fishery Conservation Management Act may change increase flexibility in rebuilding requirements. this study we evaluate performance status quo approach stock United States against 3 alternatives have been proposed improve...
Relative abundance indices derived from nominal catch-per-unit-effort (CPUE) data are a principle source of information for the majority stock assessments. A particular problem with formulating such pelagic species as tuna is interpretation CPUE fleets that have changed distribution over time. In this research, spatial population dynamics simulated to test historical pattern fishing effort basis making inferences about relative abundance. number age-structured, spatially disaggregated models...
A new indicator is described that uses multivariate posterior predictive data arising from management strategy evaluation (MSE) to detect operating model misspecification (exceptional circumstances) due changing system dynamics. The statistical power of the was calculated for five case studies which fishery stock assessments have estimated changes in recruitment, natural mortality rate, growth, fishing efficiency, and size selectivity. importance component types inform also calculated....
Abstract Stock assessments are often used to provide management advice, such as a total allowable catch (TAC), fishery managers. Many stocks not assessed annually, and the TAC from previous assessment is maintained in years between assessments. We developed two interim procedures (MPs) that update estimate of current vulnerable biomass surveyed index abundance adjust assessment. These MPs differ how they handle uncertainty observed indices. Using closed‐loop simulation, we evaluated (with...
Uncertainty about reporting rates of tags returned by fishermen has often prevented tagging data from being used in stock assessments. In this study we conduct a meta-analysis to estimate tag commercial tuna fleets comparing their return with those the USA longline pelagic observer program. The Venezuela and are estimated report 0.8% caught, compared less than 0.1% for Canadian, Spanish Japanese fleets. For some sparse or that do not overlap fleet, rate estimates sensitive changes...