Catch-only stock assessment methods have been developed to manage data-limited fisheries where only catch data is available. This research evaluated the ability of four catch-only stock assessment methods to correctly classify a stock of concern based on population trends. To accomplish this, true trends from simulated stocks and the trends produced by the models were used to classify stocks into threat categories based on percent change. ROC curves and PR curves were then used to test the effectiveness of the four models as classifiers. ROC curves indicated that the models performed well under most scenarios. However, the confusion matrices and PR curves revealed low precision values for all models. The high number of stocks falsely classified as threatened were masked in the ROC analysis by the imbalance of few threatened stocks compared to numerous non-threatened stocks. This is an important caveat, as it could lead to inappropriate threshold selection.
Vancouver’s Renewable City Strategy aims for 100% renewable energy and lower greenhouse gas emissions by 2050. To see if Vancouver’s policies will achieve this, I used the CIMS energy-economy model to evaluate the impact of potential policies. I simulated Vancouver’s energy use and greenhouse gas emissions under different policy scenarios: (1) current policy, (2) renewable city scenario-specific policies Vancouver has proposed, and (3) additional policies focusing on fuel switching. My results show that fossil fuel use and emissions increase relative to 2015 under current policy by about 10%. The renewable city scenario policies decrease fossil fuel use and emissions by 30% and 25% respectively, but fail to meet Vancouver’s targets. Only additional stringent policies reduce fossil fuel use and emissions to near zero, thereby meeting the targets. These result show that to meet its targets, Vancouver must implement policies that specifically focus on fuel switching in buildings and vehicles.
This study used the energy-economy model CIMS to assess policy options for achieving Canada’s 2030 emissions reduction commitment under the Paris agreement, with a focus on electricity and transportation sector reductions. The results found that existing and promised policies will likely be far from sufficient to achieve the Paris target. Two alternative approaches to close the gap to achieving the target were explored: one relying solely on emissions pricing and one relying primarily on flexible regulations. While emissions pricing is generally regarded as the most economically efficient way to reduce emissions, the results found that an emissions price on the order of $200/tCO2 would likely be required to achieve the Paris target, which would likely be very difficult politically to implement. The proposed flexible regulations approach offers an alternative that may be somewhat less economically efficient but may have a better chance of being implemented and thus achieving the target.
Bottom longline fishing gear can damage sensitive benthic areas (SBAs) in the ocean; however, the risks to these habitats are poorly understood. In this study we describe a collaborative academic-industry-government approach to mapping SBAs and measuring gear interactions with seafloor habitats via novel deepwater trap camera and motion-sensing systems on commercial longline traps for Sablefish (Anoplopoma fimbria) within the SGaan Kinghlas - Bowie Seamount Marine Protected Area. We obtained direct presence-absence observations of cold-water corals and sponges that were used to develop species distribution models of gorgonian corals (Alcyonacea) in fished areas. Video, accelerometer and depth sensor data were used to classify gear movement, estimating a mean bottom footprint of 3 200 m2 (95% CI = 2 400 - 3 900 m2) for a 60-trap Sablefish longline set approximately 3 km in length. Our successful collaboration demonstrates how research partnerships with the fishing industry offer new opportunities for conducting SBA risk assessments over large spatial and temporal scales.
This case study examines co-management in national parks and protected areas using theory on institutional arrangements of common pool resources. I apply a co-management framework to evaluate how characteristics of the community, of the resource, of the state agency, and of the institutional arrangement support co-management in a partnership between Parks Canada and Hul’qumi’num communities in the Gulf Islands National Park Reserve (GINPR). Results show that state and community partnerships can foster co-management even without formal structures for sharing power and decision-making. Notably, the nature of the institutional arrangement, which focuses on restoring a clam garden, supports co-management by challenging conservation approaches that restrict human activities in order to protect biodiversity. In the GINPR, informal processes were integral to successful outcomes. These processes directed energy to address local priorities using conservation approaches that are driven by local First Nations values. Nevertheless, co-management is limited without equitable sharing of power in key management functions: planning, policy making, data collection, and analysis.
The effective management of industrial and commercial chemicals in the environment requires good public policy based on sound science. The overall objective of this research is to improve national and international regulatory programs for the environmental management of industrial and commercial chemicals by developing and testing methods for the assessment of bioaccumulation of chemicals in biota. Bioaccumulation is a key consideration in the assessment of the environmental impacts of chemicals on environmental and human health. A review of regulatory approaches to the assessment and management of chemicals shows that current methods for assessing chemical bioaccumulation lack a priori consideration of the ability of organisms to biotransform chemicals and methods to assess bioaccumulation in species other than fish. The specific objective of my research is to develop and test a scientifically sound and cost-effective method for assessing bioaccumulation of chemicals in a mammalian species that incorporates the ability of mammals to biotransform chemicals. A thin-film sorbent-phase dosing method was developed and tested to measure the in vitro biotransformation rates of hydrophobic chemicals in rat and fish liver S9 fractions. The results showed that the biotransformation rates measured using the sorbent-phase dosing system were significantly higher than those measured using conventional solvent-delivery dosing methods. The sorbent-phase dosing system demonstrated several advantages over traditional solvent-dosing methods for hydrophobic chemicals by (i) eliminating incomplete dissolution of very hydrophobic substances in largely aqueous liver homogenates; (ii) providing a method for measuring the unbound fraction of substrate in solution; and (iii) simplifying chemical analysis. Also, an in vitro-to-in vivo extrapolation (IVIVE) method was developed to estimate whole body biotransformation rate constants and biomagnification factors (BMFs) of hydrophobic chemicals in rats from in vitro biotransformation rates. The IVIVE methodology was evaluated and found to be consistent with IVIVE models for pharmaceuticals and produced estimates of rat whole body biotransformation rate constants and BMFs for benzo[a]pyrene which were within the range of empirical values. The proposed IVIVE model for bioaccumulation assessment requires fewer physiological and physiochemical parameters than those used for pharmaceutical drug research; does not involve interconversions between clearance and rate constants in the extrapolation; and may be a useful method for conducting regulatory bioaccumulation assessments in a mammalian species. Finally, recommendations for improving regulatory assessment and control of potentially hazardous commercial chemicals in Canada are presented.
The retail landscape is continually subject to changing market trends and conditions. Increasingly researchers use resilience concepts to understand how retail systems adapt and respond to change, which can help communities and retailers better anticipate and prepare for the inevitable altering conditions. This project analyzes local stakeholder perceptions to understand aspects of resilience and vulnerability in the context of Whistler BC’s destination retail system. Through qualitative interviews and an online survey of local retailers, this research identified factors perceived as influential to local retail sector performance. The study highlights Whistler’s retail system elements that link to its resilience and vulnerability, including components of its retail sector composition; customer qualities; local social, physical, and economic conditions; and its governance processes. This investigation offers an original Destination Retail Resilience Framework that integrates resilience and vulnerability concepts drawn from relevant literature, for application within a resort retail system.
Cumulative effects are the accumulated spatial and temporal impacts to environmental and socioeconomic values from multiple projects and other activities. Cumulative effects assessment (CEA) assesses these accumulated impacts. This project used best practices for evaluating CEA under environmental assessment (EA) through a case study analysis of LNG Canada’s proposal to build a liquefied natural gas plant and port in Kitimat, British Columbia. Strengths and weaknesses of the current CEA process are identified. Overall, the evaluation found that only two of seventeen best practices were met. Recommendations are made to mitigate the deficiencies, including undertaking CEA as part of a comprehensive regional planning process instead of as part of EA.
In-season methods that produce accurate and timely forecasts of returning salmon abundances allow fisheries managers to alter fishing plans in order to meet conservation and harvest objectives. In-season methods are challenged by variability in catch statistics due to factors external to abundance, specifically, fluctuations in the migration timing of target and co-migrating stocks. I apply genetic stock identification (GSI) data to develop catch indices for the five Fraser Chinook management units, and use these indices to forecast returns for each management unit according to four in-season model forms. I evaluate models using three performance measures to determine forecasting errors. Results show that forecasts for Spring 52 and Summer 52 Chinook can be produced with reasonable accuracy early in the fishing season. Forecasts of Spring 42, Summer 41, and Fall Chinook are less accurate. Results indicate that this technique shows promise for providing accurate and timely forecasts for the five Fraser Chinook management units, particularly as additional years of data are GSI-analyzed.
Visually classifying species is the most common method used in fisheries to estimate catch compositions for commercial and survey data, but catch records can be confounded when two or more morphologically similar species are classified as a single species (i.e., cryptic species)—as is the case for Blackspotted Rockfish and Rougheye Rockfish. To partition catches between the two species, I used genetic species identification data in regression models relating the proportion of Blackspotted Rockfish relative to the overall Rougheye/Blackspotted Rockfish catch to measures of set depth, location, and bottom ruggedness. The best model included a negative relationship with longitude and positive relationship with bottom ruggedness. I also used large-scale spatial predictors to estimate historical landings of each species, finding that the inclusion of trap longline commercial data after 2006 caused an increase in the relative proportion of Blackspotted Rockfish caught (out of the total Rougheye/Blackspotted Rockfish landings). Finally, I examined observer accuracy in distinguishing Blackspotted and Rougheye Rockfish and found that while 86% of fish were identified correctly, Blackspotted Rockfish were more likely to be misidentified, leading to a 55% overestimate of the actual Rougheye Rockfish catch and a 14% underestimate of the Blackspotted Rockfish catch. My results indicate that set-specific variables are most useful in estimating proportions of Blackspotted Rockfish and can be used to estimate how spatial shifts in fishing efforts will impact fishing mortality of Blackspotted Rockfish and Rougheye Rockfish.