Research

My research focuses on understanding the social and ecological processes that structure risk and resilience in fisheries. I explore this theme by working in collaborative teams to develop quantitative models, infer trends and key drivers of variation, determine population status, and assess “what if?” questions of future management. Through this work, I distill the rich dynamics underlying complex ecosystems into simpler insights for decision-makers. In recent years, I have pursued this theme through a few lines of inquiry: (1) what are the spatial-temporal processes underlying the dynamics of fisheries in Pacific Canada?, (2) are there general characteristics and drivers of risk and resilience in fisheries?, and (3) how do we assess risk and navigate trade-offs in a more inclusive way in this era of co-governance? Together, my research aims to translate pluralistic values and objectives into quantitative information that generates novel insights and serves collaborative governance processes.

Life-history variation in exploited fishes

Fish life-history traits like growth, reproduction, maturation, and survival influence individual fitness and the size- and age-structure of fish populations. The response of these traits to variable environments may ultimately determine species resilience to ecosystem changes, like exploitation and climate change. I’ve used theoretical and empirical case studies to understand several of these aspects in a variety of exploited fishes including:

• Lake trout life-history variation tracking climate, productivity, fish community, and exploitation clines (see Wilson et al. 2019 J. Anim. Ecol.)
• Black crappie growth in response to density-dependent and-independent variation (see Wilson et al. 2015 NAJFM and Matthias et al. 2018 Fish. Res)
• Fish recruitment dynamics emerging from density- and size-dependent growth and survival (upcoming article with Post et al.)

Spatial-temporal variation in spatially structured fisheries

Over the past century, fisheries in Pacific Canada have faced substantial declines in stock status. While trends vary among species and across space – with increases for some populations and others remain in a state of collapse – and declines appear particularly evident for groundfish and wild salmon. Disentangling the uncertainties that arise from spatial-temporal variation can improve our understanding of major fish stocks and help maintain Indigenous rights and food security and the well-being of commercial and recreational fishers. In the past, I have worked on understanding broad-scale processes influence landscape-scale outcomes in inland fisheries, like BC rainbow trout and lake trout, to help advise managers on areas of concern for management actions. (Carruthers et al. 2019; Wilson et al. 2020). Currently, I am addressing these questions through complementary studies for groundfish and wild salmon.

Coupled feedbacks between people and nature

Why are some ecosystems prone to collapse while others remain resilient to environmental changes? Understanding this question can allow us to find a safe operating space that sustains exploited ecosystems, like fisheries, into the future.

Biodiversity underpins resilient and stable fisheries, but this diversity has many dimensions. Life history diversity allows fish to respond to stressors in different ways (some positively, some negatively), which stabilizes ecosystems on the aggregate. Disentangling how life-history traits diversify can help understand species’ responses to changing environments. My past research addressed these ideas in Canada’s lake trout by revealing that life history diversity in growth and maturation arises from plastic responses to environmental variation (Wilson et al. 2019). We estimated lake trout’s reaction norms to climate and exploitation highlighting how plasticity drives response diversity and confers resilience to environmental changes. I followed up this work more broadly during my postdoctoral research by using theory to quantify how diversity in population traits, like dispersal and productivity, shapes how ecosystems like Pacific salmon fisheries, California and Alaska Sea Otters, and Everglade Snail Kites respond to disturbance and achieve recovery targets (Wilson et al. In Prep).

Fisheries encompass not only diverse animals but also peoples. Yet, research on the mechanisms underlying fishery resilience typically ignores socio-cultural diversity. My previous work shows that varied social preferences shape diverse feedbacks between fish and fishers (Ward et al. 2016; Wilson et al. 2020). For example, people tend to prefer the largest fish in a population, and fish populations compensate to this size-selective harvest with increased growth and survival creating feedbacks between fish and fishers. Subsequent work on rainbow trout identified that the spatial interplay of these feedbacks affects the sustainability of the whole fishery (Wilson et al. 2016; Carruthers et al. 2019). In my PhD, I used field and quantitative work to show that fishing pressure cascades outward from urban centres causing local fishery collapses like a line of dominoes across the landscape (Wilson et al. 2020). This leads to halos of depletion where effort is particularly concentrated (Wilson et al. 2016; Mee et al. 2016). Studying social and ecological processes together allowed us to better understand the feedbacks between people and nature that structure risk and resilience in aquatic ecosystems.

Here more about this research on CBC Yukon.

Navigating tradeoffs in fishery management

How do we balance the resource needs of today while conserving fish for future generations? Navigating this trade-off is vital to sustainable management but remains difficult. In fisheries, quantitative frameworks, like management strategy evaluations are increasingly used to implement structured decision making and balance trade-offs. Through these frameworks, elicited values are translated into quantitative criteria to assess how scenarios perform against uncertainties. My research attempts to address these challenges and help management design robust policies that can balance trade-offs in management objectives. Specifically, I link social and ecological processes (see section above) into integrated ecosystem models to explore “What If?” scenarios to design robust and sustainable policies.

In collaboration with BC FLNRO (Joe De Gisi), Environment Yukon (Oliver Barker) and Anne Farineau, I designed a novel social-ecological model linking the life history diversity and population dynamics of 425 lake trout populations with the preferences from 15,000 anglers from 239 towns across British Columbia and Yukon. I used this model to explore how conservation and management outcomes, such as risk of collapse, are mediated by environmental variation and angler behaviour. I then quantified whether climate-, effort-, or area-based policies improved management goals to aid in decision-making. Overall, we found that a simple policy that protects young fish and the first-maturing cohorts better maintained angler harvest while reducing widespread risks.

Currently, I am expanding on this research to address these challenges on salmon and groundfish by building assessment models that directly serve collaborative governance processes (more to come!).

Improving assessment and monitoring designs

Another core aspect of my research is to use and develop novel methods, from gear deployments to quantitative techniques, that improve fishery assessments and monitoring. One of the components I’ve done the most work on this frontier is in estimates of fish growth and maturity resulting from polyphasic life histories and size selective sampling (Wilson et al. 2015; Wilson et al. 2018; Hashiguti et al. 2019). I’ve used simulations to inform study designs for estimating fish mortality (Rogers et al. 2014). Lastly, I developed one of the first uses of underwater video to assess freshwater fish communities in dense macrophytes (Wilson et al. 2014; Wilson et al. 2015).