Author Jennifer Provencher shares her team’s latest study that trials a novel tool that helps factor the multiple stressors to seabirds in the Canadian Arctic identified by experts into a graphical ‘cognitive map’.
Wildlife populations are commonly subject to multiple, interacting stressors (e.g. pollution, climate change), which makes predicting the outcomes of management actions and identifying priorities a challenge. In data-poor locations like the Arctic, limitations in data leave us with knowledge gaps that can prevent us from considering all stressors simultaneously to manage species.
Even scientific experts engaged in co-management with decades of experience can struggle to account for the compound pathways by which stressors are interacting to influence wildlife populations. It is truly hard to see the forest for the trees.
The northern fulmar
Take the northern fulmar (Fulmarus glacialis), a medium-sized seabird that breeds in cliff colonies and forages on the ocean’s surface on a diverse selection of prey in the Canadian Arctic – and whose numbers are declining.
Northern fulmars from two colonies in the Baffin Bay–Davis Strait region of the Canadian Arctic have been found to range up to 500 km from their colonies in search of food and thus are subject to a diverse range of stressors as they span a marine region covering >300,000 km2. This is on top of living in a warming Arctic with consequent changes in prey populations and increasing human activity.
Yet, the jurisdictional and logistical challenges of managing migratory species in remote locations mean we have limited data to assess the causes of population declines or the merits of potential policy tools and management options.
Approaching the problem
Expert opinion can help us develop wildlife management models that can incorporate diverse pathways of effects on wildlife populations. We can then interrogate these models to understand potential interactions among multiple stressors and the possible outcomes of different management or conservation actions. In our study, we used Fuzzy Cognitive Mapping (FCM) – a tool to graphically represent the arrangement of key factors and their interrelationships.
In 2020, we leveraged expert opinion of nine members of Environment and Climate Change Canada’s Seabird Technical Committee and the Canadian members of the pan-Arctic Conservation of Arctic Flora and Fauna (CAFF) committee in a workshop to develop an FCM of northern fulmar population size in the Baffin Bay–Davis Strait, and to quantify the strength and uncertainty of relationships between 58 key stressors, grouped into seven key themes: (1) hunting and fishing, (2) research, (3) shipping, (4) mining, oil and gas exploitation, (5) pollution, (6) climate change and (7) interactions among species.
Because some of these stressors are more subject to management controls (e.g. technological solutions, policy tools, regulations) than others, we were also able to discern the degree to which management controls affect populations and the degree of uncertainty among the stressors.
Our findings
We found strong agreement among experts on the main stressors affecting northern fulmar population declines, with 41% of the 58 defined stressors either included or completely exempt from all nine FCMs generated for each of the experts interviewed.
A consensus map of all nine FCMs included 55 of the 58 stressors connected by 330 individual relationships.
This complexity illustrates the challenge inherent in cumulative effects approaches – but the consistency among expert conceptualizations of the system and the importance of different stressors and pathways reveal that experts can possess a profound understanding of wildlife populations and the stressors influencing them. FCMs can therefore help experts formalise and investigate their understanding of complex systems.
Highlighting the crucial need for a cumulative effects lens, over 50% of the total influence on northern fulmar was attributed to the indirect effects of stressors that interact with other stressors. Interestingly, nearly 60% of total influence of stressors was considered manageable under existing policies.
Details about the methods and the consensus model we developed can be found in our article.
Next steps
Our next step is to repeat the FCM process with Indigenous knowledge holders in the Arctic, to determine how their views, knowledge and experience, in collaboration with our scientific knowledge, may generate practical conservation actions.
Read the full article: “Fuzzy cognitive mapping as a tool to assess the relative cumulative effects of environmental stressors on an Arctic seabird population to identify conservation action and research priorities” in Issue 4:2 of Ecological Solutions and Evidence.
