Are we accurately estimating the potential role of pollution in the decline of species at risk in Canada?

Abstract

Pollution is a pervasive, albeit often invisible, threat to biodiversity in Canada. Currently, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) relies on expert opinion to assess the scope (i.e., the proportion of a species’ population that may be affected) of pollution to species at risk. Here, we describe a spatially explicit, quantitative method for assessing the scope of pollution as a threat to species at risk in Canada. Using this method, we quantified the geographic co-occurrence of 488 terrestrial and freshwater species and pollution sources and determined that, on average, 57% of the mapped occurrences of each species at risk co-occurred with at least one pollution source. Furthermore, we found a weak correlation between the scope of the threat of pollution as assessed by COSEWIC expert panels and the geographic overlap of species occurrences and pollution sources that we determined with our quantitative method. Experts frequently identified scope of pollution as absent or negligible even for species with extensive co-occurrence with pollution sources, especially vascular plants. Clearly, a quantitative approach is needed to make accurate estimates of the scope of pollution as a threat to species at risk in Canada.

Toward a wild pollinator strategy for Canada: expert-recommended solutions and policy levers

“…Ray et al (2021) fault a myopic approach to development and natural resource extraction in Canada that exacerbates threats to biodiversity posed by habitat loss. Development proceeds one project at a time, on a sector by sector basis and tacitly accepts the loss of wildlife habitat as something of a foregone conclusion (McCune et al 2019;Olive 2019). While not addressing root causes as to why quality habitat might be fragmented or degraded in the first place under the current system of governance, participants' focus on building networks inherently considers pollinator habitat at a landscape scale.…”

Canada’s human footprint reveals large intact areas juxtaposed against areas under immense anthropogenic pressure

“…For terrestrial studies, the greatest coverage spans the largest ecological area of Canada, the Boreal/Taiga (Pasher et al 2013). Other terrestrial maps cover sections of western Canada (Mann and Wright 2018;Shackelford et al 2017), part of eastern Canada and the United States (Woolmer et al 2008), and the whole of Canada to display the number of pollution pressure categories present (McCune et al 2019). In addition to human footprint maps, a map exists showing the presence and absence of access into nature across Canada (Lee and Cheng 2014).…”

Early warning indicators of population collapse in a seasonal environment

“…Wildlife populations have declined dramatically in recent decades (World Wildlife Fund, 2018), with as many as one million species threatened with extinction by the end of the 21st century (Intergovernmental Science‐Policy Platform on Biodiversity & Ecosystem Services, 2019). Major anthropogenic drivers of declines in wild populations include habitat loss and degradation (Haddad et al., 2015; Iwamura et al., 2013), urbanization (Sol et al., 2014), climate change (Møller et al., 2008; Moritz & Agudo, 2013) and pollution (McCune et al., 2019). As a consequence of these ongoing environmental changes, rapid shifts in or destabilization of population dynamics can lead to population collapse, local extirpation or even global extinction of threatened species.…”