In EffetsCumulatifsNavigation/ceanav: Research compendium for project on the assessment cumulative effects of marine vessel activities in the St. Lawrence

Cumulative exposure {#cumexpresult}

The method used to obtain the following results is presented in section \@ref(cumexpmethod) of the report.

As a reminder, the spatial distribution of cumulative exposure is entirely constrained by the areas of overlap between environmental stressors and valued components, i.e. stressors and valued components must occur within the same environments to obtain a cumulative exposure value. The cumulative exposure assessment shows that valued components are exposed to stressors throughout the study area (Figures \@ref(fig:cumExp) and \@ref(fig:cumExpNorm)). However, some environments appear to be particularly exposed to stressors. In the fluvial sector, the Quebec City area and the southern part of Île d’Orléans, as well as the shipping channel between Trois-Rivières and Montreal, including Lake St. Pierre, are especially exposed to stressors. In the marine sector, the area most exposed to stressors is the mouth of the Saguenay River within the Saguenay-St. Lawrence Marine Park, particularly on the north shore of the St. Lawrence River up to the portion of the Saguenay that covers the crossing between Tadoussac and Baie-Sainte-Catherine.

High-exposure environments are characterized by a significant diversity of valued components (Figure \@ref(fig:cvCum)) and environmental stressors (Figure \@ref(fig:stCum)). For example, the Sorel-Tracy region, which extends into Lake St. Pierre, has several habitat types, areas of interest, and erosion-sensitive environments (Figure \@ref(fig:cvPanel)); this same region is also characterized by a significant presence of commercial shipping, commercial fisheries, anchorage sites, accidental spills, shipwreck sites, annual dredging operations, and a greater risk of marine pollution (Figure \@ref(fig:cvPanel)). Similarly, the mouth of the Saguenay River is characterized primarily by high shipping pressure (Figure \@ref(fig:stPanel)) that overlaps with a significant diversity of marine mammals (Figure \@ref(fig:cvPanel)); in addition, there are several habitats and sites of importance, as well as more ad hoc stressors such as spills, anchorage sites, and commercial fishing (Figures \@ref(fig:stPanel) and \@ref(fig:cvPanel)).

knitr::include_graphics("./figures/figures-output/cumulative_exposure.png")

knitr::include_graphics("./figures/figures-output/cumulative_exposure_norm.png")

knitr::include_graphics("./figures/figures-output/cumulative_exposure_panel.png")

EffetsCumulatifsNavigation/ceanav documentation built on April 17, 2023, 1:02 p.m.