Data from: A human impact metric for coastal ecosystems with application to seagrass beds in Atlantic Canada

Coastal biogenic habitats are vulnerable to human impacts from both
terrestrial and marine realms. Yet the broad spatial scale used in current
approaches of quantifying anthropogenic stressors is not relevant to the
finer scales affecting most coastal habitats. We developed a standardized
human impact metric that includes five bay-scale and four local-scale (0–1
km) terrestrial and marine-based impacts to quantify the magnitude of
anthropogenic impacts to coastal bays and nearshore biogenic habitats. We
applied this metric to 180 seagrass beds (Zostera marina), an important
biogenic habitat prioritized for marine protection, in 52 bays across
Atlantic Canada. The results show that seagrass beds and coastal bays
exist across a wide human impact gradient and provide insight into which
are the most and least affected by human threats. Generally, land
alteration, nutrient loading, and shellfish aquaculture were higher in the
Gulf of St. Lawrence, whereas invasive species and fishing activities were
higher along the Atlantic coast. Sixty-four percent of bays were at risk
of seagrass decline from nitrogen loading. We also found high within-bay
variation in impact intensity, emphasizing the necessity of quantifying
impacts at multiple spatial scales. We discuss implications for management
and conservation planning, and application to other coastal habitats in
Canada and beyond.