Fishing pressure

Layer type(s): Pressure

Data description(s):
Spatial fishing data from Watson & Tidd (2018) were used to represent total biomass removed through fishing. The raw data was provided in tabular format and included data on species, gear type, fishing type (industrial/non-industrial) and tons caught (bycatch, landings & discards) per half-degree cell globally for the years 1950 to 2015.

Methods summary
The raw data on global half-degree cells was rasterized and then cropped to our region of interest, the US Northeast, to identify half-degree cells that fall within the region. This subset of cells was used to filter the data specific to our region. Data was further refined to only include catch from 2000 onwards. Both industrial and non-industrial catch (tons) across all catch types (bycatch, landings & discards) was aggregated per cell, divided by ocean area to get tons/km2 and rasterized for each year to create annual total catch rasters for the US Northeast. Each raster was rescaled between 0 and 1 using the 99.9th quantile across the entire region and time series (2000-2015) as our reference point, which was 43 tons/km2. All values greater than this were assigned a value of 1.

Pressure layer
Final pressure scores for each region and year were calculated by taking the average value of all cells within each region.

Gapfilling
They years 2016 and 2017 were gapfilled with 2015 values since the dataset stopped at 2015.

References
Watson, Reg. A., and Tidd, A. (2018). Mapping nearly a century and a half of global marine fishing: 1869–2015. 93, 171–177. doi:https://doi.org/10.1016/j.marpol.2018.04.023.