16  Apps

The MST provides two primary interactive web applications for exploring sensitivity data, plus several legacy applications from earlier development phases.

These tools allow stakeholders, scientists, and decision-makers to understand the underlying components contributing to an area’s sensitivity to offshore energy development, supporting better planning and impact assessment.

16.1 Current Applications

16.1.1 Scores — mapper of aggregate sensitivity scores

The Scores application is the primary tool for exploring composite sensitivity scores across BOEM Program Areas. Key features include:

  • Multi-resolution viewing: toggle between cell-level (0.05° grid) and Program Area aggregations
  • Study area selection: focus on specific Program Areas or subregions
  • Layer selection: view individual species category scores or composite metrics
  • Flower plot: interactive summary showing scores by species category with weighted center value
  • Species table: sortable table of species present in selected area with extinction risk details
  • Treemap: hierarchical view of species contributions to sensitivity
  • CSV export: download data for selected area or species

Under the hood, the Scores app composes three types of map layers — all driven from the same DuckDB source of truth (Figure 10.1):

  • Cell-values raster — on-the-fly PNG tiles from the msens TiTiler factory. The Shiny server builds the SELECT via cell_sql(metric_key, subregion_key), fetches the stats for a stable legend via msens::cell_stats(), and passes the tile URL template to msens::add_cell_tiles(). The browser fetches only the tiles intersecting its current viewport; Varnish caches each tile for 7 days. No ∼4 GB full-raster transfer on initial load (see Figure 10.2).
  • “Cells outside Program Areas” mask — same factory, single-color color=#222222 render path, with a SQL returning cell_metric cells not in any zone row where fld='programarea_key'.
  • Program Area choropleth — when the user switches unit to Program Area, polygon geometry comes from a static PMTiles file served by Caddy; per-area fill colors come live from DuckDB’s zone_metric table via a mapbox-gl match expression pushed through the Shiny proxy (see Figure 10.4).

See Appendix: scores for details.

16.1.2 Species — mapper of individual species distributions

The Species application enables exploration of individual species distribution models. Key features include:

  • Species selection: search by common or scientific name, filter by species category
  • Model display: view merged models or individual source dataset layers
  • IUCN masking toggle: compare masked vs. unmasked distributions
  • Species info panel: ESA listing, IUCN Red List category, MMPA/MBTA protection flags, extinction risk score
  • Deep-linking: URL parameters support direct links to specific species

See Appendix: species for details.

16.2 Legacy Applications

Earlier versions of the MST included several prototype applications developed during the research phase. These are documented in the Appendix under Applications (Legacy) for reference.