The Chesapeake Bay Program’s target species listed in Habitat Requirements for Chesapeake Bay Living Resources, Second Edition (1991) which had habitat requirements that could be directly affected by nutrient over enrichment (e.g., dissolved oxygen) or sediments (e.g., light penetration) were arrayed by water column and bottom as their principal habitats. These included all the fish and shellfish species in that document, with several fish species and related layers added for newer potential habitat information was available. Priority areas for Submerged Aquatic Vegetation (SAV) were considered separately. Priority Living Resource Areas were identified based on the co-occurrence of habitats for multiple water column and bottom species.