Primary constituent elements
(3) Primary constituent elements. Within the GOM DPS, the primary constituent elements (PCEs) for the conservation of Atlantic salmon include sites for spawning and incubation, sites for juvenile rearing, and sites for migration. The physical and biological features of the habitat that are essential to the conservation of Atlantic salmon are those features that allow Atlantic salmon to successfully use sites for spawning and rearing and sites for migration. These features include: (i) Deep, oxygenated pools and cover (e.g., boulders, woody debris, vegetation, etc.), near freshwater spawning sites, necessary to support adult migrants during the summer while they await spawning in the fall; (ii) Freshwater spawning sites that contain clean, permeable gravel and cobble substrate with oxygenated water and cool water temperatures to support spawning activity, egg incubation and larval development; (iii) Freshwater spawning and rearing sites with clean gravel in the presence of cool, oxygenated water and diverse substrate to support emergence, territorial development, and feeding activities of Atlantic salmon fry; (iv) Freshwater rearing sites with space to accommodate growth and survival of Atlantic salmon parr, and population densities needed to support sustainable populations; (v) Freshwater rearing sites with a combination of river, stream, and lake habitats, that accommodate parr's ability to occupy many niches and to maximize parr production; (vi) Freshwater rearing sites with cool, oxygenated water to support growth and survival of Atlantic salmon parr; (vii) Freshwater rearing sites with diverse food resources to support growth and survival of Atlantic salmon parr; (viii) Freshwater and estuary migratory sites free from physical and biological barriers that delay or prevent access to spawning grounds needed to support a recovered population; (ix) Freshwater and estuary migration sites with abundant, diverse native fish communities to serve as a protective buffer against predation; (x) Freshwater and estuary migration sites free from physical and biological barriers that delay or prevent emigration of smolts to the marine environment; (xi) Freshwater and estuary migration sites with sufficiently cool water temperatures and water flows that coincide with diurnal cues to stimulate smolt migration; (xii) Freshwater migration sites with water chemistry needed to support sea water adaptation of smolts; and (xiii) Freshwater and marine sites with diverse, abundant assemblages of native fish communities to enhance survivorship as Atlantic salmon smolts emigrating through the estuary. (4) Habitat that meets the definition of critical habitat in occupied habitat areas on Passamaquoddy Tribal Indian lands and Fee lands or lands held in Trust by the Penobscot Indian Reservation within the range of the GOM DPS are excluded from designation. Per request of the Penobscot Tribe, critical habitat does include occupied habitat that makes up the Penobscot Indian Reservation. The Indian lands specifically excluded from critical habitat are those defined in the Secretarial Order 3206, including: (i) Lands held in Trust by the United States for the benefit of any Indian Tribe; (ii) Lands held in trust by the United States for the benefit of any Indian Tribe or individual subject to restrictions by the United States against alienation; (iii) Fee lands, either within or outside the reservation boundaries, owned by the tribal government; and (iv) Fee lands within the reservation boundaries owned by individual Indians.