Holocene Foraminiferal Distribution Patterns on the Shelf and Slope, Yakataga - Yakutat Area Northern Gulf of Alaska

Faunal trends in Gulf of Alaska, Holocene, benthic foraminiferal populations define seven faunal assemblages related to bathymetric zones and substrate types. The data base consists of 112 stained samples from transect stations across the shelf and slope between Cape Yakataga and Yakutat, Alaska, and from within Yakutat Sea Valley and Yakutat Bay. Samples were recovered from water depths between 15 and 1372 meters. Three littoral and three bathyal faunal assemblages are recognized. A seventh faunal assemblage is restricted to shelly gravelly mud on submarine banks and shelf edge relict sediment areas. Where data is adequate for depth zonation on live populations, zones determined on live and live-plus-dead populations are approximately the same. The Yakataga-Yakutat shelf/slope area, bathymetric faunal assemblages correspond in depth to bathymetric faunal assemblages from other areas of the Northeast Pacific margin: the only marked difference is a deeper boundary between the inner and middle sublittoral zones at about 50 m, which corresponds with the deeper sand-mud transition on the Gulf of Alaska shelf. The fauna from Yakutat Sea Valley, a glaciated trough with a floor 100-150 m below the shelf, represents a salient of outer sublittoral and upper bathyal faunas into the shelf.