Evidence of Successful Spawning and Other Life-History Aspects ofAlosa sapidissima(American Shad) in the Penobscot River and Estuary

Abstract

Abstract Diadromous fish populations in Maine are near historically low levels. In the Penobscot River, ME, annual runs of Alosa sapidissima (American Shad) numbered in the millions prior to a collapse in abundance in the late 19th century. Today, the vast majority of historical American Shad spawning habitat is inaccessible to the fish; thus, there is uncertainty in terms of origin of the few extant American Shad that remain in the Penobscot. We used several types of sampling gear in the lower Penobscot River and Penobscot estuary as part of a community survey that documented the presence of juvenile American Shad throughout the estuary from July through August 2012. Our surveys indicated the presence of premetamorphic American Shad upstream of a salinity barrier, and therefore we conclude that there is a population of American Shad successfully spawning in the Penobscot River. Such evidence of a local stock is vitally important as managers weigh restoration options, such as stocking with donor stocks, e...