by Catherine Schmitt May 16, 2014, Endangered Species Day. I went to the Piscataquis River, a major tributary of the Penobscot River, to monitor Atlantic salmon (Salmo salar) smolts with state and federal fish biologists. Shadbush and trout lilies bloomed along the stream banks. People sold fiddleheads from the trunks of their cars. Nearly 70 read more Counting smolts in May: a story of Atlantic salmon survival.