Introducing shadia

Introducing shadia: contributed by Dan Stich

Posted 9-12-18: Introducing shadia the first R package for modeling American shad populations! The new R package allows users to run dam passage performance standards models for American shad in northeast Atlantic Coastal Rivers (Connecticut, Merrimack, Penobscot, and Susquehanna rivers currently). The models combine classical cohort-based projection models for annual vital rates with an individual-based migration model using a recently published approach. Users can specify upstream and downstream passage effectiveness, and timeliness of passage, at dams to predict population responses to different management strategies, fishery harvest rates and more, all over a user-specified time-frame. New features, updates, and patches are released regularly based largely on fishery management needs. The most recent version, including installation instructions, is always available on GitHub: Don’t see your favorite river yet? Notice an area for improvement? Send us a request at [email protected] or submit an issue on our GitHub page. Collaborations, corrections, and helpful suggestions are welcome! Coming soon: incorporation of climate change scenarios in phenological and growth submodels.

Stich, D. S., E. Gilligan, and J. M. Sperhac. 2018. shadia: American shad dam passage performance standard model for R. v 1.3.0. Available at: