Propagation of American shad in Pennsylvania: Techniques and applications

Culture of American shad (Alosa sapidissima) for restoration efforts in Pennsylvania began in 1976 with the construction of the Van Dyke Research Station for Anadromous Fishes.  This facility is capable of propagating 20 million American shad and 20 million hickory shad (A.mediocris) larvae annually.  Egg sources currently include tank spawning of Susquehanna River shad (American and hickory) and strip spawning of American shad on the Potomac and Delaware rivers.  Fertilized eggs are processed and introduced into incubation jars within 12h of collection.  Hatching occurs within 5-7d (at 16^oC) into large circular rearing tanks (6L/min flow at 18^oC).  Egg viability of all combined egg sources (1976-2009) ranges between 25.2% and 68.3% (averaging 47.6%). Larval shad are fed a diet of live Artemia nauplii and dry feed from 3-5d of age until stocked (up to 40d).  Since 1985, all shad reared at Van Dyke receive otolith marks via tetracycline antibiotic immersion.  Stocking occurs throughout the Susquehanna Basin, and in the Lehigh and Schuylkill Rivers, with replenishment fry going to the Potomac and Delaware rivers.  Survival (larvae stocked/viable eggs) averages 64%, ranging from 19% to 94%.  To date, nearly 255 million American shad larvae have been stocked from the Van Dyke hatchery.