Embryo Survival and Fry Emergence from Two Methods of Planting Brown Trout Eggs

Abstract

Survival of larval trout through the swim-up stage was determined for eyed eggs of brown trout (Salmo trutta) planted both in the streambed and in Whitlock Vibert boxes. Tests were made in first-, second-, and third-order streams and intragravel environmental factors were evaluated. Direct plants produced 2 times more sac fry than box plants and 3.5 times more swim-up fry. Sediment deposition was approximately 100% greater in first- and second-order streams than in third-order streams, and sediments accumulated disproportionately in box plants. This seemed to accoimt for survival differences between planting techniques and among stream orders.