We used longline fishing to determine the effects of distance from the ocean, season, and short‐term variation in abiotic conditions on the abundance of juvenile bull sharks ( Carcharhinus leucas ) in an estuary of the Florida Everglades, U.S.A. Logistic regression revealed that young‐of‐the‐year sharks were concentrated at a protected site 20 km upstream and were present in greater abundance when dissolved oxygen (DO) levels...