Hematological assessment of temperature and oxygen stress in a reservoir population of striped bass ( Morone saxatilis)

Abstract

1. 1. Hematological characteristics of a reservoir population of adult striped bass were monitored for 15 months to evaluate their responses to seasonal changes in water temperature and dissolved oxygen concentration. All fish were caught and removed from gill nets within 1 hr. 2. 2. All hematological parameters measured varied significantly with month of capture. In general, red blood cell counts, hematocrits, hemoglobin concentrations, and mean corpuscular hemoglobin values were highest in autumn and winter and lowest in summer. 3. 3. Most hematological parameters measured were significantly correlated with both water temperature and dissolved oxygen concentration at the site of capture. 4. 4. The hematological changes observed in this study suggest that fish were stressed by high water temperatures and low concentrations of dissolved oxygen in summer 1987, and that this stress probably resulted in secondary nutritional problems and extensive mortality.