Patterns in Abundance, Growth, and Mortality of Juvenile Red Drum across Estuaries on the Texas Coast with Implications for

• Main Authors: Stock Enhancement, Frederick S. Scharf
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Red drum; Sciaenops ocellatus
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.525.1041; http://people.uncw.edu/scharff/publications/2000 TAFS (Scharf).pdf

Abstract.—The interannual variation in patterns of abundance, growth, and mortality of juvenile red drum Sciaenops ocellatus was examined with long-term monitoring data from nine estuaries along the Texas Gulf Coast during a 20-year period. Estimates of abundance and mortality exhibited order-of-magnitude differences. Growth rates varied two- to threefold across years within each estuary and across estuaries within a single year. For age-0 juveniles, abundance was typically highest in late fall, length increased exponentially, and mortality was generally low. Variation in growth and mortality was not related among estuaries, suggesting that the factors affecting the feeding and survival of young red drum are specific to individual estuarine systems. Estimates of age-0 red drum abundance were characterized by the intermittent occurrence of strong year-classes and were positively correlated across estuaries, indicating that factors determining abundance and distribution vary on a large spatial scale. Correlative evidence suggests that compensatory mech-anisms affect the survival of age-0 red drum. Variation in abundance during early juvenile stages was not related to abundance variability in later juvenile stages and was significantly reduced by the end of the first year of life, indicating that processes occurring during the juvenile stage may be important in regulating the year-class strength of red drum. Clear effects of increased stocking