Patterns in abundance, growth, and mortality of juvenile red drum across estuaries on the Texas Coast with implications for recruitment and stock enhancement

The interannual variation in patterns of abundance, growth, and mortality o f juvenile red drum Sciaenops ocellatus was examined with long-term monitor ing data from nine estuaries along the Texas Gulf Coast during a 20-year pe riod. Estimates of abundance and mortality exhibited order-of-magnitude dif ferences. Growth rates varied two- to threefold across years within each es tuary and across estuaries within a single year. For age-0 juveniles, abund ance was typically highest in late fall, length increased exponentially, an d mortality was generally low. Variation in growth and mortality was not re lated among estuaries, suggesting that the factors affecting the feeding an d survival of young red drum are specific to individual estuarine systems. Estimates of age-0 red drum abundance were characterized by the intermitten t occurrence of strong year-classes and were positively correlated across e stuaries, indicating that factors determining abundance and distribution va ry on a large spatial scale. Correlative evidence suggests that compensator y mech anisms affect the survival of age-0 red drum. Variation in abundance during early juvenile stages was not related to abundance variability in l ater 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 rates of hatchery-reared fingerlings during t he last decade on the abundance of age-0 and age-1 red drum were not detect ed.