BAFFLE USAGE IN COVERED RACEWAYS

摘要

Baffle usage was examined during culture of rainbow trout Oncorhynchus mykiss in covered raceways at McNenny State Fish Hatchery, Spearfish, South Dakota. Baffles had no noticeable impact on fish growth, feed conversion, or mortality. However, rainbow trout reared in baffled raceways had greater pectoral and pelvic fin erosion than fish raised in unbaffled systems. Dorsal fins, though apparently unaffected by baffles, decreased in proportionate length after just 46 d of rearing. Outflows of total suspended solids were similar in baffled and unbaffled raceways. Baffles are effective tools to move fish waste, maintain raceway cleanliness, and help hatcheries meet pollutant outflow regulations. However, the decrease in fish quality, as measured by fin erosion, should be considered before baffles are used.