Comparison of Electrofishing and Hoopnetting in Lotic Habitats of the Lower Mississippi River

Abstract

We compared catch rates and sampling costs of two types of hoop nets (61 cm and 122 cm diameter) and two types of pulsed DC electrofishing (500 V/60 Hz and 1,000 V/15 Hz) in lotic habitats in main and secondary channels of the lower Mississippi River. Forty fish species were collected in 474 hoop-net-nights and 320 electrofishing samples (5 min each). Two species were collected only by hoop nets, whereas 19 species were collected only by electrofishing. Using field personnel time as the unit of effort, electrofishing catch per unit of effort for most species was higher and less variable than for hoop nets. Electrofishing collected wider length ranges of fish and cost less per fish collected than did hoopnetting. Compared to hoopnetting, we found low frequency (15 Hz) and high frequency (60 Hz) pulsed DC electrofishing was an effective method for assessment of fishes in lotic habitats in the lower Mississippi River.