Catch Rates and Size Structure of Two Ictalurids Sampled with Different Sizes of Hoop Nets

Autor: Jim Milligan, Jeff S. Tillma, Christopher S. Guy
Rok vydání: 1997
Předmět:
Zdroj: Journal of Freshwater Ecology. 12:315-319
ISSN: 2156-6941
0270-5060
DOI: 10.1080/02705060.1997.9663538
Popis: Hoop nets with initial openings of 0.6 m and 0.8 m were set in a Missouri River tributary stream to determine if catch per unit effort (CPUE) and size structure [length (mm)] of channel catfish Ictalurus punctatus and flathead catfish Pylodictus olivaris differed between the two sizes of nets, set baited or unbaited. Catch per unit effort for channel catfish varied from 0 to 12 and was higher in 0.6-m hoop nets independent of bait; however, CPUE was only significantly higher in unbaited 0.6-m hoop nets (P = 0.03). Length of channel catfish captured in unbaited 0.6-m hoop nets was significantly (P = 0.03) lower than in unbaited 0.8-m hoop nets. Similar trends were observed for flathead catfish; however, sample sizes were low and subsequently statistical power (1-β) was < 0.13. Nevertheless, these data indicate that standardizing initial hoop size is important, especially if comparative information is sought.
Databáze: OpenAIRE