Comparisons of Cove Rotenone and Electrofishing Catch-Depletion Estimates to Determine Abundance of Age-0 Largemouth Bass in Unvegetated and Vegetated Areas
作者:
StevenJ. Rider,
MichaelJ. Maceina,
DonnyR. Lowery,
期刊:
Journal of Freshwater Ecology
(Taylor Available online 1994)
卷期:
Volume 9,
issue 1
页码: 19-27
ISSN:0270-5060
年代: 1994
DOI:10.1080/02705060.1994.9664423
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
We compared cove rotenone sampling and Leslie catch-depletion estimates of age-0 largemouth bass (Micropterus salmoides) abundance in vegetated and unvegetated areas of Lake Guntersville, Alabama, in July—August 1992. With the Leslie catch-depletion method, bass abundance was estimated in 0.05 to 0.32-hectare areas enclosed with a block net. A 4.3-meter direct-current electrofishing boat was able to completely fish each enclosure with five to seven consecutive sampling runs and constant effort. Size-selectivity was not evident as no significant correlations existed between mean length and mean weight at capture for each sampling interval. In addition, catchability remained constant over time. In a cove that contained Eurasian watermilfoil (Myriophyllum spicatum), we estimated 1,088 age-0 largemouth bass/hectare from the two electrofishing catch-depletion samples compared to 1,386 bass/hectare by subsequent rotenone sampling. Cove rotenone density and biomass estimates in four unvegetated coves (1.2-hectare each) averaged 86 age-0 largemouth bass/hectare and 0.52 kg/hectare and were not significantly different from electrofishing catch-depletion density and biomass estimates which averaged 104 bass/hectare and 0.78 kg/hectare. This method appears to be a reliable and less costly method than cove rotenone sampling to estimate abundance of age-0 largemouth bass.
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