Document Type

Report

Department/Program

Virginia Institute of Marine Science

VIMS Department/Program

Marine Advisory Program (MAP)

Publication Date

1-1-2019

Series

Fishery Resource Grant FRG 2018-01

Abstract

The Chesapeake Bay is currently inundated with invasive blue catfish (BCF) which are a serious threat to the ecosystem balance ofthe watershed.The only reasonableway to reduce BCF numbers and biomass is by utilizing new and improving traditional BCF commercial fisheriestechniqueswith emphasis on removing small BCF. In the Mississippi region pots set in a vertically orientation are easier to fish and outperform pots set horizontally. The purpose of this project was to see how pots set in two vertical orientationswould perform compared to thetraditional horizontal orientation. During the project 7275lbs of nonnative catfish were harvested, 3088in vertical pots and 4187lbs in the horizontal pots.A permutation analysis (10,000 iterations) showed no significant difference between pots suspended from a float (mean = 4.1lbs) compared topots in the traditional horizontal orientation (mean 4.4lbs). There was a significant difference between vertical pots attached to the bottom with an anchor (mean = 15.6lbs) when compared to partnered horizontal pots (mean = 22.6lbs). A nonparametric Wilcoxon Ranked sum test concluded there was no significant difference (p=0.327) between the suspended vertical pot and paired horizontal pots but there was a significant difference (p=2.88e-09) between the vertical pots attached to the bottom and horizontal pots. Many external factors influenced this project includinggearloss (likely due to theft), extremely high water flows throughout the year due to heavy rains and using pots with mesh so large that small BCF could escape. Pots suspended from floats are the easiest and quickestto fish but theft makesthe technique impractical in the upper James River. Unfortunately neither of the vertical orientations outperformed their associated horizontal configuration pots so switching techniques would not benefit commercial fishers. We feel we did make some important observations in regards to bait and share ideas on how to improve bait retention which should increase harvest weights.

Keywords

Fishing gear, catfish

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