Electrified Benthic Otter Trawl

Description

Electrified Benthic Otter Trawl example
Image Details

Electrifying trawls, especially benthic Otter Trawls, to improve catch rates in rivers has been under development at least since the late 1960’s to early 1970’s. Literature exists showing improvement compared to non-electrified trawls, lately in Pennsylvania. This is a brief overview of electrical otter trawls, limited to ongoing work in Pennsylvania (Pennsylvania Fish & Boat Commission, Pennsylvania State University). There are no instructional videos. 

For associated information, reference the Introduction to Trawls module.

TypeActive, hybrid system or electrified nets
Habitat deployedSmall to large rivers, backwaters, flooded tributaries, and lakes.
Target speciesMany different species and smaller life stages.  Small to intermediate-sized fishes include darters, minnows and shiners (Cyprinidae), Gar (Lepisosteidae), Suckers (Catostomidae), Sunfish and Black basses (Centrarchidae), Shads (Clupeidae), Common carp (Cyprinus carpio)

Example Electrified Otter Trawl Structure

Example Electrified Otter Trawl Structure
Image Details

This is an electrified benthic Otter trawl. In particular, the Otter trawl is called a “Missouri Trawl” since it has two layers of netting, a larger mesh internal netting and a smaller-sized mesh external netting. The trawl is powered by electrofishing equipment onboard the boat.

Field Methods

The electrified Otter trawl is being deployed off the bow
Image Details

The electrified benthic Otter trawl (“Missouri Trawl”) depicted above is being bow trawled in this picture (see Introduction to Trawls module). Trawling is manual but could be mechanized (see Push Trawl and Benthic Trawl modules).

The electrified Otter trawl is being deployed off the bow. The Otter boards are visible as are the trawl mouth, netting, and floats on the headrope.

Literature

Freedman, J.A., T.D. Stecko, B.D. Lorson, and J.R. Stauffer, Jr. 2009. Development and Efficacy of an Electrified Benthic Trawl for Sampling Large-River Fish Assemblages. North American Journal of Fisheries Management 29:1001–1005.

Herzog, D.P., V.A. Barko, J.S. Scheibe, R.A. Hrabik, and D.E. Ostendorf. 2005. Efficacy of a Benthic Trawl for Sampling Small-Bodied Fishes in Large River Systems. North American Journal of Fisheries Management 25:594–603.