GRANT
NUMBER:
NA57FD0033
NMFS NUMBER:
93-SER-004
REPORT
TITLE:
To Introduce New TED Designs to the Southeastern Atlantic
Shrimp Fleet and to Compare their Bycatch Exclusion Rates
and Shrimp Retention Rates with those of Established TED
Designs
AUTHOR:
Vendetti, Richard A.; Overman, Robert G.; Parker, Lindsey
G. and Harrington, David L.
PUBLISH
DATE:
March 1, 1996
AVAILABLE
FROM:
National Marine Fisheries Service, Southeast Region, 9721
Executive Center Drive, North Koger Building, St. Petersburg,
FL 33702. PHONE: (813) 570-5324
ABSTRACT
In response
to increasing numbers of Leatherback turtles on the southeastern
Atlantic shrimp grounds and a similar increase in strandings,
emergency rules were implemented in the spring of 1993.
Because no existing TED could accommodate such large specimens,
the National Marine Fisheries Service (NMFS) allowed modifications
to the TED exit hole that would enable large sea turtles
to escape. Exit hole modifications are critical
to fish reduction and shrimp retention. This project
assesses the shrimp retention and fish exclusion rates
of TEDs modified to exclude Leatherback turtles.
This project also made every attempt to involve the commercial
shrimping industry in the process of developing technological
remedies in TEDs.
Two primary
modifications were tested--one soft TED modification and
one hard TED modification. Catch comparisons were
conducted between nets fitted with standard TEDs (controls)
and modified TEDs (treatments). The two TED types
analyzed were the Morrison TED and the Super-Shooter style
hard TED. Tests were conducted by towing the two
pairs of TEDs simultaneously in side-by-side trawling
with the commercial shrimp fleet. Analyses of initial
tows and subsequent submersible video observations indicated
a possible problem in the soft TEDs; therefore the soft
TEDs were reinstalled in the middle of the project.
Although the
hard TEDs appeared to function properly throughout this
work, a great deal of force was needed to stretch the
webbing sufficient to meet the new escape opening specifications
cited in the Federal Register. Nevertheless,
the tows were conducted over the course of an entire shrimping
season, and the data indicate that a large escape hole
could be an acceptable and commercially viable option.
The predominant species of finfish that make up the vast
majority of finfish weight had reduction rates similar
to those of the standard TEDs. These species include:
the Atlantic menhaden, Atlantic spot, Atlantic croaker,
and southern kingfish. In addition, the soft TED
showed a marked effectiveness at finfish bycatch reduction.
