Fisheries-Related Mortality and Turtle Excluder Devices (TEDs)
341
A technological solution to separate turtles from shrimps in trawls was available
by the early 1980s. A turtle excluder device (TED) incorporates a trap door in the
trawl, just before the tailbag or codend, to allow sea turtles to escape from the nets
(Seidel and McVea, 1982) (Figure 13.1). Shrimp pass through the bars or webbing
of the TED into the tailbag. Turtles and large bycatch are blocked by the TED and
exit the opening (Figure 13.2). When installed properly, TEDs reduce turtle mortality
and allow the fishery to continue unimpeded. Some shrimp loss may occur, but this
usually is not significant (Renaud et al., 1993; Robins-Troeger et al., 1995), and the
loss may be offset partially by increased efficiency realized by reduced bycatch.
Decreased bycatch results in a higher quality product for the market and less work
sorting catch (High et al., 1969; Brewer et al., 1998).
FIGURE 13.1 Schematic of a turtle excluder device showing the position of the TED in the
trawl, just before the codend or tailbag. (Figure provided by NOAA Fisheries, Mississippi
Laboratories, Harvesting Systems and Engineering Division.)
FIGURE 13.2 A loggerhead turtle, Caretta caretta , exiting a bottom-opening TED during
TED trials in the eastern Gulf of Mexico. (Photo provided by NOAA Fisheries, Mississippi
Laboratories, Harvesting Systems and Engineering Division.)
1123 book.book Page 341 Thursday, November 14, 2002 11:50 AM
341
A technological solution to separate turtles from shrimps in trawls was available
by the early 1980s. A turtle excluder device (TED) incorporates a trap door in the
trawl, just before the tailbag or codend, to allow sea turtles to escape from the nets
(Seidel and McVea, 1982) (Figure 13.1). Shrimp pass through the bars or webbing
of the TED into the tailbag. Turtles and large bycatch are blocked by the TED and
exit the opening (Figure 13.2). When installed properly, TEDs reduce turtle mortality
and allow the fishery to continue unimpeded. Some shrimp loss may occur, but this
usually is not significant (Renaud et al., 1993; Robins-Troeger et al., 1995), and the
loss may be offset partially by increased efficiency realized by reduced bycatch.
Decreased bycatch results in a higher quality product for the market and less work
sorting catch (High et al., 1969; Brewer et al., 1998).
FIGURE 13.1 Schematic of a turtle excluder device showing the position of the TED in the
trawl, just before the codend or tailbag. (Figure provided by NOAA Fisheries, Mississippi
Laboratories, Harvesting Systems and Engineering Division.)
FIGURE 13.2 A loggerhead turtle, Caretta caretta , exiting a bottom-opening TED during
TED trials in the eastern Gulf of Mexico. (Photo provided by NOAA Fisheries, Mississippi
Laboratories, Harvesting Systems and Engineering Division.)
1123 book.book Page 341 Thursday, November 14, 2002 11:50 AM