Sea Turtle Bycatch Reduction in Trawl Fisheries: Summer Flounder Trawls
Feedback is needed on the following modifications under consideration for summer flounder trawl gear.
Current TED Requirements
TEDs are currently required off Virginia and North Carolina in the Summer Flounder Fishery-Sea Turtle Protection Area (50 CFR 223.206(d)(2)(iii)). The Flounder TED and Modified Flounder TED are currently allowed in the fishery (50 CFR 223.207).
Image from Salerno and Eayrs 2010
Catch Retention Testing
- Tested 32 by 51 inch grid with smaller top escape opening
- Target catch: 35% loss, but no difference in the size distribution of retained summer flounder
- Other non-target catch: No statistically significant difference
- Other bycatch: 36% reduction in total unwanted fish bycatch
- Tested 32 by 51 inch grid with large top escape opening
- Target catch: Non-statistically significant 17% increase
- Tested 43⅜ by 51 inch grid with large top escape opening
- Target catch: Non-statistically significant 13% loss
- Other bycatch: 34% loss (of all species, but dominated by skate)
Catch Retention Testing
- Target catch:
- No statistically significant difference in catch rates between modified flounder TED (with 6-inch bar spacing, small escape opening) and flounder TED (with small escape opening)
- No statistically significant difference in catch rates between modified flounder TED (with large escape opening) and large flounder TED (with large escape opening), but modified flounder TED marginally improved catch retention
- Other bycatch: No statistically significant difference in bycatch between modified flounder TED and large flounder TED with large escape opening, but modified flounder TED marginally decreased bycatch levels
Trawl tow durations of less than one hour are expected to result in low turtle mortality. Tow duration data loggers measure the amount of time the net is in the water beyond a certain depth. The logger, which is attached to the trawl door, is ruggedized to withstand marine conditions and handling on deck. The data logger indicates when tow durations have been exceeded, allowing for monitoring and enforcement.
Data loggers were found to reliably record and monitor limited tow durations and withstood fishing conditions. We are continuing to test the latest technology to ensure that the monitoring and enforcement of limited tow durations is feasible.
- Catch efficiency of the NMFS certified, standard TED required in the Mid-Atlantic summer flounder fishery
- Evaluation of large escape opening in Flounder TED
- Catch retention using a larger TED and opening in the summer flounder trawl fishery
- Comparison of Flounder TED and Modified TED in the summer flounder fishery
- Comparison of large Flounder TED and Modified TED in the summer flounder fishery
- Development and testing of a tow time data logger to monitor and enforce tow time restrictions in trawl fisheries
Modifications Under Consideration
- Extending the existing TED requirement (using any NMFS-approved TED) northward, given that the current summer flounder TED requirements do not cover the area in which sea turtles and fishing effort co-occur.
- Larger escape opening in all TEDs in this fishery to allow larger sea turtles to escape.
- Limited tow times with data loggers, if feasible and enforceable, as an alternative to the TED requirement to provide flexibility to the fishery.