| Popis: |
Tow time restrictions have been discussed as a potential alternative for sea turtle conservation in fisheries where Turtle Excluder Devices (TEDs) are known to reduce the targeted catch. Although the length of time a turtle can remain submerged in a trawl is still being evaluated, tows less than 1 hour are expected to result in a negligible number of sea turtle mortalities. Discussion about the feasibility of tow time restrictions often results in concerns about the feasibility of monitoring and compliance with any limit on tow times. The Protected Species Branch of the National Marine Fisheries Service (NMFS)'s Northeast Fisheries Science Center (NEFSC) solicited a contractor to develop and construct a robust, simple, and inexpensive data logger that can be used to enforce tow time restrictions on commercial bottom trawl fishing vessels. These loggers, which are attached to the trawl net or the trawl doors, record the time the units are below a predetermined depth and have a signal (light) alarm to indicate when the time limit has been exceeded. Additionally, the units have a battery life of approximately 4 years and can store up to 4 months' worth of data with the option to overwrite the oldest memory. The units were tested for their ability to reliably record trawl fishing tow duration and detect when a tow has exceeded a time threshold. The loggers have been tested on 9 different vessels fishing for 7 different target species and have held up to the abuses of the salt environment and the shock and vibration of commercial fishing practices. Additionally, because these loggers are programmable, they may have applications in other fisheries where there is a need to monitor, record, or enforce soak durations. |
