A scalable acoustic system for ropeless fishing applications

An increasingly urgent need in underwater acoustics is a low-cost, easy to deploy solution to fishing without vertical lines in the ocean. We are working with the Lobster Foundation of Massachusetts as a part of a National Fish and Wildlife Foundation (NFWF) project “Grappling with Technology” to demonstrate a one-way travel ultra-short baseline (USBL) approach to low-cost pingers on lobster traps. We present the pinger technology developed as a part of this program, as well as the AcLocalize, a USBL with automatic multi-contact tracking for collaborative and non-collaborativetargets. Due to the limited processing power and cost constraints of embedded systems, and the need for robust, predictable performance in consumer-facing applications, the selected approach uses a layered architecture consisting of well-understood methods at each individual stage. These layers can then be instantiated systematically to accommodate an increasing number of contacts, up to a performance limit driven by the computational power available on the embedded system, and by the choice of array geometry. Results from simulations and early field tests will be presented, with a focus on the use of multi-contact tracking in ropeless fishing operations, as an alternative to using surface buoys known to cause whale entanglement.