Lobster Trap Acoustic Recorders for Broadscale Right Whale Detection

The risk of critically endangered North Atlantic Right Whales becoming entangled in lobster trap gear in the Gulf of Maine is an ongoing concern. The high cost of commercial monitoring equipment combined with unreliable fisheries data has left much of the area of concern for right whales in the Gulf of Maine unmonitored. A low-cost monitoring device that can be attached to lobster traps and be used collaboratively with the lobster industry for deployment, is the subject of this research. The data collected from this device could be used to keep track of whale populations and migration patterns to ascertain locations where lobstering does not interfere with the whale population and take preventive measures only where necessary. The acoustic recorder consists of a hydrophone, amplifier, analog filter, data storage, Wi-Fi, and a microcontroller, all housed in a waterproof case. This sensor would detect the acoustic waves sent out in whale calls as well as any other present underwater sounds. Analyzing the patterns and frequency of the data collected could determine if any whales were detected within the range of the acoustic recorder as well as their species. Prototype units were constructed and deployed up to a depth of 150’ in Frenchman’s Bay for a 24-hour period, along with a commercial underwater acoustic recorder. An underwater speaker was used to generate test signals which were detected by the recorders demonstrating that the sensors had a comparable response to the commercial unit, with a detection range up 2 kilometers. Newer models have been tested in a saltwater tank to have detection capabilities of over 10 km displaying detection ranges only 17% lower than the tested commercial unit. The designed acoustic recorders cost 97% less than comparable commercial devices providing a low-cost alternative with similar capabilities.