Some of the most powerful technological tools in fisheries biology open up the underwater world by making the invisible visible. While visually observing fish is possible in clear and shallow water, conducting surveys in deep or turbid environments, or at night, presents a greater challenge. The Adaptive Resolution Imaging Sonar (ARIS) and Dual-frequency Identification Sonar (DIDSON) cameras developed by Sound Metrics address this challenge by transmitting and receiving sound pulses that allow them to “see” underwater. These sound pulses bounce off of underwater animals or objects and are converted into high-resolution digital images, similar to a medical ultrasound.
This technology allows for real-time counts and observations of fish in their natural habitat without the need for visible light, and also provides quantifiable data on fish length, depth, and distance from the camera. With the ability to capture details as small as a few millimeters, and view targets at a range of up to 40 meters, the ARIS can be deployed to survey fish and their habitats in a variety of settings. FISHBIO has used ARIS and DIDSON cameras to monitor restored wetlands and mitigated river levees, estimate adult salmonid escapement, and observe fish behavior in relation to changes in hydroelectric facility operations. We have also paired the ARIS with traditional video recording systems and fish sampling methods (such as seining or boat electrofishing) to collect complementary data or investigate how fish may avoid other types of sampling gear.
As part of this work, our FABLAB has constructed a number of customized ARIS and DIDSON mounting and positioning systems that control the depth, pan, tilt, and roll of the camera, whether mounted on shore or on a boat. This combination of tools provides the versatility to effectively acquire data in many settings where other types of methods may be limited. Contact us to explore how the ARIS can be applied to address your project needs.