Use of CDMA Acoustic Telemetry to Document 3-D Positions of Fish: Relevance to the Design and Monitoring of Aquatic Protected Areas

Abstract

Knowledge of animal spatial ecology is essential for the design and siting of proposed aquatic protected areas (APAs), as well as the assessment and monitoring of existing ones. Acoustic telemetry is one of the primary tools for the assessment of animal movements in aquatic systems through either manual tracking or the establishment of fixed receiving stations. Recent technological developments in code division multiple access (CDMA) acoustic telemetry now enable the simultaneous real-time monitoring of numerous individual fish at fine time scales providing APA researchers with a robust new tool. Fish can be positioned in three-dimensions with sub-meter accuracy in both deep and shallow waters. Here, we describe a whole-lake environmental observatory that includes a 13-hydrophone acoustic telemetry array that has been used to monitor the position of 22 tagged fish at 15 sec intervals. Although we use a freshwater fish and environment as a case study, this telemetry system is equally useful for marine environments including under-ice. We evaluate the applicability of CDMA MAP technology to address pressing questions in applied APA research. The CDMA MAP system provides the flexibility to collect information at multiple spatial-temporal scales, responding to the varied levels of detail and precision required for different applications in APA research. When combined with the suite of other telemetry and monitoring approaches available, CDMA MAP technology will enable researchers to document the spatial ecology essential for improving APA science. Furthermore, because numerous animals from different trophic levels can be tracked in real time, CDMA MAP technology will also aid in our understanding of complex community-level dynamics consistent with the shift towards ecosystem-based APA management.

Long-term effects of surgically implanted telemetry tags on the nutritional physiology and condition of wild freshwater fish

“…The study was conducted in a small freshwater research lake in eastern Ontario, Canada, that is equipped with a whole-lake acoustic telemetry array (Cooke et al 2005a, Hasler et al 2007, Hanson et al 2007a Hanson & Cooke in press). We used these sensitive physiological indicators based on the premise that if the devices or the surgical procedure were causing stress, disease/infection, or reductions in feeding or digestive function over the long term, we would be able to detect a significant difference relative to size-and temporally-matched controls.…”

Heat transfer in fish: are short excursions between habitats a thermoregulatory behaviour to exploit resources in an unfavourable thermal environment?

“…5-15 s intervals; Cooke et al, 2005;Brewitt and Danner, 2014). Furthermore, advances in technology continue to reduce the size and mass of temperature-sensitive tags, which allows study of the thermal ecology of a wide range of fish species and sizes (applying the 2% rule of thumb for tag/fish mass ratio; Mellas and Haynes, 1985;Bridger and Booth, 2003;Cooke et al, 2004).…”

Montage: Combine frames with movement continuity for realtime multi-user tracking

“…[3] proposes a FDMA based solution to estimate the number of mobile devices present in an area, however when users are moving, the FDMA methods may fail due to the Doppler effect. Many work,like [16] and [8] , propose CDMA based systems using a high frequency acoustic signal and a hydrophone array to enable simultaneous submeter tracking of multiple targets. [1] proposes an ultrasonic multicode despreader allowing simultaneous acoustic ranging in real time by embedded sensors.…”

“…The acoustic based methods on commercial mobile handset address the issue of meter-level pair-wise ranging, e.g., [18], [19]. Some other solutions use code division multiple access (CDMA) acoustic telemetry to simultaneously monitor the movements of numerous individual users, e.g., [1], [8], [16]. Those schemes, however, require either accurate synchronization or a synchronized hydrophone array which is quite difficult to be implemented on commercial phones.…”