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

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 spatialtemporal 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. E Roly Tinline Warner Lake Ecological Observatory Consortium, Queen’s University Biology Station, Department of Biology, Queen’s University Geographic Information Systems Laboratory, Department of Geography, Queen’s University David P. Philipp Warner Lake Ecological Observatory Consortium, Queen’s University Biology Station, Department of Biology, Queen’s University Program in Ecology and Evolutionary Biology, University of Illinois, and Center for Aquatic Ecology and Conservation, Illinois Natural History Survey I N T R O D U C T I O N fforts to conserve and restore both marine and freshwater environments are increasingly focusing on the use of aquatic protected areas (APAs) (Murray et al., 1999; Houde and Roberts, 2004). These protected areas are intended to achieve a diverse array of objectives such as protection of critical habitat, reduction of fishing effort and harvest (i.e., exploitation), and provision of spawning and recruitment refugia (Polunin, 2002; Shipley, 2004). Despite some disparate results, a growing accumulation of research supports the notion that aquatic protected areas are effective strategies for managing and conserving both freshwater (Saunders et al., 2002; Crivelli, 2002) and marine (Mosquera et