Linking Movement and Management
iTAG is committed to facilitating the integration of data and disparate expertise to improve our understanding of the causes and consequences of movement to management and conservation. Given that acoustic tracking is the primary method of tracking animals which remain submerged, the initial focus of iTAG has been primarily on fish and how movement can improve our understanding of fisheries science and management. Although movement has always played an important role in fisheries science, movement patterns are changing with changing ocean conditions affecting availability to capture, the spatial scale of needed governance, and our food supply. Because movement determines where a fish is in space and time it affects all levels of fisheries management, from traditional single species stock assessments to ecosystem-based approaches (Lowerre-Barbieri et al., 2019).
As fish change their distributions they may no longer be effectively sampled by surveys designed to sample their prior high-use habitat affecting our ability to estimate abundance. Tracking data is also one of the few ways to assess mortality and help decrease by-catch (Hazen et al., 2018) and discard mortality and improve spatial management. This data is also critical to understand ecosystem service transfers and biodiversity hotspots.
iTAG’s Orphan Exchange
The orphan data exchange is a platform that allows array owners to upload tag numbers which were detected in their arrays but do not belong to animals they had tagged. The uploaded “orphan” tag numbers can be viewed by other iTag members, and if a member finds any of their own tagged animals amongst the orphan tags, they “adopt” these and the array owner shares the detection data. This “connects the dots” in terms of movement but also connects these scientists, building opportunities for collaboration.
Fish image credits: Diane Peebles, NOAA, Pencil Sessions, Marc Dando, King Sailfish Mounts, Fishwatch.gov, Oregon Coast Aquarium
The image below shows the number of tags, by species, that have been adopted through iTAG.
Linkages
For bio-logging data to inform management in the next decade, we need to develop scientific platforms that synthesize or increase the scale of tracking data, as well as bring together ecologists and assessment scientists. Obtaining movement data for animals at the Large Marine Ecosystem scale that can inform population models is challenging due to technological limitations and cost of doing so. Current efforts to solve this issue include the synthesis of tracks from archival tags across studies or building acoustic telemetry networks to share data across receiver arrays. There are also many efforts underway to consolidate movement data on large marine megafauna, link movement across marine, terrestrial, and aerial realms, and train researchers novel methods for analyzing movement data.
Movement determines encounter rates affecting:
mortality, reproductive success, catch per unit effort, and by-catch and ecosystem services
This concept is driving new models of management, such as dynamic ocean management, defined as the use of near real-time biological, oceanographic, social and/or economic data for management occurring at shorter spatio-temporal scales—more in sync with the resources being managed (Lewison et al., 2015).
An example of using tracking data to help move toward dynamic ocean management is Hazen et al., 2018 who develop integrated species-specific probabilities of occurrence for a target species and three high-probability by-catch species. They then use this to develop a single predictive surface, weighing the contribution of each species by management concern. Their results suggest that movement data can be used to develop much smaller dynamic closure areas while still providing needed protection to endangered non-target species.