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Development of 'Business Card' Tags: Inter-individual Data Transfer

Progress Reports (PDF): FY 2010, FY 2009, FY 2008, FY 2007

OBJECTIVES
The overall objective of the project is to assess the feasibility of a two-way receiver tag (called 'business card' tag), through:

(1) The development of a two-way 'receiver tag' prototype. The receiver tag prototype should be able to identify and store acoustic signals sent by other acoustic tags. The receiver tag should be small enough to be mounted on/in tunas or similar sized animals

(2) Tests of these prototype tags. The prototype tags wil be tested on captive fish (controlled situation) and in situ.

BACKGROUND
One of the main priorities when studying the behavioral ecology of fish is to determine how long they stay in particular places, how long they stay with conspecific schooling companions and how long they interact with other species. In the case of tropical tunas, one key 'location' is fish aggregating devices (FADs) and much is still to be learned about the biology and dynamics of this particular associative phenomenon (Fréon & Dagorn 2000 ; Castro et al 2002 ; Dempster & Taquet 2005).

Currently available sensors used in electronic tags can provide information on the position of a fish (including depth) and information on internal and external temperature. However, there is no way of collecting data about other aspects of the fish's environment such as whether it is near a FAD or swimming with other conspecifics or other fishes. Such information is crucial for interpreting the movements and behavior of fish (Dagorn et al. 2001). Fisheries managers need such information to develop appropriate management regimes.

Based on experiences with using individually coded acoustic tags to monitor the movements of tuna within a FAD array (Dagorn et al., submitted to Marine Biology) and with 'CHAT' tags that are implanted in sharks and use two-way "acoustic modems" to download data through the water column to anchored data loggers (Holland et al., 2001), project researchers propose to use small acoustic tags to permit two-way communication between adjacent fishes and between fishes and acoustic beacons affixed to points of interest (e.g., FADs).

Basically, each transmitter/receiver unit would be small enough to implant in fish and be capable of detecting and archiving the identity of the other tags and the time at which the signal was detected and stored. Although this first generation of two-way acoustic tags will only work underwater, researchers see this development as a first step towards the creation of hybrid acoustic/radio tags that could allow fishes and air breathing animals such as turtles, seals and whales to communicate with each other. This corresponds to the concept of the 'business card'. Communication between the air breathers and the fish would be mediated acoustically but air breathers could, in turn, report these interactions via satellite uplink.

Project goals pertain to monitoring fish movements near FADs and elucidating school cohesion in tuna. Currently, residency time of tuna at FADs is measured by attaching listening stations to FADs and equipping fish with coded acoustic tags that are detected by the listening station. Each listening station stores the IDs of the tagged fish swimming close to the FAD. In other words, the FAD is listening to acoustic tags carried by fish. However, fish equipped with the proposed new two-way receiver tags could also listen to FADs that would be similarly equipped with two-way devices. Because the tags developed in the proposed work will be cheaper than current devices, many more FADs could be equipped with these instruments. While current studies are limited to a few instrumented FADs, this new technology will allow the instrumentation of hundreds of FADs in a region. For instance, all FADs of the Hawaiian archipelago (around 50) could easily be equipped with such new acoustic beacons, which will allow monitoring the movements of tuna tagged throughout the archipelago. Moreover, this technology will allow work on networks of drifting FADs, which are of major importance in all industrial tuna fisheries.

PROPOSED ACTIVITIES
Project researchers will oversee the technological work which will be done by the Vemco Division of Amirix Systems (Nova Scotia, Canada, www.vemco.com), a widely recognized company in the world of its acoustic tags. During the first year of the project Vemco will develop the first receiver tag prototype according to researchers' specifications.

Once the tags and the beacons are available, testing will commence using the University of Hawaii's Institute of Marine Biology facilities (HIMB, Coconut Island, Oahu). Testing will include:

(1) Range testing of receiver tags implanted in dead fish around FADs equipped with acoustic beacons, to determine range detection, depth effects, and efficiency of the tag/beacon coupling.
(2) Use captive tuna and sharks in tanks and lagoons at HIMB to evaluate fish-to-fish data transfer in "good" conditions.
(3) Test "receiver tags" on wild tunas around Hawaiian FADs. Receiver tags will be placed in tuna captured at FADs around Oahu, Hawaii. The objective is to observe if the receiver tags can detect other tagged fish, and signals sent by FADs equipped with beacons. The FAD-mounted receivers will act as the data conduit for the tagged tunas. However, because the recapture rate of FAD-associated tuna is about 40%, researchers anticipate that, even with the quite low numbers of prototype tags released, they will recover several tags deployed in fish and this will provide an excellent additional opportunity to assess the functionality of the new tag.

Year 1 funding for this 2-year project to be available mid 2006.

References
Castro J.J., Santiago J.A., Santana-Ortega A.T. 2002. A general theory on fish aggregation to floating objects: An alternative to the meeting point hypothesis. Rev Fish Biol Fisheries 11: 255-277.
•Dagorn L., Bertrand A., Bach P., Petit M., and Josse E. 2001. Improving our understanding of tropical tuna movements from small to large scales. In: J.R. Sibert and J. Nielsen (Eds.), Electronic Tagging and Tracking in Marine Fisheries, Kluwer Academic Publishers, The Netherlands, 2001, pp. 385-407.
• Dempster T., Taquet M. 2005. Fish aggregation device (FAD) research: gaps in current knowledge and future directions for ecological studies. Rev Fish Biol Fisheries 14(1): 21-42.
Fréon P., Dagorn L. 2000. Review of fish associative behaviour: toward a generalisation of the meeting point hypothesis. Rev Fish Biol Fisheries 10: 183-207.
Holland K.N., Bush A., Kajiura S.M., Meyer C.G., Wetherbee B.M., Lowe C.G. 2001. Five tags applied to a single species in a single location: The tiger shark experience. Rev. Fish Biol. and Fisheries. In: J.R. Sibert and J. Nielsen (Eds.), Electronic Tagging and Tracking in Marine Fisheries, Kluwer Academic Publishers, The Netherlands, 2001, pp 237-247.

Principal Investigators:

Dr. Laurent Dagorn
IRD
Centre de Recherche Halieutique
Avenue Jean Monnet - BP 171
34203 Sete cedex
FRANCE
email: dagorn@ird.fr

Dr. Kim Holland
Hawaii Institute of Marine Biology (HIMB)
University of Hawaii at Manoa
Coconut Island
P.O. Box 1346
Kaneohe, Hawaii 96744 USA
Phone (808) 236-7410/533-4110
FAX (808) 236-7443
email: kholland@hawaii.edu

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This page updated September 28, 2010