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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.
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