TAG
–A-Giant 2006 is in North Carolina NOW:
Tag Begins: January 4 , 2006 and Ends: January 30, 2006
TAG Scientists Shoot for the 1000th Electronic
TAG on Atlantic Bluefin Tuna
Beaufort, NC, January 2006. The first wave of a large, multi-institutional
scientific team arrived at Duke Marine Lab in Beaufort, N.C.
today to continue a research program that has become a winter
tradition along the Crystal Coast of North Carolina. TAG-A-Giant
(TAG), now spanning a decade, focuses on learning more about
the travels and behaviors of Atlantic bluefin tuna. Led by
Dr. Barbara Block of Stanford University and Charles Farwell
and Dr. Tom Williams of the Monterey Bay Aquarium, the team
consists of Stanford and Duke Ph.D. students (e.g. Andre Boustany,
Steve Teo, Kevin Weng, Gaelin Rosenwaks) and technicians from
the Monterey Bay Aquarium (Robert Schallert, Matt Price).
The TAG team will once again work with a cadre of sport fishing
boats from Morehead City, and private boats moored in Beaufort
to carry out the arduous work of tagging large bluefin in
winter seas.
This close knit group of scientists and fishers hopes to put
100 electronic tags on medium and giant bluefin. The TAG team
would like to reach the decade long goal of placing 1000 electronic
tags in bluefin by the end of January. “We set the 1000
tag goal early in 1996 and it has taken a bit longer than
I first estimated to get there. I am pleased that we have
the opportunity this year to potentially reach our goal. Only
weather and fishing conditions will hold us back”. “The
TAG team's scientific efforts together with the local charter
and private boaters who help to transfer and tag fish have
resulted in the collection of critical data on how bluefin
tuna from the western Atlantic use the ocean”. Block
said from her office at Stanford University.
Block and her team pioneered the use of two types of electronic
tags. One is inserted in a quick surgical operation on pitching
decks- called the implantable archival tag. The second rides
externally and “pops up” to transmit the data
via radio signals to Earth orbiting satellites. The archival
tags remain in the fish until the fish is recaptured. Fishers
must recognize a green external “spaghetti tag”
that explains how to return the internal tag to the researchers.
The journey of a tag can include 7 years at large in a tuna,
and then a maze of hand-offs between fishers, government scientists,
Stanford scientists and engineers to recover the data from
the electronic tag.
The pop-up satellite tags remain on the fish for as long as
9 months and are capable of delivering information similar
to that obtained from the archival tags. What makes both tag
technologies novel is the capacity to record a continuous
journey of a fish while it remains submerged beneath the sea.
The tags record, light, temperature and depth along the path
of the fish. From the light data they calculate the time of
sunrise and sunset- even while the fish is diving to over
300 feet in the water column. From the dawn and dusk measurements
the researchers use astronomical tables and algorithms to
calculate local apparent noon. This of course requires a highly
accurate measurement of time, a problem that plagued early
sailors. The tags carry a very precise crystal clock and can
calculate a longitude to within 60 nm of the fish’s
true position. To estimate latitude we use temperature data
collected at the surface of the ocean to map the position
along the known longitude to the sea surface temperature in
a satellite image. Together the two pieces of data (light
level longitude and SST based latitude) provide the geoposition
for a fish that remains completely submerged. “Our dream
when we started this program in 1996 was to learn the movement
paths of the bluefin tuna as they swam underwater- I am pleased
that we have recovered tags that logged tracks ranging from
one to almost five years. We know much more now about how
bluefin use the North Atlantic and it’s primarily because
of our team’s collaboration with the fishers of the
North Atlantic who help us both deploy and recover tags.”
From the data- Block and her colleagues have published landmark
papers in the prestigious journals Nature, Science and Proceedings
of the National Academy. As a result, the scientific community
has learned that there are at least two populations of bluefin
that occupy the North Atlantic. One that breeds primarily
in the Gulf of Mexico, Bahamas and Straits of Florida, and
a second that forages in the west but goes into the Mediterranean
to breed. The tagging data have provided an immense amount
of new information on the biology and ecology of the Atlantic
bluefin tuna delivering much needed information on habitat,
migrations and behaviors. Bluefin are primarily fish of the
top 50 meters of the water column although they have been
shown to dive to over 1000m. The fish experience temperatures
as frigid as 0.7 C and as warm as 31 C. The spatial distributions
and movements of the Atlantic bluefin are being examined by
four Ph.D. students (Steve Teo, Andre Boustany, Andreas Walli,
Gaelin Rosenwaks) who are conducting their studies at Stanford,
UCSC, and Duke Universities. A recently minted student (Dr.
Michael Stokesbury) finished his Ph.D. at Dalhousie University
this past year and focused on the movements of fish from the
New England assemblage.
Who
We Are?
The tag team is made up of scientists from Stanford University,
Duke University, and the Monterey Bay Aquarium. Our research
is supported primarily by private funds and by occasional
federal grants and contracts from the National Marine Fisheries
Service. North Carolina vessels, in particular, have been
instrumental in placing tags on the bluefin tuna off Morehead
City and Hatteras, North Carolina. Fishermen play a key role
in our team deploying and retrieving tags. To date, over 90%
of the 820 electronic tags have been placed on fish off the
coast occurred off the coast of North Carolina in winter months,
often when weather and conditions are the worst along the
eastern seaboard. In addition, we have deployed tags off the
coasts of Massachusetts and Ireland and have worked with commercial
fishers in Louisiana and Texas to deploy tags from longliners
working in the Gulf of Mexico.
How
Can You Participate?
Transfer
the Tag team a fish and you’ll be on the scoreboard
and eligible for prizes. TAG team scientists will be working
on the water from January 4th- January 30th with the F/V Calcutta
and F/V Last Deal. The goal is to tag 100 fish in the region.
Check here for daily updates on the progress of the tag effort.
If you hook up a fish, you can transfer the fish for tagging
to the TAG surgery vessel by contacting the Captains of each
boat. Come join us on the water in January 2006.
View
2005 TAG
North
Carolina 2005
North
Carolina Reports 2005
Transfer
Competition 2005
Photos
2005
Deployment
Images 2005
Rich
Novak Bluefin Tuna Scholarship Fund
