February 15, 2008

Students and parents succeed in a scientific treasure hunt


Science, a storm, and school children came together on the morning of Valentine’s Day to rescue a special electronic tag from the flotsam and jetsam on a Frisco beach.  It was a tag that popped off a bluefin tuna and that contained valuable information about the travels and habits of the big migratory fish.
Here’s the way it happened.

On Wednesday night, Feb. 13, Dr. Molly Lutcavage, director of the Large Pelagics Research Lab at the University of New Hampshire, e-mailed some local boat captains, asking them to help recover a small, black pop-up satellite tag that had apparently come off a bluefin tuna.

“The tag came off the fish a day or so ago,” her e-mail said, “and it looks like it got blown onshore.  It may be on the beach by now unless the tide or wind takes it out again.”
The juvenile, 48-inch bluefin was tagged in a special project last August off Cape Cod.

The Large Pelagic Research Lab initiated its Tag a Tiny program in the summer of 2005. The goal is to study the annual migration paths and habits of juvenile bluefin tuna in order to better understand and conserve this highly sought after gigantic tuna whose populations are threatened by overfishing. 

A total of 98 juvenile fish were implanted with archival tags in 2005, and another 25 tags were implanted in 2006 – all off the coast of Cape
Cod or Virginia. Last summer, the scientists began attaching a new archival tag, the X-tag.  It is smaller than the standard tag with some extra features. 
According to Lutcavage, the tag is manufactured by Microwave Telemetry, Inc., of Columbia, Md. 
“We deployed 32 X-tags on juvenile bluefin in 2007,” Lutcavage said in an e-mail, “and eight more on giant bluefin (in Canadian waters). They're programmed to report after 12 months. Sometimes the tags release early from the fish, and they are programmed to transmit their data if they do. This was an early release. We’ve had three reports in the past few weeks -- two near Cape Hatteras and one northeast of Bermuda.”

And now one of the $4,000 tags was off the fish and floating toward land. The messages being received from the satellite tag indicated that it was bobbing around in the rough seas off Hatteras Island.  All day Wednesday, heavy winds had whipped up large waves and high tides along the island.

On Thursday, Feb. 14, the morning after Lutcavage sent her e-mail to local captains, Nuno Fragaso of the Large Pelagics Research Lab, contacted Tracy Shisler, a science teacher at the Cape Hatteras Secondary School of Coastal Studies, and asked her for help.  He asked if parents of the students might go the beach, to the area from which the tag was transmitting a radio signal
and search for the tag before it got washed out again in the tide. If the tag wasn’t found by the end of the school day, he asked if students might join the search. Lutcavage could see, using Google Earth, that the tag seemed to be located on the beach, near the airport.

“We get data via satellite for about 30 days,” Fragaso said in an e-mail to Shisler, “then our migration path modelers do their magic and we get a track. Because of transmission schedules, we don't get 100 percent data recovery. Having the tag allows us to get 100 percent recovery, which is why we are so eager to get it back.”

Recovering the tag would guarantee not only 100 percent recovery of the data, but the costly tag can also be refurbished and implanted on another juvenile bluefin this summer.

Fragaso e-mailed Shisler a picture of the tag, Google maps, and GPS coordinates for the location of the tag on Thursday morning. He also noted that there was a $250 reward for the return of the tag.
The students got on the phone with their parents, and Shisler sent the information to all of them with e-mail accounts. 

Ashley Hodges, 13, a seventh grader in Shisler’s class was one of the students who called her parents.  She reached her mother, Alex, who was on her way from Buxton to Hatteras after having delivered another child to school.

The GPS coordinates put the tag on the beach very near Ramp 49 in Frisco.  Alex Hodges has a GPS unit in her vehicle, so she turned off the highway and headed to the beach. She’s a parent who is supportive of the school and its new coastal studies mission, and she picked up on her daughter’s excitement about the hunt for the tag.

Hodges says she drove the beach for almost a half hour and saw nothing.  She was ready to leave when she thought about getting out and walking a while on the sunny but cool morning. In just a few minutes, she noticed the debris line up near the dunes from the storm’s high tides.  She walked up and started poking around.

And there it was – the elusive satellite tag.

Hodges took it to school for Ashley and her classmates to see.

“The students were very excited about the parent finding the tag,” says Tracy Shisler. “Alex Hodges brought the tag in and the kids were thrilled to be able to see what the tag looked like. I was e-mailing back and forth with Nuno, and I would read them the emails. They thought of it as an adventure unfolding before their eyes. 

Alex and Ashley had their picture taken with the tag, a photo that is now posted on the Large Pelagic Research Lab Web site.  Alex and her husband, Dr. Al Hodges, donated the $250 reward for the tag to the school for a trip the middle school students plan to the Smithsonian Institution in Washington, D.C.  Other parents, Dan and Jennifer Johnson, arranged for special FedEx packing to send the tag back to Microwave Telemetry in Maryland, the company that makes the tags and will recover the data.

In another interesting twist to the great tuna-tag hunt, the inventor and head of Microwave Telemetry, Inc., is Dr. Paul Howey, who has a vacation home in Hatteras village and knows Tracy Shisler and her family.

“The process of recovering this tag has been a great interactive learning opportunity for the Large Pelagics lab and the Hatteras students and their parents, Molly Lutcavage wrote in an e-mail. “The tag finders now know more about their local marine resources and have had a first hand look at the very latest technologies that fisheries scientists use to track marine animals.”

The students in Shisler’s sixth- and seventh-grade are involved in a fish and oyster hatchery program. Shisler says they are raising black sea bass, which will be tagged and released this spring. They are getting ready to stip spawn oysters to help with the oyster reef restoration project.
“A major theme of my teaching,” Shisler says, “is that we need to be better stewards of our planet Earth. I am hoping that they realize that whenever they get the opportunity to help care for the Earth, they should step forward and help. I also want them to realize that science is exciting, fun, and interactive.”


From Dr. Molly Lutcavage, director of the Large Pelagics Research Center at the University of New Hampshire:

The X-tags record depth and temperature every 15 minutes and light levels more frequently. We attach them to the fish via a nylon dart and a monofilament tether. At the programmed time, the nose cone of the tag releases from the tether, the tag pops up to the surface, and its radio transmitter sends the logged data to a receiver on a NOAA satellite. The data is then relayed to me (and Microwave Telemetry, Inc., in Maryland) via a French company, Service Argos, Inc., which distributes data from ocean buoys and satellite tags.

If the dart pulls out of the fish and the tag is prematurely released, or if a fish dies, it will start transmitting the data. The tags transmit the logged data for about 30 days. We use the light data to reconstruct the migration path of the fish, as well as its depth and temperature for the entire time the tag was on the fish. Our collaborator, Dr. Greg Skomal, of the Massachusetts Division of Marine Fisheries, was the tagger for this particular fish- which was about 48 inches and released on August 13,  2007.
With these early releases, we know that none of the fish died, but that the tag detached from the fish. Keeping tags on any marine animal is a challenge, and usually only a portion of the tags remain attached for up to a full year. Actually, we were pretty happy to have data coming in early, because this is the first time anyone has been able to put a popup satellite tag on juvenile bluefin, and we were anxious to learn where they would go
after leaving New England waters in the fall. Very little is known about where they go after leaving coastal waters in the summer and fall until they show up again the next season.

We start tagging juveniles off Wachapreague, Va., in late June and July and finish farther north, off Cape Cod and other areas of New England later in the season. From conventional tagging conducted by fishermen over the past decades, we know that some of these juvenile bluefin tuna cross the Atlantic and visit areas such as the Bay of Biscay off Spain.

Since 1997, we've used Microwave Telemetry's full-size PSAT tag for giant bluefin in New England and Canadian regions. Until they produced the miniature pop-up, or X-tag, we were required to use implanted data loggers for juveniles. With our collaborators, we released 127 juvenile bluefin with tags placed in the belly cavity of fish. These types of data loggers must be recovered along with the fish, so they are dependent on a fishermen catching the fish and returning the tag to us. The PSAT tag does its work without any intervention, so we get the data back when the tag is released from the fish.

Bluefin tuna are an extremely valuable fisheries resource that has been in the news for months. They are heavily overfished in the Mediterranean Sea and East Atlantic and by pirate fleets. The fish that we see in our coastal waters live up to 30 years, and may travel back and forth across the Atlantic many times, where unregulated fishing may occur.

Despite being one of the most valuable fish in the sea, there are huge gaps in knowledge that need to be filled -- where do they spawn, how often, what do they eat, what makes them shift their distributions?

When these PSAT tags are recovered, more data that can't be transmitted to the satellite can be recovered, so we obtain more details about the fish. And finally, the best part is that the tag can be refurbished and deployed on another fish next season. At close to $4,000 each, each tag is an extremely valuable resource for the LPRC.

To learn more, go to the Web sites:

Comments are always welcomed!

     Subject :

     Name :  (required)

     Email :  (required, will not be published)

     City :   (required)    State :   (required)

     Your Comments:

May be posted on the Letters to the Editor page at the discretion of the editor.