On the Eve of the Fifth Annual HIBT Great Marlin Race

Tournament Founder and Director Peter Fithian has briefed all the teams, all of the national anthems have been sung, the taiko drummers have played, the Kona restaurants have feasted the anglers, and the Start Fishing call is just a short night sleep away. I am joined at this year's Hawaiian International Billfish Tournament by Aaron Carlisle - the new IGMR Post Doc, and a long-time member of the Block Lab. This will be Aaron'he s first marlin tournament - and it's almost impossible to believe that it will be my fifth HIBT - making it the Fifth Anniversary of the Great Marlin Race! Who knew, when Peter Fithian and Tournament Coordinator and IGFA Representative Bob Kurz called Dr. Block back in 2009, that the Great Marlin Race would even work once - let alone grow into an international research and conservation effort.

39 teams from 13 different countries attend the pre-tournament briefing

Yet here we are again - having deployed more than 100 tags, for 6,416 days of tracking, over more than 65,000 nautical miles, since we started five years ago. We have enjoyed incredible generosity from the tournament organizers with whom we've worked, as well as the anglers, captains and crews who have made it possible. As we begin our day tomorrow, we already have sponsors for 8 of the 10 tags, and we are grateful for everyone's willingness to get involved.

A local taiko drumming team wows the crowd

Aaron and I will be riding along with Mitch and Marty Firestein from the Balboa Angling Club tomorrow, on board the Humdinger. This will be a new boat for me, but I've heard nothing but good things. Here's hoping that we and all the anglers are successful in this year's event!

Tagging Moroccan Giants at the Pillars of Hercules

(Post from Tag A Giant director Dr. George Shillinger)

On the heels of the ICCAT meeting in Tenerife, I joined Dr. Pablo Cermeño (TAG/Stanford University, WWF, KAI Marine Services), and a team from the Moroccan National Institute of Fisheries Research (INRH) (Noureddine Abid), ICCAT’s Atlantic-wide Research Programme for Bluefin Tuna (GBYP) (Dr. M’Hamed Idrissi), the World Wildlife Fund’s (WWF) Mediterranean Programme (Dr. Gemma Quilez-Badia, Naima Rodríguez López), and the tuna trap "Es-Sahel" (Larache, Morocco), owned by "Société Maromadraba".  

The Morocco 2013 tuna tagging team. From left to right: Dr. Pablo Cermeño, Dr. Gemma  Quilez-Badia, Naima Rodríguez López, Dr. M'Hamed Idrissi, Dr. George Shillinger, and Noureddine Abid.

Geographical location of the El Sahel trap and other Moroccan traps along the Atlantic coast (Abid et al., ICCAT SCRS/2011/081).

Artisinal fishing boats in the harbor  at Larache.
Image: George Shillinger

Fishing boats in the harbor at Larache, Morocco.
 Image: George Shillinger

View of Larache, Morocco from the harbor.
Image: George Shillinger

Dr. Cermeño initiated this exciting collaboration for TAG during 2012, after working with ICCAT and WWF during 2011 to tag tuna caught within the Moroccan tuna traps. Société Maromadraba had reached its quota in two days and was prepared for us to commence tagging fish remaining in the Es-Sahel trap, as per the research agreement established with ICCAT and partners. The trap was now filled with over 4000 giant tuna, estimated to average over 2.25 meters and weigh over 220 kgs apiece.

 Boats, floats, nets, and anchors comprise the Es-Sahel tuna trap off Larache, Morocco.
Image: George Shillinger

Artesinal fishermen working at the Es-Sahel tuna trap off Larache, Morocco.
Image: George Shillinger

The goal of the tagging expedition was to deploy acoustic tags, mini-PATs tags, and conventional tags on this enigmatic aggregation of Atlantic bluefin tuna.  Fish tagged during the 2012 deployment by the ICCAT-GBYP and WWF at the Es-Sahel trap travelled to putative Mediterranean spawning grounds in the South Balearic Islands and off the coast of Libya, and to Atlantic habitats off the Azores and Madeira.

Tracks of nine Atlantic bluefin tagged off Larache, Morocco during 20012 by ICCAT-GBYP and WWF (Quilez-Badia et al., ICCAT SCRS/2012/143).

This year’s addition of acoustic tags to the tracking effort will potentially allow us to obtain longer-term data about movements and residency patterns within Mediterranean and Atlantic foraging habitats that are equipped with receiver arrays.  It is anticipated that a line of acoustic receivers deployed by the Ocean Tracking Network (OTN) will eventually span the Strait of Gibraltar (“Gibraltar Curtain”), between Spain and Morocco, enabling us to record the passage and seasonal movements of the tagged fish between the Atlantic and Mediterranean.

Bluefin tuna are linked to all the ancient civilization inhabiting the Mediterranean. Aristotle (384 BC – 322 BC) in his “History of Animals” described not only the species but also migration along the Mediterranean. Bluefin tuna have been a source of food for millennia; Phoenicians started fishing tuna in the Mediterranean c. 3000 year ago with a net that evolved into modern day tuna traps. Similarly Romans, Greeks and Middle age Dukes exploited this resource, and the fishing continues today.


Tuna traps use a passive net system anchored near shore to capture migratory bluefin tuna. A wall net coming from land to off-shore tries to direct the tuna to a labyrinth of nets during its spawning migration to the Mediterranean and in some areas when leaving the Med after spawning. Once the tuna reach the final chamber the fishermen bring up the tuna capturing them with the help of hand-hooks.

Schematics of ancient Mediterranean tuna traps (source unknown).

Image depicting fishermen at a Mediterranean tuna trap (origin and site unknown -- possibly Zahara, Spain). Source:http://www.zaharaenlaweb.com/es/paginas/almadrabas-de-zahara-de-los-atunes  

La pêche du thon (La pesca del tonno), acquaforte di Jean-Pierre Houël, 1782.
Source: Voyage pittoresque des Isles de Sicile, de Malte et de Lipari. Paris, 1782. 

The Atlantic Moroccan tuna trap fishery contributes on average up to 70% of Morocco’s total bluefin catch (~ 1450 metric tons), and comprises approximately 5% of the total bluefin catch within the Eastern Atlantic and Mediterranean (Abid et al., SCRS/2011/081).  The first Moroccan traps were established nearly a century ago.  Today the traps occur along the north Atlantic coast of Morocco to the Strait of Gibraltar. They are typically situated around 3 nautical miles offshore, extending to depths of around 60 m. Since the trap fishery is primarily directed at the spawning fraction of the Eastern Atlantic bluefin stock, it provides a unique opportunity for generating abundance indices to monitor stock status and inform stock assessments.  Relatively easy access to the trapped fish also provides researchers with a unique opportunity to deploy electronic tags on fish that would be otherwise inaccessible or extremely challenging to encounter through conventional (e.g. recreational sportfishing) tag deployment methodologies.

Proportion of East Atlantic and Mediterranean tuna traps catches by area and by flag. (Abid et al., ICCAT SCRS/2011/081)

the Chagos Archipelago

The mission to the Chagos Archipelago has begun...we finally arrived in the Maldives after two days of traveling...crossing 13 time zones. The Bertarelli Foundation has joined forces with TRCC/TAG/GTOPP to tag apex predators in one of the most remote and protected reef systems in the world. In 2010, the Chagos became the largest marine protected area in the world at 644,000 square kilometers. We have 65 tags (15 miniPAT and 50 acoustic) to deploy on various species...from tuna to sharks to rays. And a 10 receiver acoustic array to set-up.

This morning we will fly across the equator to meet our hosts aboard the Vava II...the 314 foot ship is docked in Gan Island on the southernmost atoll in the Maldives. From there we head due south 500 kilometers.

-Robbie Schallert

Sea Surfing “Wave Glider” to Search for Bluefin Tuna and Striped Bass off the North Carolina Coast

The Wave Glider Carey begins her latest mission

A mobile robot called a Wave Glider outfitted with acoustic receivers to detect free-swimming tagged fish was put in the ocean off the coast of Beaufort, North Carolina today. The glider was launched from the Duke ship R/V Susan Hudson outside the Beaufort Inlet by Drs. Dick Barber and Joe Bonaventura of Duke University.  The Glider is part of a collaborative experiment to test the capacity of the unmanned robot designed for biological ocean observation, to detect where animals are in relationship to ocean conditions. For this first test off the North Carolina seaboard, scientists from Stanford, Duke and Eastern Carolina University are working together to listen for tagged bluefin tuna, striped bass and sturgeon that overwinter in North Carolina waters.

Monitoring marine species is valuable not only for the data about their whereabouts but also to better understand our changing oceans and climate. These species can act as roving reporters providing knowledge of their presence or absence in relationship to ocean conditions.  Bluefins and striped bass overwinter in the coastal waters of North Carolina to feed on Menhaden an oily forage fish that is a coastal favorite of both species.

“I am really enthusiastic about the role of the Wave Glider, this new ocean robot, to help us detect where fish are” said Dr. Barbara Block a professor from Stanford University. “We’ve been tagging bluefin tuna for years, through the Tag-A-Giant program, off the Carolina coast and we’re now moving into the phase of developing techniques to long-term monitor their presence or absence along the eastern Seaboard. The glider provides an opportunity to experiment with how to do this in the rough winter conditions of the Hatteras coastline.”

The Stanford team tags a giant bluefin

The bluefin tunas Block is searching for were tagged with long-term acoustic tags in Canada this past summer and fall. Block estimates there are over 50 bluefin with tags roaming the Atlantic seas, and is hoping that the hot spot region off Carolina will attract the tagged fish into the region. She and her team have studied bluefin tuna for years determined previously this foraging hot spot is like a favorite restaurant where the tunas tend to gather from several populations roaming in the North Atlantic. By deploying the Wave Glider in this region, they hope to hear the tags’ acoustic pings, which allow them to detect and identify individual tunas.

In addition, ECU professor Roger Rulifson is leading a team on the R/V Cape Hatteras, an NSF ship managed by Duke University, which will be out tagging stripped bass acoustic tags.  “We hope that the Glider can pick up some of the new animals we’re releasing in the next few weeks and help monitor the presence of a variety of fish and sharks we’ve been tagging in the region the past few years,” said Rulifson.  Like Barbara, he is investigating how mobile receivers can aid in the teams capacity to monitor where fish are in the rough winter conditions off the Carolina coast.

Duke University Professor Dick Barber stands with the Carey glider

The glider is was deployed by two of Block’s mentors, Drs. Joe Bonaventura and  Dick Barber from Duke University, where Block got her Ph.D. in 1986. “Ocean Observation is critically important, and I am pleased to see the next steps in biological observation being tested here off North Carolina,” says Professor Dick Barber. “I was fortunate to know Frank Carey, the pioneering tuna scientists from Woods Hole Oceanographic, and a Duke Post-doc, after whom the Carey Glider was named, and he would be very pleased to know of the experimental importance of this mission- chasing Atlantic bluefin and striped bass off our coast”. 

The Wave Glider is manufactured by Liquid Robotics of Sunnyvale California. The project is funded by a Rolex award to Block, The Tag A Giant Fund, Duke University, Stanford University and Liquid Robotics.

The Shogun Returns

The Shogun team collecting bluefin moved into the second half of the trip focused on tagging bluefin and collecting bluefin and yellowfin tuna. They searched the ocean on the US side of the border and moved back and forth between the waters south of San Clemente Island and Mexican waters. During the day they connected with a large school of bluefin tuna that Captains Aaron and Cole were able to put the team on. Once there tagging commenced and approximately 30 fish were released. A new load of bluefin was collected with fish that were just ranged from 14-25 lbs. 40-50 lb fish were also mixed with the school. It was a great day of fishing, and an enthusiastic crew working together with the scientists managed to get all the tags out- and collect a load of fish for scientific study.

-Dr. Barbara Block

Ted Dunn owner of Shogun, Dr. Block and Chuck Farwell enjoying sunset on Shogun after a super day of tagging and collecting bluefin In October off the waters of San Diego! 

We could have tagged. 100 if we had only had tags!

The Shogun back in San Diego

Alex prepares to move bluefin from the hold

Moving fish

Bluefin swimming in the pool

The movers and the shakers - Nick, Ben, John and Dane

5 for 5

Bluefin tuna circling before getting tagged

TAG Director Dr. George Shillinger, Robbie Schallert and Captain Dennis Cameron measuring a 259 cm bluefin

Dr. George Shillinger and Robbie Schallert discussing tagging operations

Guest angler Keith Brander battles a bluefin tuna

Dr. Shillinger deploys an acoustic tag

Final sunset over Northumberland Strait

Team Canada, including guest angler Keith Brander and Halifax native Naomi Pleizer, had another epic day on the water...5 hooked and 5 fish left the F/V Bay Queen IV with electronic tags. The bite happened around 2 pm with all three boats (Bay Queen IV, Carrie Anne and Nicole Brandy) simultaneously hooked up. The Bay Queen IV hooked two more fish just before sunset on a flat calm day in the Northumberland Strait.

-Robbie Schallert

Shogun Expedition, October 7-8

The Tuna Research and Conservation Center team is on the Shogun in October this year- a bit of an unusual time for our bluefin tagging team. The trip started with an enthusiastic team of students, staff and post-docs. On board this year are Chuck and Barb, Stanford Graduate student Dane Klinger, Post-doc John Dale, Technicians, Ethan Estes and Alex North. The team on board is also composed of a trio of Stanford@SEA former undergraduates, Ethan, Laura Lilly and Nick Mendoza. Visiting scientists aboard from CICESE are Oscar, Ana and Maria from Dr. Tim Baumgartner’s and Axa Rocha lab to help in a collaborative research.  We fished to the south- and quickly got into to small spots of yellowfin tuna exactly of the right size we were looking for. This season we’re looking for fish to swim in our flume and starting out with a 15 lb tuna helps as the smaller 8-10 lb fish will occasionally turn around making the studies challenging.  We collected about 5 of this size and continued to the south. The conditions were a bit rough and never improved but the fish showed up bright and early the second day of fishing. We had a wonderful set of stops on kelps where the entire pelagic community was hanging out- with yellowtail, Mahi and yellowfin tuna. Petrels flew above and it was a super fun stop with lots of great fishing action and a loaded vessel with yellowfin. We’re heading back up the line to drop the fish off for truck transport back to the lab. We plan to collect and tag some bluefin tuna in the next few days.

-Dr. Barbara Block

Yellowfin tuna collected on the first leg of the trip