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Article written by CCA CAL State Board Member Greg Stotesbury

On August 19, 2022 CCA CAL board member Greg Stotesbury organized a bluefin tuna tagging trip with Dr. Barbara Block of Stanford University. The one-day trip resulted in the most successful effort yet in this 4 year old CCA and Dr. Block partnership to tag large bluefin with sophisticated electronic tags.

With help from Capt. Jim Kingsmill of San Clemente, we put together a tagging trip aboard Larry Jacinto’s beautiful 84’ Jones-Goodell sportfisher “Castigo” out of Dana Point, CA.  Larry’s Captain Adam Cargill, along with crew Grant Morgan and Jeremiah May graciously donated their time and all the expense to get archival and pop-up tags from Dr. Block’s team deployed on Pacific bluefin. These men are all high liner local experts on capturing bluefin tuna on sportfishing gear in local waters, as well as down south in Mexico.  Jim Kingsmill, Greg Stotesbury and Dr. Block’s and TAG A Giant (www.tagagiant.org) research scientist Rob Schallert rounded out the deck crew on Castigo.  Their vessel is perfectly equipped with Omni sonar, huge bait capacity, top notch gear and deck layout for handling large tuna.  In addition to Castigo, we had Ray Arida’s 25’ Parker “Cabo Magic” with Stanford’s technician Ted Reimer aboard helping in this years the tagging effort.

Dr. Block’s team has tagged over 850 Pacific bluefin to date and most of these were smaller fish that showed extensive residency in west coast waters. She has since 2015 been very interested to get as many electronic tags in large CA bluefin as possible to try and better understand just how old pacific bluefin are when they return to spawn in Japan and Taiwan waters.    Her tags reveal a trove of scientific information on migration routes, growth, feeding and environmental conditions which can only be accurately studied through the use of the very expensive and specialized tags Dr. Block is using several types of tags inserts, one that is called archival and inserts into live bluefin freshly captured and properly handled by the capture crews.  This surgery takes place in less than 2 minutes and the tag is stitched up inside with a long stalk that comes out with sensors. The bluefin carry a green conventional and reward address and $250 is provided to anglers if returned.  A second tag, called a pop-up satellite tag records the same information but detaches from the bluefin at the end of its one-year sojourn on the tuna. When it pops up it providers her team with an exact location to recover the tag and transmits the data. While we were out a tag put on a Monterey bluefin popped off on San Clemente’s east side and her team recovered it.  The electronic tags are expensive with the cost rivaling a laptop computer! Some of the tags inserted into bluefin on this trip were funded by CCA CAL Board Members and CCA CAL Life Members.

Timing is everything on these trips.  A combination of weather, access, boat and crew availability and fish population in range of capture boats all has to come together for the mission to be successful.  On this day in August all of these elements came together perfectly!  On Castigo we caught 13 bluefin with 12 over 100lbs and 2 over 200lbs.  We were able to get either satellite pop up or archival tags in 12 healthy bluefin.   Ray’s Cabo Magic with Dr. Block’s technician Ted Reimer aboard was able to tag 3 more fish for a grand total of 15 large tuna tagged in a single day by Dr. Block’s team!  To say we were all overjoyed with the success of the mission would be an understatement!  We all learned so much from Dr. Block on this trip, and Castigo owner Larry Jacinto said it was one of the most interesting and successful trips ever in the 20-plus years he’s been chasing tuna. Dr. Block’s team will continue the bluefin tagging in Monterey and aboard the F/V vessel Shogun in October and hopes to get another 40 tags out this season.  If you are interested in tagging, please contact her at bblock@stanford.edu