Tradition Collides With Technology In Fish Tagging Program

My first exposure deploying a satellite tag was in the mid-1980s when my fishing team and I were racing back to San Diego from Avalon aboard my 42-foot Uniflyte, the “WaterCloset.” We had fished the three-day Avalon Billfish Tournament, hosted by the Los Angeles Billfish Club.

On the last day, having not seen a striped marlin for the entire event, we had pulled the plug and were returning to our home port with our proverbial tail between our legs.

As luck would have it, we spotted a feeder, baited it and hooked it.

After we had called the Tournament Committee to announce our hookup and intention to release the fish, we received a call from James Squire, of California Department of Fish & Game, (now California Department of Fish and Wildlife) asking if we would be willing to wait to release the fish until their Fish & Game boat could reach us and deploy a satellite tag.

We did just that. Don McAdams, the angler, had great fun keeping the fish connected while we waited, and waited until Fish & Game arrived and successfully deployed their tag. As I recall, the fish was successfully tracked for several days before the tag ceased transmitting down the Baja Coast.

The concept of utilizing the services of marine anglers in the tagging of large marine game fish, such as tuna and billfish, was originally developed by Frank J. Mather III of the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts.

The first cooperative tagging of billfish in the Pacific was by NOAA, National Marine Fisheries Service, Southwest Fisheries Center in La Jolla, Calif., in 1954 when tagging equipment was furnished by Mather to anglers fishing for billfish and tuna. James Squires of CFD stepped in, helped coordinate the program. His report follows, in part:

During 1954-1971, 15,540 billfish were tagged. Records show 9,849 striped marlin (Tefrapturus uudar), 4,821 sailfish (Isriophoms platyperus), 622 black marlin (Makuiru indica). and 248 blue marlin (Mukuira nigricans) were tagged during this period. Ninety-seven tag recoveries have been made: these include 85 striped marlin, 10 sailfish, and 2 black marlin. Eighty-one percent of these recoveries were by longline fishing vessels, the remainder by marine sport fishermen. The tag recovery rates were 0.88% for striped marlin, 0.32% for black.

Fast forward to approximately six years ago when Bill Dobbelaer, general manager at Gray Taxidermy, Pompano Beach, Fla and Dave Bulthuis, vice president of sales at Costa Sunglasses, designed a concept for an international, fully-interactive fish tagging program powered by the world’s largest network of fishing professionals, some 10,000 charter boat captains and mates.

By 2015, their vision became a reality when non-profit Gray FishTag Research (GFR) was launched with the assistance of Gray Taxidermy employees Kim Underwood, office manager for Gray Taxidermy; Jonas Masreliez, creative and social media manager; with the recruitment of newcomer Travis Allan Moore, fisheries scientist; this talented team was just what was needed to assemble all the moving parts of this ambitious project.

On Saturday, after the 2015 Los Cabos Tuna Jackpot Tournament was completed, the GFR Team invited staff members and sponsors to join them aboard boats provided by the Pisces, Red Rum and Go Deep fleets for a day of fishing and to participate in the tagging using the Gray spaghetti tags first-hand. The day’s activity netted three dorado and one blue marlin successfully tagged and released.

By then, Dobbelaer and his team’s collaborative effort had begun to make headway encouraging Tag and Release in the thriving International sport fishing community.

The fleets of Los Cabos had already embraced the tagging program in a big way.

At less than one year old, the organization had assembled an impressive advisory panel of industry leaders – all game-changers in their own right – who recognized potential international possibilities that would combine recreational angling,sport fishing operations, scientists and researchers globally.

In 2016, just prior to the WON Los Cabos Tuna Jackpot, Tracy and Marco Ehrenberg of Cabo’s Pisces Sport Fishing, arranged for members of the Gray Fishtag Research, Inc. (GFTR) group including Bill Dobbelaer; Travis Moore; and Dave Bulthuis to join them aboard the Tag Team, a 61-foot Viking with Captain Nayo Winkler, 1st Mate Mario, 2nd mate Dan Lewis along with Rogelio Gonzalez Armas, Ph.D., from Centro Interdisciplinario de Ciencias Marinas (CICIMAR) and myself, a Gray FishTag Advisory Panel Member.

As we idled out the channel, Moore explained that Wildlife Computers, specializing in marine animal behavioral research through the development of tag and telemetry technology, had contacted him several days prior to his departure to Cabo San Lucas, indicating they were willing to contribute two of the $5,000 specialized satellite tags for deployment in striped marlin.

Less than 30 minutes after we arrived at the Finger bank – just a click over 50-miles north of Lands’ End – the historic first pop-up satellite archival tag (PSAT) was deployed on a striped marlin in Cabo waters. The tagged and released fish was named “Bill Gray” in honor of the founder of Gray Taxidermy.

The second fish of the day was soon grey-hounding across the wake.

Bultheis returned to the fighting chair where he began the pump-and-wind rhythm that served him well with the first fish. Before long, Moore has skillfully placed tags (both spaghetti and satellite) in fish number two. In less than an hour, their task was completed and Captain Nayo steered “Tag Team” back toward the IGY Marina.

This striped marlin was christened“Tracy” in appreciation of all of the Ehrenberg’s support of Gray Fishtag Research, Inc. Outfitted with a prototype satellite tag on Nov. 1 on the Finger Bank as well, it was estimated at 79 inches (lower jaw fork length) and in excellent condition at the time of release.

As a footnote: Tracy, was recovered 72 hours later on Nov. 4, by the charter boat Mucho Bueno, captained by Ernie Cosìo Mijares and first mate Ernie Jr. The recapture location was on the Golden Gate Bank, approximately 30 miles away from the original tag deployment location. The marlin put up a short fight and once Captain Ernie saw and realized that the marlin had a satellite tag attached to it, he promptly recorded the contact information, the length of the fish, and then he released it in healthy condition.

This year, the GFR group included Dobbelaer along with his wife Pamela; Moore; Tracy Ehrenberg; Bulthuis; Bill Pino, Squidnation and Ray Gardner, Yo-zuri aboard the Tag Team, along with Rogelio Gonzalez Armas, Ph.D., and myself.

Last year’s success and the data it had provided had persuaded Tracy Ehrenberg of the importance of continuing the program, so she agreed with the owners of Tag Team and volunteered to fund a tag herself and for the team to return once again to the Finger Bank – just a click over 50-miles north of Lands’ End.

The game plan was to deploy the one satellite tag she provided and as many spaghetti tags as possible, as well as allow several of the team members to catch their first striped marlin ever. Both Moore and Pamela Dobbelaer were candidates to take striped marlin off their bucket list.

While Moore and Dobbelaer, loaded the tag sticks and double-checked the video cameras to be sure the team’s efforts would be recorded, the boat crew brought out the tackle and made sure everything was in order. Soon, a handful of sportfishers appeared on the horizon along with high-circling frigate birds, a sure sign of both bait and striped marlin underneath.

Out went the Squidnation dredges and daisy chains as those high-flying frigates became heat-seeking missiles as they plunged toward the telltale white water and the commotion caused by hapless baitfish fleeing the slashing bills of the predators beneath them.

Live mackerel were pinned onto circle hooks before being placed back in bait tanks. Soon Pino roared “Right side dredge” before his words were covered up by the steady rumble of the engines as two baits silently slid back in the wake.

“Fish on!” he yelled, as Tracy, the designated angler, hopped into the fighting chair. Rhythmically pump and winding, she soon had the small leaping striper close to the transom. Seeing the fish, Moore shouted, “Spaghetti tag only!” indicating the fish wasn’t frisky enough to gamble with the $5,000 tag.

During the next several hours, Ehrenberg, Bulthuis, Moore, Pamela Dobbelaer, and Pino, managed to deploy seven spaghetti tags and the one satellite tag.

fish tagging

The striped marlin named “Misha” was outfitted with a satellite tag on October 31, 2017 while fishing the Finger Bank offshore of Cabo San Lucas.

fish tagging
Following each tagging session, Gonzalez gathered plankton and larvae samples with a large small-mesh net.

Small dorado are common-place this year, as the larger ones remained scarce. Releasing was encouraged in order to avoid filling anglers’ limits before the larger ones showed up and introducing the opportunity to tag was an excellent alternative.

Aboard Redrum Sportfishing’s “El Nuevo,” while fishing with Captain Alex and mate Christian, angler Kerri Persons of Bonney Lake, Wash., agreed to tag and release a 27-inch dorado weighing around six-pounds. She dubbed the dorado “Walter.

Traveling south for 19 days, averaging 26 miles per day, the small dorado avoided becoming a predator’s meal until it reached the West Coast of Mexico, 30 miles south of Manzanillo off of San Patricio, Jalisco, where Walter swam into a gillnet!

When captured, Walter had grown three inches: he was now 30 inches long, and weighed 6-pounds, 8-ounces, indicating an age of slightly less than one year.
Captain Hernan Ramos received his pair of Costa Del Mar sunglasses, a Tag & Recovery Certificate, and Gray FishTag gear for reporting the tag recovery. The El Nuevo charter boat crew and angler who tagged Walter also received Gray FishTag gear for their efforts.

The success of the program would only be possible with the participation of the hard-working fishing professionals at their Official Research Centers throughout the world as well as by the generous contributions from donors and sponsors.

GFR’s pledge in return is to continue to offer all tags, applicators, data cards, hands-on training and support to the professional fishermen for free as the path to accurate data and the success of the program.

The Los Cabos Sportfishing Community has embraced the tagging program in a big way. Tracy and Marco Ehrenberg, (owners of Pisces Sport Fishing) and long supporters of releasing billfish and other species, own and manage more than 35 sportfishing charter boats, and were among the first agreeing to create a Cabo Research Center — the Pisces Research Center — almost three years ago, collecting the data cards from in excess of 400 active charter boats in one marina in Cabo along with Redrum Sportfishing. Since then, other operations have also joined the program including Baja Anglers, Sunrise Anglers and the Smokehouse, plus Jen Wren Sportfishing, East Cape; Gary Bulla, Fly-fishing Adventures; The Roldans, Tailhunter International, La Paz, and many others.

At last year’s Gray Fish Tag symposium in Florida, Tracy Ehrenberg and Dave Bulthuis volunteered the answers to “Why We Tag.”

  • Over the past three years, six different species of fish have been tagged and released in the Baja Sur region.
  • For the entire GFR program, more than 80 different fish species have been tagged worldwide.
  • More than 22,000 conventional tags have been distributed to anglers via charter boats.
  • Deployed conventional tags on fish representing 80+ species.
  • Recovery rate is continuing to shatter the expectations with 100+ recaptures to date which is truly amazing.

The data is available and freely being shared on the website.

Gray FishTag also has partnered with the Guy Harvey Ocean Foundation to conduct research on roosterfish to learn more on this sought-after species, successfully deploying electronic tags on four roosterfish during the ongoing Roosterfish Study in Costa Rica.

“The roosterfish is a favorite of mine to both paint and catch, and they are an immensely popular game fish, yet very understudied. The GHOF is excited to partner with Gray FishTag Research to better understand the movements of these animals,” world renowned artist, angler and conservationist, Guy Harvey, of Guy Harvey Ocean Foundation, confided.

In addition, GFR participates with the Costa Rican Fisheries Federation (FECOP) to provide scholarships and internships for selected students to pursue degrees in marine science areas.

GFR allows fish species in every ocean to be monitored. Billfish and shark as well as general offshore and inshore fish species are being tracked and recorded producing results that provide scientists and biologists with valuable information on migration patterns, fish stocks, growth rates, habitat depths and much more.

From soliciting funds to recruiting volunteers to assist in promoting the sustainability of marine game fish, as well as increasing public resource awareness and collecting information in real-time directly from fishermen in every part of the world, they produce valuable scientific data; plus they link professional fishermen and angling enthusiasts with the scientific community, which was desperate for relevant data.

And, most importantly of all, the data collected is being analyzed and used for scientific purposes and shared with any interested parties … at NO COST to the recipient.
For more information visit

fish tagging

  • The Striped Marlin “Tracy” was caught by angler Dave Bulthuis of Costa Sunglasses, and tagged with a satellite tag (PSAT) on Nov. 1st, 2016. The PSAT stayed on the fish and collected data for 38 days.
  • Fish length at capture: 79” LJFK
  • At its closest point, the fish was 9.05 km (5.6 mi) from the beaches of Los Cabo. The Striped Marlin in total traveled an approximate distance of 1488 km (924 mi) in a southeast direction. During that time period, the fish traveled over the Mazatlán Basin and went on to spend 10 days around the Rivera Fracture Zone.
  • The Striped Marlin exhibited a large vertical movement pattern which varied depending on daylight or darkness.
  • At nighttime, the average depth was surface to 3 m with occasional dives to 50 m.

During the daytime, the fish had extensive vertical movements with an average depth of 55 m, and rapid dives to 70 m followed by rapid ascents to 30 m.

  • Both Striped Marlin “Bill Gray” and “Tracy” were tagged on the same day, however one fish went north to the Sea of Cortez and the other fish went south. They both also demonstrated a vertical movement pattern similar in profile to swordfish, with nighttime hours spent at the surface and daytime hours spent at depths 40-80 m.
  • The Striped Marlin “Bill Gray” was caught by angler Dave Bulthuis of Costa Sun glasses on Nov. 1st, 2016 and tagged with a satellite tag (PSAT). The PSAT stayed on the fish and collected data for 68 days.
  • Fish length at capture: 81” LJFK
  • At its closest point, the fish was 2.66 km (1.65 mi) from the beaches of Los Cabo. The Striped Marlin traveled a total of approximately 2,485 km (1,544 mi) in a track around the tip of Baja and North into the Sea of Cortez. While in the Sea of Cortez, it made large circle patterns exhibiting a feeding behavior until it was finally caught and harvested near Isla Carmen.
  • The Striped Marlin exhibited a very large vertical movement pattern which varied depending on daylight or darkness.
  • It had an average nighttime depth of surface to 10 m with an occasional dive to deeper depths. The fish illustrated extensive vertical movements during the daytime, with rapid dives to 125 m followed by ascents to 15 m. Overall the Striped Marlin had a daytime average depth of 50 m.
That Baja Guy-Gary Graham, the BD Outdoors Baja Editor, has more than five decades fishing experience off of Southern California and the Baja Peninsula. From light tackle and fly up to offshore marlin fishing, Gary has experienced all facets of this fishery. He's set several fly-fishing world record...