General Movement Patterns | Dolphinfish Research Program | Mahi-Mahi | Mahi | Dorado | Dolphin | Dolphinfish
Dolphinfish Research Program
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General Movement Patterns

Dolphin Movements by Geographic Location

The Dolphinfish Research Program is constantly gathering new data relative to all the locations that anglers tag dolphin for the program.  There are five regions, however, where we have already acquired enough data to begin to analyze the species annual, semi-annual, and/or seasonal movements.  Those regions include the Bahamas, Eastern Tropical Pacific Ocean, Caribbean Sea, U.S. East Coast, and Florida (icons left to right above).  You can view articles and data published on the movements of dolphin in those regions by clicking the icons above.

2022 Dolphin Tagging Progress

June 2022

A total of 67 individual vessels have participated so far in 2022, which represents an average amount of annual participation to this point in the year, yet the number of tagged fish to date is the 4th lowest in our 21-year history.  For June alone, the number of tagged fish is the 5th lowest in 21 years.  Even our top tagging boat in the Florida Keys, Killin’ Time II, has exuded tremendous effort (17 June outings) but only logged 196 June tag deployments.  In previous years, Killin’ Time II deployed 394 (2017), 347 (2019), 300 (2018), 285 (2020), and 166 (2021) tags in June in fewer outings (with the exception of 2021).  There are several factors that could be attributing to fewer fish tagged.  First, our assumption is with participation at the current level as well as record tag kit distribution to date (357 tagging kits with 3,950 tags to 345 anglers), angler involvement in the DRP is not a strong factor.  Second, while it’s possible some anglers are keeping more fish (and tagging less), our tag numbers are mostly reflective of fish less than the legal limit from Key West, FL, through SC, so unless anglers are harvesting illegal fish (which is likely not the case), this is also not a strong factor.  Third, anglers could be making less trips due to fuel prices, illness from COVID-19, or held back due to weather, all factors that could contribute to low tagging numbers.  Lastly, it is unknown how bait and Sargassum can influence the ability for vessels to successfully tag or land fish, factors that merit future research.  Based on feedback from our consistent taggers, plus the amount of fishing effort reported and logged with our program, the abundance of schoolies, and large fish, is low so far this season from the Mexico Yucatan to South Florida, and perhaps their arrival to the western Caribbean Sea and Straits of Florida is delayed.  An important observation to note, however, of the fish tagged off Florida (n = 422), 5 have been reported (or 1.18%), which is a low recovery rate that suggests fish abundance should be high.  While an exact cause of this year’s low tagging numbers and relationship to overall dolphin abundance off Florida is complex and possibly an impossible comparison, it is important to publish these questions and comparisons as we strive to better understand dolphinfish fishery dynamics in the region.  For example, two of the four recoveries from Florida-tagged fish this year were both off North Carolina for fishing tagged and released on March 28th, 2022, off Cudjoe Key by Killin’ Time II.  Both of those fish moved to a very similar location but in 64 and 89 days.  Why did it take so long for those fish to move to NC when the average movement between those locations has historically been 32 days?  Where did those fish go while at large?  All of these questions, comparisons, and records in this short article point to the importance of tagging to document seasonal and interannual trends of this game fish.  To get involved, request a kit at this link.

Major Dolphinfish Recoveries East of Antigua and Barbuda and North of the Dominican Republic

April 2022

Every year, our tagging program receives recapture reports from anglers within the Caribbean Sea for fish released off the U.S. East Coast, but seldom do we receive multiple.  So far in 2022, we have received three Caribbean Sea recoveries for fish released in the Keys/South Florida region. The most recent recapture report was from north of the Dominican Republic and east of Antigua and Barbuda.  In February, we reported about a recovery off Venezuela as well as one off DR, but we include the latter here to serve as a reference to the difference in timing of movement from the Keys/South Florida region to the northern Greater Antilles and northern Lesser Antilles.  The new recovery reported to us last month by a commercial angler out of Antigua and Barbuda was tagged and released by the Wam-Jam fishing team last June off Marathon, Florida.   Total time at liberty for Wam-Jam’s 14″ fish, which grew to 42″, was 284 days, versus Killin’ Time II’s 18″ fish, which grew to 39″, in 210 days.  The difference in travel time, based on the timing of previous movements to these locations in the Caribbean Sea, points to a shorter circuit taken to DR versus a longer circuit taken to Antigua.

February and March 2022 dolphinfish recaptures off the Dominican Republic and east of Antigua and Barbuda.
David Wamer tags and releases a small dolphinfish aboard Wam-Jam in June 2021.
Captain Don Gates tags and releases a small dolphinfish aboard Killin' Time II.
New Recoveries off Venezuela and the Dominican Republic
Minimum straightline distances between mark (circles) and recapture (stars) sites.

Throughout the 21-year history of this tagging program, we have had some pretty rare and exciting tag recovery reports.  For example, back in August, 2015, a tag was removed from a dolphinfish fillet in a Whole Foods in Omaha, Nebraska!  We have also received reports from beach combers who have found tags on different beaches or barrier islands.  While these reports do not constitute valid recoveries, they still provide some information about the fishery and tagging activity.  Recently, we had another unique report but it was discovered with a modern twist.  Chef and angler Cedric Taquin of Arecibo, Puerto Rico, was looking through the Instagram feed of a Venezuelan angler, Captain Luis Ferrera, and noticed Captain Ferrera had posted a tagged dolphin in the past.  We reached out to Captain Ferrera and he confirmed that he caught the 24 lb female on February 2nd, 2019, while fishing La Guaria Bank, VZ.  The image he shared on Instagram was posted the day of the event!  We did not learn of this recapture, however, until last month.  The fish was actually tagged by Captain Jeff Salter while fishing aboard Lady Helen off South Florida on June 21st, 2018.  Captain Salter measured a fork-length of 19″ which puts the growth of this female at 26″ in 226 days or .12″ per day.  This is the second recovery for our program off Venezuela but the first from our network via Instagram.  Another exciting recovery we received recently via WhatsApp was from Lixandra Mayeli Alcequiez of Cabrera, Dominician Republic, whose father recaptured a fish tagged and released by Captain Don Gates and the Killin’ Time II fishing team last July off Cudjoe Key, Florida.  Lixandra’s father reported the fish weighed 16 pounds gutted and was caught at a fish aggregating device (FAD) 10 miles off Playa del Puerto, DR, on 2.20.2022.  Captain Gates measured 18″ to the fork.  This is our third recovery from the Keys/South Florida region to the north coast of the Domincian Republic.  With these two new international recoveries, the Dolphinfish Research Program has documented 22 movements from the U.S East Coast to locations throughout the Western Central Atlantic and Caribbean Sea.

The first recovery we had in Venezuela also occurred in February but that fish was tagged and released aboard Summergirl on June 8th, 2007, off Charleston, South Carolina, and was recovered 263 days later on February 26th, 2008.  As for the additional recoveries in the Dominican Republic for fish tagged and released along the U.S. East Coast, the Miami based charter boat the Thomas Flyer had two of their tagged fish recaptured along the north coast of DR.  The first fish was tagged and released off Miami, FL, on June 3rd, 2010, and the fish was recaptured 192 days later on December 12th, 2010.  Similar to the most recent recovery, Thomas Flyer’s second DR recovery was tagged and released in July and the fish was recovered in February.  Total time at large for the Thomas Flyer’s 2017 DR recovery was 223 days, only 13 days slower than Killin’ Time II’s 2022 recovery.

A 24 lb female caught by Captain Luis Ferrera at La Guaira Bank, Venezuela, with a tag in it. Chef Cedric Taquin discovered the recovery when browsing through Captain Ferrera's Instagram.
New Recoveries in the Dominican Republic
October conventional dolphinfish recoveries reported at fish aggregating devices along the north coast of the Dominican Republic. Black Numbers = Days at Liberty; Stars = Recovery Sites; Yellow Ovals = Tagging Sites

Since 2008, our tagging program has documented dozens of dolphin movements for fish tagged within the U.S. Caribbean Sea as well as  those tagged along the U.S. East Coast that have been recovered in the northeastern Caribbean Sea (click here to read about that work).  This past month, thanks to the effort of angler Jeffrey Liederman and the Sandman fishing team, we received our first four recoveries for dolphin tagged and released within Dominican Republic (DR) waters, which provided the first glimpse at in-country movements and dolphin fishery dynamics along this portion of the Greater Antilles.  When averaged, these four recoveries together indicate a swift rate of 18.6 miles per day toward the northwest.  This is much faster than the combined movement rate for fish recovered along the north coast of Puerto Rico (PR), which equates to less than 5 miles per day. One factor that could be responsible for this

Angler Jeffrey Liederman showcases one of the 69 dolphin he has tagged aboard Sandman off the Dominican Republic since the last week of September. Pic: Sandman

difference is along the north coast of PR there are five major rivers that pour into the tropical Atlantic, whereas there are only two along the north coast of DR, both of which are tucked into large bays which may reduce the potential flotsum and local variation in currents that may influence the movements of dolphin offshore. Another major difference between the dolphin fishery along the north coast of PR versus DR is the abundance of fish aggregating devices (FADs) off the coast of DR. Each dolphin recovery off DR this past month was both tagged and recaptured at a moored fish aggregating device. The existence of likely

Conventional mark and recovery movements for dolphinfish off the north coast's of Puerto Rico and the Dominican Republic. Black Arrows - 2021 Movements / Grey Arrows 2008-2020 Movements

hundreds, if not thousands, of these structures along the north coast of DR, could be the reason why Sandman’s recovery rate is an astonishing 6.67%, higher than even Killin’ Time II’s and WamJam’s historically high recapture rates observed during June and July in the Florida Keys in past years. A major difference between these recoveries is that all recoveries within the Keys are reported by recreational or charter fishermen while the fish reported this past month off DR were all small-scale artisanal anglers. Recorded commercial landings for the Dominican Republic have been highly variable since 1967, with abnormally high landings recorded in 2007 (figure above). Since 2014, however, a steady rise in commercial landings has put the DR back to one of the top landing commercial countries in the region, higher than U.S. Atlantic commercial landings, and the fact that four individual artisanal anglers reported recoveries over the first two weeks of October at four different FADs highlights the need for increased data collection on this species and the FAD fishery within the DR to ensure a sustainable dolphinfish fishery for both the country and the region.

Entire time-series of dolphinfish landings from the Food and Agricultural Organization's global capture production dataset for the Dominican Republic.
Gulf of Mexico - Upper Florida Keys Recovery
Black text = 2021 recovery. Grey text = 2012 recovery

September 2021 – Each year, recoveries of dolphinfish tags follow a somewhat predictable pattern given the number of tag deployments per location and the fishing effort in those areas.  A primary example are dolphin tagged in the Florida Keys and recovered off South Florida.  This year, 41% of tag recoveries fall into this category, and over the history of our program, 15% of all recoveries pertain to short-term movements between these areas.  This data is useful for a host of scientific and fishery management uses (click here for articles on that) but beyond the scope of this article, each year, rare tag recoveries occur whose details unlock a multitude of new comparisons, analyses, thoughts, and theories about the movements of this epic gamefish.  With an annual average of only  32 dolphin tagged in the Gulf of Mexico (GOM) over the past two decades, recoveries generated from the GOM are statistically low (now 3 of 561 fish) but the revered Whoo Dat fishing team beat the odds this year.  Recently, Captain Charlie Rogers of Against the Grain fishing charters based out of Key Largo, Florida, reported Whoo Dat’s tag number for a fish they tagged 95 miles south of Grand Isle, Louisana, on July 20th, 2021.

Against the Grain client catch on 9.12.2021 that included the fish tagged by Whoo Dat. Pic: C. Rogers

Coincidentally, a surface drifter (4201703) was deployed six days after and only 30 miles south of where Whoo Dat tagged the 24″ dolphin, which provides a potential route this fish may have taken to swim to the Florida Keys (and possibly beyond if it had not been recovered). A swift surface drifter movement from the Loop Current to the North Atlantic in just 28 days raises the question of whether dolphin swim through the system at the same pace. We do not have an

Surface drifter track July 26th, 2021, to August, 22nd, 2021

example of that type of movement, but our fastest single day movement is 120 miles, fastest movement between south Florida and North Carolina is 7 days, and fastest movement from the Florida Keys to the Mid-Atlantic Bight in 10 days suggest that it is possible. What this recovery does show is that a 24″ fish tagged south of Grand Isle, Louisiana, grew 6″ in 54 days when it was recovered off the Upper Keys. This supports our position that management for dolphin along the U.S. East Coast should both include dolphin that occur in the U.S. GOM, which are connected on very short time-scales, and establish an increase in fish reproduction and biomass by extending the SAFMC’s 20″ minimum size to the GOM, so that dolphin either remain within the GOM and grow to the size of Tessa’s first dolphin (pictured above) or toward the East Coast for anglers like Against the Grain’s clients to catch like they did in early September.  And, with three new recovieres in the MAB since our August newsletter, these examples provide further evidence of how small fish tagged off the Keys can grow to larger sizes before being caught in northern areas along the eastern seaboard.  Captains Mark LaRocca, Erik Dahl, and angler

Captain Bob Felinski poses with Tessa Clague after she caught her first dolphin in the GOM off Texas this past summer. Pic. T. Felinski
Black text = recent recoveries Grey text = last month's recoveries

David Pereira are the latest to recapture tagged dolphin in the MAB.  Captain LaRocca’s fish was tagged by Captain Kevin McDermott 18 days before it was recovered.  The 20″ fish was tagged at a lobster pot 25 miles northwest of the mouth of Hudson Canyon and recaptured at another lobster pot after growing 3″ in an area known as the 100 square in Hudson Canyon, 42 miles southeast from where it was tagged.  Captain Dahl’s fish was caught with his family only 9 miles east of Barnegat Inlet, NJ, 81 days after Captain Don Gates and the Killin’ Time II fishing team tagged the fish.  After 81 days at liberty, the fish grew from 17″ to 32″.  Lastly, Captain Tim Heiser and his wife Michelle tagged and released a 15″ fish off Ft. Lauderdale on May 1st, 2021, that angler David Pereira recaptured as a 28″ fish aboard Captain Tom Randall’s charter vessel Longer Days 20 miles out of Cape Hatteras, NC, on September 8th.  Average daily growth for all fish reported in this article equates to .13″/day (.91″/week; 3.64″/month) and in three of the four examples show small young-of-the-year fish (<20″ FL) growing 3″ to 15″ in the same calendar fishing season within the Loop-Gulf Stream current system.  Click here to read more about this year’s recoveries on our regional movements page.

Dolphin recoveries since our August newsletter.
30,000 Dolphin Tagged!

August 2021 – Just under two decades ago, during a mid-April fishing trip aboard Summergirl off South Carolina, Don Hammond tagged the first dolphin for this tagging program.  Earlier this month, the Wam-Jam Fishing Team, fishing out of Marathon, Florida, tagged the 30,000th dolphin!  While surpassing our 30,000th tagged dolphin is not a scientific goal of the program, it is symbolic of our program’s history and dedication to distribute tags and tagging kits, recruit and engage anglers, and log the data to determine the movements and life history traits of this species throughout the Western Central Atlantic and Eastern Tropical Pacific Oceans.  Given the program’s stready growth in participation, which we estimate has grown to 6,000 anglers throughout our history, the level of data collection has subsequently grown,

and as a result, we have learned a tremendous amount about this species’ annual, semi-annual, and seasonal movements by tagging region (see table above).  As with most scientific studies, there remains much work to be done; for our program, the two major locations for which we have very limited data are the Mid-Atlantic Bight (MAB) and the Gulf of Mexico (GOM).  Recently, two tagged dolphin were reported in the MAB (see article here) and thankfully, this year, we have had tagging participation within both regions.  With a steady level of participation by anglers in the MAB andand GOM, we hope that over the course of the next several years, as we push toward 40,000 tagged dolphin a significant proportion of those fish come from those zones. When combined with our satellite tag deployment efforts, we can effectively fill in knowledge gaps that exist for this species which can aid in improving species management and conservation.  To learn more about our effort in the MAB, visit beyondourshores.org/mab, or to help this effort wherever you fish and reside, click here to request tags.  A special thanks goes out to the  thousands of anglers that have participated as well as the individuals, fishing industry companies, and organizations that have supported our work to achieve at this significant milestone in our history!

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