Guy Harvey's exclusive account of tagging mako sharks to unlock secrets of their abundance and migrations
Guy Harvey, Ph.D.
September 9, 2014
Makos Lurk Off Mexico
The population of mako sharksthat lurks in the swift, north-flowing current off Mexico’s Caribbean coast is not a complete secret. Capt. Anthony Mendillo, who operates Keen M International, can tell you as much. Makos attack his dredges when he’s fishing for sails and white marlin. Sometimes they grab hooked sailfish, and they love to chew on the jumbo-size bonito (little tunny) that frequent these waters. I joined Mendillo in late March with mako in mind. Mendillo had hoped to get his favorite bait for Isla Mujeres makos, dolphin fish (dorado). But dolphin, which would be more abundant later in spring, were scarce at that time. The solution: Make decoy dolphin.Doug Perrine
Guy Harvey’s custom dolphin decoy!
Next thing I knew, we were trolling two hookless dolphin decoys on the right short and long rigger line. On the left rigger, Mendillo pulled dead bonito armed with a large, single J-hook. We had been working the edge of the current line in 200 to 300 feet of water when — kaboom! — a 400-pound mako skied on the short decoy. We watched it go airborne with the decoy firmly in its jaws not 30 feet off the transom. The shark arched and flipped in midair, landing heavily on the water’s surface, then mounted another attack on the decoy in a burst of foam. Not happy with the taste of pinewood, it crossed our wake like a blue marlin to grab the swimming bonito.Courtesy Guy Harvey / Nova SE University – Guy Harvey Research Institute
Amazing Sport, Amazing Science
Then we were truly hooked up, line pouring off the Shimano reel as the mako raced away across the surface, throwing curtains of water. This, I thought, is very much like marlin fishing, but for sharks. But we were there for more than just the (amazing) sport of hooking makos. Three years ago, Nova Southeastern University’s Guy Harvey Research Institute began tagging and tracking makos from Isla Mujeres. At that time, I deployed three pop-up archival transmitter tags (PATs), two of which went the full six-month term before popping up. Shortly after that, the GHRI sent satellite-reporting SPOT (Smart Position and Temperature) tags to New Zealand for deployment on makos there by our colleagues Dr. Malcolm Francis, Scott Tindale and Dr. Clinton Duffy. (At left: Guy battles a mako off Isla Mujeres.)Courtesy Guy Harvey / Nova SE University – Guy Harvey Research Institute
“Carol” — One Moving Mako!
Based on their results, Dr. Mahmood Shivji, director of the GHRI, realized that these tags were working extremely well (which was gratifying, since they’re not cheap at $1,700 per tag plus about $1,000 more per tag for satellite time per year). The tags were providing information on these sharks’ movements in unprecedented detail because the makos were coming to the surface multiple times each day. More so than the PAT tags, SPOT tags provide accurate, multiple daily detections, helping scientists to a rare view of the migration patterns of makos. A SPOT tag enabled us to follow a Kiwi mako dubbed “Carol” as she covered nearly 10,000 miles from northern New Zealand to Fiji and back, and then up to Tonga, in just under a year. She made headline news in the process, averaging 60 miles per day. The map at left shows Carol’s track. In less than a year, this small female put aobut 10,000 miles on her odometer, travleing from New Zealand to Fiji to Tonga, averaging 60 miles per day. You can track individual sharks interactively in both the Atlantic and Pacific here.Courtesy M. Shivji – NSU-GHRI
Maryland mako joins the tag party
At the same time, Shivji and Dr. Brad Wetherbee (standing, in photo) were deploying SPOTs on makos out of Ocean City, Maryland. From our previous studies on tiger sharks in Bermuda and the Bahamas, we know that tigers and oceanic whitetip sharks spend a great deal of time at the surface; this allows a SPOT tag to transmit its approximate location to satellites. Successes like that of Carol sparked our decision to switch from PAT tags to SPOTs for Mexican makos. For that operation, we turned to Mendillo. He has been fishing his 41-foot Mike Fitz (a single-engine boat, and the best day boat I have fished anywhere) off Isla Mujeres for more than a decade, concentrating on different species at different times of year. The run of makos off Isla occurs during March and April, along with sailfish in the early part of the year. White marlin go off in May and June, whale sharks from June into September, and swordfish whenever it’s calm enough to catch them while deep-dropping in the daytime.Courtesy George Schellenger / NSU-GHRI
The Breath of Life — Via an Irrigation Hose
Armed with several SPOTs, Wetherbee, filmmaker George Schellenger and I all went back to Isla Mujeres at the end of March 2013. The weather gods were against us, and we battled horrendous seas for four days but still managed to deploy three SPOTs. Unfortunately, we could not work on the sharks secured alongside the boat because it was so rough. We brought them into the boat, secured them, covered their eyes and irrigated them while the SPOT was attached to the dorsal fin and then released. It was definitely not as easy as that might make it sound. Schellenger and I filmed all the releases and watched as the chunky makos took off into the blue — very gratifying. On our first day, we had four mako bites but caught just one. Through the week we also raised sailfish, white marlin and blue marlin.Courtesy Guy Harvey / NSU-GHRI
A Platform Custom Made for Mako
I booked Mendillo for 10 days at the end of March this year too. Little did I know that he had embraced this project big time — so much so, he had actually built an aluminum derrick and lifting platform on the stern of Keen M before we arrived. The platform could be moved on rollers across the transom and would allow us to load a mako on the platform and then raise it out of the water. Scientists could attach the SPOT easily and without having 200 pounds of charged-up shark actually in the boat. Graced with beautiful weather this time, we trolled decoys and fresh bonito for makos with astonishing results. While a few makos would sneak up and bite just on the rigged bonito, the majority, particularly the bigger fish, would launch on the dolphin decoy from underneath or by coming across from the inside out and crash the decoy just as crazily as would a 500-pound blue marlin.Courtesy Guy Harvey / NSU-GHRI
Makos: Fast and Unpredictable
With makos, there’s never any warning. Veteran fishing photographer Scott Kerrigan, on board for several days, waited patiently on the flying bridge for the shot. But neither he nor any of us were fast enough to get that first jump. TV-fishing-show host Diego Toiran joined me for a day and caught a fine 200-pound mako, which he’d show later as an episode of his show, Fishing the Keys. His SPOT-tagged mako is named Diego; all these sharks, as well as other pelagic species we work on, can be followed on the interactive GHRI tracking site: ghritracking.org. George did rig GoPros on each dredge, and we were fortunate to have a couple of makos devour the mullet off a dredge (after taking a shot at the camera housing!). This footage makes for very exciting content, with makos fast and agile, and their black, expressionless eyes menacing. Typically we would catch one of every three makos that we raised. Many that seemed well hooked came off; in fact, some were hooked several times and still got away. I considered the likelihood these were simply holding onto the bait, not wanting to let go. We did hook a couple of makos using the pitch-bait approach, so bait-and-switch tactics with the decoys did work to a certain extent.Courtesy George Schellenger / NSU-GHRI
SPOT Tag in Place and Ready
We raised 36 makos, all but four of which bit, during this expedition. From those 32 strikes, we caught and tagged a total of 11 in this expedition. No great catch numbers but some incredible action. Prior to releasing it, we measured each shark, took a fin clip for DNA analysis, and removed the hook as the platform was lowered into the water so we could release the mako. George and I went into the water with each mako to get shots of the SPOT tags in place underwater and to get the departure shot. We also revived them when necessary by towing them behind the boat using a small barbless hook in their lower jaw. This approach to fishing makos — still evolving — is much more exciting than drifting or being at anchor to set up a chum line. It allows you to fish in heavy current where makos frequent, and where there might be no opportunity to anchor. At left, Dr. Brad Wetherbee checks a SPOT tag just attached to the dorsal of a shortfin mako.Courtesy George Schellenger / NSU-GHRI
Quick Outpatient Procedure, then Back into the Water
Given the incredible results we were getting in New Zealand and Mexico, the GHRI expanded its mako shark research in the Atlantic off the United States in May this year by joining forces with Capt. Mark Sampson, who operates Fish Finder Adventures based in Ocean City, Maryland. With Sampson’s long-standing shark-fishing and shark-handling experience, the GHRI team deployed eight more SPOT tags on makos — although this time by lifting the 5- to 6-foot sharks into the boat and onto a mat with specially designed tailers. At left, team works to quickly finish SPOT-tagging a mako off Maryland and finish measurements prior to its release.Courtesy George Schellenger / NSU-GHRI
Kit-Glove Handling and Speed of the Essence
The Mexican team took advantage of the custom aluminum platform to prep sharks, as at left. The Maryland team, on the other hand, had to put sharks in the cockpit. After a very short struggle and expert handling by Sampson, including quick removal of the barbless circle hooks, the sharks calmed down astonishingly quickly. The eyes of the sharks were covered with a wet towel, and a seawater hose was inserted into the shark’s mouth, keeping the gills well aerated. That’s when the GHRI “pit crew” moved in to quickly attach a SPOT tag under the watchful eye of Sampson. The entire process from lifting the makos into the boat to tagging, measuring, DNA sampling and release took just minutes. To release the fish, the mat with a shark on it was lifted over the gunwales, allowing the shark to “dive” into the ocean. This diving action seemed to really help revive the sharks quickly, as they all swam off very strongly. All eight tagged sharks have been reporting multiple times daily following their release (see Project 3 on the GHRI tracking website).Courtesy Guy Harvey / NSU-GHRI
Looking for Answers
The important bottom line for this whole exercise is to learn more about the abundance and migrations of this species in the western Atlantic and the Gulf of Mexico. We hope it will produce answers to questions such as: Is there a connection between these makos and those that roam the western Atlantic farther north in cooler climates? How much time do they spend in Mexican waters? How much time in U.S. waters or roaming the Caribbean? Where is the greatest fishing effort and by which country? Who is managing these fish? According to latest catch statistics, approximately a half-million mako sharks are killed each year in the North Atlantic. Of all the sharks harvested commercially, makos have the best-quality meat, plus their fins and teeth fetch a high price.George Schellenger / NSU-GHRI
Satellite Tags Helping to Provide Answers
One of our tagged makos, JoAnn, was caught by a commercial fisherman from Isla Mujeres in March this year after being at large just short of a year and providing the GHRI with some valuable data. Two makos tagged off Ocean City last year were caught and killed by commercial fishermen off Nova Scotia and Newfoundland at the end of the summer. We have definitely scratched the surface when it comes to understanding the movement patterns of these amazing sharks, but much remains to be learned.Courtesy Guy Harvey / NSU-GHRI
Let The Great Mako Race Begin
The GHRI is promoting the Great Mako Conservation Race, scheduled for March and April 2015 off Isla Mujeres. The project’s goal is increasing public awareness and understanding of this fascinating shark in a fun way, while at the same time increasing participation in citizen science and conservation, involvement I find that so many recreational fishers appreciate and are passionate about. Anyone who wants to be a part of this event and study can sponsor a SPOT tag and the satellite time for $3,500. This private sponsorship of tags will allow studying the movement behavior of these makos in exceptional detail, a key requirement for proper management and sustainable fishing. You can also charter one of Anthony Mendillo’s game-fishing boats and catch your own mako; the shark will be given your name. The tag batteries last nine to 14 months, depending on how frequently the tag is able to report information to satellites. Our record with makos is 16 months (and counting), and three-plus years on two different tiger sharks. The Great Mako Conservation Race winner (the longest distance achieved in six months from tagging date) will receive a fishing trip with hotel accommodations in Isla Mujeres. Ed. note: Mako sharks have long figured prominently in many of Guy Harvey’s original paintings such as “Fast Food,” shown here. His work helps fund research projects like this.Courtesy Guy Harvey Inc.