Saving the Scalloped Hammerhead: The Pacific Battle

Published: 09 June 2026. The English Chronicle Desk. The English Chronicle Online.

The unmistakable fluted T-shape of a scalloped hammerhead shark slides silently through the deep blue waters. A diver holds his breath while gripping a metal spear that resembles an extra-long snooker cue. The sharp spear quickly hits the creature right behind its dorsal fin during the brief encounter. The two-metre shark immediately darts away into the ocean feeling disgruntled but remaining otherwise completely unharmed. Carlos Robalino is a passionate marine biologist from the remote and beautiful Galápagos Islands. He originally trained as a professional shark researcher within the coastal waters of Mexico. Now he is back home working as a dedicated junior researcher for the foundation. When we meet in March he is participating in a critical marine research expedition. The team is exploring Darwin and Wolf which are the most northerly islands here. For three or four hours each morning and afternoon Robalino is in the sea. He is constantly honing his free-diving skills to get close to the sharks. This allows him to take vital samples of their skin for scientific analysis.

Scalloped hammerheads are super-sensitive and very nervous creatures according to ecologist Simon McKinley. The trick is to wait for the shark to pass directly under his body. He waits until they cannot possibly see him floating quietly in the water column. Then he can safely dive down to collect the necessary tissue sample today. The small plug of skin from the tip of the spear is valuable. It is added to a decade worth of biopsies collected from these sharks. The magnificent species visits these specific islands in absolutely massive numbers throughout the year. However the species is critically endangered having declined by eighty percent globally so far. This devastating decline is largely due to relentless overfishing across the open oceans. Yet you would not guess this while diving at Darwin and Wolf today. On most dives during the trip dozens of these sharks swim by beautifully. Later in the year during the cold season food becomes much more abundant. More sharks migrate to the archipelago and the local population quickly quadruples online.

At its peak about one hundred and fifty sharks roam each hectare here. This is roughly the area of the famous Trafalgar Square in London. There can be so many sharks that they literally blot out the sun. Despite their local abundance studying these animals in the Galápagos is very difficult. Researchers cannot simply catch these sensitive sharks because handling stress could easily kill them. Therefore the foundation team has successfully developed several innovative and less invasive techniques. They are deploying advanced underwater cameras to monitor overall shark numbers over time. Chemical analysis of skin biopsies shows exactly what the sharks are eating now. This removes the need to cut open their stomachs to see contents. From twice-yearly visits to these islands the team builds a long-term picture. They track how sharks are responding to changing environmental conditions across the region. This includes the major heatwaves linked to the big El Niño of twenty-twenty-six. More immediately the team is tracking where these sharks go after leaving here.

Scalloped hammerheads are not permanent residents but set off on long seasonal migrations. To learn about this part of their lives requires another advanced diving technique. Away from the free-divers at Wolf Island Pelayo Salinas de León waits. He sits patiently on the seabed using a specialised closed-circuit rebreather device today. This advanced equipment recycles his exhalations and removes harmful carbon dioxide very efficiently. It adds more oxygen as needed so he can dive safely for hours. He enjoys bubble-free tranquillity without scaring off the sensitive hammerhead sharks nearby. Like his colleagues he uses a spear with a satellite transmitter tag attached. This high-tech tag is worth close to two thousand dollars or fifteen hundred pounds. He has worked as a senior marine ecologist here for fourteen years. Salinas de León has experimented with different methods to perfect this stealthy approach. He enjoys sneaking up on sharks while they are swimming completely freely online.

This was how he deployed a critical satellite tag back in twenty-twenty-three. That tag tracked a scalloped hammerhead swimming from the Galápagos to Panama successfully. This represented an incredible eight-hundred-mile journey across the vast and perilous ocean. After that the shark embarked on a westerly migration of another eighteen hundred miles. Since then he has successfully tagged dozens more hammerheads within the protected archipelago. Eight out of ten tagged sharks have swum directly to Panama waters. Judging by their bulging bellies most are probably pregnant females nearing birth. They are reaching the end of their typical nine-month gestation period right now. They give birth in the sheltered waters of coastal mangrove forests nearby. These vital habitats are in short supply along the rocky Galápagos shores. Uncovering these birthing migrations is proving absolutely crucial for conserving the endangered species. Signals from the satellite tags deployed on the latest expedition show great results.

Some sharks had already left the islands and were travelling towards Panama quickly. This happened at the same time that protection measures were dialled up globally. In March Salinas de León took his scientific findings to an important meeting. He attended the Convention on the Conservation of Migratory Species in Brazil recently. A crucial vote was taken to recategorise these sharks into Appendix One status. This status gives them the highest level of legal protection under the convention. Our science has shown that these are highly migratory sharks across the oceans. Their migrations are entirely periodical cyclical and predictable according to the lead researcher. This evidence ticks all the boxes for securing the new protective listing today. The vote passed and signatory countries must introduce strict new domestic laws now. They must fully protect the species within their territorial waters going forward safely.

Throughout their long migrations from the islands these hammerheads face immense danger daily. They pass through numerous jurisdictions and encounter countless fishing nets and lines today. Their perilous journey always starts in the protected waters of the Galápagos islands. Even though these islands lie within a marine reserve illegal fishing still happens. During the March twenty-twenty-six expedition the team found multiple illegal longlines floating. One line was tens of metres long with dozens of hooks attached. This dangerous line got tangled around their research boat during operations unexpectedly. Another line was threaded around the iconic sea stack known as Darwin Arch. It had unfortunately hooked two green turtles before the team rescued them safely. Last year they released a hammerhead shark from an artisanal longline here. Between Galápagos and Panama there are several important no-fishing zones established today. The hammerheads should be safe within the expanded Hermandad marine reserve boundaries.

This protected area extends eastwards towards the famous Isla del Coco national park. But there are still massive gaps along the way where fisheries operate. There is a legal free-for-all in many parts of the ocean today. There are hundreds of thousands of boats that are fishing legally there. If they can reach Panama pregnant sharks are still at major risk. Panama recently banned the international shark trade but artisanal fishing remains permitted. Baby hammerheads and pregnant females are still being caught regularly by locals. They are being sold and consumed as ceviche in local markets daily. The foundation team is now working closely with authorities in Panama today. They want to introduce much greater protections for the sharks in nurseries. The Panama nurseries are key to the survival of this entire species. It is vital to implement additional management to reduce the catches there.

This breeding season surviving hammerhead mothers will turn tail after giving birth successfully. They will head due west past the Galápagos islands once again. They will continue another twelve hundred miles to the Pacific equatorial front area. Yet more troubles await them in this distant region of the high seas. Mixing ocean currents stir up a massive profusion of marine life there. This attracts female sharks that need to feed and restore energy reserves. However it also attracts massive industrial fishing fleets to exploit the rich waters. This is where the research team hopes to take their operations next. They want to work out if seasonal closures could help protect sharks. You can have a false impression of security while diving here today. You see hundreds of hammerheads because this site has been protected since ninety-eight. The Galápagos represents a beautiful bubble frozen in time for marine life. You can still see the ocean of the past filled with sharks. But they are still dying elsewhere so we must do much better.

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