The Shark That Draws the Map - THE SCALLOPED HAMMERHEAD SHARK

Picture this.

You are moving through warm sea water, not hurried, not lost and not especially interested in anyone’s opinion.

Fish pass in flashes. Light breaks above you into silver pieces. Somewhere out there are reefs, open water, boats, nets, hooks, markets, records and rules. None of them are drawn on the water, of course. The sea is not thoughtful enough to provide signboards.

And then there is your head.

It is not subtle. It looks like a radar dish, a dinner tray and a very confident piece of navigation equipment had a meeting and somehow all got promoted.

This is the Scalloped Hammerhead Shark, Sphyrna lewini. It is a large, wide-ranging marine predator, recorded from Sri Lankan waters. It moves through a world where borders are invisible, but consequences are not.

In other words, this is not just a story about a strange-looking shark.

It is a story about routes.

It is a systems story wearing a very strange hat.

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Why The Scalloped Hammerhead Shark Matters

The Scalloped Hammerhead belongs to the hammerhead family, Sphyrnidae. It is not endemic to Sri Lanka. It moves through warm temperate and tropical seas, including the Indian Ocean, where the species is recorded from Sri Lankan waters.

It feeds on open-water fish, rays, other sharks, squid, lobsters, shrimps and crabs. That does not make it the “boss of the ocean”, which would be a silly thing to say and, frankly, an administrative nightmare. But it does place the species in the upper levels of marine food webs.

A peer-reviewed study from Mexico classified it as an opportunistic, higher-level predator, using diet studies and chemical clues in the shark’s tissue. In plain English, scientists looked at what it eats and what its body chemistry reveals about where it sits in the food web. For Sri Lanka specifically, strong evidence on its exact ecological function has not yet been confirmed.

So we should be careful.

We know it plays a predator role.

We do not yet know enough to make grand claims about exactly what its decline means in Sri Lankan waters.

That caution matters because good conservation storytelling should not behave like a man in a meeting who has just discovered a laser pointer.

The story of the Scalloped Hammerhead in Sri Lanka is not simply, “Look at this strange shark.” It is, “Look at what needs to work for a strange shark to remain visible inside a complicated marine system.”

This shark is globally assessed as Critically Endangered in the 2019 IUCN Red List assessment, with a decreasing population trend, across a wide warm-temperate and tropical range where large reductions are inferred from fisheries-related evidence and exploitation across much of the species’s range.

That is the anchor.

Not panic. Not drama.

A compass point.

And once you have a compass point, the next question is obvious: what is the route passing through?

The Challenge Is Not One Villain

The Scalloped Hammerhead’s problem in Sri Lanka is not one villain with a moustache and a boat.

It is more ordinary than that, which somehow makes it harder.

The main verified pressure is fishery mortality, which is the tidy technical phrase for sharks dying because they are caught in fishing operations.

In Sri Lanka’s case, the issue is not usually a boat going out with a sign that says, “Today, we hunt Scalloped Hammerheads.”

The shark appears inside a larger fishing system built around tuna, billfish, gillnets and longlines. A gillnet is a wall of netting in the water. Fish swim into it and get caught. A longline is a long fishing line with many baited hooks. Neither is cartoon-villain technology. They are ordinary fishing methods. The problem is that ordinary fishing methods can still catch extraordinary species. That means a Scalloped Hammerhead can be caught while fishers are pursuing other species. Once caught, sharks may still be retained as bycatch. Bycatch means an animal was not necessarily the main target, but ended up in the fishing gear anyway, which is rather like going to the supermarket for bread and coming home with a sofa, except much worse for the sofa.

In a 2019 Sri Lankan shark fisheries survey, Daniel Fernando and Akshay Tanna recorded 43 Scalloped Hammerheads. That number matters, but carefully. It is a survey result, not a national population estimate.

The wider Indian Ocean evidence also points to a practical problem: gillnets. The species has been described as extremely vulnerable to gillnet fisheries, and gillnet, handline, trolling and longline were listed among main gears for the species from 2011 to 2014 in the Indian Ocean context.

So far, this sounds like a fishing story.

Then comes the second layer: visibility.

This shark can become hard to see in two ways.

First, its wider population is under pressure.

Then, if we are not careful, it can vanish from the records.

Sri Lankan studies show that shark products can be difficult to identify when they are processed and no longer have visible features. A piece of shark meat is not always carrying a helpful little name tag saying, “Hello, I was a Scalloped Hammerhead; please update your database.”

This is why species-specific landing data, DNA barcoding, regular assessment and better recording are not boring technical details.

They are the map.

Without them, everyone is navigating with fogged glass and a great deal of confidence, which is one of the more dangerous human combinations.

There is also a trade and enforcement layer. Sri Lanka has a shark-management framework through the National Plan of Action for Sharks, with the Department of Fisheries and Aquatic Resources (DFAR) identified as the main implementing body in the 2013 document. Hammerhead sharks also connect to CITES-linked trade governance through non-detriment findings.

But the current public record does not yet give us a neat, species-level dashboard for S. lewini in Sri Lanka.

So the honest version is this:

The evidence is strongest for landings, bycatch, trade, reporting, identification problems and management needs. It is weaker for Sri Lanka-specific population size, nursery sites, migration routes and ecological function.

So the challenge is not simply, “Can Sri Lanka protect the Scalloped Hammerhead?”

The challenge is, can Sri Lanka see the hammerhead clearly enough, in the right places, at the right time, to make better decisions?

That is not a failure of the story.

That is the story.

And it explains why the work around this shark does not look like one grand rescue mission.

Who’s Doing Something About It

The people and systems visible in the public record are not gathered around a single “Save the Scalloped Hammerhead in Sri Lanka” programme.

The living system is broader.

It is shark and ray fisheries monitoring. Species identification. DNA work. Fisher engagement. CITES and non-detriment findings. Customs enforcement. National fisheries management. Regional Indian Ocean recovery planning.

That may sound less glamorous than a lone scientist leaping into the sea with a clipboard and perfect hair.

But it is probably closer to how conservation actually works.

The route is built by people who count, identify, sample, review, train, coordinate, check permits, improve records and ask better questions.

In other words, it is not one heroic doorway.

It is a corridor with many careful hands keeping the lights on.

The People Already Helping

Follow the route back from a shark landing record, and one of the clearly visible names is Daniel Fernando. He co-authored the 2019 Blue Resources Trust paper that documented Scalloped Hammerhead records in Sri Lankan shark fisheries survey work. His current public role connects to broader shark and ray work in Sri Lanka, including field visits to fishing sites, species identification in catches, fisher engagement and long-term monitoring.

Akshay Tanna, who co-authored the same 2019 paper, is also part of that visible route. Blue Resources Trust lists him as Director, Operations, connected to monitoring, species identification, data collection, tissue sampling, national checklist updates, CITES and CMS input, and e-NDF development. If Daniel is part of the map-making, Akshay appears closely connected to keeping the map usable. A map no one maintains is just a decorative rectangle.

Further along the route, where a shark can become difficult to identify by sight alone, Lankika Anjani is publicly linked to genetic identification work on Sri Lanka’s sharks and rays. Her documented work is not Scalloped Hammerhead-only; it also addresses one of the core problems affecting this species: knowing what shark is actually in the landing, market or trade pathway.

That same visibility problem also runs through the 2021 DNA-barcoding study led by M Aravinda Kishan Peiris and colleagues. Their work included Sphyrna lewini among shark species identified from Sri Lankan fishery landings and markets. This matters because DNA barcoding can help reveal species that ordinary market identification may miss, especially when products are processed.

None of this should be overstated. The public evidence does not show a current Sri Lanka-based, Scalloped Hammerhead-only project lead. What it does show is a network of people helping make sharks more visible in a system where invisibility is one of the problems.

And where visibility is the problem, the people who improve identification are not doing side work.

They are helping draw the route.

This is where the shark story becomes less cinematic and more useful.

The Systems That Quiet Work Runs Through

One part of the route runs through the Blue Resources Trust Fisheries and Policy Programme, one of the most visible non-governmental systems in this space. Its work includes long-term shark and ray monitoring, species identification, tissue sampling, checklist updates, training, CITES and CMS input, and e-NDF development.

If that system failed, Sri Lanka would lose a major visible channel for shark and ray monitoring and policy support.

The Sri Lanka Elasmobranch Project and the Blue Resources Trust field monitoring interface connect the work to fishing sites and fishers. Many answers are not found in offices alone. They are also found at landings, in conversations, in catch records and in the patient work of identifying what has actually come ashore.

The Shark and Ray Genetics Lab and DNA identification pathway help address the problem of species invisibility. When a shark is processed, the clues can be lost. Genetic work can help bring those clues back.

At the national-management end of the route sit the Department of Fisheries and Aquatic Resources (DFAR) and the Sri Lanka National Plan of Action for Sharks (NPOA). The 2013 NPOA identifies the DFAR as the main implementing body and places shark management within a wider fisheries system.

Its current implementation status needs updated verification, but the framework matters.

NARA and national shark fishery review systems help with catch review, gear analysis and understanding which fisheries contribute to shark catch. Without this layer, interventions become much harder to target well.

At the border end of the route sit Sri Lanka Customs and CITES trade enforcement. In 2021, Sri Lanka Customs reported a seizure of dried shark fins from CITES-listed shark species. The species-level details for S. lewini need case-by-case care, but the system itself is relevant.

CITES Non-Detriment Findings and e-NDF systems help evaluate whether exports of listed sharks and rays are legal and not detrimental. This is the sort of system that rarely gets applause, possibly because “non-detriment finding” sounds like something a printer says before giving up.

But it matters.

Beyond Sri Lanka, the route widens into the IOTC Scalloped Hammerhead recovery-planning system. For a wide-ranging shark, Sri Lanka is one part of a wider route. Regional reporting, stock assessment, bycatch mitigation, mortality reduction, species identification, habitat mapping and partnerships all matter because the shark does not politely stop at borders.

That is the awkward thing about sea creatures.

They have very little respect for paperwork, but their future often depends on whether the paperwork, people and practices can keep up.

What You Can Do

Easy

You could learn the name: Scalloped Hammerhead, Sphyrna lewini.

That sounds small, but naming matters. A shark hidden under “shark” is harder to protect than a species people can recognise, ask about and record properly.

You could forward this to someone who works in fisheries, marine science, customs, hospitality, food sourcing, education, media or government.

If this made you pause, forward it.

And if not, that’s okay too. You have still learned the shape of a problem most people never see.

Practical

When buying fresh fish or ordering seafood at a restaurant, ask one calm question:

“Do you know how this fish was caught?”

You may get a detailed answer. You may get a simple “I’m not sure.” Both are useful.

If the seller or restaurant knows the gear type, ask whether it was caught by gillnet, longline, handline, trolling or another method. Gillnets and longlines are part of the verified pressure picture for sharks, including Scalloped Hammerheads, in the Indian Ocean evidence.

The goal is not to embarrass anyone.

It is to make better seafood questions normal.

Because when customers start asking, suppliers and restaurants may begin asking too, and somewhere along the line, a shark that used to vanish into the word “bycatch” can become more visible.

That is one small way better questions can begin to spread.

One polite question at a time, which is generally how humans improve systems when we are not busy inventing more confusing ones.

Deep

You could help connect the people who hold different pieces of the route.

Fishers see the landings. Scientists verify species. Customs officers see trade pressure. Fisheries authorities shape management. Communicators help the public understand why it matters without turning it into theatre.

So if you know someone in fisheries, marine science, customs, hospitality, food sourcing, education, media, government or conservation, share this article with them and invite them to add what they know at www.srilankasendangered.com/respond

They may be able to correct something, add a missing detail, point us to better data, share a photograph, identify another expert or help us understand how this system really works from the inside.

The shark does not need louder panic.

It needs better navigation.

And navigation gets better when more people know what to ask.

You do not need to become a marine biologist by Thursday. Just make the invisible a little more visible.

We’ll soon include a link here that takes you to all the organisations already helping to fix these challenges. If you know someone doing great work, share this page (click) with them. We would love to feature their story and help them reach the world.

Your One Move

Ask, kindly and casually, “What fish is this, and how was it caught?” whenever you buy fresh fish, order fish or help choose fish for a home, hotel, event or restaurant.

Why This Matters

The strongest public action link is not dramatic rescue. It is helping make species and fishing methods less invisible.

Scalloped Hammerheads are caught within wider tuna, billfish, gillnet and longline fishery systems, and better species-specific information is one of the clearest needs.

A simple question, repeated by many people, may gently encourage better sourcing habits, better conversations and more respect for traceable seafood.

When You Might Actually Use This

This is an everyday action if you buy or eat fish even occasionally.

Most people will never meet a Scalloped Hammerhead at sea. But many do meet the seafood system at markets, restaurants, hotels, family meals and events. When enough ordinary people ask calm, practical questions, the culture around unidentified fish may slowly become more careful.

How To Do This

Ask, “What fish is this?”

Ask, “Do you know how it was caught?”

If the answer is unclear, simply say, “No worries, I’m trying to learn more about traceable fish.”

If the moment feels right, you could also share this article with the restaurant manager, fish sales manager, chef or buyer for a hotel and say, “I found this helpful because it explains why knowing the fish species and catch method matters.”

If You Can Do More

If you work in hospitality, events, catering, food purchasing or retail, add “species name” and “catch method if known” to your sourcing checklist.

If you know a fisher, fish seller, chef, buyer for a hotel or marine professional, share this idea gently: better identification helps everyone understand what is really moving through the system.

What We Still Need To Know

Nature and Science: Where is this shark actually using Sri Lankan waters?

This lens matters because conservation can become precise only when the animal’s real patterns are better understood.

Do Scalloped Hammerheads use particular Sri Lankan coastal areas more than others, or are most records connected to wider offshore and high-seas fisheries?

Are young sharks appearing in Sri Lankan landings in ways that suggest nursery use, or is the nursery question still open?

What would tagging, genetics, diet studies and regular landing assessments tell us about whether Sri Lankan records are part of local, regional or wider Indian Ocean movement patterns?

People and Culture: How do fishing communities experience this shark?

This lens matters because the shark is not moving through an empty ocean. It is moving through livelihoods, habits, markets and daily decisions.

When fishers encounter hammerheads, what choices are actually available to them at sea?

What do buyers, sellers and consumers know about the difference between shark species?

Could fisher knowledge help improve species reporting, if the system was designed with fishers rather than simply delivered to them?

Systems and Policy: What part of the route is weakest?

This lens matters because a wide-ranging shark needs working systems, not just concern.

Are Sri Lanka’s current shark-management actions clearly updated, publicly visible and connected to species-level data?

Can catch reporting, CITES trade controls and non-detriment findings speak to each other more clearly?

Where does the chain become blurry: at capture, landing, market, export or reporting?

Innovation and Technology: How can we make the invisible visible?

This lens matters because processed shark products and mixed-species landings can hide the truth.

Could DNA barcoding become a regular part of market and landing-site checks for threatened sharks?

Can digital tools support faster, clearer non-detriment findings and better species-level records?

How could citizen observations become useful without flooding experts with unverified claims?

Moral and Emotional Lens: How do we care without pretending we know more than we do?

This lens matters because honest care is stronger than dramatic certainty.

Can we teach people to care about a shark even when the story is incomplete?

Can we admit uncertainty without losing urgency?

Can we build public trust by saying, “Here is what we know, here is what we do not know and here is who can help us improve Version 2”?

Final Thought

The Scalloped Hammerhead does not fit neatly into our boxes.

That may be because it already has a better instrument on its head.

It moves through a sea without signboards.

We move through systems full of labels, forms, markets, permits and reports.

The least we can do is make sure they point to the truth.

For Advocates:

You’re not just reading, you’re lighting the way. Forward this to at least one other person.

For New Readers:

If this found its way to you, welcome.

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Version 2 — Whom We Want To Hear From Next

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If you’re that expert, click here or reach out to experts.srilanka@theplayn.com.

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