Are Sharks Getting Smaller? Could Hammerhead Sharks Be Next on the Banned-Catch List? Touring a Fishing Port with Expert Hsu Hua-Hsun

Full reprint from the Environmental Information Center: "Are Sharks Getting Smaller? Could Hammerhead Sharks Be Next on the Banned-Catch List? Touring a Fishing Port with Expert Hsu Hua-Hsun"

At Chenggong Fishing Harbor in Taitung, rows upon rows of catch are spread out on the ground. Fishermen work in teams: some weigh the fish and slap on price-and-weight tags; others slice off fins, heads, and organs; a few grab flexible hoses to wash away the slime and blood pooling underfoot.

A fishing boat pulls alongside the dock. Fishermen haul one Blue Shark after another — locally known as water sharks — up onto the wharf; their skin gleams and slides under the light, their eyes still clear and bright. A startled murmur runs through the small crowd: a large Scalloped Hammerhead Shark is being brought ashore. Despite the panoramic vision those distinctive heads afford, this one clearly never saw the net coming. Thwack. Thwack. Two more Hammerhead Sharks, each no longer than a forearm, are stacked up and left to wait for the next round of weighing, cutting, and shipping. These apex predators of the sea have stopped struggling.

In many parts of the world, sharks caught as bycatch or subjected to finning-and-discarding are described as "wasteful shark killing." In Taiwan, however, the Fisheries Agency frames sharks as a case of "whole-fish utilization" — smoked shark served at local eateries, fish-paste products with no declared origin or ingredients, fish liver oil: shark turns up everywhere.

Dr. Hsu Hua-Hsun, a shark-resource and conservation expert with more than 20 years in the field, accompanied his students and a reporter from the Environmental Information Center on a walk through the harbor, observing and explaining the state of Taiwan's shark resources as he went. He believes that seeing things first-hand is what plants — and nurtures — the seed of conservation.

Hammerhead Sharks Enter the Fishing-Ban Discussion — But a Transition Period Is Needed

In early March 2025, the Ministry of Agriculture announced a forthcoming ban on catching Zebra Sharks, Blacktip Sharks, and Mobulidae rays in coastal and offshore waters, to take effect on 1 January 2026. Combined with the existing protections for Great White Sharks, Whale Sharks, and Megamouth Sharks, Taiwan now has six species of shark under a capture ban.

When the reporter accompanied Hsu Hua-Hsun on a visit to Chenggong Fishing Harbor earlier this year, Hsu mentioned that Hammerhead Sharks were also expected to become a protected species in Taiwan — yet they did not make it onto this latest ban list.

Three species of Hammerhead Shark appear regularly in Taiwan's catch: the Great Hammerhead Shark, the Smooth Hammerhead Shark, and the Scalloped Hammerhead Shark.

Of these, Hsu says the Great Hammerhead is now caught "extremely, extremely rarely" — possibly fewer than ten individuals per year. At a November 2024 consultation meeting on management measures for coastal and offshore cartilaginous fish, the Fisheries Agency, fishing associations, academics, and relevant stakeholders agreed to include the Great Hammerhead in the capture ban, noting that "it would have virtually no impact on fishermen." The management approach for the other two species is still being deliberated, because the sizes landed on Taiwan's east and west coasts differ, and so do the fishing methods used; further study is needed to determine the most effective management framework.

It is worth noting that all three Hammerhead species are already banned from capture in the Atlantic. In response to the Environmental Information Center, the Fisheries Agency stated that Hammerhead Sharks attract significant attention both domestically and internationally. CITES has listed them under Appendix II — meaning they face no immediate extinction threat but require regulated trade to prevent jeopardizing their survival. The Agency noted that import and export trade in Hammerhead Sharks will comply with convention requirements; it has already asked the Ministry of Economic Affairs' Bureau of Foreign Trade to add the relevant tariff codes for the species, and plans to conduct coastal and offshore surveys and resource assessments for hammerhead species this year, with management regulations to follow based on the results.

Hsu consistently stresses that any ban should minimize the impact on fishermen. If enforcement does proceed, he suggests starting with a total allowable catch: once the limit is reached, fishermen could simply bring the shark to the side of the boat, cut the line, and release it back into the sea. Fishing-method restrictions are also part of the equation — for example, limits on coastal trawling and drift gill-netting.

Implementing a ban has never been easy. Hsu says fishermen need a transition period — it cannot happen overnight. He uses the Whale Shark as an illustration: resource surveys began in 2001; a catch quota system was introduced in 2002 at 80 individuals per year, gradually reduced to 30 by 2007; from 2006, capturing Whale Sharks shorter than 4 m in total length and the use of harpoons were prohibited. A full ban on Whale Shark fishing and product trade only came into force in 2008 — "complete conservation, eight years in the making."

On this long road toward conservation, Hsu sometimes tells fishermen that the Philippines began reforming shark fishing in the 1990s, at a time when Filipino incomes were lower than Taiwan's — and yet they managed to protect the sharks. That, he says, gives Taiwanese fishermen cause for reflection.

Sharks Are Part of Fishermen's Livelihoods — But How Much Are They Worth?

Hsu explains that most sharks in Taiwan's coastal and offshore waters are bycatch. Shark meat does not fetch a high price, but it still contributes to overall earnings: "They still have a value" — NT$10 per kilogram, so 50 kg brings in NT$500. There are also practical fishing considerations: going out once a day to set a net does not make it worthwhile for fishermen to spend the time and effort hauling gear just to release a few sharks. "If the catch is small that day, the sharks become part of the income; if the catch is large, there's no time to deal with them — the priority fish get processed first." The sharks left over can, of course, end up dead.

The most valuable part of the shark is the fin. Fins are typically processed domestically and used as shark fin for restaurants and the trade; they are exported primarily to Singapore, followed by China and Hong Kong. Shark meat is exported mainly to South American countries and South Korea.

At the end of 2024, the IUCN published its first comprehensive report on sharks, rays, and chimaeras in 20 years — The global status of sharks, rays and chimaeras. The Taiwan section was co-authored by Hsu Hua-Hsun and two other researchers. The report notes that the Fisheries Agency announced Taiwan's first National Plan of Action for Sharks (NPOA-Sharks) and International Plan of Action for Sharks (IPOA-Sharks) in 2006, and subsequently formulated a second NPOA-Sharks in 2012 — which has yet to be implemented.

Hsu also points out that there are marked differences in habitat type and fishing methods between Taiwan's east and west coasts, and that understanding the habitat use of common species on both sides is crucial to developing further management policy. He adds that biological and ecological research on these species remains scarce; molecular techniques need to be applied to identify species within certain population groups. Research on heavy-metal and pollutant accumulation in sharks, rays, and their products — particularly benthic and deep-sea species — is also insufficient.

Hsu elaborates that because the habitat, species, fisheries, trade, and utilization of sharks, rays, and chimaeras are so varied and complex, establishing a single large-scale marine protected area (MPA) for them is extremely difficult. He recommends starting with targeted management and protection of key species and populations — for example, size limits, gear restrictions, and total allowable catch limits; requiring that whole specimens be landed (finning at sea banned); designating area-specific MPAs; and mandating more comprehensive catch or landing reports. NPOA and IPOA frameworks must also be reviewed and updated.

The Fisheries Agency, for its part, states that it has established "Guidelines for the Handling of Shark Fins by Fishing Vessels" to eliminate finning-and-discarding, and that it cooperates with international fisheries management organizations on shark management measures, rolling out adjustments to relevant management and control measures based on resource assessments, with the goal of achieving sustainable use of shark resources. The Agency emphasizes that an outright ban is a last resort, not a necessary first step.

Students Who Love Diving Don't Want to Study Dead Things

In fact, Hsu does not advocate a blanket ban on shark fishing. "I wouldn't object to people eating them — I just think they can be utilized, but sustainably."

He has loved the ocean since childhood. More than 20 years ago he entered the field, enrolling in the fisheries department at a maritime university, going out to sea for a month of practical training, learning longlining, and even sailing from Taiwan to Japan — "a truly rare experience." In the early days, fisheries departments focused on teaching students "how to catch fish more efficiently" and "where fish can be found"; later, curricula expanded to include the environmental impacts of catch, and resource and ecological management.

Hsu serves as a research assistant at the Coastal and Offshore Fisheries Biology Research Center of the Fisheries Research Institute under the Ministry of Agriculture, and concurrently as an adjunct assistant professor at the Institute of Marine Ecology and Conservation at National Sun Yat-sen University. Over the course of his research career, he has observed that overall shark catches have been declining for nearly 20 years. "Fishermen themselves know the sharks are getting fewer and smaller."

Much of Hsu's research data comes from fishermen, which requires investing considerable time in building trust. "You have to patiently listen to their conversations — though their experience isn't always accurate," he notes. A fisherman might only remember the one trip when the catch was enormous, for instance; the actual situation still needs to be independently observed and filtered.

Beyond this, there is a chronic shortage of researchers. Fishing markets are smelly with blood, wet, and dirty — not an appealing environment — and Taiwan has relatively few programs or graduate institutes focused on marine ecology. Graduates who do pursue fisheries resource and conservation work face not only the likelihood of "not being able to make much money," but also constant travel between the main island and outlying islands, making it hard to attract newcomers to the field.

Beyond staffing, funding is the most critical issue. "The Fisheries Agency has a smaller budget and too many things to manage. The Ocean Conservation Administration has more resources and can conduct more surveys."

Yet Hsu remains optimistic about the future of shark conservation. He feels that today's students have far more opportunities to engage with the ocean than previous generations — "Those who love diving don't want to study dead things" — and he hopes Taiwan will develop more immersive ocean tourism, such as boat dives to observe cartilaginous fish, which would also give fishermen a direction for transitioning their livelihoods.

"Of course I hope sharks aren't only seen at fishing markets, or only in aquariums — I want people to truly encounter them in the sea. Because when you see them, you feel something," he says.

Further Reading

• Original article: Are Sharks Getting Smaller? Could Hammerhead Sharks Be Next on the Banned-Catch List? Touring a Fishing Port with Expert Hsu Hua-Hsun
• Fisheries Agency Announces Coastal/Offshore Ban on Zebra Sharks, Blacktip Sharks, and Mobulidae — Violators Face Fines of up to NT$150,000