Tiger Sharks: Size, Facts, and Fuvahmulah's Population

The tiger shark (Galeocerdo cuvier) is a large apex predator reaching around 5 m, listed as Near Threatened on the IUCN Red List (2019). Fuvahmulah hosts the world’s largest documented aggregation — 239 identified individuals, 84.5% female — and a 2024 study found 26 of 28 scanned females pregnant, the first known gestational ground in the Central Indian Ocean.

That combination is what makes diving with tiger sharks here different from anywhere else. To understand why, it helps to separate two things: what a tiger shark is as a species anywhere in the world, and what is specifically, measurably extraordinary about the animals at Fuvahmulah. This page covers both, starting with the biology.

What is a tiger shark?

The tiger shark is one of the largest predatory sharks in the ocean and the only living member of its genus, Galeocerdo. It takes its name from the dark vertical bars along its flanks — bold in juveniles, fading as the animal ages. A tiger shark is easy to recognize underwater: a stout body tapering to a slender tail, a broad blunt snout, and large dark eyes.

Adults typically measure 3.25–4.25 m (10–14 ft) and weigh 385–635 kg, though the species grows larger. Females outgrow males, and the largest reliably verified tiger shark was a 5.5 m female recorded in Queensland. Individuals over 4.5 m are genuinely rare — perhaps one in two hundred — which is worth remembering when you hear the big Fuvahmulah females described as “five-meter” sharks. Newborns are already 51–90 cm at birth.

Tiger sharks are found worldwide in tropical and warm-temperate seas, using both coastal shallows and open ocean across their lives. They are apex predators, sitting at the top of the food web wherever they live, and they have the broadest diet of any shark: fish, rays and other sharks, crustaceans, molluscs, sea turtles, sea snakes, seabirds, marine mammals, and — notoriously — indigestible debris they’ve swallowed. Their teeth are the tell: large, curved, and finely serrated with a deep notch, purpose-built to shear through hard prey like turtle shells. Juveniles take smaller prey and shift toward larger animals as they grow.

Movement is where tiger sharks surprise people. Across their range they are among the most mobile of all sharks: individuals have been tracked on annual round trips of more than 7,500 km in the Atlantic, and one South Pacific shark logged roughly 17,000 km over 468 days. Many populations show seasonal migrations tied to water temperature and prey, and their range has been creeping poleward as seas warm. That global wanderlust is exactly what makes Fuvahmulah’s resident, returning females so unusual.

One more piece of biology matters for the Fuvahmulah story: how tiger sharks reproduce. Unlike most of their relatives, they don’t use a placenta. Embryos develop from large eggs and, once the yolk runs out, switch to feeding on uterine fluid — a strategy called aplacental viviparity. Gestation runs roughly 13–16 months, and litters can range from about 10 to 80 pups. That long pregnancy is central to what researchers found here.

IUCN status: Near Threatened

The tiger shark is listed as Near Threatened on the IUCN Red List, assessed in 2018 and published in the 2019 assessment (Ferreira & Simpfendorfer 2019) — the most recent global evaluation. The population trend is decreasing, with a suspected decline of around 30% over roughly three generations, driven mainly by fishing pressure and the fin and meat trade.

That status is part of why Fuvahmulah matters beyond tourism. The Maldives is a national shark sanctuary, and the island’s aggregation is one of the best-studied and best-protected tiger shark populations anywhere — a rare bright spot for a species in slow global decline.

Why Fuvahmulah’s population is scientifically exceptional

Here is where the numbers become genuinely remarkable. A 2024 study in Scientific Reports (Vossgaetter et al.) photo-identified 239 individual tiger sharks at Fuvahmulah between 2016 and 2023 — the largest documented aggregation of the species anywhere on Earth, in a single geographically restricted spot a minute’s boat ride from the harbour.

Three findings from that study explain why divers see so many, so consistently. The resighting rate was 77.8% — most identified sharks were seen again across the seven-year study, the hallmark of a resident population rather than transient visitors. Study dives averaged 10.4 sharks each. And on any given day the site held roughly 26 adult females plus around 16 juveniles. Adult females showed strong site fidelity within and across years, with a mean residency of about 61 days and a mean absence of about 110 days before returning — a pattern of leaving and coming back, not passing through.

The single most striking figure is the sex ratio: 84.5% of the identified sharks were female, wildly skewed from the roughly 1:1 ratio tiger sharks are born at. The explanation came from a second 2024 study, in Frontiers in Marine Science (Sulikowski et al.), which used a submersible ultrasound to scan the big females. Of 28 adult females scanned, 26 were pregnant — one of the highest pregnancy rates ever recorded for the species, and the evidence that Fuvahmulah is the first confirmed tiger shark gestation ground in the Central Indian Ocean.

Put those together and the picture is of a nursery for expectant mothers. Pregnant females appear to gather here through their long gestation, in warm, calm water with a steady food supply, returning across years — which is exactly why “any month” is an honest answer for tiger shark sightings. The photo-ID work also logged 54 pregnancies across 39 individual females and several sharks pregnant in consecutive cycles, hinting the population may breed more often than the once-every-few-years cycle assumed elsewhere. This is wonder measured in numbers, and it is why researchers keep coming back.

Solitary hunters that turn out to be social

Tiger sharks have a reputation as solitary, mostly nocturnal hunters, and across most of their range that holds — they roam and forage alone. The long-term work at Fuvahmulah complicated that picture. A 2025 study of 40 photo-identified mature females here documented 36 non-random, pair-wise social interactions: sharks giving way to one another, swimming in parallel, following, and standing back, along with newly described antagonistic behaviors researchers labelled submission and push-away.

Those interactions point to a size-based dominance hierarchy, with a handful of individuals accounting for most of the encounters — structure you wouldn’t expect from a purely solitary animal. For a diver, it’s a useful reframe: the sharks circling the sand aren’t a random crowd but a set of returning individuals with recognizable relationships, which is part of why researchers can name and track them year after year.

The honest part: provisioning and Tiger Harbour

It would be misleading to describe Fuvahmulah’s tiger sharks as a purely wild aggregation that simply happens to gather offshore. The concentration at Tiger Harbour is at least partly provisioned, and the history is worth knowing.

Fuvahmulah’s traditional tuna fishery goes back centuries, and boats have long discarded fish waste at sea — sharks have gathered around returning vessels for generations. The modern dive site formed more recently: the harbour was built in 2003 with a fish market, and fish waste dumped there drew tiger sharks in. When regulations moved waste disposal outside the harbour in 2017, a dive operation began placing fish scraps at the harbour entrance, concentrating the sharks at what is now Tiger Harbour, on a sand plateau at about 8–10 m depth.

So the reliability of the encounter is genuine, and the resident, pregnant population is genuine — the science on both is solid — but the animals are drawn to a specific spot by a food source managed for diving. Provisioning of wild sharks is a real and debated conservation topic, and there are as yet no standardized Maldivian regulations for provisioned shark dives; the codes in place are voluntary and operator-issued. Knowing that context lets you dive here with clear eyes rather than a marketing version of the story.

Observing tiger sharks responsibly

Because this is a provisioned dive with a large apex predator, how you behave in the water matters — for the sharks and for you. The most concrete local standard is the Guidelines for Ethical Diving at Tiger Shark Point, issued by the Fuvahmulah Scuba Club (an operator, not a government body). Its rules are a good baseline whoever you dive with:

• No touching or handling the sharks — the single firmest rule.
• Stay in a compact group and hold your position on the sand, rather than spreading out or chasing.
• Dark wetsuits; flashy colours are discouraged, and cameras are kept away during descent and ascent.
• One guide per four divers, a maximum dive time around 45 minutes, and a depth range of roughly 5–30 m.
• The code recommends Advanced Open Water certification and 100 logged dives — above what some operators require, but a sensible bar for a current-exposed dive with big animals.

The guiding principle behind all of it: you are a visitor at close range to a wild predator that lives here, so let the guides manage the encounter and let the sharks set the terms.

Next step

Reading about a 239-shark aggregation is one thing; kneeling on the sand as a line of them cruises past is another. The tiger shark diving guide covers how the dive actually works — the site, the depth, the certification you’ll need, and what the encounter feels like from the first briefing to the safety stop.