Gladden Spit and Silk Cayes Marine Reserve

Lore & Background

The reserve was declared on 18 May 2000 (Gazette No. 68/2000). In 2001, the feeding site of the whale sharks was declared a special protected zone, and tourism regulations were drafted to regulate the increasing number of whale shark tours. Since 2003, the reserve has been divided into a general use zone, a no-take zone around the Silk Cayes, a conch restoration zone, and a whale shark and reef-fish spawning aggregation conservation zone.

Gladden Spit is a promontory forming the southernmost tip of the sunken atoll, with a short sloping shelf that drops off steeply at about 40–2000 metres in depth within 10 kilometres of the reef. Three small cayes—North Silk, Middle Silk, and South Silk—lie south of Gladden entrance just inside Queen Caye. A nesting colony of terns has been recorded on North Silk Caye. The reserve contains some of the healthiest parts of the reef system due to its elevation and good water quality, and Gladden Spit itself hosts over 25 species of reef fish.

Since the 1920s, fishermen have congregated here to harvest mutton snapper and grouper during their ten-day spawning aggregation period that occurs between March and June. Historically, fishermen recorded substantial catches, and whale sharks—who come to feed on the eggs—were sighted in large numbers. It is the only place worldwide where this activity is known to occur.

Reader's Guide

The significance of Gladden Spit and Silk Cayes Marine Reserve lies in its unique ecological phenomenon: the only known location globally where whale sharks feed on the eggs of spawning reef fish. This event, tied to the ten-day spawning aggregation of mutton snapper and grouper between March and June, has drawn fishermen since the 1920s and later whale shark tours. The reserve's zoning system, established since 2003, reflects a management approach that balances conservation with regulated use, including a special protected zone for whale shark feeding declared in 2001. The reserve also contributes to the broader 1.2 million hectare Important Bird Area off Belize's coast, supporting species such as white-crowned pigeons, red-footed boobies, and roseate terns. Its healthy reef sections, attributed to elevation and good water quality, underscore its role in preserving part of Belize's Barrier Reef system.

From Dispute to Protected Waters

In the early 1980s, the waters surrounding Ambergris Caye and Caye Caulker faced a growing tension between two competing interests. Fish stocks were visibly declining, while tourism to the Cayes was climbing. At the heart of the conflict lay the Hol Chan cut, a natural break in the reef that served as both a productive fishing ground and a magnet for snorkelers and divers. When proposed fishing bans were turned down, the situation stalled until public consultations on a marine protected area began in the mid-1980s. International bodies, including the New York Zoological Society and the Peace Corps, lent their voices to the cause, pointing to the channel's unique geology, its rich conch and lobster populations, and the rare opportunity to protect an interconnected system of reef, seagrass, and mangrove habitats. Between 1985 and 1987, environmentalist Janet Gibson campaigned tirelessly among citizens, businesses, fishermen, and the Belizean government, and in 1986 she authored the Draft Management Plan that laid out the project's feasibility. The reserve was formally established in July 1987, backed by funding from WWF and USAID, with active enforcement of its rules beginning in 1989 and visitor fees for Zone A introduced the following year.

A Landscape of Four Zones

Spanning roughly 18 square kilometres of coral reef, seagrass beds, and mangrove forest, Hol Chan is organized into four distinct management zones. Zone A centres on the Hol Chan Cut itself, a natural gap in the barrier reef measuring about 23 metres wide and 9 metres deep. The name Hol Chan translates from Mayan as "little channel," a fitting description for this passage where the sea can drop to just 1.5 metres around the edges before sloping outward into the Caribbean. Zone B encompasses the seagrass beds within the reef and contains Boca Ciega Blue Hole, a sinkhole that opens into a larger underwater cavern, though its danger to inexperienced divers keeps most visitors away. Zone C covers the mangrove swamps along southern Ambergris Caye, where commercial fishing is prohibited but licensed sport fishing is allowed. In 1999, Zone D was added: Shark Ray Alley, a shallow sandy-bottomed stretch inside the reef that became a gathering ground for sharks and stingrays, originally drawn by the food scraps left when fishermen cleaned their nets nearby.

A Living Corridor of Species

Because the Hol Chan Cut opens directly to the sea beyond the reef, it functions as a living corridor through which marine creatures move freely between the lagoon and the open Caribbean. More than 160 species of fish have been documented within the reserve, alongside forty varieties of coral, five sponge species, two types of seagrass, three species of sea turtle, and three marine mammals: the short-beaked common dolphin, the pantropical spotted dolphin, and the West Indian manatee. The rocky outcrops shelter lobsters, moray eels, and sea anemones, while brain coral, elkhorn coral, and finger coral form the structural backbone of the reef. Jacks, groupers, snappers, and barracuda are regular sights, and spotted eagle rays and southern stingrays glide along the channel floor. The mangrove forests serve as critical nurseries, harbouring juvenile and adult blue striped grunts, French grunts, white grunts, gray snappers, French and gray angelfish, and seahorses. In Shark Ray Alley, nurse sharks and rays congregate in the clear shallow water, making the area a prime snorkelling destination.

Sustaining the Reserve: Goals and Pressures

When the reserve was created in 1987, its charter set four core objectives: preserving the coral reef ecosystem, balancing recreational and tourist use with the area's continued value to fisheries, creating a space for education and scientific research, and conserving genetic resources. Day-to-day oversight now falls to the Hol Chan Marine Reserve Trust Fund Committee, which took over from an informal advisory body in 1994. The committee's primary revenue stream is not direct ticket sales but a yearly licensing scheme applied to the boats of tour guides who access Zones A and D. After WWF funding ended in 1995, this model became essential. The results have been mixed. Fish stocks within the reserve have rebounded, yet the broader fishing industry in the region has continued to shrink. Adjacent mangrove clearance, over which the committee has no jurisdiction, still degrades connected habitats. Meanwhile, the very success of Hol Chan as a tourist draw is creating new pressures: rising visitor numbers strain facilities in San Pedro and Caye Caulker, and the growing foot traffic on the reef poses a tangible threat to coral health.