Roatan Institute for Marine Sciences
Anthony's Key Resort
Roatan, Bay Islands, Honduras
+504 9556-0212

Marine Habitats and Study Areas

Coral Reefs

  • Divers 2 students & instructor Dr Roy

The narrow crescent shape of Roatán has produced very distinct coastlines on the north and south.  The island possesses a narrow shelf width (1mile/2km) that typically drops off 150 m from shore.  Flourishing on this narrow shelf are miles and miles of coral reef. There are over 40 dive sites accessible from the resort by boat within 30 minutes.  While the reefs of Roatán are fringing or barrier in nature, each of these dive sites offers something different: steep and sudden walls, narrow canyons, overhangs and well developed spur and groves.  Most of these sites are also accessible to snorkelers.

Most of the diving and snorkeling site the students will visit are on the north side of the island and are located inside the Roatán Marine Park. The reefs on the northern coast of Roatán possess the characteristics of a barrier reef and are found further from shore and separated from land by a lagoon.  The lagoon on the north side ranges from several hundred meters in width near the western end of the islands and widens to over 1000 meters near the middle and eastern areas of the island.  The extensive back reef is dominated by extensive seagrass beds and healthy patch reefs. 

The island shelf is narrower on the south side and reef development is variable with no continuous barrier reef.  Reefs are fringing and nonexistent at the mouths of the many bays and harbors.  The reefs on the south are extremely different from the reefs on the north and are noted for their more pronounced drop offs and walls that tend to start in much shallower water. Due to the stronger currents that are often present on the south side there is a greater abundance of octocorals, sponges and other filter feeders on this side.

For a more detailed description of the reef environment  and dive sites please download the Instructor's Guidebook.

Mangrove Environments

Mangroves can be found lining the bights, bays, and coastline of Roatán and cover over 5% of the total land area on the island.  The most extensive cover of mangroves is found at the eastern end of the island and connects Roatán to the small island of Santa Elena. This area is a protected zone. Fortunately there is an area much closer to home for students to explore this diverse habitat.

  • mangrove snorkel

Man'O'War Key is located about 30 minutes to the east of RIMS. This is an ideal location to get up close and personal with a mangrove community. The key was formed through the land reclamation activities of the Red Mangrove (Rhizophora mangle). Currents have carved out deeper areas among the dense network of mangrove roots and undercut some areas creating a perfect area to snorkel.

Seagrass Communities

Where sediment has built up in the back reef, seagrass beds form rich underwater habitats. These highly productive communities serve as transitional zones between the mangroves and the coral reefs.  Turtlegrass (Thalassia testudinum) is the most common seagrass found on Roatán and is extremely abundant in the calm lagoons of the north shore.  There are xountless sites around the island for students to explore seagrass communities and the calm shallow waters they are found in make them easily accessible. Some sites can be accessed directly from RIMS.

East of RIMS the back reef area offers calm, relatively shallow seagrass beds are only minutes away from the facility.

Bailey's Key is another ideal area for exploring seagrass habitats and is a short taxi boat ride from RIMS. The shallow water ranges in depth from 2-15 ft (> 5m) .  This is also a great site for night snorkelling.

Blue Harbor Bight is where Man'O'War Key is located and offers one of the more undisturbed areas to snorkel.  The extensive mangrove community lining the shore and turtle grass beds in the lagoon leave the water crystal clear.  This area is outside of the marine reserve and is about 20 minute by boat from RIMS

Intertidal Environments

  • goucher intertidal crop

Most of the intertidal areas on the island are composed of the remains of ancient coral reefs.  This fossilized reef is the result of biolithification: a process over time and under intense pressure that cements together the remains of calcareous organisms. 

The resulting limestone is highly soluble and dissolves as waves and surf beat up against it, as rainwater runs over it, and boring organisms grind into it. The forces of erosion eventually produce a pitted, gnarled and gouged surface which the locals call ironshore". The ironshore is filled with channels, gullies and pools that hold an interesting diversity of marine life. There are several rocky intertidal areas to explore around Roatán. Some are minutes from RIMS

Bailey's Key is a short boat taxi ride from RIMS and several paths provide easy access around the island.

Anthony's Key is another short boat ride across the channel from RIMS and the backside of the key is a great place to have students wade around the ironshore

Flower's Bay Intertidal requires a 20-minute bus ride to the south side of the island. A short walk along the shire opens up to a large shallow bay of coral rubble and seagrass. The rubble is a great place to explore to find organisms unique to the intertidal.

West Bay Intertidal is located on the northwest tip of the island and requires a 15-minute bus ride. Rocky shoreline, ironshore, coral rubble areas can be found at this location. This site is one of the best places to observe the zonation of intertidal organisms.

Maya Key

Maya Key is the most recent addition to Anthony's Key Resort. This peaceful 11.5-acre key is conveniently located just three minutes across the bay from the town of Coxen Hole. There is a wide range of activities for students to engage in and a visit to Maya Key is included in the student package. One day a week students can plan to enjoy a BBQ lunch and spend several hours here between lectures and dives. Currently the Maya Key trip is on Monday. Please keep that day in mind when planning your itinerary. While students are on the key they can:

  • Visit the Bay Island's interpretation Center and Ethnic Honduran Art Exhibit Center and learn about Honduras' rich cultural heritage.
  • Explore life size replicas of the Copan Ruins.
  • Take a guided tour of the Animal Sanctuary and Rescue Center and see native Honduran wildlife such as jaguars, ocelots, margays, monkeys, parrots and reptiles.
  • SNORKEL!  A marked UW trail just of the scenic pier will lead students across the reef crest where they can explore some impressive reefs.
  • Enjoy the daily nurse shark, stingray and sea lion interactions.
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Geological sites

Roatán lies upon the Bonacca Ridge, an undersea extension of the Sierra de Omoa mainland mountain range, which extends ENE. To the north, the Swan Island Fault Zone separates the ridge from a deep ocean trench called the Cayman Trough. The movement along this transform fault zone is left later with the Bonacca Ridge area moving east relative to the Cayman Trough which is moving west.  To the south, the Bonacca Ridge is separated from the mainland of Honduras by the Tela Basin or Gulf of Honduras. The boundary between the ridge and the Tela Basin is a normal fault.  All of these features are part of the North Ameican/Caribbean plate boundary zone and consequently, the geology here is quite complex.

There are several locations and interesting outcrops along the island to study geological formations. A bus trip is required to visit these locations.