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Boulder Star Coral

Orbicella annularis


Previously known as Montastrea annularis, Orbicella annularis is one of the most dominant species across the Caribbean and Gulf of Mexico where it can form extremely large colonies which vary in morphology.

Unfortunately this species is also classed as ‘endangered’ due to high population declines. For example, 90% of the coral cover of this species was lost off the coast of Jamaica in 1994. Within the same year this species was split into three distinct species; O.annularis, O.faveolata and O.franksi.

The considerable morphological variation within this species is characteristic throughout the Orbicella genus and there has such has been much debate over specific taxonomic affinities. The sheer size of the species in this genus makes them ecologically and structurally important additions to coral reefs as they provide refuges for reef dwelling species and can alter microclimates to suit other coral species.

  • Order: Scleractinia
  • Family: Faviidae
  • Trend: decreasing
  • Depth Range (m): 1 - 82

EDGE Score

EDGE Score: 4.35 (?)
ED Score: 8.67 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct


O.annularis is found across the Caribbean, Gulf of Mexico, Latin America and north to Bermuda.

Habitat and Ecology

O.annularis is a common species within its range and is often one of the most abundant and dominant species in shallow water reef environments.

Given the right water conditions and light penetration it can be found down to depths of 82m!

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Conservation Actions

For each key category of conservation action, we calculated a conservation attention score based on expert information. In this graph, a higher score means the action is being carried out more intensively over more of the species range. The colour shows how important each action is considered to be for the conservation of this species.

Engaging stakeholders
Addressing threats
Status of knowledge
Management plan
Capacity building
Behaviour change
Awareness raising
  Score: 100 means the activity occurs at high level across more than 75% of the species range
Very Low

Overall Conservation Attention

We combined all of the expert information on conservation actions to calculate an overall conservation attention score for this species. Please help us to reach our goal of establishing dedicated conservation attention at “High” levels for all EDGE species.

Very Low Low Medium High

More information

Recent studies have grouped all possible conservation activities for any species into nine key categories (Washington et. al 2015). For each action, we asked experts for each species to assess the extent to which that action is being carried out and how much of the species’ range that action occurs in. For each action we used these two pieces of information to calculate the conservation attention score per action. A score of 100 means that the action is being carried out to a high level across at least 75% of the species range. We then combined the scores for all actions into an overall conservation attention score for the species. The experts also judged how important each category was to the conservation of that particular species.

Download the survival blueprint for this species below either in English or Spanish. Each survival blueprint is compiled by an EDGE Fellow working on the species with input from collaborators and stakeholders. The Survival Blueprint provides a status review (information on the distribution, protection status, habitat & ecology, threat and stakeholder analysis) and more information on the action programme listed here.

Vision (30-50 years)

Persistence of Orbicella populations and coral reefs in Morrocoy National Park and Cuare Wildlife Refuge, Venezuela

Goal (5-10 years)

Improve local management and awareness of coral reefs and Orbicella populations in Morrocoy National Park and Cuare Wildlife Refuge, Venezuela


Promote an updated Management plan for MNP, based on novel scientific knowledge, to include special zoning for key reefs where Orbicella annularis colonies still occur High
Improve local knowledge about the importance of Orbicella species and coral reefs for their wellbeing and livelihoods Critical
Design and implement a monitoring program of Orbicella species to update information on the status of this subpopulation to inform management and conservation strategies Critical
Design and implement a program to monitor spatial and temporal changes in land-based pollution and thermal stress to coral reefs Critical

Ana Yranzo Duque

  • Project name: Orbicella status after two decades of the massive death, Morrocoy, Venezuela
  • Project site: Morrocoy National Park, Venezuela
  • Active: 2018 - 2020
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