Invasive Cup Coral

A cluster of bright yellow-orange coral polyps
A yellowish version of orange cup coral observed at Sonnier Bank in 2010. (Image: FGBNMS/Hickerson)

Orange Cup Coral (Tubastraea sp.) is a hard coral species from the Indo-Pacific that has established itself throughout the Tropical Western Atlantic, which includes the Caribbean and Gulf of Mexico.

Although it is a hard coral, it is classified as ahermatypic, meaning that it is not considered a reef-building coral.

A section of a platform leg covered in cup coral colonies, sponges and hydroids
On some sections of platform HIA389A, within sanctuary boundaries, cup coral is more prevalent than hydroids and sponges. This image shows colonies of orange cup coral in two color variations--yellow and orange. (Image: FGBNMS/Schmahl)

Orange cup coral also lacks any symbiotic algae and is, therefore, not dependent on photosynthesis for food production. In fact, it actually prefers shaded vertical areas such as dock pilings, small caves, and walls beneath overhanging ledges.

The Invasion

Orange cup coral was first observed in Puerto Rico and Curacao in 1943. Since 1948 several specimens have been found attached to ship hulls, leading scientists to speculate that this is most likely how it arrived from the Indo-Pacific in the first place. Ship ballast water is another suspect.

From Puerto Rico and Curacao, orange cup coral spread via typical current patterns in the Caribbean, gradually migrating to the southeast along the coast of Brazil and northwest into the Gulf of Mexico.

A section of a platform leg covered in cup coral colonies, some closed and some with tentacles extended
Invasive cup coral is the dominant hard coral species on platform HIA389A and most other platforms in the Gulf of Mexico. (Image: FGBNMS/Schmahl)

In the Gulf, it seems to have found ideal habitat in the form of oil and gas production platforms, where it is the dominant coral species. Hundreds of thousands of colonies may exist on a single platform (Sammarco et. al. 2010).

With 2,000-3,000 platforms in the northwestern Gulf of Mexico at any time, and about 100 within 25 miles of the sanctuary, it's easy to see how orange cup coral arrived at the Flower Garden Banks.

The Concerns

Many studies of orange cup coral have been focused in Brazil where it has spread unchecked across much of their shallow reef ecosystem. Studies have also taken place in the Gulf of Mexico, focusing on oil and gas platforms. Through these studies, scientists have identified two main concerns.

  1. Orange cup coral displaces native corals and sponges. The more hard surface areas are colonized by invasive cup coral, the less space is available for native corals and sponges to establish themselves. In addition, some studies indicate that the cup coral uses chemical defenses to prevent other benthic invertebrates from settling nearby and predators from eating it.
  2. Cup coral colony on the reef at Geyer Bank
    Other area banks also show evidence of the orange cup coral invasion. This photo was taken in deep habitat at Geyer Bank. (Image: FGBNMS)
  3. Orange cup coral can reproduce within about 1.5 years of settling. The reproductive process involves the release of planula larvae that may float with currents for up to 14 days before settling, allowing plenty of time for them to travel to new locations.

The Response

The primary response to the presence of orange cup coral (Tubastraea coccinea) has been physical removal from the reef. By keeping the cup coral population from becoming too established, we hope to lessen its impact on native coral and sponge populations.

In July 2012, for example, sanctuary researchers discovered a section of reef at West Flower Garden Bank that was covered in orange cup coral and removed over 200 colonies of the invasive species in about 45 minutes.

Cup coral colonies at West Bank
Closed polyps of orange cup coral (Tubastraea sp.) appear more yellow than orange in this section of reef at West Flower Garden Bank in July 2012. (Image: FGBNMS/Schmahl)
Hundreds of orange cup corals inside a cooler of seawater
A cooler full of orange cup coral that was removed from the section of West Flower Garden Bank pictured above. (Image: FGBNMS/Schmahl)

Sanctuary regulations only allow for removal of invasive cup coral by sanctuary staff and others with appropriate permits.

At this time, there is no plan to remove colonies from artificial structures such as the platform located inside sanctuary boundaries at East Flower Garden Bank (Platform HIA389A).

What You Can Do

You can help us monitor the situation by reporting any sightings of orange cup coral within the sanctuary. Please include the date, time, and location of the sighting as well as an approximate heading and distance from the nearest mooring buoy.

A colony of cup coral with tentacles withdrawn
Closed polyps of orange cup coral (Image: FGBNMS/Schmahl)

During the daytime, colonies are usually closed and may not be as recognizable. At night, orange cup coral is usually feeding so its tentacles will be extended. Color may range from pale yellow to brilliant orange.

To report a sighting, please email us at flowergarden@noaa.gov