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  • Writer's pictureKat Hickey

A Closer Look at CCA Coverage on IntelliReefs: Uncovering the Role of Crustose Coralline Algae in Ocean Ecosystems.

Updated: Mar 11


A Closer Look at CCA Coverage on IntelliReefs

Site Location: Sint Maarten, Caribbean

[Photos taken 14 months after deployment.]

Nature Metrics DNA-based monitoring
"Crustose Coralline Algae (CCA) observed on IntelliReefs has higher coverage compared to nearby natural reefs."

What is Crustose Coralline Algae (CCA)?

Crustose Coralline Algae (CCA) represent a ubiquitous and ecologically significant component of marine benthic ecosystems, encompassing a diverse assemblage of calcified red algae species. These encrusting organisms play pivotal roles in reef ecology and carbonate accretion processes through their production of calcium carbonate deposits, thereby contributing to reef structure and stability. Characterized by their hard, crust-like thalli adhering firmly to various substrates, CCA exhibit a remarkable array of morphological and physiological adaptations facilitating their survival in a range of environmental conditions, from polar to tropical regions.

Crustose coralline algae, a natural reef binder, attracting coral spawn for healthy coral settlement.

14 months after deployment

Furthermore, their vivid pigmentation not only endows them with aesthetic value but also serves as a vital indicator of reef health and resilience. Despite their inconspicuous stature, CCA serve as ecological engineers, exerting profound influences on nutrient cycling, sediment stabilization, and the settlement of coral larvae. Understanding the intricate ecological functions and dynamics of CCA is imperative for effective reef conservation and management strategies in the face of escalating anthropogenic stressors and climate change impacts.


CCA: The Partner of Oceanite

The Law of Attraction Underwater


IntelliReefs CCA Scientific Report

Image 2: Picture highlighting the biodiversity found on one  of the IntelliReef structures after 14 months from initial  deployment
Image 2: Picture highlighting the biodiversity found on one of the IntelliReef structures after 14 months from initial deployment

During our second data collection trip between January 27-31, 2020, funded through the Waitt Foundation’s Rapid Ocean Conservation (ROC) Grant, our scientists found that the IntelliReef structures had nearly 100% coverage of biological organisms after just 14 months (Image 2).

From these initial surveys and the ongoing analysis being performed, we have documented the settlement of species that facilitate the growth of a healthy, diverse, and resilient benthic coral reef community, including crustose coralline algae (CCA), macroalgae, scleractinian (reef-forming) corals, and sea sponges (Image 3).

Image 3. Natural coral recruit found on the IntelliReef structure
Image 3. Natural coral recruit found on the IntelliReef structure(14months)

Our data also shows the important role IntelliReefs play in fostering the marine biodiversity needed in the blue carbon uptake cycle. The Reef Life Foundation’s team of scientists has documented these important findings in a scientific publication that can be found on our website or made available upon request.

“I can see extensive CCA coverage with entoprocts and ectoprocts colonizing. Amazingly fast growth of good algae!" - Caribbean Researchers

Results and Significance

Interior cut of IntelliReefs: completely covered by calciferous organisms
Interior cut of IntelliReefs: completely covered by calciferous organisms
“The CCA shows that the reefs will be ready for spawning season and may already have live coral settlement." - Caribbean Researchers
Oceanite 14 Months Submerged Interior Cut
Oceanite 14 Months Submerged Interior Cut

Evaluating the efficacy of artificial reefs (ARs) in enhancing or sustaining biodiversity on coral reefs is vital for understanding their performance in reef restoration. The initial results from our observational Oceanite AR pilot study off the coast of Philipsburg, Sint Maarten indicates an incredible potential for using our structures to increase local biodiversity and provide optimal conditions for rapid species growth due to the physical and chemical designs of our structures. We compared composition of the benthic (i.e. seafloor) community and associated fish assemblages on ARs deployed at a coral reef marine protected area (MPA) and two unprotected seagrass beds. After 14-mo underwater, the ARs were covered in a vibrant community of benthic plants and animals.

Figure 1. Infographic showing the diverse coverage of marine life found on the IntelliReef
Figure 1. Infographic showing the diverse coverage of marine life found on the IntelliReef

We found differences in the total percent cover of benthic organisms and community composition between substrate orientations (horizontal vs. vertical) and among AR sites. Horizontal substrates were dominated by algae and sponge species, and vertical substrates supported a diverse assemblage of suspension- or filter-feeding invertebrates (e.g. sponges, bryozoans, ascidians, etc.). Total percent cover of benthic invertebrates and calcifying organisms was higher on vertically-oriented substrates than horizontally-oriented substrates for all ARs.

14 months after deployment
14 months after deployment

The AR that was deployed on a coral reef in the MPA had the highest total cover of algae and invertebrates on both substrate orientations, at nearly 100% (See Figure 1). The community composition also differed between the AR in the MPA and the adjacent MPA reef, which is dominated by soft corals. We found that crustose coralline algae (CCA) cover was highest on the AR in the MPA, and both surface orientations had more CCA than the adjacent natural coral reef. CCA is a functional group of calcifying algal species that facilitate coral settlement through the formation of calcium carbonate and microbial communities, supporting healthy coral reef development. Oceanite mixtures are specifically designed to attract and incorporate calcifying organisms (e.g. corals, CCA, bivalves, polychaetes, etc.). Finding high levels of CCA on the structures suggests that the chemical/mineral mixtures are performing as expected (or better), and have the potential to be scaled up in future projects to facilitate settlement of reef-building species on regional to global scale.

“This is unprecedented CCA Growth on any known man-made oceanic substrates.”

This Substrate attracts a "Desirable Community" Univ. Hawaii

Early Stages of Sint Maarten Project

Photos June 5th 2019 show massive increases in CCA and multiple oceanic creature settlement
Photo taken 6 months after deployment: shows massive increases in CCA and multiple oceanic creature settlements.
  • Week 1: A variety of marine life began aggregating around the IntelliReefs including large fish, tiny plankton, goat fish, blue tang, sturgeon, and sharks.

  • Week 3: Rapid growth of crustose coralline algae “I believe I can see some CCA, the precursor to coral reefs, and entoprocta and ectoprocta colonizing.” - Caribbean Researchers

  • 7 months: Sponges, diverse coral, CCA, and a variety of marine organisms have attached and continue to grow on the IntelliReefs.


Our Biodiversity Expansion System

IntelliReefs Oceanite Module Cut in half

Above photo: an interior cut of an Oceanite Module, 14 months after deployment in the Caribbean.

Ian Kellet photographing the interior cut of IntelliReefs module (pictured above)14 months after deployment.


Coral Researchers, WE ARE HERE FOR YOU! Contact us to get the best marine substrate on the market, "IntelliReefs: Made with Oceanite"



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