Reef Ramblings- Coral Coverage: Fiji Reef Analysis
Posted January 14th, 2008 by Adam Blundell
For years now I’ve been a bit perturbed by the hobbyist view of a coral reef. Some of this is just unfortunate circumstance in that the vast majority of hobbyists will never experience seeing and interacting with a real coral reef. Secondly, those who are fortunate enough are often distracted by the colors of the sea to really observe what is there.
This article is part of a series I have conducted (along with numerous research partners) on several reefs around the world. I’m using Fiji as an example here because of the important role this small nation of islands plays in the hobby. As you all know a large portion of our corals/fishes/invertebrates are found and collected in Fiji. This area serves as a template for most reefscapes in the hobby.
Video Analysis
The information presented here is a single survey event. A healthy reef bommie (think of a mountain of coral the size of your house) was videotaped and played back to serve as the survey area. The video was played digitally on a computer and a random sequence of positions was analyzed. This was done by dividing the computer monitor into 20 spaces from left to right, and 20 spaces from top to bottom. Then, a 20 sided die was thrown and the number on top was used to pick the space horizontally, again a 20 sided die was thrown for the vertical measurement. This was done 10 times to get 10 separate points of analysis. From here, the pair of 20 sided dice were thrown to pick how many seconds later to pause the video between each analyzed frame.
20 Sided dice used for the random sequence
The random points of analysis drawn on a transparency
Shown here the transparency is attached to the computer monitor
A photograph of the computer monitor with the points of analysis
Results
The 100 points of analysis are listed in the charts below. Surprisingly to the author I didn’t have any “can’t identify” points of analysis. The reason for this was because on this initial survey the breakdown of points was very general. For instance nearly half of the points (48 out of 100) are listed as “rock” without any further breakdown of coralline encrusted or dead coral skeleton or fleshy algae or any other distinction. Also with ongoing debates on coral species identification the identification to a species level was not even remotely considered.
So here are the results. Think of this as looking at your aquarium at home. By looking head on at a reef, approximately 3 feet away, here is what was seen…
Percentage of substrate cover are: Rock (48%), Hard Coral (30%), Soft Coral (6%), Cryptic Dark Zones (6%), Sand (2%), Open Water (4%), Mobile Invertebrates (3%), Fleshy Algae (1%).
A breakdown of the reef analyzed in this project: Acropora (3%), Algae (1%), Base of Corals (1%), Non Acropora Branching Stony Coral (2%), Cryptic Zones (6%), Encrusting Montipora (4%), Gorgonia (4%), Mustard Coral (2%), Pocillopora (5%), Porites (3%), Rock Area (48%), Loose Sand (2%), Seafans (2%), Staghorn Coral (2%), Table Acropora (8%), Open Water (4%), Worm Casings (3%).
Conclusion
While only an initial review of the south pacific reef settings, this project was most certainly worthwhile. To have a starting point for exploration is very important. This project utilizes video transects to paint a picture of coral reef coverage. Aspiring hobbyists can use this information as a platform for recreating reef systems. Further analysis would allow for more data and a better understanding of these ecosystems.
Acknowledgements
This article was made possible by the Aquatic & Terrestrial Research Team. Contributions were made by Project AWARE, Koli Emberson, Marzena Blundell, and Reef Builders Magazine.
Author Information
Adam Blundell M.S. is a hobbyist, lecturer, author, teacher, and research biologist. Adam works for the University of Utah’s School of Medicine in Pathology and in Marine Biology. He currently helps run the Wasatch Marine Aquarium Society, of which he is a former president. Adam is also the director of the Aquatic & Terrestrial Research Team, a group which bridges the gap between hobbyists and scientists. Adam can be reached by his author forum.
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