Coral and Limu Watch

In order to monitor the benthic habitat in Waikīkī and understand the changes in density, abundance, diversity and coverage of different benthic habitats, we are examining two different areas of interest:

1. Coral size and frequency
2. Algae diversity in benthic habitat

20 random points were chosen in the Waikīkī MLCD. Due to depth restrictions and limitations with snorkel gear, we decided to extend the survey site 200 yards from shore, instead of the full 500yds encompassing the Waikīkī MLCD.

METHODS

1.) Coral Size and Frequency

• 25 meter transect line at each random point
• 2 meter belt
• identify, count and measure each coral colony in the 2 meter belt
• coral size classes:

Coral Size	Code
0-5cm	A
6-10cm	B
11-20cm	C
21-40cm	D
41-80cm	E
>80cm	F

2.) Benthic Habitat Grid-Intercept and Photoquadrat

• 25 meter transect line at each random point
• Alternating left and right side of transect, placing quadrat every 5 m
• 0.5m² quadrat used for grid point-intercept and photoquadrats
• 10 random points where the lines intersect on the quadrat visually sampled

MATERIALS

• 25 m transect line                                                                                            
• 0.5m² quadrat
• Waterproof camera: Canon PowerShot D10
• Weights
• Two dive slates
• Waterproof paper
• Dive float
• Measuring stick
• GPS
• Compass
• Snorkel gear

EVENTS

If you wish to attend any of benthic habitat surveys, you must be extremely comfortable in the water and have advanced snorkeling skills with the ability to dive down a few feet while holding your breath. Please keep in mind that the surveys are dependent on the weather and swell, meaning the survey may be canceled on the morning of the date.

If you wish to participate in a benthic habitat survey, please contact reefmail@hawaii.edu

TRAINING MATERIALS

• Benthic Habitat Point Intercept Data Sheet
• Coral Size and Frequency Data Sheet
• Coral Cards
• Algae Cards
• Benthic Habitat Protocol Presentation
• Common Coral Quiz
• Quiz: Red Limu
• Quiz: Green and Blue-Green Limu
• Quiz: Brown Limu

USEFUL LINKS

Coral:

• World Register of Marine Species
• Coral Watch
• Hawaii Coral Reef and Assessment Monitoring Program
• Keoki and Yuko Stender’s Marine Life Photography
• BYO Guide Coral Finder
• Coral Hub

Limu:

• World Register of Marine Species
• Algae Base
• HCRI Alien and Invasive Algae in Hawaii
• UH Manoa Botany-Marine Algae of Hawaii
• UH Manoa Botany- Invasive Marine Algae of Hawaii
• UH Manoa Botany- Hawaiian Reef Algae
• Looking at Limu Educational Resources
• Getting to Know Hawaiian Algae: A Glossary
• Alien Algae Prevention and Tool Kit
• A Guidebook of Introduced Marine Species in Hawaii
• ReefWatcher’s Field Guide to Alien and Native Hawaiian Marine Algae