Index | Overview | Methodology | Coral standards | Fish standards | Calibration | Data processing | Data sheets
Corals  Prior to conducting a benthic transect survey, a surveyor should be proficient in: coral identification of all major reef building coral species on the AGRRA list, distinguishing colony boundaries, estimating diameter and heights, and estimating partial mortality. In addition, they should be familiar with different types of condition (e.g., bleaching, disease, predation) on the Disease and Predation Identification Cards (Bruckner and Bruckner 1998). To maintain and quantify accuracy and consistency between benthic observers during the survey, the surveyors should calibrate standards every other day of the survey or as many times are necessary to attain >90% accuracy. Standard calibration for benthic transects: 1)
Using a set transect line or pre-identified coral colonies, have each
observer estimate and record the following for at least 5 different coral
colonies:
2)
To calibrate between observers, the following should be maintained
while still at the site. 4)
Assess additional coral colonies if necessary to maintain >90%
accuracy.
Prior to conducting algal quadrats, surveyors should
be proficient in: identifying the main functional algal groups (crustose coral,
fleshy macro-, and calcareous macroalgae), estimating % abundance of each, and
measuring algal height of fleshy- and calcareous macroalgae. In addition, they
should be familiar with recognizing small corals (<2cm). To maintain and
quantify accuracy and consistency between algal observers during the survey, the
surveyors should conduct standards every other day of the survey or as many
times are necessary to attain >90% accuracy. Standard calibration for algae: 1)
Have observers assess the same five (5) algal quadrats.
2)
To calibrate between observers, the following should be maintained:
3)
Compare results after the calibration and discuss differences (if any)
and variations between observers while still at the site. 4)
Conduct additional algal quadrats if necessary to maintain >90%
accuracy. Prior to conducting a fish belt transect survey, a
surveyor should be proficient in: fish identification of all species on the
AGRRA list; visualizing a 2 m belt transect, and be able to attain >95%
accuracy in estimating observed fish lengths compared to actual measurements. To
maintain and quantify accuracy of fish lengths during the survey, have the fish
surveyor (s) conduct at least 10 standards every other day of the survey or as
many times is needed to attain 95% accuracy. Standard
calibration for estimating fish lengths: 1)
Find 10 immobile objects (e.g., pieces of coral, sessile invertebrates,
or fish models, etc) 2)
Estimate and record the length of each object using the fish size
categories (0-5 cm 6-10 etc) staying at least 2 m from the object. Use the t-bar
for estimating measurements. 3)
Then measure the actual size of the object and record length. 4)
Compare the differences between actual and observed. 5)
Continue to collect standards until estimation accuracy is at least 95%
or greater. 6)
Include this data as part of your final report.
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