Index | Overview | Coral standards | Fish standards | Calibration | Data processing | Data sheets
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: · Species
Identification · Maximum
diameter and height · %
recent and old mortality 2) To
calibrate between observers, the following should be maintained · Species
identification should be consistent and accurate between all observers · Maximum
diameter and height measurements should be within 10 cm · % recent and old mortality estimates should be within 5-10% for each. 3) Compare results after the calibration
and discuss differences (if any) and variations between observers 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. · %
absolute abundance of crustose coralline · %
absolute abundance of fleshy macroalgae · Average
height (cm) of fleshy macroalgae · %
absolute abundance of calcareous macroalgae · Average
height (cm) of calcareous macroalgae 2) To
calibrate between observers, the following should be maintained: · %
abundance of algae estimates between observers should be within 5-10% · Algal
height measurements between observers should be within 2 cm of each other 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.
© 2000-2006 - AGRRA |
