Introduction
Phil Pepe (28)5-7106
PEPE.PHIL at a1.pc.maricopa.edu
Tue Mar 4 15:36:00 EST 1997
The following abstract is of a paper presented by the authors at the 26th
Annual Meeting of the Association of Marine Laboratories of the Caribbean in
1994. We have since used visual methods for censusing parrotfish and
surgeonfish populations on the outer reef flats of Roatan, Honduras. We will be
returning to Roatan this summer to continue our work.
Comments would be appreciated!
A NEW VISUAL CENSUSING TECHNIQUE FOR ENUMERATING
LARGE, DAY ACTIVE REEF FISHES
Philip Pepe (Phoenix College, Phoenix, AZ 85013
and Oceanic Society Expeditions, San Francisco, CA 94123),
Nicole Crane (Hopkins Marine Station,
Stanford University, Pacific Grove, CA 93950
and Oceanic Society Expeditions, San Francisco, CA 94123),
Geoff Stein, Monica Cervinek, Kevin Kittredge,
Tasha Bair and Nancy Osborne (ReefWatch Volunteers)
ABSTRACT
The Kick Cycling Visual Technique (KCVT) for censusing fishes was
developed and tested. The KCVT does not require the advance deployment of
markers as does the Strip Transect Visual Technique STVT. Divers need only a
compass and a slate to carry out a census and use a standard timed kick cycle
method for estimating the distance covered while swimming along a compass
heading. This is of great advantage when time is limited and the goal of a
census is to visit multiple sites over large reef areas.
The KCVT was used to census parrotfish and surgeonfish at four
locations at the northwest end of Lighthouse Reef Atoll, Belize. All censusing
was done in outer reef flat environments on the seaward side of the reef crest
at depths of 30 to 45 feet.
The census data was used to study the precision of the method. The
Precision Statistic (P=SE/M) ranged from 10-26%.
There is a strong similarity in the distribution of parrotfish and
surgeonfish between sites. There were no significant differences between the
KCVT surgeonfish censuses at all four sites (Kruskall-Wallis p=0.05). The
sample distributions from three sites were not significantly different from one
another in both parrotfish and surgeonfish (Kruskall-Wallis p=0.05). However
the mean number of parrotfish was greater and significantly different at
Lighthouse Wall (Kruskall-Wallis p=0.05).
Paired STVT and KCVT censuses produced similar sample distributions at
Manta Point. There was no significant difference between the STVT and KCVT data
pairs (Mann-Whitney U Test, p=0.05). The results support the hypothesis that
the KCVT provides a similar degree of accuracy and precision as the STVT for
censusing large, day active reef fish.
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