The
REEF Fish Survey Project is an ongoing project that enlists
trained volunteer divers to collect and report information on
local marine fish populations. The divers utilize the Roving Diver
Technique (RDT), which is a visual survey method where the divers
swim freely throughout a dive site and record on a slate all the
fish species they observe on that dive. The count begins as soon
as the diver enters the water and as the goal is to identify as
many species as possible, divers are encouraged to search under
ledges and throughout the water column. After the dive the divers
record on a REEF designated scantron the fish species they observed
and basic information about the dive site location. The scantrons
are submitted to the REEF headquarters in Fort Lauderdale and
put into a national database, from which reports are generated
on species distribution and population trends, for a specific
reef or large geographic regions.
The Fish Survey project began in 1990 and has been highly successful,
meeting four major objectives designated by REEF which include:
1) The ability to collect large quantities of presence/absence
and relative abundance data.
2) Indication of species distribution throughout a geographical
area based on sighting frequency and abundance.
3) Specific species presence/absence and abundance lists may be
presented for any given region, subregion, zone or site
4) Measures of similarity in species composition may be computed
between any combination of geographical areas.
Here at the Channel Islands National Marine Sanctuary (CINMS)
REEF surveys are completed on a regular basis. To date 1,151 REEF
surveys have been conducted throughout the CINMS, totaling up
to 770 hours of underwater observation! In this time over 123
species have been identified at 89 separate sites in the sanctuary.
One of the more recent surveys was a multi day trip aboard the
Shearwater to the Channel Islands. From May 5-8 six REEF divers
spent many hours underwater identifying and counting fish. In
the end they had completed 69 surveys at eight separate dive sites
and identified 42 fish species. These eight sites were chosen
specifically as part of a field design with the purpose of assisting
the CINMS and California Fish and Game in evaluating the marine
reserves and providing an in depth inventory of near shore fish.
The sites take into account areas inside and outside the protected
reserves so as to allow a comparison between species numbers and
diversity in the protected and unprotected regions. While eight
sites were visited on this trip, there are twenty additional sites
that will be visited in the near future to further evaluate the
marine reserves.
