TNC-CORDIO coral reef monitoring manual_book_coral1

3.0 Underwater coral reef monitoring
This manual covers three underwater survey methods
for measuring the health of coral reefs. They are
done by a team of 4 people within a 250m 2 survey
area marked by a 50m tape measure or rope laid
on the sea bed.
The methods cover the main animals (fauna) and
plants (flora) that dominate coral reefs, namely the
reef building corals and fish, seagrass and algae,
large invertebrates such as sea cucumbers, shells
and starfish. Together these give a measure of
the state or health of the reef and its biodiversity.
Included in the invertebrates are sea urchins,
which are well known indicators of poor reef health
because large numbers can cause a decline in reef
condition.
The three methods are as follows and are
described in detail below:
♦♦
♦♦
♦♦
Belt Transect for fish density and sizes
Point Intercept Transect for coral and substrate
cover
Belt Transect for macro-invertebrate density.
A description of how to analyse and interpret your
results is also given for each of the three methods.
Templates of datasheets, tables and graphs for data
analyses are given in Appendix 4.
13