simplex JournalPLVol4No1 O. JournalPLVol4No1 O
44 Pesisir Lautan Volume 4, No.1, 2001
Mapping of species distributions
The specimen-based database was used to pre- pare a distribution list for each species in ASCII
format, including site coordinates for each speci- men record. These lists were used to plot the distri-
bution records for each species in Indonesia, using a MAPINFO Geographic Information System
package for WINDOWS.
Similarity between regions Comparisons between regions were based on
Jaccard’s similarity coefficient. Similarity = aa+b+c, using the number of species in common, where a =
number of species shared by two regions being com- pared, b = number of species in sample 1 and not
in sample 2, and c = number of species in sample 2 not in sample 1. Note that a+b+c = the total
number of species in the two areas. This measure was chosen for simplicity and because it is not sen-
sitive to the presence of species in a wider region that are not present in the two areas being com-
pared, that is joint absences Batagelj and Bren, 1995.
Sampling and database protocol At the 146 survey sites, sampling followed a
standard protocol, using SCUBA, or occasionally snorkelling or reef-walking on shallow sites. The
presence of Acropora species was recorded, begin- ning from the greatest depth at which they could
be located usually 25-28 m and continuing up- wards to shallow water, over a horizontal distance
of 100-400 m. Sites were assigned to the following overall reef types: fringing, coral cay, sand cay, sub-
merged reef, shoal, patch reef, rocky reef, volcanic ash slope, deep reef flat, barrier reef, and pinnacles
Tomascik, 1997. Within each reef type, the par- ticular habitat sampled was categorised according
to the following categories: 1 recent volcanic sur- face, 2 reef slope and associated flat, 3 reef wall
and associated flat, 4 lagoons, sheltered inlets or submerged reefs Wallace and Wolstenholme,
1998. Habitat features and dominant benthic groups were noted for each site. Small samples of
each species encountered were taken for verification and more colonies were sampled for taxonomic
description when unusual forms were encountered. Most specimens were photographed in situ before
collection. An initial identification, including colour of the colony, unusual size or colony shape, and
depth were recorded. A numbered plastic label was attached to each specimen as it was collected. After
sampling, specimens were bleached in 3 NaOCl, rinsed in fresh water, and dried. Specimen identifi-
cations were later verified by microscopic examina- tion in the laboratory. A complete set of voucher
specimens for the sites is stored at the Museum of Tropical Queensland in Townsville, Australia, and
registered on a database that includes coordinate data for GIS mapping.
Additional sets of specimens were deposited with the Indonesian Institute of Science LIPI, LIPI
Research and Development Centre for Oceanology PPPO at Ancol, Java Sulawesi Sea and Bay of
Tomini collection; LIPI PPPO at Ambon, Moluku Province Banda Sea collection; and De-
partment of Marine Science, Bung Hatta Univer- sity Padang, Sumatra Sumatra collection.
Table 3. Number of Acropora species in each distribution category for each region within Indonesia.
Two new species included in this distribution category.
Distribution Sumatra
Indonesia Indonesia
Sulawesi Bay of
Banda Category
Central South
Sea Tomini
Sea Indian Ocean
2 1
2 1
1
Shared IND Indo-Pacific
36 53
59 59
58 58
Indonesian I-P Pacific Ocean
1 6
4 10
13 4
Shared PAC Indonesia Only ARC
1 1
2 6
2
Total number of species
40 59
65 73
78 65