Rapid assembly of
Invertebrate data for
the SE Regional
Marine Plan.
T.D. O’Hara, G.C.B. Poore, S. Ahyong, D.A.
Staples
Museum Victoria
September 2002
2
Table of Contents
Abstract ...................................................................................................................... 6
1. Introduction............................................................................................................ 8
The tasks for this project included ......................................................................... 8
2. SE continental slope .............................................................................................. 9
2.1. Methods........................................................................................................... 9
2.2. Results ........................................................................................................... 12
2.3. Summary ....................................................................................................... 13
2.4. East vs west fauna ......................................................................................... 13
2.5. North vs South Fauna.................................................................................... 14
2.6. Eastern Tasman Rise ..................................................................................... 14
2.7. Comparisons between taxonomic groups ..................................................... 14
2.8. Change in distribution with depth ................................................................. 16
2.9. Species endemic to the SE region ................................................................. 17
3. Macquarie Ridge .................................................................................................. 19
3.1. Methods......................................................................................................... 19
3.2. Results ........................................................................................................... 21
3.3. Summary ....................................................................................................... 21
4. Conclusions .......................................................................................................... 22
4. Participants .......................................................................................................... 23
5. References ............................................................................................................ 23
3
List of tables and figures
Figure 1. Map showing the SE region and some of the place names used in the text. .. 7
Table 1. Geographic spread of the number of species recorded for each 0.5 degree of
latitude (including interpolated records). ............................................................. 10
Table 2. Geographic spread of the number of collection stations by latitude (rows) and
longitude (columns). Heavily surveyed cells include the Tasmania seamounts
(44ºS) and off far-eastern Victoria (37.5-38.0ºS, 149-150ºE). Few samples have
been collected from the East (43.5ºS, 149-150ºE) or South Tasman (<44ºS)
Rises. .................................................................................................................... 11
Table 4. Spearman Rank correlation coefficients between the entire dataset and
selected taxonomic groups for each depth strata on either side of the SE region.
The number of cells of latitude is kept constant even if not all taxonomic-groups
were present. ........................................................................................................ 15
Table 5. Spearman Rank correlation coefficients between the entire dataset and
selected taxonomic groups for each depth strata on either side of the SE region.
Only the cells of latitude that contained all taxonomic groups are included in the
analysis. ................................................................................................................ 16
Table 5. Apparently endemic species from the continental slope of the SE region. ... 18
Table 6. Geographic spread of the number of species recorded in each cell from the
Macquarie Ridge (including interpolated records). ............................................. 20
Table 7. Geographic spread of the number of collection stations by latitude (rows) and
longitude (columns) from the Macquarie Ridge. Heavily surveyed cells include
the Macquarie Island (54.5ºS) cell. ...................................................................... 20
Figure 2. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 200-500 m.
Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 24
Figure 3. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 500-1000 m.
Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 25
Figure 4. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 1500-2000
m. Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 26
Figure 5. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 1500-2000
m. Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 27
Figure 6. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 2000-2500
m. Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 28
Figure 7. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from below 2500
m. Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 29
Figure 8. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the western SE Australian continental slope from 200-500 m.
4
Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 30
Figure 9. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the western SE Australian continental slope from 500-1000 m.
Data consists of presence/absence of each species in cells of half a degree
latitude and longitude. .......................................................................................... 31
Figure 10. Stacked plot of the number of species per grid. ......................................... 32
Figure 11. Stacked plot of the species richness for each 100 m depth strata for all
stations across the SE region................................................................................ 33
Figure 12. Species richness from various collection methods for 100 m depth strata
across the SE region. ............................................................................................ 34
Figure 13. Species richness, species turnover and effort (no of samples) for 100 m
depth strata across the SE region. ........................................................................ 34
Figure 14. Cluster diagram of all samples from the SE region collected using an
epibenthic sled (species abundance data is square root transformed). ................. 35
Figure 15. MDS ordinations of species from the Macquarie Ridge, based on the
presence/absence of each species along the Ridge in cells of one-degree latitude.
Macquarie Island is located at 54ºS. .................................................................... 36
Figure 16. Cluster diagram of species from the Macquarie Ridge, based on the
presence/absence of each species along the Ridge in cells of one-degree latitude
between 500-1000 m. Macquarie Island is located at 54ºS ................................. 37
5
Abstract
The distribution of echinoderms, decapods and pycnogonids from 1) the continental
slope (>200 m) of the Australian SE region, and 2) the continental shelf and slope
around Macquarie Island are analysed for geographical and bathymetric patterns.
The patterns along the SE continental slope are indicative of a gradient from a
temperate fauna of the Tasman Sea to the subantarctic fauna of the South Tasman
Rise. This temperate fauna persists as far as mid Tasmania (approximately 42ºS), and
possibly will be found further south with increased collection effort. Subantarctic
species become progressively more important in the region south of Tasmania. The
fauna on the Southern Tasmania seamounts is particularly distinctive. There is a large
apparent difference between the eastern and western slopes, and much of this is due to
the greater collection effort off the East Coast. Nevertheless, there is a small fauna
(1.6%) that is only known from the western slope, and a larger (but as yet
unquantified) fauna that is restricted to the Tasman Sea. The low collection effort
precludes an analysis of the fauna of the southern and eastern Tasman Rises.
There is a rapid turnover of species occurrence between the shelf fauna and the upper
slope (150-300 m), followed by gradual change until 2500 m, after which there is
another pronounced faunal change. There are no samples from the abyssal plain
(>4000 m). Communities were divided into shelf (<200 m), upper slope (200-1000 m)
and mid-lower slope categories (>1000 m). For at least one taxonomic group
(ophiuroids) there is a peak of diversity at mid-slope (1000 m).
There is a gradient along the Macquarie Ridge also, with the fauna of the Northern
and Southern Ridges being distinct from each other and the fauna around Macquarie
Island. The Northern Ridge supports subantarctic New Zealand species and the
Southern Ridge Antarctic species. The shallow water fauna around the island is
composed of shelf species from New Zealand and subantarctic species that have
presumably arrived on kelp holdfasts from islands further west.
However, this study must be considered preliminary as uneven sampling effort, both
geographically and bathymetrically, is a major impediment to fine-scale analysis.
6
Port Macdonnell
Bass Strait
Gabo Is
East
Tasman
Rise
Tasmanian
Seamounts
South
Tasman
Rise
147°E
Macquarie
Island
(54S)
Figure 1. Map showing the SE region and some of the place names used in the
text.
7
So
Ma
1. Introduction
Museum Victoria, in conjunction with the Australian Museum and CSIRO, was
contracted by the National Oceans Office to prepare information on the community
composition and distribution of key invertebrate groups (echinoderms, decapods and
pycnogonids) on the outer shelf and slope of three Large Marine Domains so that it is
available to be integrated with other datasets to develop an Interim Bioregionalisation
for the South-east Marine Region.
The tasks for this project included




A matrix analysis of community composition of the benthic fauna along the
eastern continental slope from the northern limit of the SE region (southern NSW)
to the Tasmanian seamounts. The presence of each echinoderm, decapod and
pycnogonid species will be scored for cells of resolution 0.5 degrees latitude by
200 m depth. Gaps in sampling effort will be compensated by interpolating from
neighbouring cells. The final matrix will be analysed using multivariate statistics.
A comparison of the fauna from the continental slope on the eastern and western
sides of Bass Strait.
A comparison of the fauna from the north and south Macquarie Ridges.
A comparison of the fauna from the SE Tasmanian slope and the Eastern Tasman
Rise.
The target taxa for this project were echinoderms, decapods and pycnogonids. The
rationale is that for these taxa 1) many specimens had already been identified in
various museums and 2) taxonomic experts were readily available. Thus both existing
and new data could be assembled within the limited timeframe available for this task
(3 months). Although sessile groups such as cnidarians, bryozoans and sponges would
have been very useful, a comprehensive dataset could not have been accumulated in
this timeframe. Identification of these groups would be a major taxonomic exercise
requiring many months if not years of effort. Pycnogonids were selected as a target
group as they have a close association with hydroids and bryozoans may reflect the
same factors influencing sessile-faunal community structure.
8
2. SE continental slope
2.1. Methods
Data
 Most material was collected by the Endeavour (1910-1913), Kimbla (1973), BSS
(1979-1983), Franklin (1986-89), Soela (1982-88), Kapala (1973-97) and CSIRO
Southern Surveyor (1997, 2000) research vessels. This was supplemented by
material collected on an ad-hoc basis from Fisheries Vessels.
 In all there were 574 species in 5100 collection (species/station) lots representing
61670 individual specimens.
 The material was collected using bottom trawls, an epibenthic sled, box corer and
traps, but predominantly by trawling.
 The material is stored at Museum Victoria (MV), the Australian Museum (AM),
the Tasmanian Museum and Art Gallery (TM) and CSIRO Marine Laboratories.
Material at the South Australian Museum was not accessed due to lack of time.
 The dataset for this analysis included Echinodermata (Ophiuroidea,
Holothuroidea), Decapoda, and Pycnogonida collected below 200 m). Although
identified, asteroids, echinoids and crinoids were excluded from the final analyses,
as the resulting dataset was not geographically comprehensive enough for a
balanced analysis.
Analysis
 The data were summarised into the presence/absence of each species in cells of
one half a degree latitude for each of the eastern and western continental margins
of the region (36-47ºS). The amount of longitude covered in each grid varied with
the width of the continental slope at each latitude.
 For both the western and eastern slope, two additional cells were created
representing the northern (<=35ºS) and southern (>=48ºS) borders of the region
based on whether each species is known to occur at more northern or southern
latitudes. The data were sourced from published literature and collection
databases.
 Although the target depth segment was 200 m, not enough material was present at
all longitudes to facilitate stratification of the dataset in this way. Consequently,
depth strata of 200-500, 500-1000, 1000-1500, 1500-2000, 2000-2500, 2500+ m
were finally used in the analysis. A species that occurs at the limit between depth
strata (eg 500 m) was included in the next depth strata (500-1000 m).
 The actual data were supplemented by interpolated data, generated by recording a
species as present for cells that are between known occurrences for each depth
strata.
 The data were analysed using multivariate statistics, including MDS ordinations
and cluster diagrams, using Bray-Curtis similarity coefficients and group-average
linkage. The use of the Bray-Curtis similarity measure on presence/absence data is
equivalent to using the Sorensen Binary coefficient.
 Patterns generated by different taxonomic groups were compared to the full
dataset by Spearman Rank correlating the underlying similarity matrices.
9
Table 1. Geographic spread of the number of species recorded for each 0.5 degree of latitude (including interpolated records).
Eastern slope (>=147ºE)
Depth (m) 35+ 36.0 36.5 37.0 37.5 38.0 38.5 39.0 39.5 40.0 40.5 41.0 41.5 42.0 42.5 43.0 43.5 44.0 44.5 45.0 45.5 46.0 46.5 47.0 47.5 48+
200-500
35
41
44
56
69
85
52
54
51
43
41
39
41
28
30
5
3
2
2
2
2
2
2
2
2
6
500-1000
63
60
68
84
82 105
66
68
65
62
58
61
58
55
33
23
20
30
10
10
10
10
10
10
10
10
1000-1500
52
41
43
41
41
90
52
49
49
49
49
50
48
46
42
37
37
61
10
10
10
10
10
14
15
15
1500-2000
46
33
34
34
34
53
51
38
44
24
24
24
33
23
16
16
16
37
2
2
2
2
2
2
2
2
2000-2500
12
5
5
5
5
5
18
7
7
9
9
9
21
20
12
7
7
14
4
4
4
4
4
4
4
4
2500+
7
2
3
2
2
2
11
5
5
5
10
5
17
16
4
4
4
2
0
0
0
0
0
0
0
0
Western slope (<147ºE)
Depth (m) 35+ 36.0 36.5 37.0 37.5 38.0 38.5 39.0 39.5 40.0 40.5 41.0 41.5 42.0 42.5 43.0 43.5 44.0 44.5 45.0 45.5 46.0 46.5 47.0 47.5 48+
200
22
15
15
20
14
14
24
18
12
16
12
17
5
1
1
3
0
0
0
0
0
0
0
0
0
6
500
13
8
9
15
14
14
34
17
15
16
17
20
16
10
9
9
10
28
4
4
4
4
4
4
4
10
1000
9
4
4
4
3
5
9
4
4
4
5
6
5
5
5
7
7
26
6
6
6
6
6
6
6
15
1500
5
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
4
0
0
0
2
2000
4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
2500
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
10
Table 2. Geographic spread of the number of collection stations by latitude (rows)
and longitude (columns). Heavily surveyed cells include the Tasmania seamounts
(44ºS) and off far-eastern Victoria (37.5-38.0ºS, 149-150ºE). Few samples have
been collected from the East (43.5ºS, 149-150ºE) or South Tasman (<44ºS) Rises.
Latitude
36.0ºS
137ºE 138 139 140 141 142 143 144 145 146 147 148 149 150ºE
16
36.5ºS
1
37.0ºS
5
37.5ºS
11
4
5
1
18
36
63
6
38.0ºS
4
2
8
78
38.5ºS
1
22
8
9
39.0ºS
5
20
39.5ºS
1
10
5
40.0ºS
3
4
1
40.5ºS
11
1
1
41.0ºS
4
4
7
1
41.5ºS
6
13
1
42.0ºS
2
6
3
42.5ºS
23
43.0ºS
43.5ºS
7
4
2
1
44.0ºS
3
2
2
2
1
1
37
44.5ºS
45.0ºS
45.5ºS
46.0ºS
1
46.5ºS
47.0ºS
47.5ºS
3
4
1
11
2.2. Results
Eastern slope
Depth strata
200-500 m
(Figure 2)
Multivariate analysis
There is no area on the South Tasman Rise (<44ºS) at this depth.
The next shallow water fauna south of 48ºS is at Macquarie Island,
which is composed predominantly of subantarctic species.
Southern Tasmanian cells (43-43.5 ºS) are outliers due to lack of
sampling.
The rest of the cells form three clusters based on S. NSW, E Bass
Strait, and E Tasmania. Breaks occur at 37ºS and 40ºS.
There is a peak in collection effort off far eastern Vic. However,
many of these records are rare species, which contribute little to the
multivariate analysis.
500-1000 m
(Figure 3)
The South Tasman Rise (45-47ºS) is an outlier due to lack of
sampling at this depth.
The other cells form three clusters based on NSW, E Tas and S Tas,
with breaks at 38ºS and 42ºS.
1000-1500 m
(Figure 4)
This depth strata is very similar to the 500-1000 m strata with breaks
between the three main clusters near 38ºS and 42ºS.
There is some differentiation between the southern and northern
South Tasman Rise, although this is based on relatively sparse data.
The intensive collecting effort at the Tasmanian seamounts (44ºS)
and off Gabo Island (38ºS) can be observed.
1500-2000 m
(Figure 5)
Again very similar, except that the Gabo Island no longer represents
a peak of collection effort. The Tasmanian seamounts are still
distinct at 44ºS.
The three main clusters again break near 38ºS and 42ºS
2000-2500 m
(Figure 6)
Collection effort at this depth is patchy, mainly confined to transects
off Eastern Bass Strait (38.5, 40, 40.5ºS) and SE Tasmania (41.5,
42ºS).
The cluster diagram shows a gradient from NSW south to the
seamounts with the South Tasman Rise as an outlier. However, this
pattern is liable to be an artefact of the collection effort.
2500+ m
(Figure 7)
Similar to 2000-2500 m.
12
Western slope
Depth strata
200-500 m
(Figure 8)
Multivariate analysis
The southern cells (41.5 to 43ºS) form an outlying cluster due to lack
of sampling.
The rest of the cells form two clusters based on SA to W. Bass Strait
(36-39ºS), and the other NW Tasmania (39.5-40.5ºS).
500-1000 m
(Figure 9)
1000-2500+ m
There is only half the number of records of the 200-500 m strata
with peaks of collection effort off Port Macdonnell/Portland
(38.5ºS), and the seamounts (44ºS).
The South Tasman Rise (44.5-47ºS) is an outlier cluster due to lack
of sampling at this depth.
The other cells form three clusters based on SA, E Tas and S Tas,
with breaks at 38ºS and 42ºS. S. Tasmania clusters with the South
Tasman Rise.
Collection effort is not adequate to analyse the fauna at this depth.
2.3. Summary
Eastern slope
Excluding outliers, the dendrograms for shallow depths (200-500 m) formed three
main clusters, based on southern NSW (36-37ºS), eastern Bass Strait (37.5-39.5ºS) and
eastern Tasmania (40-42.5ºS). Unfortunately there were few records from this depth
from off Southern Tasmania. Further down the slope (500-2000 m), excluding the
South Tasman Rise, again there were three main clusters based around NSW (to
37.5ºS), eastern Bass Strait and eastern Tasmania (38-42ºS), and southern Tasmania,
including the seamounts (42.5-44ºS). From 1000-2000 m the Tasmanian seamounts
become distinct, partly because of collection effort, but also due to the unusual fauna
that is present.
The South Tasman Rise is distinct on most analyses. However, some of this effect was
liable to be due to lack of collection effort (Table 1).
Western slope
Due to low collection effort only the upper slope (200-1000 m) contained a dataset that
was worth analysing. There is a gradient in species composition from off SE South
Australia to southern Tasmania, with breaks at 39ºS and 41.5ºS for 200-500 m, and
37ºS and 42ºS at 500-1000 m. However, Southern Tasmania may be a cluster due to a
collection artefact, as there are relatively few stations from that area (Table 2). The
Tasmanian seamounts (44ºS) are distinctive.
2.4. East vs west fauna
Of the 328 species included in this analysis (ophiuroids, holothurians, decapods and
pycnogonids only), 205 were only recorded from the eastern slope, 19 only from the
western slope and 104 from both eastern and western slopes. However, the difference
between east and west was at least partly due to the much greater collection effort on
the eastern slope. Many of the eastern-only species may be found on the western slope
13
with additional collection effort. Nevertheless at least some of these species are likely
to be eastern slope endemics. A distinct eastern coast fauna has been found for shallow
water (< 100 m) decapods and echinoderms (O’Hara & Poore 2000).
Of more interest were the 19 species only found on the western slope. Of these nine
were collection artefacts of this study and have been found in other surveys off central
eastern Australia, often in shallower water (<200 m). Eight others are undescribed and
may have a wider distribution when they are better known. Only two species, the
ophiuroids Ophiomusium australe and Ophiomusium anisacanthum appear to be
confirmed western slope endemics, only 1.6 % of the western fauna. These three
species are common on the western slope across into South Australia.
2.5. North vs South Fauna
There was a decline in species richness per cell with increasing latitude (Figure 10) on
both the eastern and western slopes. Again this may be largely due to the uneven
sampling effort, although a latitudinal decline in species richness has been noted for
many other habitats (O’Hara & Poore 2000). The slopes off eastern and western Bass
Strait were the most heavily sampled areas and the areas with greatest species richness.
Another heavily sampled area, the Tasmanian seamounts, also shows as a spike of
diversity at 44ºS.
The turnover of species from north to south was also evident from Figure 10. There
was a widespread fauna, comprising 13% of the total fauna, which occurs all along the
slope as far as the Tasmanian seamounts. There was a Northern fauna (species that do
not occur >44ºS), which is numerically dominant (44 % of the total fauna) which
persisted to 42.5ºS on the eastern side and 41.5ºS on the west. There was a small
Southern fauna (species that do not occur <38ºS), comprising 15 % of the fauna, that
reached a peak on the heavily sampled Tasmanian seamounts. These are largely
subantarctic species, which in many cases are widespread throughout the Southern
Ocean. Only a few of these species persisted onto the eastern slope of Tasmania.
Finally there was a number of species (28 %) that were apparently endemic to the
continental slopes of eastern and western Tasmania and Bass Strait. However, many of
these species were either undescribed or rare, and the actual proportion of endemism is
likely to be much less than this figure with further study.
2.6. Eastern Tasman Rise
Unfortunately there were few data from the Eastern Tasman Rise. Most of the samples
were deep (<2000 m). The fauna at this depth was broadly similar to that off the
eastern slope of Tasmania.
2.7. Comparisons between taxonomic groups
The different taxonomic groups exhibit a different pattern than the entire dataset. This
is best examined by rank correlating the similarity matrices that underlie the
ordinations and cluster diagrams (Clarke & Warwick 1994). No significance is
attached to the correlations, the resulting coefficients are only used as an indicator that
two patterns are similar. Coefficients of 1.0 indicate a perfect match between the entire
dataset and a selected taxonomic group. Coefficients nearing 0 indicate a poor
14
correspondence between the patterns. Coefficients nearing -1 indicate a negative
relationship, ie the patterns are reversed.
The correlation coefficients are presented in Tables 3 and 4. Table 3 is based on an
analysis of all 26 cells of 0.5 degree latitude that occur in the SE region (from 35ºS to
48ºS). Decapods show high correlations (R>0.5) for shallower depths, and ophiuroids
are highly correlated with the overall pattern at deeper depths. Holothurians and
pycnogonids in general did not correlate strongly with the entire dataset. This is due to
the fewer specimens collected from these groups.
Cells that do not contain specimens from all four taxonomic groups were excluded
from the dataset and the analysis repeated (Table 4). With a few exceptions, the
correlation coefficients were relatively high for all taxonomic groups at all depth strata
that contained more than one cell of latitude with all groups present. This indicates that
each group exhibits broadly similar geographic patterns when enough data is present.
Slope
East
East
East
East
East
East
West
West
West
West
West
West
Depth (m) No cells
in
analysis
200-500
26
500-1000
26
1000-1500
26
1500-2000
26
2000-2500
26
2500+
26
200-500
26
500-1000
26
1000-1500
26
1500-2000
26
2000-2500
26
2500+
26
Decapods
0.93
0.96
0.89
0.47
0.45
0.51
0.86
0.88
0.85
-
Holo- Ophiur- Pycnothurians
oids
gonids
0.90
0.12
0.37
0.04
-0.42
0.51
0.71
0.06
-0.37
-
0.16
0.99
0.99
0.99
0.84
0.99
0.90
0.88
0.88
-
-0.09
0.07
0.00
0.18
-0.42
0.51
0.86
-0.33
-0.36
-
Table 4. Spearman Rank correlation coefficients between the entire dataset and
selected taxonomic groups for each depth strata on either side of the SE region.
The number of cells of latitude is kept constant even if not all taxonomic-groups
were present.
15
Slope
East
East
East
East
East
East
West
West
West
West
West
West
Depth (m) No cells
in
analysis
200-500
13
500-1000
14
1000-1500
10
1500-2000
9
2000-2500
1
2500+
0
200-500
0
500-1000
5
1000-1500
0
1500-2000
0
2000-2500
0
2500+
0
Decapods
0.93
0.92
0.98
0.94
0.72
-
Holo- Ophiur- Pycnothurians
oids
gonids
0.80
0.64
0.90
0.79
0.42
-
0.95
0.92
0.96
0.94
0.52
-
0.50
0.84
0.90
0.84
0.72
-
Table 5. Spearman Rank correlation coefficients between the entire dataset and
selected taxonomic groups for each depth strata on either side of the SE region.
Only the cells of latitude that contained all taxonomic groups are included in the
analysis.
2.8. Change in distribution with depth
Species richness of the echinoderms (ophiuroids and holothurians only), pycnogonids
and decapods at 100 m depth intervals is shown in Figure 11a. This was the sum of
samples collected in the SE region from 20 to 3500 m.. This graph showed that
maximum species richness occurs on the shelf, followed by smaller peaks at 500 and
1000 m, then a rapid decline to the lower slope, with minor peaks 1400 and 2500 m.
However much of this curve was directly related to collection effort. There were 331
samples from the upper shelf (<100 m), falling to 50 at 600 m.. Below 1900m there
were less than 10 samples per 100 m (Figure 13). Different curves were obtained when
samples collected by different methods were separated out (Figure 12). A lack of
dredge/epibenthic sled samples from the upper slope was related to the decline of
species richness from the shelf to 1000 m.. The minor peak at 400-600 m was related
to the increase in trawl samples and the peak at 2500 to additional sled samples, which
collected a large number of ophiuroids (Figure 11b).
Not all taxonomic-groups had the same curves. The ophiuroids show an increase in
diversity from the shelf to 1000 m (Figure 11 b), despite the decline in collection
effort.
The turnover in species was most pronounced from the shelf to 300 m (Figure 13).
Whether this is an abrupt discontinuity or gradual change cannot be determined
because of the low number of samples in the 150-300 m depth range. Other peaks in
turnover (at 400 m, 1000 m and 2500 m) appeared to be related to species richness and
collection efforts at these depths. The stacked plots of species richness also showed
how species that can tolerate shallow depths rapidly decline with depth (Figure 11).
Only 15% of shelf species were still present at 500 m, however one persisted to over
16
2600 m.. The upper to middle slope (to 2000 m) fauna frequently had large
bathymetric ranges. A different fauna appears around 2500 m.
The effect of depth on community structure is shown in figure 14 - a cluster diagram of
epibenthic sled samples from the SE region. The two major clusters were based on
shelf (0-210 m) and slope (> 200 m) samples. Shelf samples separated into an upper
shelf and two lower-shelf clusters. The slope cluster separated into upper slope (<1000
m) and lower slope (> 1000 m) samples from the continental slope, and a separate
cluster from the Tasmanian seamounts. The upper slope samples were further divided
into a right cluster based on Southern Surveyor (2000) samples and a left cluster based
on Franklin (1986) samples, a difference at least partially due to differences in
collection gear. The Franklin material included many smaller species indicating the use
of a smaller mesh size on the sled.
In summary, after an initial rapid turnover of species from the shelf to slope, there was
a gradual and continuous turnover of species until the lower slope (2500 m) after
which there was a more pronounced faunal change. Communities were divided into
shelf (<200 m), upper slope (200-1000 m), and lower slope (< 1000 m) categories.
However, all these patterns were influenced by the current uneven collection effort.
2.9. Species endemic to the SE region
Seventy-three continental slope species are apparently endemic to the SE region (Table
5). The majority of these species are undescribed (n=63) or described over the last 15
years (n=5). Many of these species are only known from the Tasmania seamounts. Not
enough information is known about these animals to confidently assert their
endemicity at this stage. Currently recognised deep-sea species are generally
widespread, having ranges greater than the area of the SE region. However, recent
genetic work indicates that some existing species are complexes of genetically distinct
populations that may be considered distinct species with further research (O’Hara,
unpublished).
17
Taxon
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Decapoda
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Family name
Diogenidae
Galatheidae
Galatheidae
Galatheidae
Galatheidae
Galatheidae
Hippolytidae
Hippolytidae
Hippolytidae
Hippolytidae
Hippolytidae
Hippolytidae
Hippolytidae
Paguridae
Pasiphaeidae
Polychelidae
Sicyonidae
Amphiuridae
Amphiuridae
Amphiuridae
Amphiuridae
Asteroschematidae
Cucumariidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiacanthidae
Ophiactidae
Ophiomyxidae
Ophiuridae
Ophiuridae
Ophiuridae
Ophiuridae
Ophiuridae
Ophiuridae
Ophiuridae
Ophiuridae
Genus
Paguristes
Munida
Munida
Munida
Munida
Munidopsis
Eualus
Lebbeus
Lebbeus
Leontocaris
Leontocaris
Leontocaris
Thoralus
Pagurid
Pasiphaea
Polycheles
Sicyonia
Amphioplus
Amphioplus
Amphiura
Amphiura
Asteroschema
Species
aciculus
sp MoV 2672
sp MoV 2673
sp MoV 2674
sp MoV 2766
sp MoV 2677
sp MoV 2681
sp MoV 2679
sp MoV 2680
amplectipes
bulga
yarramundi
sp MoV 2769
sp MoV 2683
kapala
sp MoV 2719
australiensis
sp MoV 2722
sp MoV 4529
sp MoV 4530
sp MoV 4531
sp.
Amphicyclus
Ophiacantha
Ophiacantha
Ophiacantha
Ophiacantha
Ophiacantha
Ophiacantha
Ophiocamax
Ophiocamax
Ophiocymbium
Ophiomitrella
Ophiomitrella
Ophioplinthaca
Ophiopristis
Histampica
Ophiobyrsa
Ophiopyrgus
Ophiura
Ophiura
Ophiura
Ophiura
Ophiura
Ophiura
Ophiurid
mortenseni
sollicita
sp MoV 2731
sp MoV 4532
sp MoV 4536
sp MoV 4537
sp MoV 4541
applicatus
sp MoV 4540
sp MoV 4539
sp MoV 2732
sp MoV 2779
sp MoV 2778
sp MoV 4535
sp MoV 4542
rudis
sp MoV 4544
sp MoV 2728
sp MoV 3580
sp MoV 4523
sp MoV 4527
sp MoV 4528
sp MoV 4545
sp MoV 2733
Taxon
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Pycnogonida
Family name
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Ammotheidae
Austrodecidae
Austrodecidae
Callipallenidae
Callipallenidae
Callipallenidae
Callipallenidae
Callipallenidae
Colossendeidae
Nymphonidae
Nymphonidae
Phoxichilidiidae
Phoxichilidiidae
Phoxichilidiidae
Phoxichilidiidae
Phoxichilidiidae
Phoxichilidiidae
Rhynchothoracidae
Genus
Ammotheid
Ascorhynchus
Ascorhynchus
Ascorhynchus
Ascorhynchus
Ascorhynchus
Cilunculus
Cilunculus
Cilunculus
Cilunculus
Austrodecus
Pantopipetta
Callipallene
Callipallene
Callipallene
Pallenopsis
Pallenopsis
Colossendeis
Nymphon
Nymphon
Anoplodactylus
Anoplodactylus
Anoplodactylus
Anoplodactylus
Anoplodactylus
Anoplodactylus
Rhynchothorax
Species
sp slope 1
sp slope 2
sp slope 3
sp slope 4
sp slope 5
sp slope 6
sp slope 4
sp slope 6
sp slope 7
sp slope 8
sp slope 2
sp slope 1
sp slope 1
sp slope 2
sp slope 3
sp slope 1
sp slope 3
sp nov
sp slope 3
sp slope 4
sp slope 2
sp slope 3
sp slope 5
sp slope 6
sp slope 7
sp. nov.
sp slope 1
Table 5. Apparently endemic species from the
continental slope of the SE region.
18
3. Macquarie Ridge
3.1. Methods
The fauna of the Macquarie Ridge was analysed separately from the SE continental
slope because of the differences in the taxa available for analysis and the lower overall
collection effort.
Data
 Most material was collected by BANZARE (1939), NZOI (1959-1965), Eltanin
(1965-1968), ANARE (1986) and CSIRO Southern Surveyor (1999) cruises to the
Macquarie Ridge.
 Material was collected using bottom trawls, except for a few epibenthic sleds
collected by the 1999 Southern Surveyor Cruise.
 The dataset included echinoderms (all classes) and pycnogonids.
 In all there were 58 species in 246 collection (species/station) lots.
Analysis
 The data were summarised into the presence/absence of each species in cells of one
degree latitude along the Ridge (49-56ºS). The amount of longitude included varied
with the width of the Macquarie Ridge at each latitude. Only material from the
relatively narrow ridge was included in the analysis.
 Although the target depth segment was 200 m, not enough material was present at
al longitudes to facilitate stratification of the dataset in this way. Nor was there
enough material to analyse depths below 2000 m. Consequently, depth strata of 0200, 200-500, 500-1000, 1000-1500, 1500-2000 m were finally used in the final
analysis. A species that occurs at the limit between depth strata (eg 500 m) was
included in the next depth strata (500-1000 m).
 Two additional cells were created representing the northern (<=48ºS) and southern
(>=57ºS) borders of the region based on whether each species is known to occur at
more northern or southern latitudes. The data were sourced from published
literature and collection databases.
 The actual data were supplemented by interpolated data, generated by recording a
species as present for cells that are between known occurrences for each depth
strata.
 The data were analysed using multivariate statistics, including MDS ordinations
and cluster diagrams, using Bray-Curtis similarity coefficients and group-average
linkage. The use of the Bray-Curtis similarity measure on presence/absence data is
equivalent to using the Sorensen Binary coefficient.
19
Table 6. Geographic spread of the number of species recorded in each cell from
the Macquarie Ridge (including interpolated records).
Depth (m)
0-200
200-500
500-1000
1000-1500
1500-2000
2000-2500
2500+
48+
3
6
15
11
8
5
49ºS 50ºS 51ºS 52ºS 53ºS 54ºS 55ºS 56ºS
6
4
4
9
5
29
4
2
2
3
4
10
15
9
10
8
7
10
8
12
3
6
6
6
6
9
5
4
1
2
2
2
3
2
4
3
1
57+
6
2
1
Table 7. Geographic spread of the number of collection stations by latitude (rows)
and longitude (columns) from the Macquarie Ridge. Heavily surveyed cells
include the Macquarie Island (54.5ºS) cell.
Lat
49ºS
50ºS
51ºS
52ºS
53ºS
54ºS
55ºS
56ºS
150ºE 158ºE 159ºE 160ºE 162ºE 163ºE 164ºE
2
1
1
2
2
2
1
5
35
4
4
4
20
3.2. Results
Depth strata
0-200 m
Multivariate analysis
Macquarie Island (54ºS) forms an outlier on the MDS. This is due
to it being the only data rich cell at this depth in the analysis.
Other cells are depauperate as there are few sections of the
Macquarie Ridge with seafloor < 200 m.
200-500 m
The data points are scattered across the MDS, reflecting the lack
of systematic collections along the Macquarie Ridge at this depth
(Table 6).
500-1000 m
This graph (Figure 15a) shows a clear biogeographic gradient
from the very north of the Macquarie Ridge, south of New
Zealand (48ºS), to Macquarie Island (54ºS). The cells along the
Southern Ridge are separate.
Three groups can be distinguished using the cluster analysis
(Figure 16):
a) Northern Macquarie Ridge (48-52ºS)
b) Central Macquarie Ridge, including Macquarie Island (5354ºS)
c) Southern Macquarie Ridge (55-57ºS)
1000-1500 m
The three groups identified for the 500-1000 m depth strata can
also be clearly distinguished at this depth.
1500-2000 m
The far north (48ºS) and far south cells (55-57ºS) can be
distinguished from those along most of the Ridge. The animals
present at this depth tend to be widespread Southern Ocean
species.
3.3. Summary
At depths where there is an adequate dataset along the entire Macquarie Ridge (5001500 m), the fauna separates into three geographic clusters, based on the northern (4852ºS), central (53-54ºS) and southern (55-57ºS) sections of the Ridge (Figures 15 and
16). This represents a biogeographic gradient from a New Zealand subantarctic fauna
to an Antarctic fauna, with the central fauna representing a mixed zone with a few
endemic species.
At shallower depths (0-200, 500-1000 m), Macquarie Island becomes an outlier. This
is partly due to the inconsistent distribution of shallow habitats along the Ridge and the
presence of Macquarie Island endemic species.
A similar widespread fauna occurs along most of the Ridge at the deepest depths
analysed (1500-2000 m), although the far north (48ºS) and far south (55-57ºS) cells
can be distinguished.
21
4. Conclusions
This study must be considered a preliminary analysis of the benthic fauna of the SE
Australian continental slope. The uneven sampling effort has been a major impediment
to conclusive analysis. There are many more samples taken from the northern sections
of the SE region, and around Macquarie Island along the Macquarie Ridge. There were
very few samples from the South and Eastern Tasman Rises. This gradient of effort
does affect the multivariate analyses.
Nevertheless, there are some useful patterns in the data. The benthic fauna of the SE
continental slopes is a gradient from a temperate fauna of the Tasman Sea to the
subantarctic fauna of the South Tasman Rise. The temperate fauna persists as far as
mid Tasmania (approximately 42ºS), and possibly will be found further south with
increased collection effort. Subantarctic species become progressively more important
in the region south of Tasmania. Many subantarctic species occur on the Tasmanian
seamounts (44ºS) (Koslow et al. 2001).
There is a large apparent difference between the eastern and western slopes, and much
of this is due to the greater collection effort off the East Coast. Nevertheless, there is a
small fauna (1.6%) that is only known from the western slope, and a larger (but as yet
unquantified) fauna that is restricted to the Tasman Sea.
There is a turnover of species with depth. There is a rapid turnover between the shelf
fauna and the upper slope (150-300 m), followed by gradual change until 2500 m, after
which there is a more pronounced faunal change. There are no samples from the
abyssal plain. Communities were divided into shelf (<200 m), upper slope (200-1000
m) and mid-lower slope categories (>1000 m). The interaction between depth and
latitude for the eastern slope was documented by Poore et al. (1994). The seamount
fauna from Southern Tasmania is also distinct.
There is a gradient along the Macquarie Ridge also, with the fauna of the Northern and
Southern Ridges being distinct from each other and the fauna around Macquarie Island.
The Northern Ridge supports subantarctic New Zealand species (O’Hara 1998) and the
Southern Ridge Antarctic species. The shallow water fauna around the island is
composed of shelf species from New Zealand and subantarctic species that have
presumably arrived on kelp holdfasts from islands further west (O’Hara 1998).
22
4. Participants
Dr Tim O’Hara (MV) identified most of the echinoderms; Dr Gary Poore (MV) and
Dr. Shane Ahyong (AM) identified the decapods, David Staples (MV) the pycnogonids
and Mark O’Loughlin (MV) the holothurians. Dr Tim O’Hara (MV) ran the analyses
and compiled this document.
5. References
Clarke, K.R. & Warwick, R.M. (1994). Change in marine communities: An approach
to statistical analysis and interpretation. Natural Environment Research Council
and Plymouth Marine Laboratory: UK.
Koslow J.A., Gowlett-Holmes K., Lowry J.K., O´Hara T.D., Poore G.C.B., &
Williams A. (2001). The seamount benthic macrofauna off southern Tasmania:
community structure and impacts of trawling. Marine Ecology Progress Series
213: 111-125.
O'Hara, T.D. (1998). Origin of Macquarie Island echinoderms. Polar Biology 20: 143151.
O’Hara, T.D. and Poore, G.C.B. (2000). Distribution and origin of Southern Australian
echinoderms and decapods. Journal of Biogeography 27: 1321-1335.
Poore, G.C.B., Just, J. & Cohen, B.F. (1994). Composition and diversity of Crustacea
Isopoda of the southeastern Australian continental slope. Deep-Sea Research 41:
677-693.
23
Eastern slope - 200-500 m
0
40
60
Eastern slope - 200-500 m
Stress: 0.01
48+
35+
36-0
36-5
37-0
37-5
47-5
47-0
46-5
46-0
45-5
45-0
44-5
44-0
43-5
38-5 38-0
39-0
40-0
40-539-5
41-0
41-5
43-0
42-0
42-5
Figure 2. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 200-500 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
24
43-5
43-0
47-5
47-0
46-5
46-0
45-5
45-0
44-5
48+
44-0
38-0
37-5
39-0
38-5
39-5
41-5
41-0
40-5
40-0
42-5
42-0
36-5
100
36-0
80
35+
37-0
Similarity
20
Eastern slope - 500-1000 m
20
60
Eastern slope - 500-1000 m
Stress: 0.02
38-0
37-5
37-0
42-0
41-5
38-5
39-5
41-0
39-0
40-0
40-5
42-5
47-5
47-0
46-5
46-0
45-5
45-0
44-5
43-5
43-0
48+
36-5
36-0
35+
44-0
Figure 3. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 500-1000 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
25
43-5
43-0
42-5
44-0
47-0
46-5
46-0
45-5
45-0
44-5
48+
47-5
37-5
37-0
36-5
35+
36-0
41-0
40-5
41-5
40-0
39-0
38-5
39-5
100
42-0
80
38-0
Similarity
40
Eastern slope - 1000-1500 m
20
60
Eastern slope - 1000-1500 m
Stress: 0.01
44-0
42-5
43-542-0
43-0
41-5
38-5
41-0
40-5
40-0
39-5
39-0
46-5
46-0
45-5
45-0
44-5
38-0
47-0
47-5
48+
37-0
36-0
37-5
36-5
35+
Figure 4. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 1500-2000 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
26
37-0
36-0
37-5
35+
36-5
39-5
39-0
41-0
40-5
40-0
41-5
38-5
42-0
43-5
43-0
42-5
38-0
48+
44-0
47-5
47-0
45-0
44-5
46-5
100
46-0
80
45-5
Similarity
40
Eastern slope - 1500-2000 m
0
40
60
Eastern slope - 1500-2000 m
Stress: 0.01
39-5
38-0
37-0
36-5
41-5
43-544-0
42-5
43-0
39-0
36-0
38-5
35+
37-5
41-0
40-0
40-5
42-0
46-0
47-0
46-5
45-5
48+
44-5
45-0
47-5
Figure 5. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 1500-2000 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
27
40-5
40-0
41-0
39-0
39-5
41-5
38-5
43-0
42-5
43-5
42-0
37-0
36-5
37-5
35+
36-0
38-0
48+
44-0
47-5
47-0
46-5
46-0
45-5
100
45-0
80
44-5
Similarity
20
Eastern slope - 2000-2500 m
20
60
Eastern slope - 2000-2500 m
Stress: 0.05
41-5
42-0
44-0
42-5
38-5
38-0
37-5
37-0
36-5
36-0
39-5
39-0
43-5
41-0 43-0
40-5
40-0
44-5
47-5
47-0
46-5
46-0
45-5
45-0
48+
35+
Figure 6. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from 2000-2500 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
28
39-0
38-0
37-5
37-0
36-5
36-0
39-5
38-5
40-5
40-0
41-0
43-5
43-0
35+
42-5
42-0
41-5
44-0
47-0
46-5
46-0
45-5
45-0
100
44-5
80
48+
47-5
Similarity
40
Eastern slope - 2500 m+
20
60
Eastern slope - 2500 m+
Stress: 0.08
35+
41-5
40-5
42-0
36-5
41-0
43-5
43-0
42-5
40-0
39-5
39-0
36-0
38-0
37-5
37-0
44-0
38-5
Figure 7. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the eastern SE Australian continental slope from below 2500
m. Data consists of presence/absence of each species in cells of half a degree
latitude and longitude.
29
43-0
42-5
43-5
41-0
39-5
39-0
40-0
44-0
40-5
38-5
42-0
41-5
38-0
37-5
37-0
36-0
100
36-5
80
35+
Similarity
40
Western slope - 200-500 m
0
40
60
Western slope - 200-500 m
Stress: 0.01
41-5
48+
41-0
40-0
40-5
39-5
35+
36-5
36-0
39-0
38-0
37-5
37-0
38-5
43-0
42-0
42-5
Figure 8. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the western SE Australian continental slope from 200-500 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
30
42-5
42-0
43-0
41-5
36-5
36-0
37-0
38-0
37-5
35+
38-5
40-5
39-5
40-0
41-0
100
39-0
80
48+
Similarity
20
Western slope - 500-1000 m
20
60
Western slope - 500-1000 m
Stress: 0.05
35+
36-0
36-5
47-5
47-0
46-5
46-0
45-5
45-0
44-5
48+
37-5
37-0
38-0
43-0
42-5
42-0
43-5
41-5
39-5
39-0
40-0
40-5
41-0
38-5
44-0
Figure 9. Cluster analysis and MDS ordination of echinoderms, decapods and
pycnogonids from the western SE Australian continental slope from 500-1000 m.
Data consists of presence/absence of each species in cells of half a degree latitude
and longitude.
31
43-0
42-5
42-0
43-5
47-0
46-5
46-0
45-5
45-0
44-5
48+
47-5
44-0
39-5
39-0
40-0
40-5
38-0
37-5
37-0
41-5
41-0
38-5
100
36-5
80
35+
36-0
Similarity
40
1
8
0
1
6
0
1
4
0
1
2
0
Numberofspecies
1
0
0
8
0
6
0
4
0
2
0
0
3
6
.0 3
7
.0 3
8
.0 3
9
.0 4
0
.0 4
1
.0 4
2
.0 4
3
.0 4
4
.0 4
5
.0 4
6
.0 4
7
.0
3
6
.5 3
7
.5 3
8
.5 3
9
.5 4
0
.5 4
1
.5 4
2
.5 4
3
.5 4
4
.5 4
5
.5 4
6
.5 4
7
.5
S
ths
p
p
N
ths
p
p
E
n
d
e
m
ic
W
id
e
s
p
re
a
d
a) Eastern slope
4
5
4
0
3
5
3
0
Numberofspecies
2
5
2
0
1
5
1
0
5
0
3
6
.0 3
7
.0 3
8
.0 3
9
.0 4
0
.0 4
1
.0 4
2
.0 4
3
.0 4
4
.0 4
5
.0 4
6
.0 4
7
.0
3
6
.5 3
7
.5 3
8
.5 3
9
.5 4
0
.5 4
1
.5 4
2
.5 4
3
.5 4
4
.5 4
5
.5 4
6
.5 4
7
.5
S
ths
p
p
N
ths
p
p
E
n
d
e
m
ic
W
id
e
s
p
re
a
d
L
a
titu
d
e
b) Western slope
Figure 10. Stacked plot of the number of species per grid.
32
1
4
0
1
2
0
1
0
0
noofspecies
8
0
6
0
m
ind
e
p
th(m
)
o
fe
a
c
hs
p
e
c
ie
s
4
0
>
=2
5
0
0
<2
5
0
0
2
0
<1
5
0
0
<1
0
0
0
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
3200
3300
0
<5
0
0
<2
0
0
d
e
p
th(m
)
a) Decapods, pycnogonids, ophiuroids, holothurians
5
0
4
0
noofspecies
3
0
2
0
m
ind
e
p
th(m
)
o
fe
a
c
hs
p
e
c
ie
s
1
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
0
0
>
=2
5
0
0
<2
5
0
0
<1
5
0
0
<1
0
0
0
<5
0
0
<2
0
0
D
e
p
th(m
)
b) Ophiuroids only
Figure 11. Stacked plot of the species richness for each 100 m depth strata for all
stations across the SE region.
33
1
4
0
1
2
0
1
0
0
noofspecies
8
0
6
0
4
0
2
0
100200 0
400500300
700800600
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
3200
3300
3400
3500
0
A
ll
D
re
d
g
e
T
ra
w
l
O
th
e
r
d
e
p
th(m
)
Figure 12. Species richness from various collection methods for 100 m depth strata
across the SE region.
2
2
5
3
5
0
2
0
0
3
0
0
1
7
5
2
5
0
1
2
5
2
0
0
1
0
0
1
5
0
noofstations
noofspecies
1
5
0
7
5
1
0
0
5
0
5
0
2
5
0
100200 0
300400
500600
700800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
0
S
p
ptu
rn
o
v
e
r(L
)
S
p
pric
h
n
e
s
s(L
)
E
ffo
rt (R
)
d
e
p
th(m
)
Figure 13. Species richness, species turnover and effort (no of samples) for 100 m depth
strata across the SE region.
34
Figure 14. Cluster diagram of all samples from the SE region
collected using an epibenthic sled (species abundance data is square
root transformed).
0
20
40
60
80
10
0
< 130 m (Bass Strait)
1000-3000 620-1900
m (slope) m
(seamounts)
150-1000 m
(slope)
130-210 m (Outer shelf)
(mixed
outliers)
35
0-200 m
1000-1500 m
Stress: 0.03
Stress: 0.01
55
49
56
48+
5051
53
52
5049
51
55
54
57
+
53
48+
52
54
200-500 m
Stress: 0.01
1500-2000 m
Stress: 0
48
+
48+
53
54
52
51
50
49
55
57+56
54
52
50
49
51
53
500-1000 m
Stress: 0
48+
5657
+
49
50
51
55
52
Figure 15. MDS ordinations of species from the Macquarie Ridge,
based on the presence/absence of each species along the Ridge in
cells of one-degree latitude. Macquarie Island is located at 54ºS.
53
54
36
500-1000 m
0
20
40
Bray-Curtis
Similarity
60
80
100
55
56
57+
53
54
48+
52
49
50
51
Figure 16. Cluster diagram of species from the Macquarie Ridge,
based on the presence/absence of each species along the Ridge in
cells of one-degree latitude between 500-1000 m. Macquarie Island
is located at 54ºS
37