Associate Professor Bronwyn Gillanders presents the fourth installment of the Science Seminar Series entitled "Giant Australian cuttlefish: a globally unique species under threat."

1. The Environment Institute
Where ideas grow
Assoc. Prof. Bronwyn Gillanders
Giant Australian cuttlefish: a globally unique species
under threat?

2. Bronwyn Gillanders

3.  Population structure
 Melita de Vries
 Steve Donnellan
 Mike Gardner
 PhD/Hons students
 Jackie Dupavillon
 Nick Payne
 Leanne Trott

4.  Giant Australian cuttlefish & the issues
 Population structure
 Potential impacts of desalination brine

5. Weighs up to 13 kg
Grows up to 1 m
Lives 1-2 years
Photo: Kaufmann Productions

6. Ningaloo Reef
Moreton Bay

7. Adelaide

8. 8 km of coastline
Winter – May to August

9. Rocky reef
Habitat map: SA DEH
8 km of coastline
Winter – May to August

10. Males larger than
females
High
male:female sex
ratio
Males ‘battle’ for
females
Females may or
may not mate
with a male
Small males have
other strategies
(e.g. sneakers)
Shear numbers
impressive
Photos: Fred Bavendam

11.  Skewed towards males (4:1) based on counts
of each sex
 Assumes individuals on breeding aggregation
similar amounts of time
 Population sex ratio may be 1:1 with sexes
spending different amounts of time on the
breeding aggregation
 Predict males spend more time than females

12. Males n = 13
Females n = 6
Payne, PhD project

13. Residence time Residence period
35 60
Mean Residence Time (days ± SE)
Mean Residence Period (days ± SE)
30 50
25
* *
40
20
30
15
20
10
5 10
0 0
Males Females Males Females
Male:Female = 3.7 : 1 Male:Female = 4.6 : 1
 Population composed of equal numbers of males & females
Payne, PhD project

14. 300
270
Renewable moratorium on
240 fishing introduced in 1998
210 Now permanently closed to
taking of cuttlefish
Catch (tonnes)
180
Need to establish long-term
150 scientific based management
plan
120
90
60
30
0
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
From: SARDI Catch Data

15.  BHP Olympic Dam expansion
 Preferred option: coastal desalination plant in USG
 Point Lowly preferred location (18 ha site)
 Bulk commodities export facility
 Feasibility study by Spencer Gulf Port Link Consortium
(SGPLC), led by Flinders Ports
 7-13 million tonnes of ore could be exported through new
facility

16.  Need to understand
population structure for
appropriate spatial
management
 Demographic processes
& population dynamics
may vary
From: Keough & Swearer (2007)

17.  Strongest inferences use a suite of
techniques
 Genetic & phenotypic approaches
 Might not necessarily expect concordance
among approaches
 Evolutionary history vs. environmental variation
 Spatial resolution varies by technique
 Genetic approaches may be more conservative

18.  Marine populations
 Genetic homogeneity over large distances
 High dispersal life history characteristics
 Squid
 High levels of gene flow among populations
 Cuttlefish
 Sepia officinalis – extensive population structuring

20.  Determine population structure of giant
Australian cuttlefish using a multidisciplinary
approach
 Molecular (microsatellite DNA markers)
 Morphometrics
 Statolith chemistry
 Investigate spatial & temporal variation in
population structure

21.  Microsatellite genotyping
 12 microsatellite loci screened per individual
 Kassahn et al. (2006) Marine Biology
 Wheaton et al. (2007) Molecular Ecology Notes
 Temporal variation
 South Australia
 Five yrs between 1998 & 2006
 Spatial variation
 18 sites across Australia

22. Ningaloo Moreton
Bay
Breeding
1998 QLD
aggregation 2000
2004
WA
Whyalla 2005 SA
2006 18
1 NSW
4 5 17
16
3 6 15
2004 2 VIC
Wallaroo 2005
14
13
Spencer
Gulf Bass Strait
GSV
Glenelg 1998
1998
Edithburg Aldinga 2005
Cape
2005
Jervis 2005
2006

23. -20500
Bayesian clustering approach
Triplicate runs for 1 (panmixia) to 6
-21500 populations
Ln Pr(X | K)
Used admixture model
-22500
Assumed correlated alleles across
populations
-23500
Examined each of K populations
further to detect sub-population
-24500 structure
1 2 3 4 5 6
K, number of populations STRUCTURE

24. Q
Estimated membership coefficients
0.00
0.20
0.40
0.60
0.80
1.00
Whyalla 1998
Whyalla 2000
Whyalla
Whyalla 2004
Whyalla 2005
Breeding aggregation
Whyalla 2006
Wallaroo 1998
Wallaroo 2005
Wallaroo
Spencer Gulf
Edithburg 2005
Cape Jervis 2005
Cape Jervis 2006
Shows overall population structure & individual assignment
Aldinga/Myponga
1998
Gulf St Vincent
Aldinga/Myponga
2005
Length of each line proportional to estimated membership in each group
Glenelg 1998
western AUS
1998-2006
Vic
WA
VIC 2002
NSW
2002/2003
NSW

25. Q
Estimated membership coefficients
0.00
0.20
0.40
0.60
0.80
1.00
Bay
Jervis Bay
Jervis
Jervis Bay
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Wollongong
Central & Southern NSW
Wollongong
Wollongong
Wollongong
Wollongong
Newcastle
Newcastle
Newcastle
Newcastle
Newcastle
Coffs Harbour
Coffs Harbour
Coffs Harbour
Coffs Harbour
Coffs Harbour
Coffs Harbour
Coffs Harbour
Coffs Harbour
Coffs Harbour
Northern NSW
Coffs Harbour
Coffs Harbour
Coffs Harbour

26.  Spatial information – sampling location
 1 to 10 populations (n=5 replicate runs)
 Fixed K at modal value to estimate assignment of
individuals to populations (n=10)
 Continued hierarchical analyses to detect
subpopulation structure
 GENELAND

27. Population 3
Population 5
Population 1 Population 4 Population 2

28. South Australia
Breeding aggregation
Population 5
Contact zone
Population 4
100 km

29.  28 measurements per individual
 Removed allometric effects of body
size
 Sexually dimorphic  sexes analysed
separately (n= 173 females & 342 males)
 No difference in size among years 
pooled years

30. 5 Breeding aggregation
GSV & Southern SG
3 Western SA
Discriminant function 2
1 90% correctly classified
3 variables used for classification
1
3 variables important: cuttlebone
width & 2 beak parameters
3
5
-5 -3 -1 1 3 5
Discriminant function 1
LRL UHL

31. 7 Breeding aggregation
GSV & Southern SG
Western SA
Discriminant function 2
3
90% correctly classified
8 variables used for classification
-1 3 beak parameters contribute to
differences
-5
-5.0 -2.8 -0.6 1.6 3.8 6.0
Discriminant function 1

32. Dissolved trace Uptake by Statolith
elements cephalopod incorporation

33. Prehatchling Hatchling
Sr:Ca statolith (mmol mol-1)
Sr:Ca statolith (mmol mol-1)
35 35
Sr:Ca prehatchling statolith (mmol mol )
30
-1
30
Sr:Ca hatchling statolith (mmol mol )
-1
25 25
20 20
15 15
10 10
5 5
0 0
0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35
-1
Sr:Ca seawater (mmol mol-1)
Sr:Ca prehatchling seawater (mmol mol )
Sr:Ca seawater (mmolmol- ) -1) 1
Sr:Ca hatchling seawater (mmol mol
Trott, Hons thesis

34. 5 Breeding aggregation
GSV & Southern SG
Western SA
Discriminant function 2
3
1 Mg:Ca, Sr:Ca & Ba:Ca
Discriminant Function Analysis
-1 All years – 77% correctly classified
2004 – 78% correct
2005 – 79% correct
-3 2006 – 83% correct
-5
-7 -3 1 5
Discriminant function 1

35.  Not one panmictic population
 Evidence for 5 populations across species range
 Breeding aggregation differs from elsewhere
 Evolutionary & ecological implications
 Possibly incipient species
 Adaptive divergence along an environmental
gradient
 Recent & rapid differentiation

36. Ocean again at ~ 7KYA
From: Andrew Hugall

37.  Mating behaviour differs
 Physiological tolerance & condition in relation to
temperature & salinity
▪ Two populations may be prevented from significant overlap due to
differing tolerances
 Are individuals from two populations able to mate, are
eggs viable, are offspring fertile
▪ Testing degree of reproductive isolation
 Determine degree of genetic isolation – genome wide
screening
 Ecological implications of morphological differences

38. Intake pipe
Proposed locations
Breeding area
Out take pipe
320 ML SW/day 120 ML FW/day via
from USG; 320 km pipeline
Salinity >40 ppt
200 ML SW/day
returned in more
concentrated form;
Salinity 78 ppt
From: Olympic Dam EIS website

39.  Discharge of large volumes of highly concentrated brine back to
ocean
 Elevated salt concentration & contaminants
 Elevated temperature & turbidity levels
 Decreased oxygen levels
 Brine high specific density  sinks to bottom
 Could impact adult mating behaviours, & benthic life history
stages

40.  Salinity effects embryonic development
 Resources diffuse across membrane
 Solubility of gases (e.g. O2) decreased in
hyper-saline water
 Increased salinity causes a diffusion limitation

41. n =12
Control Brine
39ppt 40ppt 45ppt 50ppt 55ppt
Dupavillon, Hons thesis

42. Mean field concentration
Brine: Increased Sr, Ca, K & Mg
High Mg causes mortality and
reduced mobility
High concentrations
found in 45, 50 and 55‰.
Treatment - salinity
Treatment Dupavillon & Gillanders (2009)

43. Increase 1‰ = ~7%
decrease in survival
Total mortality
Treatment - salinity
Dupavillon & Gillanders (2009)

44. Smaller size at higher salinity
Smaller individuals  less well developed for feeding & swimming
Treatment - salinity
Dupavillon & Gillanders (2009)

45.  If brine disperses & background salinity levels
reached close to discharge outfall
 May be little impact on eggs
 But
 USG already hypersaline environment
 Strong tidal currents, but are USG waters flushed
& mixed with ocean waters given bathymetry?
 Also, dodge tides
 Potential for major impact on GAC

46.  Mating behaviour highly visual
 Inbound migratory routes of cuttlefish
 Will adults move up and over high salinity, benthic
plumes?
 Will adults migrate around benthic plume to reach
breeding sites?

47.  Only known breeding aggregation of cuttlefish in world!
 Population at Point Lowly likely a different species
 Little if any input from SSG population
 Potential for brine to impact early life history stage
 Unsure about impacts on adult behaviour & migration
 Species can’t move elsewhere to lay eggs
 Cephalopods short lived (1-2 years)
 No storage effect in population
  Need to be more cautious cf. managing finfish

48. Photos: Fred Bavendam, Sean Connell, Jackie Dupavillon,
Kaufman Productions, Nick Payne, Tim Rogers
Recent ABC Catalyst story:
http://www.abc.net.au/catalyst/stories/2695601.htm

49. The Environment Institute
Where ideas grow
Next Seminar: 23 October
Assoc. Prof. Veronica Soebarto
Environmentally-sensitive design