Associate Professor Sean Connell presents the topic ‘Policy responses to a drying climate may save Adelaide's kelp forests’. Sean’s seminar is based on 10 years of experimental analyses of observations derived from the natural history of temperate Australian kelp forests. Theory-centric observations can hamper science and he happily admits where his prior biases have caused mistaken starts. Sean argues that if such bias of theory-centric science can be recognised as a possible model, its correctness can be investigated. Sean notes that a modern bias is our culture for alarming news of ecosystem change, he sees it as playing an increasing role in ecology; in not only what is funded and published, but also in how data is acquired and interpreted. Sean indicates that less research seems constructed to survive beyond short-term headlines. He passionately advocates that if we can recognise the theory-laden traps that seek to account for the will-o'-the-wisp, we may return value to research programs that are less about chasing ambulances and wild geese.

1. Environment Institute
Science Seminar Series 2009
Final Seminar Sem 1: 29 June – 12pm
Policy responses to a drying climate may
save Adelaide’s kelp forests
Presented by: Associate Professor Sean Connell

5. is playing an increasing role:
 funded and published
 how data are acquired and interpreted

6. In a race for $ and the headlines needed to lobby $...
“Since the Jamaica story was an anomaly, it makes a poor foundation
for general models of reef ecology” Bruno et al. 2009 Ecology

7. If theory ladnness can be recognised as a possible model

8. Policy

9. 1. Reconstruction of a lost-baseline
2. Drivers of habitat-loss
3. Solutions for restoration
4. Contingencies via biogeography
5. Contingencies via climate
an immersion of science

11. #1. Baseline
N
Australia
Adelaide
Urban 1
South
Australia
Agricultural 1
Victor Harbor
Urban 2
Adelaide
Natural 2
Agricultural 2 Natural 1
25 km
South North
Sites

12. #1. Baseline
Cape Leeuwin
Encounter Bay

13. #1. Baseline

15. # 2. Causes

16. # 2. Causes
0.80 Heavy rainfall 0.40
Light rainfall
Mean NOx conc. light rainfall (mg L-1)
0.60 0.30
Mean NOx conc. heavy (mg L-1)
0.40 0.20
0.20 0.10
0.00 0.00
Urban Agricultural Natural
Catchment type

17. # 2. Causes
20
Urban Agricultural Natural
Canopy-formers
mean: 5.9 mean: 9.5 mean: 11.4
PATCH-SIZE FREQUENCY
10
0
20
Turf-formers
mean: 4.1 mean: 3.4 mean: 2.3
10
0
0 10 20 30 0 10 20 30 0 10 20 30 40
Diameter of habitat patches (m)

18. # 2. Causes
0
Urban Agricultural Natural
12
uptake of urban derived nitrogen
(b)
10
δ15N (‰  SE)
Urban
8
6
Natural Agricultural
4
-22 -21 -20 -19
δ13C (‰  SE)

20. # 2. Mechanisms

21. # 2. Mechanisms
Ambient Nutrients
100 Elevated Nutrients
Percentage cover of turf
80
60
40
20
0
Summer Winter Summer Winter
Natural catchment Urban catchment

22. # 3. Restoration
Non-removal control
Turf removal
100
80
Recovery (%)
60
40
20
0
1 2 3
Turf-dominated sites

23. #4. Contingencies
Contingencies
Production & consumption via humans & biogeography

24. #4. Contingencies
• Oceanography
Bigger cities = bigger impacts?
Sydney
Environmental Impact
Perth
Adelaide
Human population

25. • Oceanography
Western Australia
20 Southern Australia
% cover of turf
Sydney Eastern Australia
10
0
0 0.5 1.0 1.5
Chlorophyll a
20
Chlorophylla (mg l-1)
15
10
5
Sydney
0
Southern Eastern
0.3 insitu sampling at depth of subtidal habitats
NOx (Milligrams/l)
0.2
0.1
Sydney
0.0 a b a b
Southern Eastern

26. • Oceanography
25 Ambient
Enriched 7.25 %
20
49.64%
Turfs (% cover)
15
1000 Km
10
5
0
south east
coast coast
Cape Jervis

27. 6000
Productivity
5000 SE Alaska
4000
Japan
3000 Norway Central California
S Chile
Southern California
2000 S Africa-South Coast
Gulf of Maine
East Australia
1000 South & West Australia
2 4 6 8 10 12 14
Integrated Monthly NO3 Flux

28. The poster child
easy ecology

29. • Consumers

30. Data courtesy of Nick Shears
75 % (n = 113 sites) have no barrens

31. 70 % (n = 60 sites) have no barrens

32. • Consumers
100
Grazers present
80 Grazers absent
Percentage Cover
60
1000 Km
40
20
0
south east
coast coast
Cape Jervis

34. A continuum
Case A: consumption is much coralline
A B
KELP CONSUMPTION
higher than production, and small
variation in either has little
world
impact.
Cases B and C: when
consumption roughly equals
production, small changes in
either can shift the system to a
different state.
Case D: production is much
C D
higher than consumption, and
small variation in either has little kelp
impact.
world
KELP PRODUCTION

35. coralline
world
KELP CONSUMPTION
Eastern Australia
Productivity is high
and varies little, but
large variation in
consumption is driven
by patchy distributions
of urchins (in both
space and time).
kelp
world
KELP PRODUCTION

36. coralline
world
KELP CONSUMPTION
Western & South Australia
Variation in herbivory is
relatively low, but large
variation in productivity is
driven by land use
kelp
world
KELP PRODUCTION

38. Policy: long-term benefits?

39. Conceptual summary of experiments
Size of Effect
Global Local Global & Local
Stressors

40. Connell (2007) Oxford University Press

41. Climate Global
Flindersia
Biogeography
Gulf
Coastal morphology
Depth
Local conditions
Individuals

42. Percentage cover of rocky habitat

43. Percentage cover of rocky habitat
year 2050
(550 ppm)

44. Percentage cover of rocky habitat

45. “Political decisions are empowered by scientific
evidence in support of policy initiatives” Steve Kennelly
(Director Fisheries, NSW DPI)
....

46. Bring back the kelp

47. Policy

49. Environment Institute
Science Seminar Series 2009
Semester 2 Series begins Friday 31 July
Program to be released shortly
www.adelaide.edu.au/environment