Deriving pressure-response relationships of SPONGES to dredge pressures

-a LABORATORY approach-DREDGING SCIENCE NODE

THEME 6.4 –MARI-CARMEN PINEDA, AIMS

Dredging Science Node

Introduction: Laboratory approach

Field

GOAL: To identify Cause: Effect pathways…

Lab

X + ComplexityX + Remote +Dangerous &+ $$

√ + Control (1 factor at a time)√ + Reliability (good replication)

Better understanding of PRESSURE:

RESPONSE relationships

To improve PREDICTION and MANAGEMENT

Dredging Science Node

Introduction: The National Sea Simulator (SeaSim)

Dredging Science Node

Introduction: Sponges

What do we know?

• Smothered by sediments• Clogging of aquiferous system• Reduced pumping activity• Decreased growth• Decreased recruitment

What do we want to know?

• Which is the main stressor? Suspended Sediments /Sedimentation /Light reduction

• Which morphologies would be more affected?• Importance of light for sponges containing

photosymbionts? • Sub-lethal thresholds?

Dredging Science Node

What are we doing?

Sponge species

Stylissaflabelliformis

Ianthellabasta

Carteriospongiafoliascens

Cymbastelacoralliophila

Clionaorientalis

Coscinodermamatthewsi

Phototrophic HeterotrophicLaboratory Experiments

Experiment 1. Sedimentation-Morphologies

November 2013

Experiment 2. Light attenuationApril-May 2014

Experiment 3. Suspended Sediments

Dec.2014-Jan.2015

Experiment 4. Smothering

May-June 2015

Experiment 5. FINAL-Long Term

February-April 2016

Treatments

250 100 25 0 NL

µg

To

tal

Ch

l/ g

0

50

100

150

200

250

Day 0 Day 7 Day 14 Day 21 Day 28 Rec 7 Rec 14

Eff

ec

tive

Qu

an

tum

Yie

ld

0.1

0.2

0.3

0.4

0.5

250

100

25

0

NL

Dredging Science Node

Results: Light attenuation

0 25

100 250

7 days later

4 w

eeks later

Results: Total Suspended Solids (TSS)

Week 1Week 2

Week 3Week 4

Recovery 1

Recovery 2

Mo

rtality

(%

)

0

20

40

60

80

1000 mg/L

3 mg/L

10 mg/L

30 mg/L

100 mg/L

Dredging Science Node

%G

row

th

(th

ick

ne

ss

)

-20

0

20

40

% G

row

th

(Su

rfa

ce

Are

a)

-20

-10

0

10

20

% N

ec

ros

ed

or

Ble

ac

he

d T

iss

ue

0 3 10 30 100

0

20

40

60

80

100

Dredging Science Node

What’s next?

Preliminary Conclusions: • Sponges seem largely tolerant of short dredging-related pressures• Light and TSS on their own do not cause severe stress (on most species)• Overall, CUP morphologies and PHOTOTROPHIC species seem more sensitive

What’s Next??• What are the effects of long-term smothering?• How do periodic dredging events affect sponge fitness?

Exp4. Smothering

Exp5. FINAL-Long Term

More questions…• Effects of dredging on sponge larvae and recruits?• Effects of dredging-related pressures in combination with other stressors (e.g.

pollutants, high temperature)• Effects of dredging on other important filter-feeders (e.g. ascidians, gorgonians)

AcknowledgmentsWoodside, Chevron and BHP and WAMSI partners for funding this research.

WAMSI DSN leaders R. Jones, R. Masini and K. Crane.

And special thanks to:

Mari-Carmen Pineda1,2, Brian Strehlow3, Alan Duckworth1,2, Nicole Webster1,2

1 Australian Institute of Marine Science, Townsville2 Western Australian Marine Science Institution, Perth3 University of Western Australia, Perth

Dredging Science Node

SeaSim TeamEduardo Arias