EHSE SPG| 14 March 2016 | Slide 1

Research Institute for the Environment and Livelihoods

Building a new life history model for barramundi

Assoc Prof David Crook

Building a new life history model for barramundi

David Crook

RIEL/School of EnvironmentKakadu Floodplain: Michael Lawrence-Taylor

BARRAMUNDI LIFE HISTORY MODEL

Source: NT Fisheries

OTOLITH CHEMISTRY

• 85 barramundi otoliths analysed

• 87Sr/86Sr core-to-edge transects, annual ageing

• Multi-collector laser ablation ICPMS (Uni of Melbourne)

• Compare otolith and water 87Sr/86Sr mixing model to make inference about ambient salinity

87Sr

/86Sr

Salinity

Water mixing model – South Alligator River

0.708

0.712

0.716

0.720

0.724

0.728

0.732

0.736

0.740

0.744

0.748

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0

3-36 ppt

<1 ppt

1-3 ppt

Barramundi (89 cm TL, female), Mary River estuary

87Sr

/ 8

6Sr

Distance from core (µm)

0.705

0.71

0.715

0.72

0.725

0.73

0.735

0.74

0 500 1000 1500 2000 2500

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<1 ppt

1-3 ppt

Barramundi (103 cm TL, female), Yellow Water

Distance from core (µm)

87Sr

/ 8

6Sr

0.705

0.71

0.715

0.72

0.725

0.73

0.735

0.74

0 200 400 600 800 1000 1200 1400 1600 1800

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<1 ppt

1-3 ppt

Annual growth increments

87Sr

/86Sr

Distance from core (µm)

Barramundi (122 cm TL, female), Mary River estuary

0.705

0.71

0.715

0.72

0.725

0.73

0.735

0.74

0 500 1000 1500 2000 2500 3000 3500

3-36 ppt

<1 ppt

1-3 ppt

1) Estuarine

2) Catadromy, sequential hermaphrodism

3) Catadromy, delayed female spawning

Fresh waterSalt water

Eggs/larvae

Juvenile

Male

Female

Initial spawning

Fresh waterSalt water

Eggs/larvae

Juvenile

Male

MaleFemale

<3 years

residence

Fresh waterSalt water

Eggs/larvae

Juvenile

Female

Female

>3 years

residence

Male

Three strategy life history model for barramundi

From Crook et al. in prep.

THREE STRATEGY LIFE HISTORY MODEL

• New life history model for barramundi

• Results used in 2016 ARC Future Fellowship application

• Results presented at:

– Water in the Bush Symposium, Australian Water Association, Darwin, October 2015.

– Australian Society for Fish Biology conference in Sydney, October 2015

• Invited paper in Marine and Freshwater Research

• PhD project on barramundi otolith chemistry and bio-chronology to commence this year

Acknowledgments:

EHSE Small Grants Scheme

Thor Saunders, Jon Taylor (NT Fisheries)

Jon Woodhead, Roland Maas (Uni of Melbourne)

Lachie Hetherington (CDU)

OUTCOMES