Impacts of climate change on Australian marine life

1. Impacts of climate change on Australian marine life Dr Martina Doblin, Senior Research FellowUniversity of Technology Sydney

2. What’s so special about the ocean? • Life in the ocean has been evolving 2.7 B years longer than on land • There are about 40 phyla (major groups of organisms) in the ocean and at least 15 of them are found only in the ocean • BUT, far fewer biological changes identified in the oceans and freshwater systems as a result of climate change (<0.3% of terrestrial systems) Earth is 79% ocean! Image source: wikipedia

3. What’s so special about plankton? Source: Dr Lisa Drake

4. Responsible for >40% of global photosynthesis • Help maintain processes that regulate global climate and cycle essential elements (such as carbon, nitrogen and water) • Form the base of the foodweb They keep the Earth livable!

5. What could happen? Photo: Miriam Godfrey Source: Miriam Godfrey; www. carleton.serc

6. How is climate change affecting the ocean? Source: CSIRO

7. Ocean circulation is changing Source: CSIRO

8. Long term monitoring Rottnest Island Port Hacking Maria Island

9. Surface warming Temperature increase over time, but only in summer

10. Change in seasonal temperature and timing 1953 - 1963 1997 - 2007

11. What is this equation? nitrate SUNLIGHT 106CO2 + 122H2O + 16NO3- + PO43- + 19H+ (CH2O)106(NH3)16H3PO4 + 138O2 and phosphate as well as other micronutrients such as silicate (Si) and iron (Fe)

12. Nutrient ratios in south-eastern Australian waters Thompson et al, in review

13. Nutrient ratios in south-eastern Australian waters Decreased silicate relative to nitrate Thompson et al, in review

14. Changes in nutrients will lead to changes in biodiversity and function Source: www.microscopy-uk.org.uk

15. Changing species composition † failed Kolmogorov – Smirnov test for normality & passed Levene median test for equal variance.

16. Increased prevalence of red tides Sources: www.carleton.serc ; www.microscopy-uk.org.uk

17. How does this all fit together? Less rain Surface warming Decreased Si

18. Summary • Evidence of: - surface warming - extended autumn season - altered nutrient ratios in south-eastern Australia (decreased availability of Si) - changes in abundance and species composition ofphytoplankton • Functioning of the ocean will change with many cascading effectsincluding those on surfers, swimmers, seafood eaters

19. Basically, this will impact you!

20. Thanks • Peter Ralph, University of Technology, Sydney • Tim Ingleton, NSW Dept. of Environment and Climate Change • David Kuo, University of Technology, Sydney research intern • Tim Pritchard, NSW Dept. of Environment and Climate Change • Monitoring teams

21. Source: www.microscopy-uk.org.uk

22. Increased CO2 and altered DIC speciation Elevated UV Higher temperatures Reduced mixed layer depth Changes in ocean currents & circulation Increased dissolution of calcifying coccolithophorids Increased prevalence of species with UV protection Changes in phytoplankton species composition Altered phenology (seasonal timing) Altered primary production Range shifts Potential climate change impactson marine phytoplankton

23. The big questions The NSW IMOS goal is to examine the physical and ecological interactions of the East Australian Current and its eddy field with coastal waters, to assess the synergistic impacts of urbanization and climate change. • Biological response to oceanographic and climate eventsBiogeochemical—carbon cycling, including C exportEcological—what are the implications of changes in the quantity and quality of food at the base of the foodweb to higher trophic levels?Ecosystem function and goods & services

24. Ocean observations oceanographiccruises Limited time seriesBefore IMOS, no coordinated sampling

25. IMOS infrastructure

26. Primary producer observations • Chl-a fluorescence • Ocean colour • CDOM • Backscatter • PAR • Dissolved oxygen • Photosynthetic rates • 14C fixation • POC/PON • HPLC pigments • Species composition Continuous Plankton Recorder* Microscope counts Flow cytometer counts • Genomics/metabolomics • Elemental isotopes • Sediment traps

27. In vivo fluorescence • Fluorescence estimates chlorophyll-a without pigment extraction (Lorenzen 1966)—highly sensitive and used over a wide range of spatial and temporal scales to be a universal indicator of phytoplankton biomass • Fluorescence yield is variable and dependent on light, cellular nutrient status, temperature, confounded by CDOMcan introduce significant errors

28. ANFOG Biooptical data • Other parameters needed forinterpreting fluorescence

29. CDOM distribution

30. Backscatter distribution

31. Bloom 2/3 along transect • Some CDOM/particulate interference at start of transect

32. Photosynthetic rates

33. Maria Island: chlorophyll a 1997 – 2006* Spring growth rates • Decline in spring biomass • Slower growth of spring bloom Mean monthly chla data *The data were acquired using the GES-DISC Interactive Online Visualization ANd aNalysis Infrastructure (Giovanni) as part of the NASA's Goddard Earth Sciences (GES) Data and Information Services Center (DISC)."

34. Implications and future research • Implications include: - temporal mismatch between trophic levels causing a change in synchrony of primary, secondary and tertiary production - changing species composition alters food quality for higher trophic levels, potentially leading to less fish production • Challenge is to not only describe patterns, but to make predictions and test hypotheses about cascading foodweb effects

35. Increased CO2 and altered DIC speciation Elevated UV Higher temperatures Reduced mixed layer depth Changes in ocean currents & circulation Increased dissolution of calcifying coccolithophorids Increased prevalence of species with UV protection Changes in phytoplankton species composition Altered phenology (seasonal timing) Altered primary production Changes in distribution: range shifts Potential climate change impactson marine phytoplankton