1. The future is now: How climate change has altered coastal ecosystem function and what can be done to make these systems more resilient
Christopher J. Gobler

2. Projected 21st century temperature trends

3. Ocean acidification
Addition of acid
Loss of carbonate

4. Ocean acidification
Caldeira and Wickett 2003

5. , Stanford University

6. The future
(2030)
(2070)
Stippling highlights watersheds with a robust change in total nitrogen flux

7. The future is now…

8. Calcifying organisms vulnerable to ocean acidification (Orr et al 2005; Doney et al 2009; Reise et al 2009; Talmage and Gobler 2009, 2010, 2011, 2012)

9. Top 10 fisheries in NYS, 2017, NMFS data
The success of NY’s fisheries depends on bivalve shellfish.
As filter feeders, bivalves rely directly on phytoplankton for food.

10. Early life stage bivalves
Abraham and Dillon 1986

12. Hard clam
Bay scallops
Low CO2
High CO2
Talmage and Gobler, 2010

14. Landings of bivalves in NY
NY bay scallop landings

15. The future is now…

16. Changes in global ocean temperatures, 1982-2012
Baumann and Doherty, 2013, PLoS One

17. 35-year trend, summer water temperature around Long Island

18. Samples for eelgrass genetic analyses
Harmful algal blooms across Long Island
PSP
Toxic blue green algae
DSP
Brown tide
Seaweeds
Rust Tide

19. Global expansion of HABs
PSP
Global expansion of HABs
In the past 40 years, the public health, recreational, tourism, fishery, aquaculture, and ecosystem impacts of HABs have increased.
PSP

20. Why have HABs expanded? More comprehensive monitoring and assessment
PSP
Why have HABs expanded?
More comprehensive monitoring and assessment
Anthropogenic transport
Anthropogenic nutrient loading
Climate change
PSP

22. Dinophysis acuminata and diarrhetic shellfish poisoning (DSP)
Okadaic acid

23. Global distribution of DSP, ~2010

24. Dinophysis acuminata, North Atlantic trend, 1982 - 2016
Trend in bloom season, days per year
Trend in mean growth rate
Gobler et al., 2017, PNAS

25. Dinophysis acuminata, Northeast US trend, 1982 - 2016
2015
2000
2011
Gobler et al., 2017, PNAS

26. Dinophysis acuminata, North Pacific, trend in bloom season
Days per yr
Gobler et al., 2017, PNAS

27. Global DSP, recent North American expansion
Post-1982
Post-2011
Post-2000

28. Alexandrium red tides and paralytic shellfish poisoning (PSP) on Long Island
Saxitoxin
Alexandrium

29. Alexandrium trend in bloom season and growth rate, North Atlantic, 1982 - 2016
Trend in bloom season, days per year
Trend in mean growth rate
Gobler et al., 2017, PNAS

30. Alexandrium trend in bloom season North Pacific
Days per yr
Gobler et al., 2017, PNAS

31. Global PSP events
Gobler et al., 2017, PNAS

33. , Stanford University

35. Decay of algae =
↑CO2, ↓ pH, ↓ DO
Nutrient
discharge into
coastal zone
Nutrients stimulate
algal blooms

36. Long Island Sound, August 2012 Western half:
Dissolved oxygen < 4 mg L-1
pH < 7.4 (total scale)
pCO2> 2,000 ppm
Ωaragonite < 1
What are the seasonal patterns of dissolved oxygen and pH?
CTDEP record
Wallace et al, 2014, ECCS
NYC

37. Excessive nutrient loading exacerbates acidification and many HABs.
Mitigating excessive nutrient loading to coastal zones will make them more resilient to impending climate change.

38. Conclusions:
Ocean acidification since the Industrial Revolution has contributed to the declines in the populations of calcifying bivalves.
For multiple regions of the North Atlantic and some regions of the North Pacific ocean warming has expanded the potential niche of PSP and DSP causing HABs since 1982.
Excessive nutrient loading can and will synergistically intensify ocean acidification and HABs.
Mitigating nutrient loading can promote resilence against climate change

39. Thank you for your attention