Richard A. Feely1, Brendan Carter1, Nina Bednarsek1,2, Simone R. Alin1 and Jan Newton3 1Pacific Marine Environmental Laboratory/NOAA 2Southern California Coastal Research Project 3University of Washington

Ocean Acidification Processes along the Pacific Coast

Photocredit:MeghanShea

Outline u Anthropogenic CO2 Increases u Effect of Increasing Revelle Factor

On behalf of the project scientists at PMEL and our many national and international partners

CaliforniaOATaskForceWebinarMay29,2018

Accomplishments:Repeathydrography(left)continuestodemonstratethegrowingglobaloceanCO2sinkwhilefixedtimeseriesstations(top)illuminatehowinterannualevents,suchas“theblob,”impactCO2flux(fromCarteretal.2017;Carteretal.inprep;Feelyetal.2018;Suttonetal.2017)

Pacific anthropogenic carbon from 1995 to 2015

Dep

th [m

]

winter/spring2014-15warm

anomaly

[µmol kg-1]

AnthropogenicCarbonDioxideConcentrationsandpCO2IncreaseintheNorthPacific

AnIntegratedFederal-StateWestCoastOceanAcidificationObservingNetwork

Alinetal.2015,inpress(L);Chavezetal.2017(R)

Tunedtolocal/regionalneedsandprovidingreal-timeinformationtostakeholdersandpartnersvia theIOOSPacificRegionOceanAcidificationDataPortal(ipacoa.org)

•  Increasing CO2 levels in the ocean increases its acidity (lowers its pH). These processes are faster in California coastal waters due to the combined effects of acidification, upwelling, and local carbon and nutrient sources.

•  Observations and modeling studies indicate that local anthropogenic carbon and nutrient sources provide significant contributions to local acidification but vary widely depending on location.

AragoniteSaturationDepth(m)(2016) AragoniteSaturationDepth(m)(2007)

NOAAWestCoastCruise8May–6June2016comparedwithMay-June2007

u  AragonitesaturationdepthindicatesstrongupwellingnearthecoastfromnorthernCaliforniatoVancouverIsland.

RichardFeely–PMEL

AnthropogenicCO2vspotentialdensityintheCaliforniaCurrentSystem

2013

200720112004

AnthropogenicCO2iscalculatedfromPO2RepeatHydrographycruisesin2004and2013andtheninterpolatedontoCaliforniaCurrentSystempotentialdensitysurfaces.

AnthropogenicCarbonDistributionsin2016

Feelyetal.,inprep

May-June2016Canthµmolkg-1

•  HighCanthsurfacevalues(55-66µmolkg-1)offshoreandtothesouth

•  LowCanthsubsurfacevalues

(40-54µmolkg-1)inonshorewatersfromHecataHeadtoPointReyes

•  LowCanthwaterseverywherebelow100m

Evolution of chemical conditions in the California Current EcosystemDecadal trend in anthropogenic carbon concentration andaragonite saturation changes from the preindustrial to present

AnthropogenicCO2(µmol/kg) Changeinaragonitesaturationstate

Evolution of chemical conditions in the California Current EcosystemDecadal trend in anthropogenic carbon rate of change in the water column

pH:lowerinWestCoastsurfacewaterssimilardecreasesfrompresent-dayΩarag:lowerinWestCoastsurfacewaterslargerdecreasesinGOMfrompresentRF=(∆pCO2/pCO2)/(∆DIC/DIC)changesmorerapidlyinthecoolerWestCoastwaters

Surfacewaterchangesovertime

Feelyetal(2018)

Past,PresentandFutureImpactsofOceanAcidification

IncoastalenvironmentsliketheSalishSea,theincreasinganthropogeniccarbonreducestheabilityofthesystemtobuffernaturalvariationsinCO2.ThisreducedbufferingcapacityleadstopreferentialamplificationofnaturallyextremelowpHandhighpCO2(s.w.) events above changes in average conditions,whichoutpacerates published for atmospheric and open-ocean CO2 change. -Pacella et al., PNAS2018

.u Our major challenge is to determine anthropogenic ocean acidification

changes and biological responses against a backdrop of large natural variability. Approach to Solve: Collaborative Monitoring and Modeling

u Co-located chemical/biological field observations provide unique opportunities to observe and understand long-term changes as impacted by ocean acidification and hypoxia. Approach to Solve: Collaborative Monitoring and Modeling

u Oyster larvae, Pteropods and Crab larvae exhibit physiological responses that appear to be impacted by ocean acidification now. Approach to Solve: Continued Collaborative Field and Laboratory Studies

Conclusions