4TH ANNUAL CAPE COASTAL CONFERENCE

Coastal & Ocean Acidification

Scott Doney & Jennie Rheuban

Ocean Acidification Basics

Feely et al. Oceanography 2009

National Climate Assessment

Walsh et al. 2014

Fossil Fuel Carbon Emissions

Rising Atmospheric

Carbon Dioxide

Changing

Seawater Chemistry

Impacts on

Shellfish &

Other Marine Life

Fate of Anthropogenic CO2 Emissions (2006-2015)

LeQuere et al. Earth Systems Science Data 2016; Global Carbon Project 2016

~10 billion tons

carbon per year +

Atmosphere

45%

Land

30%

Oceans

25%

Fossil Fuels 90%

Deforestation 10%

Rising

Atmospheric

CO2

IPCC AR5

WG1 Chap. 6

2000 1800 1500 500 0

IPCC AR5

WG1 Chap. 6

2− [CO3 ] [CO2]

100−150%

50%

2100

8.2

8.1

8.0

7.9

7.8 1800 1900 2000 2100

50

40

30

20

10

0

300

240

180

120

60

0

pH

μ

mo

l kg−1

Year

pH

CO2(aq)

CO3 2−

30% acidity

16% [CO3 ]

2000

2−

Wolf-Gladrow et al. 1999

Ocean Acidification

CO2 + H2O H+ + CO3 2-

HCO3 -

H+ + HCO3 -

CO2 + CO3

2- 2HCO3

-

Seawater pH Trend

Surface ocean water

Hawaii Ocean Time-Series (HOT)

Calcium Carbonate Solubility Saturation State

Ca + CO3 CaCO3 (solid) 2- 2+

Saturation State

= [Ca2+][CO32-] / Ksp

>1 saturated

<1 undersaturated

CaCO3 solubility

-depends on mineral form

-increases with pressure

Feely et al. Nature 2005; Bednaršek Nature Geosci. 2012

Saturation

State along

Northeast

Shelf

Wang et al. Limnology &

Oceanography 2013

Distance From Shore (km)

Low saturation

state on shelf

De

pth

(m

)

Gledhill et al.

Oceanography 2015

Marine Life Susceptible to

Ocean Acidification

-Winners & losers

-Reduced shell & skeleton

formation (calcification)

-Habitat loss

-Less available prey &

smaller fisheries

-Other effects on growth,

behavior, diseases, …

Biological

Impacts on

Molluscs

Kroecker et al. (2009; 2013)

positive effect

negative effect

Negative Impacts of CO2 on Mollusks

Talmage et al.

PNAS 2010

Present

Future

(estuaries)

Eastern Oyster

Larvae

US Northeast Fisheries (Landings Value)

Gledhill et al.

Oceanography 2015

Cooley & Doney

Environ. Res. Letters

2009

Sea Scallop Fishery

Hart and Chute 2004

Cooley et al.

PLoS One

2015

pH

Biomass

Revenue

Integrated

Assessment Model:

• biogeochemistry

• sea scallop

population

dynamics

• fishery socio-

economics

Other Local Sources of Coastal Acidification

Doney et al. PNAS 2007; Doney Science 2010; Kelly et al. Science 2011

Ocean Biological Pump, Acidification & Low Oxygen

O xygen (mm ol/L)

0 100 200 300 400

pH

(to

tal,

ca

lc)

7 .0

7.5

8.0

8.5

W aquoit Bay 2008 - 2010

1/1/08 1/1/09 1/1/10 1/1/11 1/1/12

Ox

yg

en

(m

mo

l/L

)

0

100

200

300

400M enauhant

Childs R iver

1/1/08 1/1/09 1/1/10 1/1/11 1/1/12

pH

(to

tal

sc

ale

)

7 .0

7.5

8.0

D. McCorkle

WHOI

Excess nutrients from local

pollution sources can lead to

low oxygen & acidic waters

Buzzards Bay Water Quality

Buzzards Bay

Coalition

Citizen Science Network

collecting summertime

data from 1992-present

Buzzards Bay Eutrophication

Chlorophyll

Total

Nitrogen

Rheuban et al.

Biogeosciences 2016

Chlorophyll

trend

Total Nitrogen

trend

Chlorophyll

Shellfish Suitability & Coastal Acidification

American Oyster

Bay Scallop

Blue Mussel

European Oyster

Quahog

Razor clam

Soft-shell clam

Surf clam

Human Nitrogen Source Trends

Williamson,

Rheuban et al.

Frontiers of Marine

Science, submitted

Animal Waste

Atmospheric

Deposition Wastewater

(treatment plants)

Fertilizer

Wastewater

(septic)

Ocean Acidification Depends

on Human Activities

Recent Carbon

Emission Trends

Stabilizing

Van Vuuren et al.

Climatic Change 2011

Le Quere et al.

Earth System Science Data

2016

Ocean & Coastal Acidification Fossil Fuel CO2 Emissions

Rising Atmospheric CO2

Changing

Seawater Chemistry

Impacts on Shellfish

& Other Marine Life

-Rising atmospheric CO2 levels are

causing increased ocean acidity

-Acidification can be exacerbated

in coastal waters by local nutrient

pollution

-Shellfish may be vulnerable to

ocean & coastal acidification

-Improved chemical & biological

monitoring are needed for coastal

waters

-More targeted work needed on

sensitivity of key commercial &

recreational shellfish fisheries

Extra Slides

Valued Human Uses for Buzzards Bay

Uses with economic value in terms of avoided costs

Uses with diminished economic values from eutrophication, which

may be exacerbated by warming, increased intense precipitation

Biological Impacts: Winners & Losers

Kroecker

et al.

Global

Change

Biology

(2013)

positive effect

negative effect