Climate Change Management in Marine Ecosystems … · Climate Change Management in Marine Ecosystems: ... Ocean Acidification is the “other CO2 problem”: Ocean pH decreases when

Climate Change Management in Marine Ecosystems:

Ocean Acidification and Hypoxia

Ken Schiff Southern California Coastal Water Research Project

www.SCCWRP.org

“The Other CO2 Problem”

Feely et al. (2009)

pH data from the Hawaii Ocean Time Series Station (HOTS)

Atmospheric CO2 data from Mauna Loa Observatory, Hawaii

O H C

O

O 2. Reacts with water

to form bicarbonate ion

O C O

1. Dissolves in the ocean

H+ and hydrogen ion

3. Most of the hydrogen ions react with carbonate ions to form

bicarbonate ion O H C

O

O H+

O C

O

O

CO2

H2O

HCO3-

HCO3-

CO32-

Effect of Adding CO2 to Seawater

phot

os: D

avid

Litt

schw

ager

N

atio

nal G

eogr

aphi

c Soc

iety

Organisms under acidified conditions

Healthy Organisms

Pter

opod

U

rchi

n Se

a st

ar

The Problem is Going to Get Worse

Feely et al. (2009)

West Coast Susceptibility

Deep, cold water = lower pH, low oxygen (hypoxia), high nutirents

Feely et al. (2008)

West Coast map of depth to Corrosive water (Ω < 1)

The Problem is Today

Dissolved Oxygen Offshore California

2. Taken up by algae;

N P

1. Discharge to coastal waters

3. Algae die and sink

4. Dead Algae are respired at depth; consuming O2 and producing CO2

O C

O

Nutrients

Algae

Algal Bloom

CO2

Heterotrophs

Anthropogenic Contributions Can Exacerbate Acidification

N P

fueling algal blooms

Understanding OA Resiliency • Are local anthropogenic nutrient loads

sufficient to generate algal blooms?

• Can we measure associated changes in pH? – Biological impacts?

• Will reductions in local anthropogenic

nutrients minimize changes in pH due to global CO2 sources?

Chl

orop

hyll (

mg

m-3

)

PC

SDEN

SCRSP

Old Technology Limits pH Measurements

• Traditional glass electrode sensors >0.5 pH units

• Trying to measure changes in <0.2 pH units

• New Isfet sensors measure pH <0.1 units

- Ocean X-Prize achieving pH<0.05

∆pH

Count

pH (mCP - ISFET)

-0.3 -0.2 -0.1 0.0 0.1 0.2 0.3

Cou

nt

0

5

10

15

20

25

30All SitesMost Experienced Sites

∆pH

Changing Depth Distribution of White Sea Urchin

Surface Current Mapping in Real Time Using High Frequency Radar

www.sccoos.org 16June2015

Understanding OA Resiliency • Local anthropogenic nutrient loads appear

sufficient to generate algal blooms

• Testing new technology sensitive enough to assess changes in pH

• Linked oceanographic-biogeochemical models will be used to virtually assess management strategies

Example Map of Bight’13 Nutrient Sampling Sites

What is pH?

• pH is the measure “power” of the hydrogen [H+] ion in solution

• Practically it is a measure of the acidity or basicity of a solution • The more H+ the more ACIDIC

and the LOWER the pH • The less H+ the more BASIC and

the HIGHER the pH