Environmental Change andEnvironmental Change and Altered Marine Food WebsAltered Marine Food Webs

1) Warming I. coastal Antactica (importance of communities)

2) Ozone DepletionII. Antarctica (importance of wind)

3) EutrohicationIII. HABs (importance of people)

4) Fishing Pressures IV. Globe (importance of people)

Oscar Schofield (oscar@ahab.rutgers.edu)

0

2

4

6

8

10

0.1 1 10 100 1000

Irradiance (mol photons m-2 s-1)

Pro

duct

ivit

y (m

g C

mg

Chl

a-2 h

-1)

Pmax

Ik = Pmax/Respiration

Light

Nutrient concentration (can be nitrogen, phosphorus)

Nut

rien

t Upt

ake

Ks

Nutrients

Vmax

0

2

4

6

8

10

12

diatoms coccos dinos greens

KsNO3-

KsN

O3-

(uM

)

0

0.2

0.4

0.6

0.8

1

diatoms coccos dinos greens

Vmax NO3/C

mol

N/

mol

C/d

ay

Nutrient Uptake Varies with Phytoplankton SpeciesNutrient Uptake Varies with Phytoplankton Species

Things effecting a food web include:Things effecting a food web include:

# trophic levels, trophic transfer efficiency# trophic levels, trophic transfer efficiency

What else?What else?

Cell size effects the trophic transfer of matter Cell size effects the trophic transfer of matter and energy in the food weband energy in the food web

• Cullen et al.

(Cullen et al., 2002)

Study Site

The Antarctic Penisula

64 48’ S

Hermit Island

EE

BB

Janus Island

LitchfieldIsland

TorgersenIsland

Anvers Island

Palmer

64 46’ S

Bonaparte

Point

64 04’ W

Why?

STA B - Chlorophyll a

1991-92

1992-93

1995-96

JanSept Oct Nov Dec Feb

mg

Ch

l a m

-3

5.0

2.5

0.0

Mar

1994-95

1994-95

< 3 mg Chl a m-3

< 3 mg Chl a m-3

60 m

0 10 20 30 40 50 60 70 800

50

100

150

200

250

300

350

Inte

grat

ed U

ML

Chl

a (

mg

m-3)

Upper Mixed Layer Depth (m)

Station B 1991-1992

Mitchell & Holm Hansen (1991)

Integrated Chlorophyll a vs. Upper Mixed Layer DepthIntegrated Chlorophyll a vs. Upper Mixed Layer Depth

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Cryptophytes in the Coastal OceanCryptophytes in the Coastal Ocean(Antarctica)(Antarctica)

Proportion of total chlorophyll a associated with cryptophytes

Pro

por

tion

of

tota

l ch

loro

ph

yll a

as

soci

ated

wit

h d

iato

ms Palmer StationPalmer Station

(n=162)(n=162)

Cryptomonas cryophila

Thalassiosira antarctica

Corethron criophilum

Palmer Cryptophytes --> 8 ± 2m

100m

SEM Micrographs fromMcMinn and Hodgson 1993 10m

0

20

40

60

80

100

-15 -10 -5 0 5 10

Mean Air Temperature (°C)

% C

ryp

top

hyt

es

The Ice-melt WallThe Ice-melt Wall

0

40

80

120

0

10

20

30

40

Pre

cip

itatio

n (

mm

)

Sn

ow

He

igh

t (c

m)

60

40

20

De

pth

(m

)

45

10

NO

3- (M

)

November December January

1993 1994

A

B

Salinity33.3 33.6 33.8

64°W

Palmer Station

AntarcticPeninsula

% Crypts0 25 50

65°S

65°S

From Smith (1994)

-0.8

-0.4

0

0.4

0.8

1.2

1945 1955 1965 1975 1985

Year

Mea

n S

um

mer

Air

Tem

per

atu

res

(°C

)

Faraday Station

Signy Station

R2 = 0.64

R2 = 0.73

Changes over the last 50 yearsChanges over the last 50 years

SalpsSalps

Euphausid superbaEuphausid superba

OtherGrazers

(copepods)

Diatoms& Other

PhytoplanktonCryptophytes

AutotrophicCarbon

Production

Krill Salps

Sedimentation(Microbial Loop)

Respiration(Other Losses)

Higher Trophic Levels(fish, penguins, whales)

Autotrophic Losses(Not Grazing)

0.001

0.01

0.1

1

10

100

80 82 84 86 88 90 92 94 96

Kri

ll:S

alp

YEAR

Ice

Inde

x6

4

2

0.001

0.01

0.1

1

10

100

Kri

ll:S

alp

Ice Index

0.001

0.01

0.1

1

10

100

Kri

ll:S

alp

Mean Air Temperature (°C)0-2-4

From Loeb et al., 1997

642

Where have all the good krill gone?Where have all the good krill gone?

0

10

20

30

40

50Quetin and Ross 1985

5-10 >15

0

20

40

60

80

100McClatchie and Boyd 1983

5-10 >15

0

20

40

60

80

100Boyd et al. 1984

5-10 >15

% R

eten

tion

by

Kri

ll

Phytoplankton Size (m)

OtherGrazers

(copepods)

Diatoms& Other

PhytoplanktonCryptophytes

AutotrophicCarbon

Production

Krill Salps

Sedimentation(Microbial Loop)

Respiration(Other Losses)

Higher Trophic Levels(fish, penguins, whales)

Autotrophic Losses(Not Grazing)

Consequences of cryptophytes

-Shift grazers to salp community

-Decrease carbon to higher trophiclevels by ~ 50-60%

-Increase carbon flux to benthosby a factor of 3-4 (given one yearsalp life)

-Mobile higher tropic levels moveto preferred food source in the south

Changes in physical environment impact Antarctic Changes in physical environment impact Antarctic phytoplankton community composition. This willphytoplankton community composition. This willimpact elemental cycling and higher trophic levels.impact elemental cycling and higher trophic levels.

HUMANS?

Myers and Worm, Nature 423: 280-284

Chavez et al. Science 2003

Diversity of HAB Toxins

Saxitoxins

Domoic Acid

Ciguatoxins

Brevetoxins

N

N

NH

NH

OHOH

NH2

NH2

R1

R 3 R 2

R4

N

HCH3

HCOOH

CH3

COOH

COOH

R2

O

OO

O O

O

O

O

O

O

O

O

OR1

CH 3 CH 3

H3C

CH 3

CH 3

CH 3

CH 3

OH

CH3

CH3

OH

o

o

o

o

o

o

HO

CH3

o

oo

o

o

oCH3

o

R2

R1CH3

oo

oCH3OR5

OR4 CH3

CH3

o o

o

OR5

OR5 CH3 R3

R2

OR1

O

o

Okadaic Acid

Unknown Toxins?

Azaspiracis

Yessotoxin

GymnodimieSpirolides

1982 199505

10152025

Po

pu

lati

on

(M

)

1982 1995

Year

Pearl River Delta Estuary

Environmental Controls: 1973Environmental Controls: 1973

19200

100

200

300

To

tal N

um

ber

Red

Tid

es

10

Secch

i Dep

th (m

)

Seto Inland Sea: Manabe and Ishio, 1991 Mar. Poll. Bull.and Honjo, 1993 in Smayda and Shimizu

Year1940 1960 1980

7

8

9

March 28, 2002 – SeaWIFS off the West Florida Shelf March 28, 2002 – SeaWIFS off the West Florida Shelf

Chlorophyll Chlorophyll

Backscattering (555)Backscattering (555)

Absorption (443)Absorption (443)

Feature Tracking Feature Tracking

Red Tide

30 Day Total Flow through Gate S79

0

1E+11

2E+11

3E+11

4E+11

5E+11

6E+11

7E+11

8E+11

Oct-95 Mar-97 Jul-98 Dec-99 Apr-01 Sep-02

0

1

2

3

4

5

-80-81-82-83-84-85-86-87-8831

30

29

28

27

26

25

24

Figure 2: T-S Diagram

Temperature (°C)

Sal

inity

(P

.S.U

.)

34

35

36

24 25 26 27

Figure 3B: a670 (m-1)

2

4

6

8

10

Time of Day

Dep

th (

m)

9am 1pm 5pm 9pm 1am5am

1.0

0.0

Figure 3C: b670 (m-1)

2

4

6

8

10

Time of Day

Dep

th (

m)

9am 1pm 5pm 9pm 1am5am

1.0

0.0

Figure 3D: c676 (m-1)

Time of Day

Dep

th (

m)

2

4

6

8

10

9am 1pm 5pm 9pm 1am5am

2.0

0.0

Figure 5B: bb440/b442

Time of Day

Dep

th (

m)

2

4

6

8

10

9am 1pm 5pm 9pm 1am5am

.05

.01

Historical, Synoptic, Future in

Situ/Remote Field/Error Observations

d0R0

FieldInitialization

Central Forecast

Sample Probability

Density

Mean

SelectBest

Forecast

Shooting

ESSE Smoothing viaStatistical Approximation

MinimumError

Variance

Within ErrorSubspace

(Sequential processing ofObservations)

MeasurementModel

A PosterioriResidules

dr (+)

Performance/AnalysisModules

OA viaESSE

GriddedResidules

Synoptic Obs

Measurement Model

Measurement Error

Covariance

^

cf(-)^

0

Options/Assumptions

Most Probable Forecast

mp(-)^

EnsembleMean

q{j^

Adaptive Error

SubspaceLearning

ConvergenceCriterion

Continue/StopIteration Breeding

PeripheralsAnalysisModules

Normalization

SVDp

Continuous Time Model Errors Q(t)

ScalableParallel

EnsembleForecast

+PerturbationsError SubspaceInitialization

1

j

q

1

j

q

^

^

^

uj(o,Ip)with physicalconstraints

+

(+)^

E(+)(+)

E0

(+)^

Ea(+)a(+)

FieldOperationAssumption

Key

(-)^

E(-)(-)

-+

+

+

-

+-

---

-

+

+

+

dC(-)

Data Residuals

^

+

+

+

--

+/-+

j=1

j=q

+

ESSE FlowDiagram

26

2422

20

18

16

1412

10

8

July, 200118 19 20 21

2

4

6

8

10

12

Dep

th (

m)

Thermistor 2

4

6

8

10

12

Dep

th (

m)

July, 200118 19 20 21

HR COAMPS / ROMS

KPP

2

4

6

8

10

12

Dep

th (

m)

July, 200118 19 20 21

MY2.5

Real-Time Ensemble Validation

-In an observationally rich environment, ensemble forecasts can be compared to real-time data

to assess which model is closer to reality and try to understand why.

Cocco-litho-

phores

Dino-flagellate

SedimentDetritus

PelagicDiatom

s

G. breveTricho-

desmium

Benthic Flora

Synecho-coccus

RelictDOM

PredatorClosure

LysedDOM

Iron NH4 NO3CO2

Air/SeaCO2

ExcretedDOM

Dust Physical Mixing and Advection

Light

Copepod Ciliates Hetero-Flagellet

Bacteria

Viruses

N2PO4 SiO4

Phytoplankton off the coast of Florida