environmental stressors: effects on aquatic...

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Environmental Stressors: Effectson Aquatic Ecosystems

S. Marshall AdamsEnvironmental Sciences DivisionOak Ridge National Laboratory

Outline

Concepts of environmental stressors and stress

Assessing effects of stress using multiple response measures

Examples of Stress effects in aquatic systems- stream polluted by multiple contaminants- coastal estuary experiencing eutrophication- ponds on Air Force Base affected by military activities

Relevance and Application

Definitions of Environmental Stress and Stressor

Stressor - Any environmental condition, situation, or factor that causesa biological system to mobilize its resources and increase its energy expenditure

Stress - A state produced by an environmental stressor which extendsthe adaptive responses of an organism beyond its normal range, orwhich disturbs normal functioning to such an extent that the chancesof survival are significantly reduced

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Healthy

Stressed

Damagedbut Curable

IrrepairableIncurable

Physiological Tolerance LimitDisease, Reproductive Impairment, Death

Physiological Condition

Increasing stress

Stressed

OK

DIS

ABI

LITY Disease

Death

Healthy

Repair

IMPAIRMENT

Homeostasis Compensation Non-Compensation

Zone 3

Zone 2

Zone 1

Severely Damaged

ModeratelyDamaged

AN INTEGRATED FRAMEWORK FOR ASSESSING COASTAL RESOURCE MANAGEMENT ISSUES: EX AMINING CAUSAL RELATIONSHIPS IN COMPLEX ENVIRONMENTS

S. Marshall AdamsEnvironmental Sciences Division Oak Ridge National Laboratory

VaryingPhysiochemical

Factors

HabitatAvailability Temperature

Regimes FoodAvailability

Contaminants

Integrated Response

GROWTH REPRODUCTIVESUCCESS

POPULATION RESPONSE

HydrodynamicRegimes

Eutrophication

3

Environmental Stressors

BiomolecularBiochemical

PhysiologicalPathological

Quality andquantity of food

Population

Direct Indirect

Community

Organism(growth, repro)

Behavioralactivities

Metabolic

Bioenergetic Behavioral

Physicochemical stressors

- hydrologic regimes- dissolved oxygen

Biochemical-PhysiologicalResponses

- organ dysfunction- immune function- genetic damage

Chemical Stressors- contaminant exposure- water quality

Organ-Individual Responses- condition- growth- behavior

Reproductive-populationResponses- steroid hormones- egg size & quality- abundance- size distribution

Habitatmodification- quantity-quality

Effects

Mechanisms?

Pollutants Land development-sedimentation

nutrients

Causal

Stressors

Establishing Causality BetweenStressors and Biological Effects

4

MOLECULAR

PHYSIOLOGICAL

REPRODUCTIVE

PATHOLOGICAL

BIOENERGETIC

POPULATION

COMMUNITY

Imm

unol

ogic

al

Sublethal

Low ecologicalrelevance

High sensitivity& specificity

BioindicatorsEcologicallyrelevantHigh ecological

relevance

Low sensitivity& specificity

5

Site 1 Site 2 Site 3 Site 4 REF

0

0.5

1

1.5

2

2.5

3

3.5

PCBs-SedimentPCBs-Fish

Mercury-Water

Con

tam

i nan

t Con

cent

r atio

n (P

PM

)

Stream Flow

Downstream Gradient in Contaminants

6

To ta l Taxon om ic R ichness

S ite

E FK 24 E FK 23 E FK 14 B FK 7 .6

Num

ber o

f tax

a/sa

mpl

e

0

10

20

30

40

Spatial Trends in Benthic Macroinvertebrates

Decreasing pollution

Refe

renc

e

EFK 24 EFK 23 EFK 14 BFK0

5

10

15

20

Number of species

1990

Num

ber o

f Spe

cies

Ref

eren

ce

Spatial Pattern in Fish Divsrsity

7

NUCLEOLUS

NUCLEUS

MITROCHONDRION

HEALTHY GILL CELL

MERCURY-EXPOSED GILL

8

Sewage Treatment Plant

stream flow

km =

Spatial changes in Steroid HormonesB

lood

Ste

roid

Hor

mon

es (n

g/m

l)

IndustrialDischarge

Industrial Discharge

1 2 3 4

Industrial Discharge Sewage Outfall

Reference0

10

20

30

40

EstradiolTestosterone

Industrial Discharge

Genetic Diversity of Sunfish Population

EFK2

3

EFK1

9

EFK1

4

EFK0

5

REF

1

REF

2

0

5

10

15

20

25

30

35

Decreasing Contamination

References

Res

ista

nt G

enot

ype

(% o

f pop

ulat

iion)

First Canonical Variate Seco

ndCa

noni

cal V

aria

te

Third

Can

onic

al V

aria

te

C3C4

C2

C1

Integrated Bioindicator Site Responses in East Fork Poplar Creek

References

Contaminated

9

Isabel 9-18-03

Floyd 9-16-99

Sewage plume

10

Nutrients-pollutants

Pamlico Sound

CapeHatteras

Neuse River

CapeLookout

X

NorthReference site sitena

Atlantic Ocean

Pamlico River

X

NorthCarolina

Affected site

B

A

0- 0.2 mg/L 0.2-2 2-4

4-6 mg/L 6-8

Neuse River

Lower Neuse/western Pamlico

A

B

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Hypoxic zone

Hypothesis: Fish sampled from areas in Pamlico Soundwith low dissolved oxygen are sublethally stressedcompared to fish from non-affected reference areas

Southern Flounder (ambush predator, carnivore)

Spot (omnivore, benthic forager)

12

A B

C D

Reference Pamlico Sound0

10

20

30

40

50

60

0

1

2

3

4

5

6

*

*

*

Leuk

ocrit

, Bun

, Pro

tein

Hem

atoc

rit

Hematology-Organ Dysfunction Indicators


10

20

30

40

50

60

0

1

2

3

4

5

6

7

Hematocritleukocrit

BUNSerum protein

*

Leuk

ocrit

, Bu n

, Pro

tein

Hem

atoc

rit

*

Spot

Flounder


100

200

300

400

500

600

700

0

0.5

1

1.5

2

*

*

*

Seru

m tr

igly

cerid

es (m

g/dl

)

Som

atic

indi

ces

Condition indicators


200

400

600

800

0

0.5

1

1.5

2

2.5

3

Serum lipidLiver-somatic index

Spleno-somatic indexCondition factor

Ser

um tr

igly

cerid

es (m

g/dl

)

Som

atic

indi

ces

Spot

Flounder

13


200

400

600

800

1000

1200

0

10

20

30

40

50

60

70

*

* *

*

Perc

ent

Pla

sma

ster

oid

horm

ones

(pg/

ml)


200

400

600

800

1000

0

20

40

60

80

testosterone (F)estradiol (F)

% ovaries developed % female estradiol non-detects

**

Per

cen t

Pla

sma

ster

oid

horm

ones

(pg/

ml)

*

Spot

Flounder

Reproductive Indicators

SpotReference

SpotPamlico

FlounderReference

Flounder Pamlico

First canonical variate

Seco

nd c

anon

ical

var

iate

0-1-2-3 +1

0

-1

-2

-3

+1

+2

+3

+2 +3

Integrated Health Responses

8.5

6.0

Indicators used in analysis

Immunological - 7Hematology - 2Physiological - 4Reproductive - 6Condition - 5

Total= 24

(discriminant analysis)

Gopher frog range

Gopher tortoise range

Gopher frog Gopher tortoise

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A

B

C

B-70 range

RefRef

C74 range

C-52 range

High disturbanceMedium-low disturbance

Reference

Sampling design & site selectiongopher frogs-Eglin AFB

Sample site Explosive Ordinance/ Cratering/ Soil Burning/ Composite Miitaryresiduals unit area unit area disturb. scorching score impact

C52N-1 3 3 3 3 2 14 HighC52N-2 3 3 3 3 1 13 HighC52N-3 3 3 3 2 2 12 HighC52C-1 1 1 2 2 1 7 ModerateC52C-2 1 2 2 2 1 8 ModerateC52C-3 1 1 2 2 2 8 ModerateReference-1 0 0 0 1 2 3 Low Reference-2 0 0 0 1 1 2 LowReference-3 0 0 0 0 2 2 Low

Criteria for assessing military disturbance3= moderate to high2= low to moderate1= none to low

Assessment of Military Impact

Sampling design-Gopher frogs

Breeding Site

9 “Treatment” areas 3 High disturbance (C52N, C74, C52CE)3 low disturbance (C52C, C52A, B70)3 Reference

2-6 Ponds per treatment

HabitatEach Pond

Morphology, water quality, general substrate, vegetation, and military disturbance

Edge/Terrestrial2-3 transects per pondrandom plots within each

community type% cover plant layers; disturbance

metrics, no of burrows, etc.Remote sensing 300 m home range

Transect 1

Tr 2

Tr 3

XXX

XX

X

X

X

X

Plots Pond

Edge

Terrestrial

C52A range

C52A rangelow disturbance

C52N rangeHigh disturbance

Reference

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Sampling devices deployed at Eglin

• Total sites with drift fences and traps - 40• Total number of 30m drift fences with cages- 162• Total feet of drift fencing- 5700• Total number of traps at 40 sites- 940• Number of traps at each site standardized

based on pond surface area

High disturbance site- C52 bombing range

Low disturbance site-C52A range Undisturbed site-reference ponds

300m home rangeradii from pond

High activity sites-Eglin AFB

Drift fence with cages

B70 range

C52N range

C74 Range

fences + traps

fences + traps

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Low activity and reference sites-Eglin AFB

C52A rangeC52C range

ReferenceReference

Construction and installation of sampling devices

Drift fence with traps

New bomb crater

Old bomb crater

Seep on C52N range

Wet/dry pond on C52N range

Trap

Old bomb crater

Drift fence

Wet/dry pond

Drift fenceTrap

Old bomb crater

Traps

New bomb crater

Ecological Relevance

Early

war

ning

, sen

sitiv

ity, s

peci

ficity

Biomolecular

Physiological

Immunological

Reproductive

Population

- Relative abundance- Age class distribution- Size-freq distribution- Sex ratio

- Clutch size- Egg size- Steroid hormones- Hatching success- Vitellogenin

- PHA test (cell mediated)- bacterial killing (innate)- Corticosterone

- transaminase enzy.- creatinine- serum electrolytes- LDH- bilirubin- glucose- BUN- AGAP- 24 total analysis

- DNA damage- glutathione- malondialdehyde- oxidative DNA damage

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NUCLEUS

Linking indicators to health and fitness

• Canonical correlation analysis in conjunction with canonical variateanalysis used to predict and assess reproduction and population fitness based on sets of measured bioindicator variables

MolecularBiochemicalPhysiological

ImmunologicalHistopathologicalCondition indices

Reproductive variables

Population variables

Bioindicator variables Steroid hormonesFecundity

Egg-oocyte qualityOocyte atresiaVitellogenin

Relative abundanceAge class distribution

Sex ratioSize at age

correlate &

predict

correlate &

predict

correlate and predict

Hypothesis: Physiological indicators (bioindicators) can be used to assessor predict the health and fitness of TES populations at military sites

R E S P O N S E T IM ED aysM in s /ho u rs W eek s/M o n th s Y e ars B io lo g ic a l

g en era tio n s

R E S P O N S ES E N S IT IV IT Y E C O L O G IC A L

R E L E V A N C E

S u b ce llu la r/ C e llu la r

T iss ue /O rg an

O rg an ism P o p u la tion C o m m u nity

F o cu s o f F ie ld S tu d ies

B iom arkers B io ind icators

Organism-level responses provide a pivotal point throughwhich mechanistic understanding and the ecologicalconsequences of stress can be linked

Populationstructure

Community

Time scaleYearsMonths

Days/weeksHours/days

Minutes

INDIVIDUAL POPULATION--COMMUNITY

SUB-ORGANISMAL

Early Warning

Biomolecular

BiochemicalImmunological

Histopath

Ecological Risk Assessment

Sensitive

INJURY

EXPOSURE

Population fitness

Physiological

Reproductive

Ecologicallysignificant

Recovery Assessment


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Ecological significance

Mec

hani

stic

und

erst

andi

ng

Increasing integration

Biochemical

Genetic

Histopathological

Reproductive

Communities

Immunological

Populations

Physiological

Biomarkers Bioindicators

FISH PREY BASE

INVERTS

PREDATORS

PRIMARY PRODUCTION

Physicochemical Factors

Nutrients

Incr

easi

ng

Eco

syst

em

Inte

grat

ion

Incr

easi

ng M

echa

nist

ic U

nder

stan

ding

Summary

Multiple indicators of stressare useful for:

• Early warning indicators of environmental problems

• Providing insights into causal mechanisms linking stressors and biological effects

• Assessing cumulative and/or synergistic effects of stress on organisms

• Identifying sources & causes of environmentaldamage related to specific stressors

• Evaluating the effectiveness of environmental cleanup (remedial) actions

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Effects

Pollutants Land development-sedimentation

nutrients

Stressors

Establishing Causality BetweenStressors and Biological Effects

Multiple stressresponses

Establish causality

HistopathImmuneEnzymes

Blood

Blood X-Ray

UrineProfile


Geneticdamage Immune Endocrineprofile

profile

EnvironmentalDiagnosis

MedicalDiagnosis

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