Impacts of oil on biotaDiagnosis of environmental problems in aquatic ecosystems

Inari HelleFisheries and Environmental Management Group (FEM)

Department of Environmental SciencesUniversity of Helsinki

16 October 2017

Contents

I Maritime traffic and accidents

II Oil in aquatic ecoystems

III Impacts of oil

IV Spatial risk assessment: threatenedcoastal species and habitats

Hazard

identification

Risk

assessment

Risk control:

Management

Review &

update

Risk communication

Maritime traffic in the Baltic Sea

• ”On average 2 000 ships at sea every day”

• Accidents (cargo/bunker oil)

• Illegal oil discharges

Source: HELCOM

9%

52%17%

17%

5%

Passenger

Cargo

Tanker

Other

Unknown

14%

53%

19%

10%

4%

Passenger

Cargo

Tanker

Other

Unknown

Gulf of Finland

Baltic Sea

HS 11.10.2017

Oil transportation in the Gulf of Finland

Source: SYKE

Maritime accidents

Sourc

e: H

ELC

OM

(2014):

Annual re

port

on S

hip

pin

g a

ccid

ents

in the B

altic

Sea in 2

013

18%

20%

29%

29%

4%

Collision

Contact

Other type

Grounding

Pollution

Oil discharges from vessels

• In 2016, 53 detected discharges, decreasing trend

Source: HELCOM (2017): Annual report on Discharges observed during aerial surveillance in the

Baltic Sea 2016

• Crude oil

– Mixture of hydrocarbons (C, H, O, S, N)

– Especially alkanes and aromatichydrocarbons (PAHs and BTEXs)

• Refined components

– Refined from crude oil: gasoline, diesel etc.

• Properties vary a lot

– Viscosity Spreading

– Density Floating/sinking

– Water content Emulsification

Oil

A Very light oils (e.g. kerosene,

gasoline)

• High evaporation (and dissolution)

rate

• Do not adhere to surfaces

• Rich in toxic compounds

• Severe local impacts on organisms

living in water column

B — Light oils (e.g. diesel, light crudes)

• Relatively high evaporation rate

• Less toxic but adhere more firmly to

surfaces than class A oils

• Can smother shorelines

• Clean-up can be effective

C — Medium oils (majority of crudes)

• ~ 33 % evapote (24 h)

• Toxicity low

• May pollute shoreline severily

• Clean-up can be effective,

especially if started at once after

the spill

D — Heavy oils (e.g. heavy crudes,

bunker C)

• Very low evaporation rate

• Can have very severe impacts on

shoreline and birds and mammals

• May sink

• Can contaminate sediments

• Difficult to clean

Classification of oils

Behaviour of oil: weathering

Spreading

• Oil spreads over the water surface

– E.g. 1 h 0.1 mm, 3 h 0.001 mm (=1 µm)

• Light oils spread faster than heavy oils

• Waves and currents affect

Photo

: IT

OP

F

Photo: BOSC

0.05 µm Silvery sheen

0.15 µm ”Rainbow”

0.50 µm Colors begin to

dull, reddish-

brownish colors

2.0 µm Brownish colors

10.0 µm Dark colours

50.0 µm Dark brown to

black

Sourc

e: B

OS

C

Evaporation and emulsification

• Evaporation

– Depends on oil: light crudes ~ 75 %, heavy oils ~ 10 %

– Temperature, wind etc.

– Great impact on the properties and behaviour of oil

• Emulsification

– Oil takes up water → water-in-oil emulsions (”chocolatemousse”)

– Influences oil combating

• Volume of spill increases

• Slows down spreading and evaporation

• Emulsions can be very persistent

• Makes mechanical recovery more difficult

Other weathering processes

• Dispersion

– Waves and currents: small oil droplets (~1−50 µm) can become mixed into water, larger ones rise back to the surface

• Dissolution

– Especially light aromatic compounds (e.g. benzene, toluene), which are also more toxic

• Sunlight + oxygen photo-oxidation of oil

• Oil droplets + sediment particles sedimentationto the sea bed

• Micro-organisms biodegradation

Oil in aquatic ecosystems

• Negative impacts depend on

– Oil type and amount of oil

– Season, location, weather conditions

– Organisms: sensitivity to oil, development phase, behaviour…

– Other possible stress factors (eutrophication etc.)

– Community structure

• Cell > individual > population > community

?

Prediction is difficult…

Spill size(tons)

Dead birds(ind.)

Amoco Cadiz Exxon Valdez Unknown vessel

Effects of oil

Toxicity

Smothering

Death

Delayed death

Sublethal effects

Growth ↓

Developmental disordes ↑

Immunity ↓

Reproduction ↓

Communities: structure and functioning

• Acute toxicity: water-soluble components

• Aromatic hydrocarbons (BTEXs and PAHs) important

• Type of oil: ”the lighter, the more toxic”

• Sub-lethal effects occur at substantially lower

concentrations than acute effects

• Weathering may increase/decrease toxicity

• Many organisms can metabolize aromatic

hydrocarbons (cytochrome P450)

Toxicity of oil

• Oil may hinder photosynthesis

• Zooplankton more sensitive thanphytoplankton

– Ingestion, reproduction, biomass

– Impact on phytoplankton (?)

• Bacterial plankton usually increases

• Effects dependent on species

• Recovery pretty rapid (?)

Johansson y

m. (1

980) —

Mar.

Pollut.

Bul. 1

1: 284–293

Plankton

• Smotheting affects respiration and locomotion

• Toxicity, especially PAHs

• Effects depend on organisms

– Mussels may close their valves → may avoid (short-term) exposure

– Crustaceans (esp. amphipods) verysensitive

– Populations of opportunistic speciesmay increase (at least momentarily)

• Pollution of sediments

Kingston (2002) — Spill Sci. Technol. B. 7(1-2): 53–61

Lin

dén y

m. (1

979) —

Am

bio

8: 244–253

Benthos

• Adult fish

– Exposure via food and gills

– Alterations in liver, growth rate, heart rate etc…

– Able to avoid oily water?

• Eggs and fry

– Very sensitive

– Various kinds of developmentaldisordes

Carl

s y

m.

(19

99

) —

En

vir

on

. To

xic

ol. C

he

m 1

8(3

): 4

81–

49

3

Fish

• Afloat or in/on shore become easilyexposed to oil

• Smothering

• Ingestion of oil Preening/feeding immunosupression, hemolythic anaemia…

Insulation capacity of feathers decreaseshypothermia deathOiling of eggs developmental disordersof embryos

Photo: Julian Bell

• Alterations in food supply, reproduction, physiology…

• Timing of exposure more important than the volume of spill!

Birds

• Inhalation of toxic vapours: lung and nerve damages

• Direct contact: eye damages etc.

• Ingestion of oil: internalhaemmorrages, liver and kidneydamages etc.

• DWH: lung damages in newborn/stillborn dolphin cubs

• Smothering detrimental for fur-depedent mammals ((sea)otters, sealpups etc.) BUT may not be a severeproblem, if subcutaneous blubber layerthick (e.g. adult seals)

Jenssen.

(1996) —

Sci. T

ota

l E

nvir

on. 186(1

-2):

109–

118

Mammals

• Smothering: stomata may clog up

– Temperature of leaves increases

– Fotosynthesis may be prevented

• If oil penetrates the ground roots maybe destroyed

• Flowering, germination of seeds…

• Growth period sensitive time

• Macro algae: mucus may (or may not…) protect

Macrophytes

Raptors

Bivalves

Perennials, gastropods, pelagic fish, waders

Submerged plants, isopods

Green algae, brown algae, helophytes, annuals with seedbank, littoral fish, seals

Annuals without seedbank, amphipods

Gulls

Ducks

Auks

Pro

bab

ility

of

reco

very

Sou

rce

: Lec

klin

et a

l. (2

011)

: A

Bay

esia

n n

etw

ork

fo

r an

alyz

ing

bio

logi

cal a

cute

an

d

lon

g-te

rm im

pac

ts o

f an

oil

spill

in t

he

Gu

lf o

f Fi

nla

nd

. Mar

ine

Po

lluti

on

Bu

lleti

n 6

2:

2822

–28

35

.

Rare and

threatened species

and habitats?

Recovery of common species in the GoF

Plankton

Benthos

FishMacrophytes

Birds

Mammals

Cleanup

Oiling Direct

mortality

Habitat quality

reduced

No effects

Reduced habitat

occupancy and use

Physiological

stressEmigration

Food supply

reduced

Lowered

reproductive

success

Indirect

mortality

Decreased

population size

Foraging

behavior altered

Altered population

structure

Oil spill

Source: NRC (2003): Oil in the Sea III

Given the uncertainty related to

– Location of an oil spill

– Oil type

– Season

– Spill size

– Drifting of oil slicks

... what areas, habitat types and species are at thegreatest risk?

Spatial risk assessment: threatened species and habitats

Helle, I., Jolma, A. & Venesjärvi, R. (2016): Species and habitats in danger: Estimating the relative risk posed by oil spills in the northern Baltic Sea. Ecosphere 7(5): e01344.

Jolma, A., Lehikoinen, A., Helle, I. & Venesjärvi, R. (2014): A software system for assessing the spatially distributed ecological risk posed by oil shipping. Environmental Modelling & Software 61: 1–11.

Motivation: Red-listed species in Finland

Source: Rassi, P., Hyvärinen, E., Juslén, A. & Mannerkoski, I. (eds.) 2010: The 2010 Red List of Finnish Species. Ympäristöministeriö & Suomen ympäristökeskus, Helsinki. 685 p.

Habitat type CR EN VU NT Total

Baltic Sea 1 8 8 11 28

BS sand beaches 16 44 43 47 150

BS coastal meadows 9 21 24 37 91

BS rocky shores 1 0 0 6 7

BS gravel, shingle and boulder shores 3 2 1 10 16

BS open alluvial shores 2 5 0 1 8

BS flooded forests 0 1 3 3 7

Unspecified shores of the BS 0 1 2 13 16

Total 32 82 81 128 323

Motivation: Red-listed habitats in Finland

Source: Raunio, A., Schulman, A. & Kontula, T. (eds.) 2008. Assessment of threatened habitat types in Finland – Part 1: Results and basis for assessment. Suomen ympäristökeskus, Helsinki. Suomen ympäristö 8/2008. 264 p.

Gu

lf o

f Fi

nla

nd

Åla

nd

and

A

rch

ipel

ago

Sea

Sea

of

Bo

thn

ia

Kvar

ken

Bay

of

Bo

thn

ia

Wh

ole

Fin

lan

d

%o

f th

e n

um

be

ro

f h

abit

atty

pes 100

80

60

40

20

0N

um

be

ro

f h

abit

atty

pe

s

25

20

15

10

5

0Open Wooded Aquatic Comb.

BS underwater habitats BS coastal habitats

Methods

Combination of 3 elements:

1. Bayesian network describingrandom variables related to oil spills

2. Probability maps describingthe drifting of oil (SpillMod, provided by SYKE)

3. Species and habitat data

Helle

et

al. (

2016):

Ecosphere

7(5

): e

0134

4.

Bayesian networks

• Models, which describe variables and probabilisticdependencies between them

• Can integrate knowledge from different sources: modelling results, statistics, expert knowledge etc.

Accident location

Accidenttype

Location

A0 0.14

A1 0.11

A2 0.15

A3 0.11

A4 0.14

A5 0.35 LocationA0 A1 A2 A3 A4 A5

Accident type

Grounding 0.75 1 0.33 0.33 0.75 0.4

Collision 0.25 0 0.67 0.67 0.25 0.6

SpillMod oil drifting maps

• 8 locations

• 3 oil types

• 6 spill sizes

• 3 seasons

• 6 years

2592 simulations

Source: SYKE

Species and habitat dataSpecies• Locations• Conservation

value• Mortality

Habitat types• Locations• Conservation

value• Recovery

potential

Combination of data

• Spill: location G3, spring (other variables in the BN regarded uncertain)

• Value: Number of threatened species

Spatial risk

Risk = Pr(oil)i× Valuei

Pr(oil)i = probability that cell i becomes oiledValue = Value of cell i

RiskTOT = i=1n (Pr(oil)i× Valuei)

n = number of grid cells

Ecological value

Oil spreading

Combined

Helle et al. (2016): Ecosphere 7(5): e01344.

Habitat-specific risk

RiskH = i=1n (Pr(oil)i× PropHi)

RiskCH = i=1n (Pr(oil)i× PropHi) × (1 − REPH)

n = number of grid cells in which habitat H is presentPr(oil)i = probability that cell i becomes oiledpropHi = proportion of H present in cell iREPH = recovery potential of habitat H

1: Coastal sand beaches

2: Seashore meadows

3: Coastal dunes

4: Alnus glutinosa swamps

5: Calcareous rock outcrops on seashores

6: Glo-lakes (coastal lagoons)

7: Flada-lakes (coastal lagoons)

8: Herb-rich forests with broadleaveddeciduous trees

Helle

et

al. (

2016):

Ecosphere

7(5

): e

0134

4.

Managing risks

Prevention

– Ships: Structure and equipment

– Mariners: training and working conditions

– Navigation: VTS, reporting systems, piloting, ice-breakingservices, waterway safety…

Post-spill measures

– Mechanical recovery: response vessels; booms and skimmers

– Dispersants and other chemicals NOT IN THE BALTIC!

– Micro-organisms and nutrients

– Other: in-situ burning, shoreline clean-up

More information

• NRC (2003): Oil in the Sea III: Inputs, Fates, and Effects.

• Finnish Environment Institute’s oil pages: http://www.environment.fi/oil

• HELCOM: http://www.helcom.fi/action-areas/response-to-spills/• NOAA’s Office of Response and Restoration:

https://response.restoration.noaa.gov/oil-and-chemical-spills

• ITOPF: International Tanker Owners Pollution Federation: http://www.itopf.org/

• Helle, I. & Kuikka, S. 2010: Itämeren öljykuljetusten riskipeli. In: Bäck, S., Ollikainen, M., Bonsdorff, E., Eriksson, A., Hallanaro, E-L., Kuikka, S., Viitasalo, M. & Walls, M. (eds.), Itämeren tulevaisuus, pp. 190–205. Gaudeamus University Press, Helsinki. In Finnish.