diagnosis of environmental problems in aquatic ecosystems · –e.g. 1 h 0.1 mm, 3 h 0.001 mm (=1...
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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.