VERTIMAR-2005
SYMPOSIUM for monitoring of Accidental Oil Spills Projects in Marine Environment
related with VEM2003 Program of Ministry of Education and Science (Spain)
The Erika oil spill. An overview of temporal trends through the
Erika scientific programme
Emina MAMACA1, Lucien LAUBIER2 and Michel MARCHAND3
1Technological
Researches and Tests Department, Centre Ifremer de Brest, Z.I. Pointe du Diable BP 70,
29280 Plouzané, France.
2 Oceanographic Institute of Paris, 195 r St Jacques 75005 Paris.
3 Biogeochemistry and Ecotoxicology Department, Centre Ifremer de Nantes , BP 21105, 44311 Nantes
Cedex 3, France.
ABSTRACT
On December 11, 1999, the tanker Erika, loaded with 31 000 tonnes of heavy fuel oil, sank about
thirty nautical miles south of Penmac’h Pointe (Brittany, France). This wreck caused a huge 19 000 tonnes oil spill along
400 km of the French Atlantic coast. Crude oil is composed mainly by hydrocarbons, such as saturated hydrocarbons,
aromatics, resins and asphaltenes which are highly noxious compounds as they exhibit toxic, mutagenic and
carcinogenic properties. On February 28, 2000, the French government decided to implement programmes which would
focus on the ecological and ecotoxicological consequences of the Erika oil spill including four different topics:

The spatial and temporal extent of the contamination and its spread along the coast.

The transformation and bio-availability of contaminants.

The impact on living organisms, including impact on both supralittoral and intertidal species.

The monitoring of the clean-up operation and the restoration of the coastline.
1. INTRODUCTION
On December 11, 1999, the Maltese tanker Erika, laden with 31,000 tonnes of heavy fuel,
was making its way from Dunkerque (France) to Livorno (Italy) in very rough sea conditions
(Westerly wind, force 8 to 9, with 6 m waves) and was faced with structural problems off the Bay
of Biscay. After sending an alert message, the vessel was breaking in two and sank (12-13
December) close to the Atlantic coast of France (South of Penmarch Point, Finistère, France).
Both parts lay in 120m of water and were located 10 km apart. Consequently to its sinking,
about 19 000 tonnes of heavy fuel oil were spilled into the sea and drifted for several days with
the currents. On the 23th of December, the first slicks reached the coast and the major oil came
ashore between December 24 and 27. A violent storm occurred on December 25 which resulted
in the deposition of oil slicks along 400 km of coastline in the French departments of Finistère,
Morbihan, Loire-Atlantique, Vendée and Charente Maritime (Fig 1). The heavy fuel oil
transported by the Erika tanker came from the Flanders refinery at Dunkerque and was a highly
viscous No-2 fuel oil (a No-6 fuel oil according to the British classification) containing about 4250% of aromatic hydrocarbons including 14% sulfur-containing aromatic compounds, 23-36%
resins and asphaltens, 22-30% saturated hydrocarbons, and respectively 40 and 90 mg.kg -1 for
nickel and vanadium (source: IFP, French Petroleum Institute). Total polycyclic aromatic
hydrocarbons (PAHs) were estimated at 32 500 mg.kg-1 and most compounds are highly
noxious as they exhibit toxic, mutagenic and carcinogenic properties. On the whole, it can be
estimated that 650 tonnes of PAHs, 1 tonne of nickel and 2 tonnes of vanadium were released
in the marine environment after the Erika oil spill. That’s why on February 28, 2000, the French
government decided to implement this Erika scientific programme which focus on the ecological
and ecotoxicological consequences of the Erika oil spill. This programme aimed to implement
well established methodologies rather than to develop new ones. Thirty research projects
proposed by universities, research institutes and associations were selected and funded
following an open call for proposals. Seven of these projects focused on the chemical
monitoring of contamination of the water column, rocky shore, sediments and organisms. Seven
projects dealt with the impact of the oils slick on birds and sea mammals. Fifteen projects
covered marine fauna and marine and coastal flora. One project undertaken in 2003 analysed
the modifications to the coastline brought about by cleanning operations. The results of this
programme were presented during a conference held on November 20-21, 2003, in the Ifremer
Centre in Nantes and published in the special issue of Aquatic Living Resources, Volume 17N°3, July/September 2004. Information can also be found on the website (http://www.suivierika.info)
VERTIMAR-2005
SYMPOSIUM for monitoring of Accidental Oil Spills Projects in Marine Environment
related with VEM2003 Program of Ministry of Education and Science (Spain)
2. RESULTS AND DISCUSSION
Degradation. The degradation of the Erika’s oil was studied in an intertidal environment on
different type of substrate. A preliminary laboratory study had shown that the biodegradation of
this heavy fuel was an extremely slow process. In the natural environment of the intertidal zone,
significant light exposure speeds up the photo-oxidation of the oil. The impact of the oil on
microbial mats collected within salt marshes was also investigated and yielded strains of
bacteria capable of biodegrading model hydrocarbon molecules.
Chemical pollution. From the time of the disaster until late 2003, the chemical contamination of
water, marine sediments, salt marshes, and intertidal bivalves was monitored, using polycyclic
aromatic hydrocarbons (PAH) as tracer molecules. In the most contaminated area ( Loire
Atlantique and Vendée coasts), PAH concentrations measured in the soft tissues of bivalves
led to a ban on shellfish collection and shellfish farming which remained in place until early
2001. For the sum of the 16 priority PAH from the list selected by the US-EPA, the French
Agency for Food Health and Safety (AFSSA) set a guideline value of 500 µg kg -1 dry weight,
and the Directorate of Sea Fishing and Farming (DPMA) then set an exclusion threshold at
twice this concentration. Maximum concentration of 3 000 to more than 5 000 µg kg -1 (dry
weight) were recorded near Le Croisic and on the west coast of Noirmoutier Island. The French
National Monitoring Network for the Quality of the Marine Environment (RNO), a long term
monitoring network supported by the Ministry of Environment (MEDD) and conducted by
Ifremer, allows a comparison between the post-spill contamination and the chronic level of
contamination (100 to 200 µg kg-1 dry weight for the sum of 16 priority PAH). Concentrations of
PAHs in mussels and oysters included unsubstituted PAHs (especially the 16 priority PAHs)
and also alkyl substituted PAHs, often 10 times higher. For example, near Le Croisic strongly
impacted by the oil, maximun concentration levels were recorded in mussels with unsubstituted
PAHs of 6 900 µg kg-1 and alkyl substituted PAHs of 83 500 µg kg-1.
Particular attention was paid to the vanadium and nickel levels as tracers of the Erika fuel
oil. In filter-feeding mussels and oysters, an abrupt rise in vanadium concentrations was
recorded in may 2000, five months after the shipwreck. Higher levels of nickel and
metallothioneins were noticed at several sites. Other studies were also carried out on species
with different feeding habits, i.e., the periwinkle Littorina littorea, the dog whelk Nucella lapillus,
the starfish Asteria rubens and populations of benthic foraminifera, etc.
Biological effects on mussels. A 3-year survey was made of several biological markers in
mussels exposed in situ to the Erika oil. After validation tests, data were evaluated for only 5
biomarkers: acetylcholinesterase (AchE), glutathione-S-transferase (GST), catalase (CAT),
malondialdehyde (MDA) and DNA adducts. No significant reduction in GST or CAT levels were
observed, levels of DNA adducts and MDA were high during the 6 months after the accident,
and levels of AchE were significantly lower during the first year of the survey, suggesting a
general stress. The results showed that mussel populations were affected by the oil spill only
during the first year following the event.
Health impact. The potential effects for consumers resulting from the ingestion of seafood
contaminated by oil spill contaminants were studied, using rats as model animals. Genotoxic
damage (COMET assay), biochemical affects (EROD activity) and genomic effects (expression
of cytochrome genes) were measured in rats fed with mussels contaminated at various degrees
by the oil. The most sensitive biological parameter reflecting the transfer of contaminants via the
food appeared to be DNA breaks studied by means of the COMET assay. Genotoxic damage,
observed mainly in the liver, was rather moderate and remained not persistent. The study
underlined the bioavailability of pollutants in fuel oil contaminated mussels for consumers. The
occurrence of related PAH compounds in addition to unsubstituted PAHs in mussels raised the
question of their implication in the registered effects.
Plant communities.The littoral plant communities were monitored during a 4 year period, using
phytosociological analyses and the study of oil products in the plant tissues. The development
of the plants did not appear to be significantly affected by the impact of the spill except at
seriously polluted sites where the vegetation was totally covered with oil. The PAH
concentrations found in the plant tissues are gradually decreasing over time. Areas that had
undergone cleaning operations were affected to extremely varying degrees in terms of plant
cover and the floral species diversity.
VERTIMAR-2005
SYMPOSIUM for monitoring of Accidental Oil Spills Projects in Marine Environment
related with VEM2003 Program of Ministry of Education and Science (Spain)
Birds. Marine Birds wintering in the Bay of Biscay were by far the most affected by the oil spill.
The common guillemot, Uria aalge was the most impacted species: in the first month following
the disaster, 64 000 – 125 000 guillemots died, of wich one-third were less than one year old.
Records suggest that the seabird populations did not decline within the 3 years that followed the
disaster. Analyses of ring recovery and biometry indicated that guillemots in the affected area
originated from a large geographic area, including colonies from across the British Isles and the
North Sea, along with more northern localities. A genetic approach using microsatellites showed
little genetic differentiation among Northeastern Atlantic guillemot colonies.
Mammals. No marine mammals were found to have died as a result of the oil spill. Grey seals
and dolphins displayed no symptoms related to the oil spill. The only noticeable effects were
change in porphyrin levels and nickel/vanadium ratios in the faeces of the otter Lutra lutra.
Marine invertebrates were particularly affected by the pollution. Initially, there was widespread
mortality of sensitive species such as sea urchins, which was followed by local ecological
succession processes. Overall, the impact of the spilled oil on the invertebrate communities and
populations could hardly be distinguished from the natural variability and the heterogeneity of
the environment and from the effects of long term anthropogenic disturbances. A subaquatic
study, conducted in the bay of Concarneau, the Archipelago of Glenan, the Island of Groix and
Belle-Ile failed to reveal any consequence from Erika pollution on the biodiversity of invertebrate
populations. Of particular note were the immunopathological lesions found in the oyster
Crassostrea gigas around Le Croisic, an area which was very badly affected by beached fuel
oil.
Fish. A benthic fish, the sole, Solea solea, was selected as a model fish species. Although no
direct mortality was observed, nor any necrosis on the ventral side (as was the case with the flat
fish living in the Benoît and Wrac’h estuaries following the Amoco Cadiz oil spill) a
multidisciplinary approach, combining observation and experimentation, provided the validation
of certain biological markers of functional integrity at the individual scale, but effects were not
detectable at the population level. The bio-accumulation and transformation of certain PAH was
monitored. Thus, bile metabolites, in Solea solea, can be used as markers of exposure and
identified 1-hydroxypyrene as the major metabolite in bile, after enzymatic deconjugation.
Coastline. Finally, the geomorphological impacts of the oil spill on the coast and the
consequences of decontamination techniques are being studied, in order to minimise excessive
interventions that endanger the littoral environment and to find alternative solutions that will
preserve the ecological equilibrium.
3. CONCLUSION
In summary, this programme gave a better insight into the impact of the Erika oil spill on
different areas of the littoral ecosystems, as well as serving to develop various chemical and
biological markers. However, the research teams have been faced with one major problem of
interpretation, i.e., a lack of knowledge about the structure and functioning of ecosystems in
”normal” time, prior to the oil spill. How can one demonstrate the effects of severe pollution
when the effects of chronic pollution remain an unknown factor? How may a change in the
ecosystem caused by an oil spill be distinguished from natural development related to climate
change? A plethora of temporal and spatial variables make the interpretation of the effects a
rather trying ordeal, especially when one considers the duration and the time scale in which
marine populations and ecosystems evolve. The natural variability inherent in the populations
introduces considerable uncertainty into the assessment of the impact and the recolonization
following accidental pollution. In order to evaluate the effects of oil spill in the marine
environment and the restoration of ecosystems, a minimum of knowledge of the structure of
populations is a prerequisite. Moreover, appreciating the influence of climatic change over a 10year period, means that one cannot expect communities and ecosystems ever to fully return to
their pre-accident status.
However, one important output of the programme is linked to the fact that it provided the
French ministry for ecology and sustainable development with good tools to monitor the coastal
ecosystems in the context of the water framework directive.
VERTIMAR-2005
SYMPOSIUM for monitoring of Accidental Oil Spills Projects in Marine Environment
related with VEM2003 Program of Ministry of Education and Science (Spain)
Figure 1:
Slick drift at sea and impacted county by the oil of the Erika on December 31, 1999
(source: Cedre)