The State of the Mediterranean Marine and Coastal Environment

Possible oil slicks detected by satellites

Illicit oil spill density, 2004

Low

High

Note: the information on this map is based on superposition of satellites images, which could not discriminate between oil slicks and natural phenomena such as height of waves and surface wind.

Sources: UNEP/MAP, State of the Environment And Development in the Mediterranean, 2009.

REMPEC by national focal points in Mediterranean countries. This database cannot be considered a comprehensive list of all the spills occurring in the Mediterranean Sea. Other inci- dents that are not reported in the database could also have had significant impacts on the ecosystems, such as damage to the seabed or input of organotin compounds from paints dur- ing ship groundings. In the last decade, nearly half of the accidents leading to sig- nificant spills (of more than 100 tonnes) that were reported to REMPEC occurred in the Western Mediterranean Sea (seven ac- cidents representing 47 % of all accidents). A third of the ac- cidents occurred in the Eastern Mediterranean (five accidents representing 33 % of the total) and a fifth of the accidents oc- curred in the Central Mediterranean. No accidents were report- ed for the Adriatic Sea. The cumulative amount of toxic substances spilled per year fol- low a different pattern. A single accident can lead to the spill of a large amount of substance, and thus the cumulative quantities are variable. The worst spill in the Mediterranean was related to

to disrupt biochemical membranes, causing changes in en- zymatic and receptor activities in affected organisms. Experi- mental studies have also shown that exposure to petroleum hydrocarbons may lead to various impacts on blood chemistry. Both laboratory and field studies have shown that petroleum hydrocarbons may result in oxidative stress. Fish exposed to pe- troleum hydrocarbons under chronic conditions often exhibit various types of lesions. Several field studies have shown such histopathological changes in biota from waters contaminated by oil. For example, after the Haven accident outside the port of Genoa, fish sampled in the contaminated area had lesions as long as nine years after the accident. Behavioural abnormalities resulting in lowered chances of survival in the natural environ- ment are also observed among aquatic organisms exposed to oil spills (Abdulla and Linden 2008). Community-level changes were detected off Livorno after the 1991 Agip Abruzzo oil spill, where several different species in the meiobenthic community reacted differently by either de- creasing or increasing their population numbers. Foraminifera, turbellarians, and nematodes were particularly sensitive, while populations of copepods increased. Further research indicated an acute initial response among these organisms with rapid re- covery. This indicates a high resilience to single oil spill incidents. Benthic macro-fauna may also be resilient to the effects of pe- troleum hydrocarbons, particularly weathered oil. Samples from the Haven oil spill showed no significant differences between tar-contaminated sites and control sites. However, other studies indicate clear impacts on the growth of shallow-water sea grass over extensive areas and for as long as eight years after a spill (Abdulla and Linden 2008).

Oil spilled in the Mediterranean Thousands tonnes, 2000-2009

0.1

Western Mediterranean

Adriatic Sea

4.2

19.2

Acute pollution events

5.5

Eastern Mediterranean

Data used in this section are extracted from the Alerts and Accidents database maintained by REMPEC. They include in- cidents that have caused, or could have caused, pollution damage. The main sources of information are Lloyd’s Casualty Reporting Service (LCRS) and the emergency reports sent to

Central Mediterranean

Source: REMPEC

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HUMAN PRESSURE, STATE AND IMPACTS ON MEDITERRANEAN ECOSYSTEMS