b) From the study of trends in the Mediterranean to a need for a response
The need to implement a sustainable operational vision in the Mediterranean area is explained by the fact that maritime traffic in the Mediterranean is not without significant and harmful effects on health and the environment, to be stopped.
Indeed, according to the “Study on trends and outlook for marine pollution from ships and activities as well as maritime traffic and offshore activities in the Mediterranean”(3) published by REMPEC in December 2021, maritime traffic constitutes a real vector of marine pollution in the Mediterranean basin (discharge of solid waste and hydrocarbons, emission of particles into the atmosphere, emission of underwater noise, invasive species). This study defines five axes corresponding to frameworks affecting more particularly the Mediterranean correlated to the main subjects mentioned.
The increase in maritime traffic leads to a higher risk of pollution caused by shipping. Although environmental regulations are strict, particularly within the framework of the MARPOL convention (International Convention for the Prevention of Pollution from Ships), polluting substances continue to be discharged into the sea. Shipping activities generate various pollution pressures chemical through the release of hydrocarbons and other chemicals. Spills can occur in accidents, during routine operations, in ports, as well as at sea. They can be intentional or accidental, resulting from human decision, human error, or a technical failure.
Marine litter is a real regional issue, from its origin to its dissemination in the marine environment. It is estimated that more than 90 million tonnes of plastics have accumulated in the world’s oceans, with around 5 to 13 million tonnes being added each year. In fact, marine debris enters the seas from land and sea sources and around 60-80% of it comes from plastic. They have various potentially harmful implications on marine ecosystems and human activities at sea. Every year, millions of species that live in the oceans are weakened, maimed, and killed by marine litter. Marine litter also poses a risk to human health and has significant implications for human well-being, negatively impacting vital economic sectors, such as tourism, fisheries, or aquaculture.
Shipping is heavily dependent on fossil fuels. About 3.5 million barrels of high sulphur residual fuel oil (bunker fuel) per day were consumed by the sector in 2017, representing about 50% of global fuel oil demand. Most of these fuels have a high sulphur content, which leads to the emission of sulphur oxides into the atmosphere. Emissions from ships are dispersed into the atmosphere for hundreds of kilometres, contributing to the deterioration of air quality on land, even if they are emitted at sea. They come mainly from the exhaust gases of ships.
With the increasing mobility of people and goods globally, the spread of invasive species (NIS) has accelerated over the past decade with a 200% growth rate over ten years. The Mediterranean Sea is one of the seas most affected by NIS, in terms of high rate of introduction, number of taxa recorded and duration of permanence (macrophytes, fish, molluscs, polychaetes, bryozoans and crustaceans).
Changes in terms of Mediterranean marine biodiversity linked to the introduction of NIS have been reported in recent years, mainly linked to maritime transport, the main route of introduction, mainly in ballast water or as fouling on the hulls of ships. NIS impact both the environment, human health and activities. For example, the jellyfish Rhopilema nomadica has been reported to negatively affect coastal power generation facilities, as well as impacting fisheries, human health, and tourism.
Noise from human activities at sea travels long distances underwater, causing increases and changes in ocean noise levels. Increased noise levels can negatively impact marine species and ecosystems that can reduce the species’ ability to hear environmental cues that are vital for its survival, ranging from a temporary reduction in hearing sensitivity and the effects behaviours to more dramatic effects such as death.