The main regulatory instrument aimed at the protection of the Mediterranean marine and coastal environment is the Convention for the Protection of the Marine Environment and the Coastal Region of the Mediterranean (Barcelona Convention) which entered into force in 2004. The Barcelona Convention’s main objectives are "to prevent, abate, combat and to the fullest extent possible eliminate pollution of the Mediterranean Sea Area" and "to protect and...

Climate change may, through effects on ocean currents, elevated sea temperatures, coral bleaching, shifts in marine life, ocean acidification and much more severely exacerbate the combined actions of accelerating coastal development, coastal pollution and dead zones, invasive species, bottom trawling and over-harvest. These impacts will be the strongest in 10-15% of the Worlds oceans. These areas, however, are concurrent with the most productive ...

All across the planet, the number and severity of outbreaks and infestations of invasive species (i.e. species purposefully or accidentally introduced in non-native environments) is growing, and invasions of marine habitats are now occurring at an alarming rate. Exotic and invasive species have been identified by scientists and policymakers as a major threat to marine ecosystems, with dramatic effects on biodiversity, biological productivity, hab...

Each of the big five stressors (not in order of magnitude), 1) Climate change; 2) Pollution (mainly coastal), 3) Fragmentation and habitat loss (from e.g. dredging/trawling, use of explosives in fishing on coral reefs etc.), 4) Invasive species infestations, and 5) Over-harvest from fisheries may individually or combined result in severe impacts on the biological production of the worlds oceans and the services they provide to billions of people ...

The locations of major problem areas for invasive species infestations or occurrence of exotic species in the marine environment. The impacted areas are concurrent with the areas subjected to the worst pollution, the most intensive fisheries and bottom trawling, and major shipping routes. The areas in the figure have been highlighted based on an overview of literature, and the delineation of the areas are approximate.

This graphic illustrates that there is a strong correlation between the world's industrial areas and the areas in which seasonally oxygen-depleted waters occur. The accompanying text explains some of the effects of land-based activities on the marine environment.

Considering the data for all the rivers at the continental level, there has been little change in nitrate (NO3-N) concentrations between the two decades under comparison. Changes in the median value were not statistically significant. European rivers showed the highest nitrate loads transported to the marine environment. Comparing data from the two decades, North American and European rivers have remained fairly stable, while major river basins i...

A significant sea level rise is one of the major anticipated consequences of climate change. This will cause some low-lying coastal areas to become completely submerged, while others will increasingly face short-lived high-water levels. These anticipated changes could have a major impact on the lives of coastal populations. The small island developing states (SIDS) will be especially vulnerable to the effects of sea level rise, and to changes in ...

Nutrients are essential to life. In aquatic systems, nitrogen and phosphorus are the two nutrients that most commonly control the growth of aquatic plants, algae and bacteria. Nitrogen and phosphorus are considered to be the primary drivers of eutrophication of aquatic ecosystems, where increased nutrient concentrations lead to increased primary productivity. Some systems are naturally eutrophic, whereas others have become eutrophic as a result o...

Physical alteration and the destruction of habitats are now considered one of the most significant threats to coastal areas. Half of the world’s wetlands, and even more of its mangrove forests, have been lost over the past century to physical alterations, the major causes being accelerating social and economic development and poor-planning (UNEP, 2002). There are currently about one billion people living in coastal urban areas. It is estimated t...

Unsurprisingly, the coastal areas with the greatest population densities are also those with the most shoreline degradation. The areas surrounding the Black Sea, the Mediterranean and southern Asia have the highest proportion of altered land, while the coastal zones of the Arctic, northeast Pacific, south Pacific, West and Central Africa, East Africa, the Red Sea/Gulf of Aden, and Kuwait have the highest proportions of least modified land. In o...

This graphic illustrates the strong link between areas with high densities of industrial activity and zones of seasonally oxygen-depleted waters. There is a strong link between areas with high densities of industrial activity and zones of seasonal oxygen-depleted waters. In recent years there has been an increasing focus on treating and reducing municipal and industrial waste, and on reducing nitrogen levels in agricultural runoff. However, less...