Graphics from the year 2000 Baltic 21 biannual indicator-based status report on sustainable development in the Baltic Sea Region (Baltic 21 Series No 1/2000). This graphic shows BSR ecosystem area where acidification and eutrophication exceeds critical loads.

The density of people per square kilometers have been calculated from various statistical sources, and displays the situation at approximately 1990. Population, and specifically cities, act as driving forces in regards to eutrophication on the Baltic Sea, primarily through nutrients (nitrogen, phosphorous) released through sewage plants.

Ratio of arable land out of total land use in the Baltic Sea drainage basin. Agriculture is one of the main contributors to the nutrient (in this case, primarily nitrogen) influx into the Baltic Sea, and thus a main driver for the eutrophication problems in the sea. The displays the situation at approximately 1990.

Ratio of pasture land total land use in the Baltic Sea drainage basin. Agriculture is one of the main contributors to the nutrient (in this case, primarily nitrogen) influx into the Baltic Sea, and thus a main driver for the eutrophication problems in the sea. The displays the situation at approximately 1990.

The graphic shows the trend of the number of harmful algal blooms in the Western Atlantic from 1970 to 1996. The excess growth of algae is often caused by pollution, and can have negative or fatal effects on some species of fish.

Dead zones (hypoxic i.e. oxygen deficient water) in the coastal zones are increasing, typically surrounding major industrial and agricultural centers. This is commonly occuring due to nutrient pollution, in the form of nitrogen and phosphorous leading to algal blooms and eutrophication

Sewage treatment is low or absent in many parts of the World, leading to eutrophication of the coastal zone, (toxic) algae blooms and dramatically reduce the ability of coral to recover from bleaching events dramatically. The data reflects the bodies of the UNEP Regional Seas programme.

This graphic shows the average bicarbonate concentrations, in milligrams per litre, at major river mouths for the time periods 1976 to 1990 and 1991 to 2000. The graphic also shows the changes in average bicarbonate levels between these two time periods. Bicarbonate is an indication of the alkalinity in the rivers which reflects the geology (rock, minerals, sand) and increases the buffering capacity, but can also increase the risk of eutrophicati...

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...

The Baltic Sea region is covered by primarily forested land and cropland. This land cover map, delineated for the Baltic Sea drainage basin, is using the dataset prepared through the BALANS project, and represents the situation around year 2000.

Percentage of wetlands out of total land area (by grid cell) for the Baltic Sea drainage basin. Wetlands acts as buffers in cases such as antropogenic nutrient releases (which leads to eutrophication) and acidification. The ratios have been estimated from various sources, and resembles the situation at approximately 1990.

Nitrogen and phosphorous represents nutrients that can be seen as pollutants, as large concentations of those increase eutrophication. Nutrients are present in primarily commercial fertilisers and in sewage. A measure of eutrophication is biochemical oxygen demand (BOD), which measures the activity in the water column. High BOD means that there is low water quality (in terms of eutrophication) and high activity of bacteria in the water. This grap...

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...

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...