|
||||||||||||||||||||||
ConclusionsEutrophication effects have been documented in all Danish marine waters every year since the beginning of the 1980s. At present it can be concluded that quality criteria has only been fulfilled in a restricted number of Danish estuaries, coastal and open water areas. The few coastal areas that meet the criteria are generally non-stratified shallow water areas with a relatively restricted load from land based sources. The causes for not fulfi lling the criteria are primarily the effects of nutrient load and oxygen depletion. With corrections for variations in precipitation, run off and other climatic related conditions it can be concluded that: NUTRIENT LOADS NUTRIENT CONCENTRATIONS DIRECT EFFECTS During the period 1989-2001 eelgrass cover at water depths above 2 meters increased in the outer part of the estuaries, but was signifi cantly reduced at shallow depths in inner estuaries and along open coasts. The depth distribution has not increased, but in the inner estuaries actually decreased, possibly due to oxygen depletion. The amount of nuisance macroalgae has been reduced (though this is not always noted in the cover) at shallow depths. Macroalgae cover at open water reefs shows no trends since 1994. INDIRECT EFFECTS
|
||||||||||||||||||||||
Danish Environmental Protection Agency & National Environmental Research Institute • updated: |