Tide and currents
Danish inshore fishing
By Martin Joergensen
When it comes to watermovement, which is very important for most salt water species, the tidal current is a major factor. The Danish tide is nowhere as extreme as that found on many oceanic cosasts like the ones of northern France and southern England. In Denmark the water level will vary maybe an avarage 0.5 meter (1½ foot or so) most places but some places more.
Still it's an important factor, because it brings about the water movenent that is so important in keeping the water fresh in the shallow coastal water. If this water was still it would soon be left void of oxygen and animal life filled with algea. Many warm summers we experience excactly that, when the production of øplant plancton gets so hing that all oxygen is used and the algea start dying with catastrophic results.
The (almost) eternal current
Look at the map of northern Europe and notice the position of Denmark. Denmark is placed as a plug in the drain of the Baltic Sea. Into the Baltic runs a lot of rivers -- a lot. The water from all these rivers has to go somewhere, and when it does it has to pass Denmark.
As you might notice there are three water passages through Denmark: Oeresund, Lillebaelt and Storebaelt (Øresund, Lillebælt and Storebælt) which are all narrow sounds with a north/south direction.
The water that passes Denmark from the Baltic has to go through these sounds and will do so in a northgoing direction. This means that the predominant direction of the current i north.