Why are shallow bays effected by over-fertilization
Man can also cause problems by stopping or redirecting water currents. As the years have passed we have built roads between different islands in the archipelagoes, for example embankments that are often built and choke the natural flow and hinder the exchange of water. Stagnant water usually results in that no new oxygen is supplied to the system. Today we have learned that by placing large piping in the embankments in a certain way, embankments can be built without choking the flow of water.
Even when building other constructions, such as piers and carparks, a large exchange of water can still occur, but careful planning is needed and measures taken so that the flow of water is not changed in an unfavourable manner.
That the occurrance of finely threaded algae is higher in northern Bohuslän compared to the southern areas can also be due to a naturally lower water exchange. Archipelagoes also have a great many islands and narrow passages that also reduce the flow of water.
|A splendid outing ?|
|Problems and expectations|
|It was better before"|
|Seawater and soluble salts|
|The sea moves|
|Coastal waters are close to us|
|What is eutrofication?|
|Sources of over-fertilization|
|How the open masses of water are effected|
|How shallow bays are effected|
|What can we do?|