Ragworm

Large numbers of ragworms live on the bottom of the fjord. They play an important role as food for several fish, especially flat fish like turbot and flounder.

You can see a lot of ragworms when they spawn. This happens when the water is above 5-7 degrees and at full- and new moon. The ragworms come up to the surface, where they all spawn their eggs and sperm at the same time, to maximise the chance of fertilisation. At this time the upper layers of water can be quite alive with them. At this time you can also find ragworms in the cast of herring gulls in their colonies. The huge supply of ragworms encourages the gulls to overeat, and as a result they vomit by their nests.


Herring gull cast consisting of ragworms.