A total of 64 new protected areas will be introduced along the east coast - from Uppsala to Kalmar County.
According to the Swedish Maritime Administration, the decision will primarily protect pike, but also pikeperch, perch and trout.
In Sörmland, there are two new protected areas: Strandstuguviken and Kuggviken, both in Nyköping municipality.
The decision means that it is not allowed to fish in the areas during the period 1 January to 15 June.
- It is during this period that these species play in the designated areas, says Martin Rydgren.
The decision also adjusts the existing conservation area Tureholmsviken in Trosa.
There, all fishing is now banned between 15 September and 15 June.
The area has also been adjusted somewhat geographically.
- The goal is to get a strong pike stock.
They are needed to get balance in the ecosystem, says Martin Rydgren.
The new rules apply from 1 April this year and apply until further notice.