The following is permitted:

• Fishing may be conducted between 06:00 and 22:00. Hand gear fishing with a fishing license between January 1 and September 14. Fishing license must be carried with all fishing and presented together with valid identification on request.
• Fishing with ONE ROD, trolling, fly or angling with ONE hook (trawls with several factory-mounted hooks allowed, eg a wobbler with more than one hook).
• In order to have better fishing in the future, we have decided to introduce a ban on keeping any fish of the species Pike, Goose and Trout. This ban applies until we see that the stock is stronger.
• Regarding the fishing license for young people up to 19 years of age, strict catch and release applies, so on this fishing license you are not allowed to keep any fish, if you want to keep fish you have to buy a fishing license.

• Keep a maximum of 5 fish per day. (e.g. 5 perches, or 1 bream and 4 perches.)
• All fish to be kept are killed immediately.
• Minimum size, Salmon 60 cm. Maximum size of Perch 35cm.
• Fish, which are not to be kept, are carefully released again. Everyone who fishes is obliged to know the current rules before fishing begins.

The following is prohibited:

• All fishing 15 September-31 December. Applies to the entire Trosaån FVO (see map below). This protection is established by Trosaån FVO, the Norwegian Fisheries Agency (FIFS 2004:36) and the County Administrative Board of Södermanland County.
• Pay attention! Fishing methods other than those specified as permitted above are completely prohibited, e.g. varieties such as net fishing, long lines, jerk fishing, sinker nets, cast nets (e.g. for bait fish), trolling, pike shears, otter boards, angling, and the use of grappling hooks is totally prohibited throughout the year .
• Fishing is prohibited from the dam in Vagnhärad to the footbridge under the railway and in the rapids at Trosa Kvarn. This applies all year round.
• Fishing from boats and bridges over the Trosaån is prohibited.
• Incorrectly hooked fish, i.e. the hook is NOT in the mouth, must be re-released with caution.
• Litter in and along the river.
• Trosaån is monitored by a number of trained supervisors, who check the fishing almost every day. These have powers that belong to the supervisory work. Violations of the fishing rules are enforced through control and action. Police and coast guard can be called if necessary. Equipment may be seized.
• All income from fishing licenses goes to fisheries conservation work, e.g. placements, training etc.
• FVO, Trosa Amateur Fishing Club and Trosa Municipality are actively working to improve the conditions for all fish, other animals and plants through the ambition to restore Trosaån and create conservation areas for spawning fish. In order to maintain the existing sea trout stock, around 2-3,000 sea trout are released into the river annually.