Ragnar the Terrible (Drubman Marina)
This side mission is available at Drubman Marina after completing Eco-Warriors. Speak to the starred NPC to begin.
Your mission is to bag Ragnar the Terrible, a venerable paddlefish. The fishing spot is the is tiny island in the middle of the lake.
Note that there's a skill mag in the camper's tent here.
Cast a line near the pier- Ragnar is the only fish biting. One strategy is to cast from the shore, then run up to Ragnar as soon as he gets close to the pier. An even better strategy is to complete The Admiral mission first, then come back here with the Wonderboy rod.
Either way, scooping him up in your clutches completes the mission.
It also satisfies the Paddlefish Caught challenge requirements, if you haven't already surpassed them, but does not count for the state fishing record.