through Dredge, you will be asked to gather items and fish for people living in the archipelagos around The Marrows. These are often straightforward, asking you to simply scour the area and fish for items. But some of these things are harder to find than others; the Researcher’s Pursuit asks for a fish that needs more than just a fishing rod: the Aurora jellyfish.
The researcher is located in the Old Fortress in the Stellar Basion, the series of islands on the southwest corner of Dredge
But the Aurora Jellyfish doesn’t show up because that requires another piece of gear: a trawl.
Where to find a trawl Dredge
You can buy a trawl if you don’t already have one, and you can upgrade it with research parts. At the Stellar Basin, you should equip the trawl and just sail around the island’s coastal areas. Make sure it’s at night. It may take a few minutes, but if you’re in the right area, you’ll eventually snag an Aurora Jellyfish. Dredge
Bring these three back to the researcher to continue the questline. Don’t wait too long to deliver them – if they rot, they’re no good. There she will send you on another mission to get equipment. This equipment is important because with it you will unlock the ability to catch fish in Abyss locations.