After rescuing the Angaran scientists during the quest "Helping Havarl’s Scientists", return to the Pelaav Research Station and talk to Kiiran Dals to update this quest, then talk to talk to Assistant Torvar and he’ll give you the navpoint to the Turian encampment. Fast travel to the Forward Station east of the Pelaav Research Station and make your way north across some rocks to reach a river running through the jungle. Well… not so much a river, more like a stream. Or rather, and elongated puddle. Whatever it is, follow this tepid little stretch of water east, southeast, then south through the jungle.
The stream will eventually terminate near the massive Remnant trench that runs north/south across Havarl, which you’ll get around to exploring in a bit. Instead, head uphill and continue south until you find the Turian camp, which is being attacked by a squad of Roekaar, including an inordinate number of Sharpshooters. Defeat them, after which more Roekaar will deploy behind you to the north via dropship.
Kill all the Roekaar, then loot the area, as there are numerous containers hidden about, along with the odd Nickel and Platinum node. Search the north, northwestern end of the camp to find an A dapted Initiative Core Tech device you can scan, then, after you’re done plundering, talk to the Turian Leader. After an unnecessary display of brutality this Turian - Avitus Rix - will chat with you and apologize for being an unhinged soldier. Wonderful. All of this is merely an excuse for him to drop his credentials, after which he’ll tell you about the Turian Ark - what little he knows about it, anyways - and their missing Pathfinder, Macen. After this, the quest will go on hold; you’ve achieved contact with some of the survivors of Ark Natanus, but little else. Oh well, at least you’ll be rewarded with 29 AVP, +2% Havarl viability and 530 XP for your trouble.
Note: This quest is, in reality, all but finished, and will end later when you visit Kadara. After advancing some story-related business on Kadara and leaving, check your Email Terminal to find the message "Got a Lead on Ark Natanus". Reading this email will end this quest and begin the follow-up quest "Turian Ark: Lost But Not Forgotten".