My family and I have caught 1,000s of fish off a lighted pier in the Arroyo. BIL has a house there a few away from the park/boat ramp. I have never really fished far up the river but assume it is the same. Also, I do know after the hurricane, the drainage of fresh water can drive out the fish for a while so that is something to ask around about.
Bring a crab trap too if you have one. Live shrimp from the bait stand (right in down town Arroyo city, you will learn what that means later) will be guaranteed success but is pricey. Use a small treble hook if you go live and hook the shrimp on the tail. If you go out into the bay, definitely grab some live shrimp and croaker.
A popping cork with glow in the dark Gulps is the best/easiest way.

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I prefer nuclear chicken...

A spec rig will work, but you will get bigger trout with gulps and a good popping action. Charge the glow gulps in the lights before you cast for a few seconds. Cast as far as you can and give it a few good strong pops and let it sit for a second or two. Then reel in slowly and repeat. They are good at spitting these gulps out so make sure to set that hook hard. Certainly we have lost 1000s also! One of the key elements is to leave the lights on and come out quietly. We are always on a noisy wooden dock and if you come out with a party, it will scare some fish away...not all, but some. Stay a little quiet and you will keep them there. Sometimes we let the kids start early then come back later and nail them.
The bugs will build up (mosquitoes are terrible because of the hurricane that hit bring off and candles) and and so will the bait fish, trout will stick on the outer perimeter of the lighted area on the water and you will see/hear them hit bait fish. In my experience cast into the sound/sighting of the hitting trout...you will see what I mean. You can get a few in the center of the lights but generally I cast as far as I can where the big mammas hang out. They are dumb enough to come into lights.
I also throw a few lines on the bottom banks of the channel with some squid for drums that run. That will be a 1 in 100 compared to the amount of trout you will get. Alligator gar is a big deal down there with some huge ones, but I am not a big fan. My nephew does bow fishing off of the docks into the lights also, so that is fun.
Don't know the reports down there since the hurricane, but the only time I don't catch anything is in 20 mph winds and the water is chocolate milk.
HTH.