You noticed that stuck under the remaining slime there were a couple of shadows that are likely the shields the plasmid was carrying. There is also a trident that appears to be trapped in an air bubble at the bottom of pool.
There hasn't been much for Bazzalan to do so he just stands back and carefully watches for anything that might bring harm to the group, and will blast anything acting aggressive toward the party.
"Do you think we could possibly hook those and pull them through with a rope and grapple?"
Rupert will remove more slime and liquid in an effort to liberate the shields and trident.
Bazz will check out the remains.
Rupert uses another couple empty barrels to scoop out as much of the slime as possible. This allows the two shields to bob to the surface of the gravity plane. Without actually getting in the water, there is no apparent way to get the trident as the bubble around it keeps it trapped at the "bottom" of the water hold.
[[OOC: I would need more details on how you would like to try to fish out the trident, remember you are dealing with an upside down pool from your perspective as you are on the opposite side of the gravity plane from the majority of the water in the hold.]]
Rupert will continue to bail water from the hold 1 barrel at a time until the water level in the hold is thin enough that the trident is no longer difficult to reach with a looped rope, unless someone else has a more efficient manner of retrieving the trident (ie. A mage hand cantrip)
Melville uses the mental link to request a rope and grappling hook be sent over from the Riposte. Anders can pass it down to Rupert once it arrives, and Rupert can use itr to fish the trident from the other side of the gravity plane.
Melville relays the request and is told it is coming. Anders withdraws back up top to get it when it comes across. Other than the sloshing of Rupert continuing to fill barrels (he has filled 5, and there are another 15 empty barrels in the hold) the Wasp falls quiet as the three of you stand waiting.
[[OOC: going to give it a little time to see if Melville wants to do a Mage Hand instead (as they don't consume a spell slot or anything in 5e, but I know you are used to the magic conservation required of 3.5)]]