Since this is just salted, fermented fish, which the scientist in the article claims he would like to taste, why does it need to be buried in plastic? Why not slowly pour it into a sewer, over the course of several months?
Sewers go places, and it is nearly a million liters of extremely concentrated stinky. If you do this, you take a single location source of stinky and smear it over a much larger set of locations that will then ALL be extremely stinky, in a way that isn’t easily cleaned with water as the fats and oils (also extremely stinky!) are of course not soluble.
The solution to pollution is dilution, and the ocean would metabolize it away fairly quickly.