The video shows a man transporting a fish from a bucket of nice fish-friendly water to a container filled with an unspecified substance (we know it's not liquid nitrogen, as the temperature is shown at -35 in the beginning, which is too warm for nitrogen to still be in liquid form, no matter the unit).
A subduction zone is formed at a convergent plate boundary when one or both of the tectonic plates is composed of oceanic crust. The denser plate, made of oceanic crust, is subducted underneath the less dense plate, which can be either continental or oceanic crust.
The convergent boundary along the coasts of South America, Central America, Mexico, the northwestern U.S. (Northern California, Oregon, & Washington), western Canada, and eastern Alaska, are boundaries along which oceanic lithosphere is being subducted beneath continental lithosphere.