Agree with previous contibutor, but just to specify a container holding water and fish on land, as opposed to anchored nets (not, nøter).
"Hele utsettet" comes from the verb "å sette ut", ie put yngel or smolt out into larger nets or containers, and in this context would therefore refer to the entire batch of fish. Et opphav, a smaller batch, not too sure, but perhaps from one spawning female, a bit context-dependent.