Breakdown of В аквакультуре найти какой-либо дешёвый способ — это сложная задача.
это
this / it is
в
in / to (direction)
дешёвый
cheap
найти
to find
Questions & Answers about В аквакультуре найти какой-либо дешёвый способ — это сложная задача.
Why use какой-либо here instead of какой-нибудь or какой-то?
Какой-то implies a specific but unknown method ("some method"). Both какой-нибудь and какой-либо mean "any method", but -либо is much more formal and often implies a categorical "any whatsoever". Because this sentence sounds like an academic or technical statement about aquaculture, the formal какой-либо is the natural choice.
Could we just use любой instead of какой-либо in this sentence?
Yes, they are very close in meaning here, but there is a slight nuance. Любой means "absolutely any (pick one, it doesn't matter)", focusing on the free choice among options. Какой-либо focuses more on the existence of the thing, meaning "any kind of cheap method, if one even exists at all."
Why is there an em-dash before это?
In Russian, when the subject of the sentence is an infinitive verb (here, найти) and the predicate is a noun (задача), they are separated by a dash. The word это is frequently added to strengthen the connection, acting similarly to the verb "is" in English.
Why don't the endings change for какой-либо дешёвый способ if it is the object of the verb?