Origin of surname Berzinski

Does anyone have any idea of the origin of the surname Berzinski? I know there are quite a few Brezinski's and variations thereof, but have so far been unsuccessful in determining anything too definite on a location or any idea of an origin.

Do you mean Brzezinski or Berzinski?

if it's brzezi 4;ski, it related to 'brzoza' = birch or rather brzezina 'a birch copse'

Berzinski. This is where my problem is. I cannot find out back in the immigration records if this is indeed the name that was brought over, or if it was changed on entry. For seven generations, though, it has been Berzinski.

If it's Berzinski, it seem to me it MAY not originally be a Polish surname; I tend to think it's more Russian/Ukrainian one...

I could have been changed on entry, as you say
Berzinski is easier to pronounce than bzhezinski
I thin a Ukrainian/Russian surname referring to the wotd birch would be 'Berezinski"

I think Berzinzki has a Latvian origin. Many Berzins in Latvia.

Berziński cannot exist in Polish. The r+z in Polish form a diagraph (two consonants forming a single sound such as sh and ch in English) which in Polish cannot be followed by the vowel i. There are 15 people who have the rather rare surname Berżyński in Poland.
If the name were of Polish origin it should read Brzeziński (as in Zbigniew). If it were Ruthenian, then it should be Berezinsky (transcribed). More likely than not it got misspelt somewhere on the Ellis Island or other POE circuit.
Brzeziński and Berezinsky would both have probably originated as toponymic nicknames to identify someone as the 'bloke from Birchwood'.
As the population increased before surnames had made the scene, there had to be a way to tell people with the same Christian way apart. So one Jędrek (Andy) was called Stasiak (Stan's boy), another Bednarz (the cooper), still another Paluch (big-fingered Andy), Śliwiński (the guy from Sliwno/Plumboro), Mazur (the Andy who moved here from Masuria), Nawrocki (the one who converted from Judaeism), etc.