Unlike the United States which considers itself a "melting pot" when it comes to immigrants, Canada has pursued an "multicultural" approach. Sure many claim to accept and adopt the culture of their new home but in a lot of instances this is lip service only. Where a Chinatown can be found in most major US cities, in Canada, we have a China town, Little Italy, Muslim, Somali, Vietnamese, Irish, Greek, Sikh etc. enclaves. I personally know some European immigrants who arrived 40+ years ago and still cannot speak more than a few words of English - they just don't have to learn if they stay within their neighborhoods. This is an exception to the norm of course, but by not being forced to "assimilate" completely, we make it easy to import the problems that people claim to be fleeing in their home countries right into the very heart of our cities and towns.
Once here in significant numbers, it's not all that difficult to organize politically and begin the legal process of promoting their own cultural realities by getting elected to school boards, city councils, then provincial ridings and eventually federal ridings. The Sikhs and the Muslims have this process down to a science as a new mosque or temple always springs up after and election, promoting even more immigrants to arrive and the process repeats.
I assume Dominican immigrants behave no differently. I haven't driven through "Little Santo Domingo" in Toronto but that doesn't necessarily mean it cannot be found if one looks hard enough.