They have an airforce and Exocet anti ship missiles. They sank British multiple Uk warships during the Falkland wars.
The problem with a lot of navies is that if you refuse to decommission old rust buckets you end up with an navy that looks impressive on paper but rarely makes it out of port and i suspect this is the case for the Argentinian navy.
you don't need dozens of blue water warships to patrol against pirate fishing, you need a few patrol boats and a few long range maritime surveillance planes.
Quite standard practice, and very much applicable in situations where these roaming fleets are steeling quota that they have no right to.
They won't go away and they WILL take every single living thing from the ocean unless someone steps in.