Europe is already destroying their boats. You don't need to kill them to destroy their business, though it certainly helps. Gurkhas are overkill.
...
Between survey ships, drones, informants and the vast security bureaus of Russia, Britain, USA, France and the rest of Yurop - well for certain their ships are fucked, and finding them will be one step ahead. Who knows, could give incentive to Western nations to finish what they started in Libya. European ships already patrol Libyan coasts (just for security reasons), countering human trafficking goes hand in hand.
...and now the smugglers are resorting to rubber boats, oil barrel rafts, and salvaged wreckages of Phoenician warships. We certainly need more rescue operations and active patrolling to stop people from drowning (
that's the priority), but trigger-happy military raids would be nothing but an expedient stop-gap measure that wouldn't help in the long run. From a humanitarian perspective, the immediate problem is that the southern coast of the Mediterranean is flooded with displaced people in unlivable circumstances who are desperate to get across by any means, and as long as more of them keep flocking to the shore, there'll be a market for horribly unethical smuggling operations.
Thing is, the boat business is just the final link in a very long and disorganized chain of smuggling that cannot be shut down simply by cutting off the other end. Daesh may have their finger in the pie, but there are no terrist criminal masterminds controlling the entire operation, just a long line of shady bastards who get their cut and pass the buck to the next guy. Even without a single floating vessel available on the coast, the smugglers in the inland countries would still keep schlepping people north with empty promises of luxury cruises and worker visas – why should they give a shit about what happens to "the cargo" in the receiving country?
The way I see it, there are only two possible "solutions" to the humanitarian crisis: Take the people in, or recolonize the African continent to pacify all conflicts and stop the wave of migration. It's no wonder that many Europeans choose the third option of going "LA LA LA" whenever the word "humanitarian" is mentioned.
EDIT: The suggestion of having processing centers in North Africa is a very good one, but even that plan requires that the people have somewhere to go after they've been "processed." It all boils down to a choice between taking them in or making their home countries safer, and unfortunately the latter is just not happening.