How are we sure of this?
We can start with less populous species that share their ecological niche with other species that can replace them in the food chain - observe the impact of removing that one species then move on to others as warranted by the results.
Answer #2: It's worth the risk. Kill them all.
We had some missteps applying technology last century but the time has come to stop being paralyzed by fear and start carefully, optimistically fixing some of this stuff.
Not really. Mosquitoes, both adults and larvae, serve as an important food source for many animals that humans eventually depend on for food. Many types of juvenile fish eat their larvae, for example, juvenile fish that eventually grow up and become a major source of protein for some groups of people.
But not for Westerners in temperate climes, so, y'know, who cares ... [that's deeply black sarcasm in case it's not obvious].
More concerning than the ecological scar left behind by the eradication of some species of mosquito is the precedent that would be set. Once you've deliberately eradicated one pest species, people will incorporate the knowledge of that action into their image of how the world works and the sort of things we're willing to do. The next time somebody proposes that a species be eradicated, there will almost certainly be less debate.
I've heard people defend the deliberate eradication of mosquitoes by pointing out how we've already deliberately eradicated viruses like smallpox. This demonstrates my concern. What will the eradication of mosquitoes be used to justify? It's already the case in the modern era that angry mobs of idiots need to be restrained from emotional outbursts against animals (https://en.wikipedia.org/wiki/Western_Australian_shark_cull). Having scientists justify the extermination of mosquitoes will only make it harder to get these angry mobs to back down.
I don't really doubt that human-feeding mosquito species could be eradicated without much harm to the environment, but these social concerns remain unaddressed.
Even with reuse it is pretty mating strategy dependent. It isn't a dial an extinction. Trying that with say feral cats would be a miserable failure or at best the equivalent of releasing a bunch of teaser tomcats into an area having only the TNR occupying effect on inhibiting population growth by claiming territory until they die of natural causes.
In short; a scientist demanding a cull will have more social impact than a politician demanding a cull. The more culls scientists demand, the easier it will be for fear-mongering politicians to demand culls.
Culling invasive species wherever they are invasive is something I support. But many people want to go a lot further than that.
As a species we’re piss poor at calculating blowback in complicated systems, ranging from the deaths of animal species, to interventions in foreign lands. Is it really surprising? We have an incomplete picture of the systems we intervene in, so the outcomes surprise us, then we rationalize our next blunder with the old saw, “this time it will be different.”
The normalization of extermination should be avoided, even if it comes at the costs of hundreds of millions of human lives per year. (There is no people shortage, but damage to the environment is often permanent. And not to put too fine a point on it, but human populations are growing too fast as it is which is a leading cause of environmental destruction. We should not be attacking the environment to encourage massive increases in human population growth; not unless we have very concrete and immediate plans on how to artificially retard the growth of human populations. Waiting for economic factors to suppress birth rates isn't good enough; that sort of milquetoast approach leads to extraordinary destruction of the environment. It's little more than an excuse to ignore the problem and do nothing.)
> "Since 2000 there have been 15 fatal shark attacks along the West Australian coast."
Yes, it's an emotional outburst. Anybody who goes in the water should know the risks. If that's the problem, put up more signs warning people. Very few people are getting killed by sharks; the shark culls are totally unjustified. If you talk to your average Australian about the Chinese slaughtering sharks for soup, they'll condemn it. But a disturbing number will defend the slaughter of sharks for an infinitesimal chance of saving some surfer who knew the risks and chose to swim with them.
> "They're just sharks."
It is this sort of shitty attitude that will only become more prevalent when the eradication of animal species is further normalized.
And congratulations. You have entirely trolled me. Not even Australians are that goofy about fish.