The main factor, according to your study.Yep - what we spray on our plants is also a factor and we need to be careful it is not insecticides that can find their way into watercourses in active forms.
The problem with this thread is that it is just going over all the same stuff that has been discussed at length already.
The problem with neonicotinoids is their potency. Even if they are "just a tiny corner of the tip of the iceberg" as you put it, that is still more than enough to kill aquatic invertebrates, and these kinds of concentrations are being detected in rivers. So, we are being told that we need to stop using them everywhere they are currently being used.
No data for pet treatments, but they guess it's a cause, behind plant spray.
No data - forgive me if I don't put too much stock in to that particular paper.