Gnats, everywhere, swarming in little clusters. They don't bite or
anything, and generally mind their own business.

Does this indicate any problem?

Most likely midges, and it means your pond must be healthy, but has enough
debris for the larvae (blood worm) to thrive. They usually hatch heavily in
spring and then slow down. Fish love to eat the larvae.

If I want them to become deceased, is there
a safe way to do it around the pond?

If you don't have predator bugs for them, you will soon. Otherwise pray for
a stiff breeze. ;o) ~ jan
~ jan