"reduce the amount of water coming in"

water = info

"reduce the amount of info coming in".

I'd look at this article too which has also been posted around the same time:

https://www.the-sun.com/news/3982976/girl-water-pistol-monkey-ufo-jellyfish-wildlife-photo-contest/

It compares jellyfish to "looking like a fleet of UFO saucers".

UFO were originally called "foo fighters".

https://en.wikipedia.org/wiki/Foo_fighter

foo fighters were presumed by witnesses to be secret weapons employed by the enemy.

The word "foo" comes from a 1930s comic strip.

Now from the article read this

In a short comment to Motherboard, EDF energy, which runs the Torness plant, said that “jellyfish blooms are an occasional issue for our power stations,” but also said that media reports claiming the plant had recently been taken offline because of jellyfish are “inaccurate.” “[There were] no emergency procedures this or last week related to jellyfish or otherwise,” a spokesperson said.

... mother board.... offline.

What else can be taken offline? A computer system. A database ect.

"Jellyfish blooms" could mean a sudden attack.

"screens prevent"

Computer protections. Firewalls that prevent hacking.

But a large attack can get through.

To me it suggests either attacks on large databases or on infrastructure through hacking.