Alexandra Popescu was with her boyfriend in the Latchford area when she noticed the aquatic creature.
“I was with my partner. We had a day off and he wanted to go fishing. We were actually sitting there in that spot when we’ve noticed it,” she said.
“I was very surprised to see it, as I had no idea you can find them in here.”
In a video taken by Alexandra, the seal’s head can be seen poking out of the river, before it dives under and swims away.
It I isn’t the first time a seal has been spotted in the Mersey in Warrington.
The animals have been seen before in the water in the Bridge Foot area, as well as in Penketh.