Fish which couldn't swim

A man went camping in the Reservoir as he had many times before. But he noticed something different this time when he began fishing. There were no bites on his line at all. He headed over to the local market to get some new bait, and the shopkeeper gave him some advice.

"Don't even bother buying any bait," said the shopkeeper

"Why's that?" questioned the man.

"There ain't no fish 'round here no more. We had a freak flood come through and wipe them all out."

"But how would a flood wipe out the fish?" wondered the man.

"There ain't never been no water 'round here, so the fish never learned to swim."