Blood Plague and Frog Plague – Times

Asking about some wort I saw.
Can a frog plague be explained naturally as the result of a blood plague? After all, if all the fish died in a blood plague, the ecological balance would be disrupted and there would be no one to eat the frog eggs, and thus they would multiply greatly.
And is this related to the duration of the plagues, since in most plagues the timing of the plague and the duration of the plague are not specified, and after a plague of blood it is written that ” and seven days were fulfilled.”