Would anyone know how saltwater fish survived? They are just *NOT* designed (by their intelligent designer, if there was one) to survive in freshwater. It's a matter of how their entire bodies function, specially their kidneys.
Seeds can survive in dormant state for long. I don't think they can survive soaked in water for a year. When I was a kid, we were taught about germination with a small glass jar, some cotton balls, water and beans. I don't remember how quick germination was, but beans were quick enough to germinate for little schoolchildren not to lose heart and wait. What substrate would these plants have in that case?
Even if seeds had survived that year, for how long would Noah have had to wait before those plants could germinate and grow to the point where they could sustain Noah and the animals, with a surplus for future growth? If we assumed that to actually happen, then pests need also be assumed to have been patient and NOT eat what they eat for a living. Everyone was on rationed food!
What about plants whose seeds need to pass through the digestive tract of animals before they can germinate? I'm not making this up (http://www.illinoiswildflowers.info/weeds/files/weed_dispersion.htm)
What about watermelons? The seeds are inside of the fruit. The fruit will rot in a matter of weeks. The seeds cannot last one year after that. How did watermelons make it?
What about mangoes, dates, apples, grapes, plums, peaches, oranges, lemons, papayas, kiwifruits?
What about plants that reproduce through runners, such as strawberries?
