In a village pond the tadpoles were not found to develop into adult frog comment
Answers
If the water in the pond is too cold due to cold weather or being in the shade, this can slow down the rate of development.
A lack of algae, which is tadpoles’ food source, is an obvious limiting factor. This may occur in new ponds or ponds that are heavily managed.
Often ponds in spring are heaving with tadpoles. As a result of this high level of competition development rates can be limited as food and space availability is reduced. This is completely natural and nothing to worry about.
Normally tadpoles will develop into young amphibians and leave the pond during the summer months but if conditions aren't right, they may choose to overwinter in the pond and finish their development the following spring. This could be seen as an advantage: as long as these tadpoles survive the winter, they will have a head start next year and have much more time as froglets to feed up before winter arrives again.
iodine was not present in water