Is our pond too shallow?

Question
Hi,
We recently reconconstructed an old pond.We've made it into a wildlife pond and do not intend to keep goldfish etc.As we also wanted it child friendly, we've kept in shallow.Also small creatures can get in and out again.Now after all our hard work and careful landscaping,I am worrying that it is too shallow.It slopes into the middle and the deepest part is between 12 inches to 18 inches deep.Could we ever keep minnows or sticklebacks? Also we had hundreds of tadpoles which always gather around the edge of the water,presumeably feeding.They seem to have disappeared at the same time as an unpleasant algae bloom has appeared.Is this coincidental or do tadpoles like warm sunshine to gather in? We haven't put in enough plants to cover the surface I realise,hence the algae.I hope you can help.
Regards,
Rowena

Answer
Where do you live?  If you're in Zone 7 or higher, it should be deep enough for small animals to overwinter.  If you're in a colder area, it may be harder for tadpoles or small native fish if you added those to survive the winter.  If you added aeration and/or heat, it might be possible.  Also, shallow ponds can get warmer in the summer.  1.5 feet deep is a respectable depth but certainly not deep.  My pond was supposed to be 3' deep but they messed up so it's only 26".  Tadpoles gather near the top edges for two reasons - more algae and foods gather there, and it's warmer.  If there's an algae bloom, the tadpoles may be feeding in deeper water.  I've seen my tadpoles seem to sunbathe too. My page on algae is at http://www.fishpondinfo.com/plants/algae2.htm
My page on wildlife ponds is at http://www.fishpondinfo.com/wildpond.htm

Good luck!
Robyn