Posted: Apr 27, 2006 6:33 pm
you can have as many as you want, but skip the eggs and take the tadpoles. we also have bunches of mosquito fish.
This answers my question about the frogs, i had stupid fish and a small pond, this is probably why the big pond was not effected.
Why Did My Fish Die After The Toads Laid Eggs?
Sometimes after toads lay eggs in a pond, fish die. There are a number of theories as to why this is. The higher the concentration of eggs to pond volume in the pond, the more likely this would happen. While American and common toad eggs are somewhat toxic, most fish know not to eat them. They may taste a few but they taste bad, and the fish gets sick. It rarely dies and learns not to eat the eggs ever again. Occasionally you may get a "stupid" fish who eats the eggs or toad tadpoles (who also are slightly poisonous and taste bad) anyway and dies. Certain other species of toad are more toxic, such as the Marine Toad (see above). If a fish test tastes one of their eggs, it may die straight away. I am not familiar with species other than the American or common toad so I cannot comment on these other species.
The most likely scenario as to why American toad eggs who kill fish is this. Toads are very prolific breeders. A single female with a few suitors can add many thousands of eggs and a high concentration of excess semen to the water. Both of these add wastes to the water just as fish waste would. Of course, while courting in the water, the toads also excrete wastes as well. This all increases the ammonia concentration in the pond. In small ponds, this may be too much load for the biological filter. All the excess organic material in the pond can also drastically reduce the dissolved oxygen content in a small pond. Large ponds (over 1000 gallons) are largely unaffected by a few breeding pairs of toads. Thus, in a small pond following a toad spawning, fish may die from lack of dissolved oxygen and/or ammonia poisoning.
To prevent die off of fish from toad spawn in a small pond, be sure to do the following. Increase surface agitation and aeration of the water to increase the dissolved oxygen content. Remove or relocate excess toad eggs from the water. If possible, do a 20-50% water change in a small pond (under 1000 gallons) following a large toad spawning. Keep the filters especially clean. Adding liquid or dried bacteria meant to improve the nitrogen cycle can also help.
I remove excess toad eggs and tadpoles from some of my ponds and put them in my other ponds. They can also be moved to local natural bodies of water. Toad eggs and tadpoles transplant well. I think it is much better to relocate them than kill them as many suggest. Adult toads are great insect eaters and pose little bother to anyone (except those people who cannot sleep through the males' trills). Toad killers suggest killing by tossing tadpoles on the lawn to dessicate, poisoning with fungal killers (adding chemicals to a pond should not be done haphazardly), or even mowing over the newly formed toads! Please, just move them to another site. All my ponds have toad tadpoles in the spring, and nothing bad has happened (since 1997).