Basic Copper Sulphate is only moderately toxic to birds, but extremely toxic to fish because the use of basic copper sulphate in lakes and ponds reduces its oxygen and causes excessive debris.

Does basic copper sulphate harm plants?

Excessive use of basic copper sulphate in the treatment of plants also destroys the process of photosynthesis and damages vegetation. For these reasons, it is extremely important to follow any indication on basic copper sulphate to avoid damaging any existing ecosystem using the compound.