Ruling on Spraying Water Springs with Toxic Substances for the Public Interest

This message came from Khaybar. It is from the historic northern city of Khaybar, which is part of the Madinah al-Munawwarah region. The presenter is the citizen Tariq Hamad al-Shanishni. He says: I present to your eminence this problem that occurred in our city of Khaybar. There are many springs in the city of Khaybar, and none of these springs is free from worms and creatures of Allah, including large and small fish, frogs, and others. A team from the Bilharzia Office in Khaybar sprayed these springs with toxic substances that destroyed all the creatures living in the flowing springs from which we generally water the palm trees and gardens. Our question is: Is there any prohibition in killing the creatures in the flowing springs, as opposed to stagnant ones, or is it permissible, given that it is the destruction of Allah’s creatures in a manner other than their natural course?
Answer: If it is known that these animals in the springs are harmful to people and to the owners of the springs, then there is a valid reason to spray them in order to remove their harm. However, if they are not harmful and are sprayed merely for no reason, then it is not permissible to spray them, nor to kill the frogs or any other fish therein; rather, they should be left alone. But if there are things that necessitate spraying them because they contain toxic, harmful substances that harm people, and these animals are known to be harmful to the people who drink from these springs and water from them, and if doctors confirm that they are harmful and contain things that harm the owners of the springs, then there is no harm in killing them to relieve the Muslims from their evil. If that is not the case, then it is not permissible to kill them. Yes.
The presenter: Naturally, Your Eminence, bilharzia plays a major role in harming people, and the fight against bilharzia always prioritizes the health of people.
The Shaykh: In any case, if there is a need for this and the doctors know that this harms people because of these animals found in these specific springs, then there is a valid reason for this for the sake of bilharzia and other such matters.
The intended meaning is: If there is clear harm that they are aware of, they have an excuse to destroy these animals if it is due to their cause, or if there is harm occurring in the spring that cannot be removed and safety from its evil achieved except by this spraying, and the spraying destroys these animals or some of them, then they are not the intended target, but it is for the removal of the harm in the springs caused by the substances that cause bilharzia, as they say. In that case, this is an excuse for them, a religious excuse; because what is necessary to remove evil is an excuse. So the animal in the... the fish or the frog or the like that is in the spring, but one cannot reach the removal of the diseases in this spring and the evils therein except by spraying it with something that kills these animals in it, then there is no harm in that, if Allah wills, as it is not an intentional killing of the frog, but it came as a consequence. Yes.
The presenter: He also says: We fear for the destruction of the animals in our lands from the toxic substances through drinking water or eating grass, and these animals are horses, cows, sheep, and others. Naturally, such toxic substances do not harm large animals like horses and cows.
The Shaykh: In any case, they know this...
The presenter: Yes. So the office knows this.
The Shaykh: Those who are tasked with these things know...
The presenter: Yes, yes, they know them very well.
The Shaykh: Yes.