We are beginning siman 9. The Chayei Adam writes that a small fish which is already in a small area, and a person uses a net to catch it, they are chayav. Although it is already a small area, since the fish is not easily captured, using a net is a melacha deoraysa. Similarly, any time an animal is in a large enclosed area and a person wishes to move it to a smaller enclosure, if the large enclosure is large enough that the animal cannot be captured in one chase, and in the smaller one it can be caught in one chase, it is assur miderabanan.
When it comes to fish, besides for tzad, removing the fish from water is considered shocheit. Even though the person is not actively killing it, removing it from the water is considered killing it. To explain, if a person puts another person into a room with no air, the assailant cannot claim that the lack of air killed the victim and not the assailant, because the assailant put the victim in the room. In a similar sense, although the lack of water is what kills the fish,the person who removes the fish from the water is considered to have killed it.
If a person has a fish tank and one of the fish dies, there is an issue of muktzah to remove the fish. Assuming for a moment that we can avoid the muktzah angle, there is no issue of shocheit to use a net to move the live fish elsewhere, because the person’s intention in moving them is not to kill them. However, the melacha of tzad will still apply (assuming the tank was large enough that the fish could not previously be caught in one chase). In that situation, using a net to remove the fish is considered tzad, even if it is only temporary. It could be argued that it is a melacha she’eina tzricha legufa, because the person is not trying to capture the fish inasmuch as to clean the tank. One should consult a rav.
Summary
Trapping animals that were already in an enclosure, but in the previous enclosure they could not be caught in one chase, is considered tzeida mideoraysa. Examples include catching a small fish with a net even if it was previously in a relatively smaller area.
If a fish died in a fish tank, and the person wishes to move the remaining fish, they should consult with their rav.
We are beginning siman 8. We raised a question in the previous shiur regarding tzad which takes place in a large area, similar to a bird trapped in a house. Both of these cases are tzad miderabanan. Similarly, trapping a bee in a large area, such as coaxing the bee into a room and shutting the door, would be tzeida derabanan. Since it is considered a melacha she’eina tzricha legufa (because the person does not want the bee itself), it becomes a shvus d’shvus. We know that amira l’achum is muttar on a shvus d’shvus, so it would be muttar to direct a non-Jew to perform a shvus d’shvus in situations of tzaar, hefsed, mitzvah or a significant need. The Pri Megadim limits this leniency to amira l’achum and not to when the Jew performs the melacha on his own.
The Biur Halacha in siman 316 and 349 seem to hold otherwise, and writes that the heter of shvus d’shvus would allow the Jew to perform the melacha themselves.
There is an additional question whether melacha she’eina tzricha legufa can count as one of the two derabanan for a shvus d’shvus. The Ran holds it cannot be used. However, in the above mentioned Biur Halacha (siman 316), the Mishnah Berurah concludes that we do not pasken in accordance with the Ran.
Rav Chaim Kanievsky ztl raises an interesting point. When the Gemara in Eruvin discusses this concept, the Gemara exclaims that a shvus d’shvus performed by a non-Jew (through amira l’achum) should be different than a shvus d’shuvs performed by a Jew, because when the non-Jew performs it, the Jew is merely speaking, but when the Jew performs the melacha, he is physically doing the action. The Gemara seems to hold that the comparison is not acceptable, unlike the Biur Halacha.
Due to this question, many poskim are not comfortable allowing a Jew to perform a shvus d’shvus, unless there are additional considerations. It is clear, however, that one could ask a non-Jew if there is tzaar. Tzaar would include emotional distress to the extent that a person is really agitated by it.
Summary
One could ask a non-Jew to remove a bee from a room, because it is a shvus d’shvus b’makom tzaar. A Jew cannot perform the melacha themselves.
