As promised, I'm going to try and give as helpful an answer as I can. I don't claim to be the expert on ethics, and this answer is not intended to be a "be all, end all" to this conversation. However, as one member of the R2R staff, hopefully I can provide at least some idea of what our "Ethical Fishkeeping" rule is aiming at. (
Btw, if anyone is not familiar with our Terms of Service, here is the link.) One of the reasons we have a team of moderators is that in cases where the ethics of a post or thread is in question, we need a team to weigh in on issues to help us all arrive at some form of consensus. None of us has a corner on ethics, and hearing from multiple voices on the subject is really really helpful. This is actually one of the beautiful things about doing things (like reefkeeping) in community.
Speaking of our "Ethical Fishkeeping" rule, here's what it says:
- The owners of Reef2Reef adhere to certain standards of ethical fish keeping. We believe that freshwater and saltwater aquarists are directly responsible for the health and well being of any aquatic animals in their care, be they fish or invertebrate. These responsibilities include providing a healthy aquatic environment, humane treatment, humane euthanasia (when required), as well as obtaining and disposing of aquatic animals in such a way that does not damage sensitive local ecosystems. Posts advocating the illegal collection of fish or invertebrates, inhumane treatment, flushing live animals down the toilet, or releasing them into the wild will be removed.
Now, there are a few words in here that are not totally defined. That's by design. This is meant to be a guiding principle to help with day-to-day conversations within our community. Yes, there will be some variance of opinion on specific actions and ideas (i.e. what qualifies as "humane euthanasia"? Is quick and efficient the only qualification?). Some variance is expected on these ideas. After all, we are a global community with lots of people from all kinds of backgrounds. We want there to be discussions...after all, isn't conversation a key component to a community like R2R to begin with? In fact, reasonable disagreements aren't bad on this (or most) topics as it's through attempting new ideas that we as a hobby (and as a society) push forward in many ways. However, I do think there are some helpful guiding principles that we can look to which are helpful.
@HankstankXXXL750,
@Eagle_Steve, and others have touched on some of these in previous posts.
Ultimately, what I believe this comes down to is the intent and attempt to treat all life within our care with respect and provide the best possible treatment we are capable of. Intentionally ending life of aquarium creatures may at times be reasonable and necessary, but it should not be done without consideration, and in cases where it can reasonably be avoided, it should be. In cases where there is no alternative, euthanasia should be performed in a way that reflects the same consideration as was given for the creature during its life in the tank...in a sense, euthanasia should be a final act of caring for the animal.
In keeping with the above principles, the way in which we advise others should also adhere to these types of ethical principles. Trolling or intentionally leading/encouraging someone to treat the animals in their care contrary to ethical standards is something that should not happen in a community like ours.
Lastly, the "Be Nice" rule in our terms of service also comes into play here. It doesn't directly impact the conduct of "ethical fishkeeping" but it does lean in on this conversation because we ought to be treating one another ethically. In conversations that are sensitive topics (i.e. euthanasia), we ought to be careful of how we address the issue and the words we choose as we encourage others to behave ethically towards their creatures. Remember that it's not just what we say, but also how we say it that conveys kindness and respect toward one another. As has been said at multiple points in this conversation, we all come from diverse backgrounds and viewpoints. Therefore, we need to consider how we treat one another in regard to the Golden Rule (and I might add that the principle there isn't just to treat others how we want to be treated, but infers that we should treat others also how we think they would want to be treated).
Now, I know this is still going to have people asking questions, and that's ok. That is where we come in as a community. We can discuss these issues and hopefully we all grow in wisdom as we discuss these things. I do hope this post is helpful in this conversation.

Happy reefkeeping!!