jbalcombe

There are as many opinions on this as there are vegans (and that's a lot!). I personally believe that respect for other viewpoints is critical for progress, and that preachiness and accusation are not effective, despite the frustration felt by those who believe fiercely in a certain position. We all have egos and they don't respond well to being beaten up on. That said, we all need to be critical thinkers, look at the evidence, and read the proverbial writing on the wall.

I discuss fish pain at some length in my book, because, unfortunately, many people continue to believe that fishes are insensate to pain. Rigorous science shows otherwise. A study of zebrafishes, for example, found that they will pay a cost to get pain relief. Individuals injected with acid ventured over to a normally undesirable (barren and brightly lit) chamber of their tank, but only after painkiller (Lidocaine) was dissolved there. Others injected with saline solution (which should not cause any lasting pain) stayed in the preferred chamber of the tank.

More on fish pain: Studies of terminally anesthetized trouts (another representative bony fish species) found that they have different kinds of nociceptors (pain receptors) for mechanical, chemical, and heat-induced pain. Other trouts injected with acid into their lips (yeah, I'm glad I wasn't one of those subjects!) stopped eating for many hours (much longer than control fishes injected with saline) and some rubbed their lips against the aquarium glass or bottom pebbles.

Several other studies support fish pain. Then there is the fact that fishes are full members of the vertebrate clan, with complex nervous systems, life histories, social engagements, and sometimes Machiavellian strategies for survival. They are highly evolved, fabulously successful group. We've missed the boat with our tired old assumptions of their being dead-eyed and primitive. If you doubt that, watch them closely, read my book, you'll see otherwise.

Great question. Sentience, the capacity to feel, is an absolute in the sense that you either have it or not (kinda like pregnancy). In that sense, it's B&W. But that doesn't mean that there aren't gradients. Elephants probably experience emotions that another species does not (and maybe vice versa). Some species may be more resistant to pain than others, especially if they have to take risks to survive (e.g., catching prey). But we should take this to mean that they are any less deserving of our respect or our moral concern.

It can only help. It also helps to use barbless hooks. There are also devices for returning fishes quickly to deeper waters if they were dragged up from the depths, which happens surprisingly often in recreational fishing (and very commonly in commercial fishing!).

There is, of course, always the option of optimizing the fishes' chances of avoiding harm by avoiding fishing altogether.