There's 6.5 billion or so people milling about the planet, there's a cause for everyone. If you can't find a cause you like but want to belong to one, make one up and be a pioneer. I've never seen a Save the Saprophytic Feeders campaign though. We could print up shirts with anti-swatting slogans like "Can't swat this!" But then we'd have the pro-swatter people with counter tee shirts saying "Keep your laws off my swatter!" lol!I'm just trying to say that there are more important things to think about and act upon than flies and fish.
I don't think people campaigning against fish manipulation (?), line-breeding dogs, factory farming, etc. takes any spotlight from other sorts of liberation or civil rights movements that involve humans. I don't see one cause as more worthy of attention than another, that's a judgment that each individual has to make. I figure it's all cumulative, eventually leading to a more progressive and better world as a whole. I'm merely glad to see people thinking and caring for something other than their immediate nervous system or culture comforts in some capacity.