This is a complicated tissue that cannot be overly simplified.
Do we need riparian zones along our streams and "ditches"? Absolutely. These zones protect the streams from many adverse effects of human development, and no where is this more important than near farms. Contamination by pesticides and fertilizers are among the most common pollutants in our freshwater systems (oil, sewage and detergent being the other 3 of the top 5 pollutants). Riparian zones set up a buffer that can naturally filter many of these pollutants out of the surface runoff before they reach the streams. These benefit more than just the sucker. It benefits every organism in the freshwater ecosystem, including our precious salmonids.
"Why does a farmer care about the value that developers put on his "farming" land? If he's only interested in farming a lower assessed value is actually a benefit since he pays less property tax."
Well, I can see a couple of reasons why farmers may be worried about the fact that the property they purchased 10 years ago for $1.4 million is now worth only $350 000 because two creeks on the property are now going to have 30 m on either side set back. Firstly, the obvious one is they just lost all their investment in the property (investment that they may have been counting on as their retirement fund). Secondly, farmers often rely on the value of the land to borrow money, just as you do with your house, this will seriously affect their ability to borrow against the value of their property since it is no longer worth as much. Finally, there is the land use itself. Since farmers are no longer able to cultivate right up to the creek, they lose huge amounts of cultivatable land, thereby reducing the crop yield and therefore their income generating potential. This is the same as the government imposing a massive tax income tax hike or demanding that you take a massive pay cut. It is going to affect their take home income. We will, therefore, undoubtedly see an equally startling increase in local food prices as they raise prices to compensate for the reduction in crop yield.
While we need to protect our environment, should we expect a few landowners (farmers) to shoulder the cost of protecting our environment?
The issue is not:
Should we protect the sucker (and the streams that house them, and thousands of other species)?
but:
Should we expropriate the land without compensating the landowner?
I am suggesting we need the latter. Whether you feel the sucker is worth it or not, the riparian zones ARE worth it and so we need to spread the cost of protecting the environment among all of us who are going to benefit from a world that doesn't sacrifice biodiversity and long term sustainability for short term economic prosperity.